# Gamma-2 (γ2) DAC Thread



## strid3r

I was poking around on MisterX's photobucket page and saw this:







 I usually go to Headwize for DIY news, but that has been down. Does anyone know anything about this?


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## amb

[updated September 15, 2009]

*News*

 - The γ2 website is now live.

*Introduction*

 γ2 (gamma2) is an extension to the γ1 full++ configuration that MisterX and I have been working on for the past few months. It builds on the "modular" idea of the γ1, and pushes the concept further into the high-end. Basically, if you take the γ1 USB and DAC boards in its original, un-broken form and then plug in the γ2 board, the whole assembly now fits into the nice and compact Box Enclosures B2-080 case.

*Circuit description*

 γ2 leverages γ1's USB and S/PDIF receiver sections and taps the I²S datastream. Then, an (optional, jumper bypass-able) SRC4192 or AD1892 ASRC chip upsamples to 96KHz. The resultant data stream is then sent to the top-of-the-line Wolfson WM8741 or WM8742 DAC chip (WM8740 also supported).

 The SRC4192 and WM874x DAC chips are clocked by an onboard ultra-low jitter 24.576MHz CMOS oscillator when the ASRC is installed.

 If the WM8741 or WM8742 is used, γ2 allows you to select between three different digital filter responses (minimum phase, linear phase slow rolloff or linear phase brickwall), as well as enable/disable the anti-clipping mode via front panel switches. WM8740 does not have these features.

 The differential analog outputs from the DAC chip is then buffered by a rail-to-rail opamp (OPA2365 or AD8656) which also serves as an analog low-pass filter (fc ~= 100KHz) and balanced-to-unbalanced converter. The output is then capacitively-coupled to the output jacks (both RCA and 3.5mm jacks are provided, and could be used concurrently to drive two amps).

 Separate onboard LDO voltage regulators are used for the analog and digital sections of the circuit, with extensive use of ferrite beads.

 The γ1 board's WM8501 DAC section can be populated and used in conjunction with the γ2 board. The result is a compact case with two different DACs in it. You can use them both concurrently. If either of these are equipped with 470uF output capacitors (Nichicon FW or KW) then it could be used to directly drive headphones down to 32Ω impedance (You'll need to use a software volume control). On the γ2, the AD8656 is recommended for headphone drive due to its high output current capability.

 The γ1 board's USB-to-S/PDIF converter section can also be fully populated, Providing front panel coax and optical S/PDIF outputs of the data stream from USB. Note that this is only possible if the γ1 is set up as a full config. Otherwise, γ2 could be plugged into a either a full or lite config γ1 board.

*Schematic diagram*

 The following is the current schematic diagram:






*Board layout*

 And here is the current PCB layout. The board has 3 copper layers, soldermask on both sides, and silkscreen on the top side. The top and bottom layers each also have a ground plane. The representative colors are: top=red, bottom=blue, inner=grey. Where the top and bottom layers overlap the color shows as lavender.






* 3D rendering*

 An updated 3D rendering of the board (partially populated):






*Parts list*

 Please see the γ2 website for the most up-to-date BOM.


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## cfcubed

Quote:


  Originally Posted by *strid3r* /img/forum/go_quote.gif 
_I was poking around on MisterX's photobucket page and saw this:_

 

Reminder to self: "Keep an eye on what I have in my Photobucket public folders"


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## MASantos

Looks great Ti! 

 Those R+,R-L+,L- are the balanced outs of the DAC right? Do they also need caps on the output?


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## amb

You have sharp eyes... 
	

	
	
		
		

		
		
	


	




 Yes, those "test points" are the differential analog outputs straight from the DAC chip. There is not enough panel space for additional jacks (let alone large, XLR ones) on the Box B2-080 case, so we did not design for balanced outputs. You could air-wire to those points if you use a larger case, and use external coupling caps. You don't get the opamp's buffering or low-pass analog filter that way.


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## Mr.Duck

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Yep, it is what it is. 
	

	
	
		
		

		
		
	


	




 I guess the cat let itself out of the bag..._

 

Oh yes yes yes 
	

	
	
		
		

		
		
	


	




 Well, I've been looking forward to this. I can hardly think of any reason or detail to change to improve this DAC.

 The only thing I'd like to ask about is the 96KHz upsampling. What's the deal with that? I mean does the DAC chips have better measured performance at 24/96 compared to 16/44.1?

 I expect the main reason to use the ASRC is for jitter removal? I understand why you choose 96 instead of 44.1 reclocking... I was just wondering if it would be possible (perhaps with a 2nd off board clock) to have a switch between 44.1 and 96? In other words to compare reclocking to upsampling.


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## Beefy

*watches with great interest*


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## amb

The ASRC's main purpose is indeed jitter removal, but the DAC chip also benefits at 96KHz with optimized digital filter performance.


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## Mr.Duck

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_The ASRC's main purpose is indeed jitter removal, but the DAC chip also benefits at 96KHz with optimized digital filter performance._

 

Ok great. Since it's going to be asked anyway, let me be the first... ETA? 

 Aww I know the answer is not going to be any exact date etc but I can't wait lol.


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## amb

No ETA yet, sorry. It will take as long as it needs, but no more.


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## digger945

An evolutionary step towards the full featured desktop dac?


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## ShinyFalcon

Darn, this pops up! This should be a good competitor to the Opus, as they are pretty similar hardware-wise (WM8741, asynchronous ASRC, balanced, etc), in one compact enclosure! Very exciting! I finished populating the Opus (four modules total), it's my second time with SMD, but man... eight hours of staring at less than 1mm components. At least I got the 28-pins perfectly 
	

	
	
		
		

		
		
	


	




. If the γ2 stays through-hole, with the exception of the crystal, which is SMD, then it's a great next step from the γ1.


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## MASantos

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Darn, this pops up! This should be a good competitor to the Opus, as they are pretty similar hardware-wise (WM8741, asynchronous ASRC, balanced, etc), in one compact enclosure! Very exciting! I finished populating the Opus (four modules total), it's my second time with SMD, but man... eight hours of staring at less than 1mm components. At least I got the 28-pins perfectly 
	

	
	
		
		

		
		
	


	




. If the γ2 stays through-hole, with the exception of the crystal, which is SMD, then it's a great next step from the γ1._

 

Actually the Opus focuses on balanced output having SE as option using a Balsie.

 THe y2 focuses on SE outputs having the possibility to "hack" balanced outputs and wire the output caps and connectors.

 Amb, any chance of having a servo to offset output voltage instead of caps?
 Is thi even possible?


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## amb

Quote:


  Originally Posted by *MASantos* /img/forum/go_quote.gif 
_Amb, any chance of having a servo to offset output voltage instead of caps?
 Is thi even possible?_

 

No, it's not possible. We're also tapping the power supply from the γ1, which is 5V single-rail. In order to have any kind of DC servo you'll need a dual-rail supply. We're also out of board space. Despite the seemingly expanses of "unused" areas on the γ2, we can't actually put anything there because they would run into parts on the γ1 when plugged together.


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## MASantos

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_No, it's not possible. We're also tapping the power supply from the γ1, which is 5V single-rail. In order to have any kind of DC servo you'll need a dual-rail supply. We're also out of board space. Despite the seemingly expanses of "unused" areas on the γ2, we can't actually put anything there because they would run into parts on the γ1 when plugged together._

 

No problem, we'll wait for that fully featured desktop DAC you've been talking about for a while...


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## nattonrice

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Basically, if you take the γ1 USB and DAC boards in its original, un-broken form and then plug in the γ2 board, the whole assembly now fits into the nice and compact Box Enclosures B2-080 case._

 

Considering I recently picked up the base components and pcb for another gamma1 to fill out an order from you I like this alot!


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## Mr.Duck

How far along is the development for the gamma 2? Are the boards ready to be ordered and beta tested or are you still working on it?


 About the filtering... the dac chip has a built in digital filter? And the op amp is also being used as a filter? If that is correct then are the op amps strictly necessary? Perhaps their purpose is to further enhance the sound quality?

 I also remember someone made a comment like "I think the twisted pear opus with zap filter sounds better than the stock twisted pear buffalo dac". I've heard lots of positive things about the zap filter, for your convenience, I've attached a schematic of it. Incase you could borrow some design ideas to improve the gamma 2 or to just compare the design.


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## smeggy

I like!!

 Nice work guys


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## MrSlim

Quote:


  Originally Posted by *Mr.Duck* /img/forum/go_quote.gif 
_
 About the filtering... the dac chip has a built in digital filter? And the op amp is also being used as a filter? If that is correct then are the op amps strictly necessary? Perhaps their purpose is to further enhance the sound quality?
_

 

The external filter is low pass only, which is required to filter out the high frequency artifacts of the D to A process. The internal filters, which operate in the digital domain, are much more sophisticated, and operate on the waveform as it is being "created" in the DAC(as I can understand it). Check out the Wolfson web pages for a more complete explanation. The internal and external filters do two different things. These digital filters, have been developed and implemented in very high end DACs, and the WM8741/2 bring their capabilities down to a much lower price range. 

 Very Exciting stuff Ti, looking forward to hearing more about your new baby as it comes closer to fruition.. 

 *Raises hand to offer assistance if builders are needed for the proto process*


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## amb

Quote:


  Originally Posted by *MASantos* 
_the Opus focuses on balanced output having SE as option using a Balsie.
 THe y2 focuses on SE outputs having the possibility to "hack" balanced outputs and wire the output caps and connectors._

 

I should also point out that γ2 is designed more as an "integrated" solution with a specific case in mind (even though it could be used in a different case), rather than just a collection of boards. The default γ2 setup would involve no wires.

  Quote:


  Originally Posted by *Mr.Duck* 
_the dac chip has a built in digital filter? And the op amp is also being used as a filter? If that is correct then are the op amps strictly necessary? Perhaps their purpose is to further enhance the sound quality?_

 

The WM874x have on-chip digital filters. The WM8741 and WM8742 have multiple filter responses that could be selected. There have been a lot of research into the behavior of different filters and their sonic characteristics. Like many things, each filter has its strengths and weaknesses, so we thought it would be great to allow the user to switch amongst them to hear the differences. It should be great fun.

 The analog filter before the output has its corner frequency set further out-of-band (~100KHz), to clean up any residual noise and artifacts without adversely affecting the audio band. As I said, the opamp that implements this filter also serves as balanced-to-unbalanced converter and buffer. We do not recommend substituting other opamps than the two mentioned, they were very carefully selected for their rail-to-rail swing capability. Not only is rail-to-rail required, how close the opamp could swing to the rails is crucial, due to the low analog supply voltage (regulated to 4.5V or 4.75V depending on the voltage regulator used). Using another opamp might cause clipping at or near 0dBFS. These opamps were also chosen for their excellent sound quality.

 We have not yet done any beta testing on a real board. Hopefully that would happen soon.


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## strid3r

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Yep, it is what it is. 
	

	
	
		
		

		
		
	


	




 I guess the cat let itself out of the bag..._

 

I guess it's time for me to start saving my pennies. 
	

	
	
		
		

		
		
	


	




 I'll change the title of the thread for future searches.


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## amb

For those who want to read the details about the various digital filters onboard the WM8741 and WM8742, refer to the datasheets, and also to a Wolfson whitepaper. You could also google for more info on the 'net, there are plenty of discussions on the subject.


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## smeggy

Looks like I've found my new DAC


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## MisterX

Quote:


  Originally Posted by *smeggy* /img/forum/go_quote.gif 
_Looks like I've found my new DAC 
	

	
	
		
		

		
		
	


	


_

 

Does that mean I will get the Gamma 1 Prototype back some time soon?


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## smeggy

Never!!!





 I'll try to get it to you soon.


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## glt

Very nice!. I suppose there are no hard-wired limitations for s/w control with a microcontroller. The Apodizing filters and digital volume control are available through the s/w interface. I think the 3 filters available in h/w mode are: linear phase slow rolloff, minimum phase slow rolloff, and brickwall (filter 1,2 and 3). Filters 4 and 5 are minimum phase apodizing and linera phase apodizing. I did a little summary of the wm8741 filters here and here.

 Also have you considered a dual frequency clock? (Silicon Labs makes them). With dual frequency you can upsample to the even and odd frequencies (44.1, 48, 88.2, 96, etc).


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## amb

glt, thanks for your comments. There is no room on the γ2 board for a microcontroller, nor is there the power budget for it (the whole thing, γ1 and γ2 combined, must run off USB power). We're trying to keep things simple (i.e., no programming, no firmware, etc), so we run the chip in hardware mode. Also, I don't see a need to upsample to any frequency below 96KHz.


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## glt

Fair enough. I was thinking external, with an option to set the chip in s/w mode and having the pins of the asrc available to switch the sampling frequency...


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## cobaltmute

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_No, it's not possible. We're also tapping the power supply from the γ1, which is 5V single-rail. In order to have any kind of DC servo you'll need a dual-rail supply. We're also out of board space. Despite the seemingly expanses of "unused" areas on the γ2, we can't actually put anything there because they would run into parts on the γ1 when plugged together._

 

TPS60403 mounted on the "bottom" of the PCB to create dual rail?


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## hopeless

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_The differential analog outputs from the DAC chip is then buffered by a rail-to-rail opamp (OPA2365 or AD8656) which also serves as an analog filter (fc ~= 100KHz) and balanced-to-unbalanced converter._

 

You can consider also the LME49721 (dual, rail to rail CMOS opamp with low distortion and the best sound I've heard from low voltage CMOS opamps), and the OPA2727 (best sound I've heard from a 4V to 12V rail to rail CMOS opamp).

 The OPA2365 sounds very good too, anyway. It's a pity, though, that it always makes that big sharp "pop" when powered on (and off). 
	

	
	
		
		

		
		
	


	




 FIY, the OPA2376 sounds good and doesn't make it.


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## fillemon

pretty impressive this is. 

 i was just looking how to make my gamma 1 even better. (i have cut the electolyte cap) was looking at putting a spare 5V line and extra caps on the chips, and now i read this,
 GREAT.

 i don't mind that there are no XLR or balanced outputs, you can wire them. 
 but to be honest, i think this dac makes it very far down the line. maybe if possible you could make a little bigger pcb where you can put extra components for dual power supply or things like that. of course you can always hack into the line. still a optional solder point for it could be nice. 

 SMD or not, pff, i rather prefer not, but then again if you have to solder a chip, why bother about an smd resistor, as long as you can put decent caps on it. 

 anyway, you know what youre doing guys, be looking forward. i think this could make the desire for a high end full blow dac away (at least for a few months 
	

	
	
		
		

		
			





)


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## amb

Post #2 of this thread has been updated:

 - Added schematic diagram
 - Added PCB layout
 - Add 3D rendering

 The current version is 0.11.


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## nattonrice

Ohhhhhhhhh I can have the y1 dac populated as well!
 The mind boggles O.O


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## JamesL

I'm thoroughly excited


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## DoYouRight

wow this is a really interesting idea. I love your designs AMB and an improved dac is really sweet. would it be very hard to make it balanced?


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## amb

Quote:


  Originally Posted by *DoYouRight* /img/forum/go_quote.gif 
_wow this is a really interesting idea. I love your designs AMB and an improved dac is really sweet. would it be very hard to make it balanced?_

 

As already mentioned in an earlier post above, you can get balanced outputs by air-wiring from the γ2's L+, L-, R+ and R- "test points" (and of course, ground). However, this solution won't fit in the default Box B2-080 casing because there is not enough panel space for two XLR jacks, so you need to use larger casing and panels. Also, this bypasses the opamp output stage, so you don't get the low-pass filter and buffering.


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## amb

I would like to enlist about 10-15 of you to join MisterX and myself in the prototyping phase, which will start soon. As a member of the team, you will be amongst the first few to build a γ2. Note that you need to also build a γ1 in order to make a functioning γ2 DAC.

 You must be willing to collect all the needed parts and build it promptly. You are also expected to provide feedback and comments to the team. I will set up a special email list for the the team. Of course there is also the possibility that the circuit would require modifications to work properly.

 If you are interested, please PM me.


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## 1UP

Could there be some way to send a word out clock (say, to a 1212M) so you could slave a transport to the DAC if not using USB?


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## amb

Quote:


  Originally Posted by *1UP* /img/forum/go_quote.gif 
_Could there be some way to send a word out clock (say, to a 1212M) so you could slave a transport to the DAC if not using USB?_

 

That isn't part of the integrated design, but if you want to hack something in yourself, you're free to do so.


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## ruZZ.il

Congrats on the advancement of this project! I've been waiting for your guys innovation to pop up.

 I would LOVE to participate in prototyping this since it gets me all excited again 
	

	
	
		
		

		
		
	


	




 But I think I'll have to wait it out, I've got exams for the next month, getting married soon 
	

	
	
		
		

		
		
	


	




 traveling a bit... and don't have a balanced setup yet, though thats probably less the issue. I've got a few windows in-between things, so Ti please inform me on projected prototype availability and I maaaay be able to sqeeze it in. If it's in November, I'm all solder-slinging hands 
	

	
	
		
		

		
		
	


	




 . else.. I'll be eagerly waiting its completion!


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## amb

Hi ruZZ.il, I am hoping to get the team assembled within a week, and begin to order the boards soon after. There will be a lead-time on the boards, but after that it will be full-steam ahead. I don't want to drag the prototyping phase any longer than necessary, so maybe we'll have production boards long before November.


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## Mr.Duck

Might be a dumb question but is there any advantage to using the balanced outputs of the dac and converting to single ended, compared to using just the positive output of the dac and then sending it on to the buffer/filter?

 I ask because if the DAC chip was to have just single ended output, then it would be nice to have some extra pads between the dac and the filter to wire up a volume control. That way you can have a USB powered DAC and headphone amp all in one. But the default config could still be made with no wires at all.


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## MrSlim

From post #2: 

 "The γ1 board's WM8501 DAC section can be fully populated and used in conjunction with the γ2 board. So the result is a compact case with two different DACs in it. You can use them both concurrently. If either of these are equipped with 470uF output capacitors (Nichicon FW or KW) then it could be used to directly drive headphones down to 32Ω impedance (You'll need to use a software volume control). On the γ2, the AD8656 is recommended for headphone drive due to its high output current capability."

 Sorry MrDuck, I miss read your question.. so my answer is inappropriate..

 Some one on HF has done it with an alien/mini3 clone, so it probably could be done. Whether you would want to is another story. I think most people here will want to use a dedicated headphone amp with a high quality DAC like this.


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## amb

Mr.Duck, if you simply used the hot (or cold) output from the DAC and discarded the opposite signal, you'll indeed have unbalanced, but you lose half the voltage swing. Also, using both the hot and cold signal and deriving an unbalanced signal from them should yield better CMRR, lower distortion and noise.


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## hopeless

Quote:


  Originally Posted by *hopeless* /img/forum/go_quote.gif 
_You can consider also the LME49721 (dual, rail to rail CMOS opamp with low distortion and the best sound I've heard from low voltage CMOS opamps), and the OPA2727 (best sound I've heard from a 4V to 12V rail to rail CMOS opamp).

 The OPA2365 sounds very good too, anyway. It's a pity, though, that it always makes that big sharp "pop" when powered on (and off). 
	

	
	
		
		

		
		
	


	




 FIY, the OPA2376 sounds good and doesn't make it._

 

amb, have you contemplated my suggestions?


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## MisterX

I can assure you that any of the op-amps you might suggest have already been "contemplated".


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## MrSlim

Hehe.. I think someone just got 0wn3d.. and rightfully so.. 

 sorry, someone had to say it..


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## amb

Despite all the hype surrounding the ESS Sabre DAC, there is an anecdotal evidence that Wolfson WM8741 sounds better:

PS Audio Discussion Forum | DAC in PWD - How was it decided


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## digger945

Not the first time I've read about the Wolfson having the better bottom end. I really look forward to putting this DAC together, and plan to have balanced outputs from the start.

 You can see also that many respected names here have high regards for thier OPUS, obviously for sonic reasons.

 BTW I have an unassembled ESS-9008 kit to kinda compare.


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## komi

Cant wait to solder that one ...


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## grenert

I hope you can produce pre-cut panels for the enclosure-making-impaired among us 
	

	
	
		
		

		
		
	


	



 I really appreciated the ones made for the gamma-1.


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## TheShaman

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Despite all the hype surrounding the ESS Sabre DAC, there is an anecdotal evidence that Wolfson WM8741 sounds better:

PS Audio Discussion Forum | DAC in PWD - How was it decided_

 

In any case (and based on the Sabre products I've heard so far) I really hope we'll see a Sabre-based DAC from AMB at some point.


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## amb

Quote:


  Originally Posted by *TheShaman* /img/forum/go_quote.gif 
_In any case (and based on the Sabre products I've heard so far) I really hope we'll see a Sabre-based DAC from AMB at some point. 
	

	
	
		
		

		
		
	


	


_

 

The Sabre DAC chips seem to be unobtanium to DIYers -- none of the normal distrbutors (i.e., Digikey, Mouser, Newark, Farnell, etc.) carry them, and it does not appear to be available anywhere in small quantities, unless you have special connections with ESStech. That makes any DIY project based on these chips un-buildable. Not only that, the chips are shrouded in secrecy. For design support, or even just the datasheets, requires that you sign an NDA with the company. Unless things change dramatically, it is unlikely that I would design anything based on them.


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## TheShaman

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_The Sabre DAC chips seem to be unobtanium to DIYers -- none of the normal distrbutors (i.e., Digikey, Mouser, Newark, Farnell, etc.) carry them, and it does not appear to be available anywhere in small quantities, unless you have special connections with ESStech. That makes any DIY project based on these chips un-buildable. Not only that, the chips are shrouded in secrecy. For design support, or even just the datasheets, requires that you sign an NDA with the company. Unless things change dramatically, it is unlikely that I would design anything based on them._

 

Sad but true.
 Let's hope they change their policy at some point.
 Keep up the good work!


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## DoYouRight

thats insane. are the sabre chips that much better?


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## digger945

Quote:


  Originally Posted by *DoYouRight* /img/forum/go_quote.gif 
_thats insane. are the sabre chips that much better?_

 

See below...

  Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Despite all the hype surrounding the ESS Sabre DAC, there is an anecdotal evidence that Wolfson WM8741 *sounds better*:

PS Audio Discussion Forum | DAC in PWD - How was it decided_


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## Beefy

As someone who has built a Buffalo, and followed that product and the ESS Sabre with great interest, it seems to me that the ESS chip is truly phenomenal IF you handle the current output and I/V conversion VERY well. It isn't a chip that you can just drop into a cookie cutter schematic and board design and expect good results from it.


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## digger945

We have all read great things about both, and many well respected and experienced names here, who have listened to more than a few high end DACs, claim great things about both. The final decision is probably best made by the individual listeners ear. 
 It's gonna be really sweet to have both Buffalo ESS9008 and Gamma 2 WM8741 to listen to very soon.


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## DoYouRight

yes I am going to do a Buffalo after my B22 is done around my B-day. So I was curious about this dac to accompany it.


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## UglyJoe

amb, just wondering, is it possible to move the coupling capacitors to before the output buffer, as opposed to after the buffer? I'm obviously mostly clueless to EE, but I thought the high input impedance of the buffer would allow for a much smaller coupling cap and maybe allow experimentation with some nice film caps or something? Would the DC offset after the buffer stage just be two high from drift in the opamps, or something? Or is there some other obvious reason that I'm not educated enough to understand at this point?


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## amb

UglyJoe, sorry, the answer is no. The opamp actually uses the VADD/2 DC offset from the DAC as a bias, because it's powered by a single supply. We _don't_ want to block the DC there.


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## digger945

You mention in your recently updated post #2 that the Y2 accepts the unbroken Y1. I'm guessing that if we already have a Y1 with the boards broken and assembled that they can be taken apart and used here the same as an unbroken board.
 I really like the Box case chosen to house this DAC, and the fact that it comes in many colors. When and if the time comes I look forward to participating in another GB for the faceplates.


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## amb

Yes, to prevent the (broken apart) γ1 boards from sagging in the middle, pad the bottom with some foam.

 you could also join back the broken-apart γ1 boards if you want. There is a row of vias (small holes) at the edges, through which you could insert cut-off resistor leads to link the two boards and then solder them down.


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## amb

We are still seeking prototypers to join the team. See post #37. PM me if you're interested.


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## MisterX

Quote:


 I really like the Box case chosen to house this DAC, and the fact that it comes in many colors. 
 

I'm glad someone does because I see it as nothing more then a PITA. 

 "Can I get a ready made Gamma 2 DAC in a red, green, blew, silver or gold enclosure?" 
 No.


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## Mr.Duck

Will AMB be supplying these cases? They might be difficult to get hold of if you're not living in the USA.

 It looks like the PCB will _almost_ fit in the smallest of the hifi2000 cases, the Galaxy GX143. Even worse, if that's true then the smallest case that would fit this dac, is going to be the far too large GX247 at 230mm x 170mm.

 Maybe it wont be so bad since it looks like the dac would fit quite nicely into a good old hammond 1455 series - 120 X 103 X 30.5.


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## nattonrice

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_"Can I get a ready made Gamma 2 DAC in a red, green, blew, silver or gold enclosure?" 
 No. 
	

	
	
		
		

		
		
	


	


_

 

haha this is gold~


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## amb

Quote:


  Originally Posted by *Mr.Duck* /img/forum/go_quote.gif 
_Will AMB be supplying these cases? They might be difficult to get hold of if you're not living in the USA._

 

I don't plan to stock any cases, but when the production board is released, I could help anyone order them and send along with the PCB and parts.

 P.S. btw, the Box B2-080 series is available from RS Components outside the US.


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## MisterX

There is a limited selection available at Farnell as well (# 1015173 for the black version)
 there is a "Multi Comp" branded version as well but that one is only avilable with a silver finish
http://www.farnell.com/datasheets/32964.pdf


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## JamesL

Since the usb board handles both i2s and power output, the y1's dac board doesn't need to be populated for a usb-only config, right?

 And of course, if you can't get the box enclosure for any reason at all, there are a variety of other manufacturers that make extruded chassis with 100mm pcb slots(if you don't mind jumpered, or panel-mounted switches). From what I can remember, hammond, LMBheeger, context engineering, lansing enclosures, ampboxaudio, elpac.de, lincolnbinns, and more I'm sure have such enclosures.. I assume none of the jack's on the y2 board are threaded, so you'd have to put something in back to keep the board from sliding.


----------



## amb

Quote:


  Originally Posted by *JamesL* /img/forum/go_quote.gif 
_Since the usb board handles both i2s and power output, the y1's dac board doesn't need to be populated for a usb-only config, right?_

 

You could skip populating (virtually) everything on the γ1 DAC board, with the caveat that you won't have support for wallwart power, S/PDIF inputs, or the "second" DAC (the WM8501). This would be the γ1 "lighter-than-Lite" config, lol. Anyway, in such a configuration, you still need to populate the JP1D 2-pin header on the γ1 DAC board, the J3 receptacle on γ2, and install a jumper across JP1 on γ2.


----------



## JamesL

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_You could skip populating (virtually) everything on the γ1 DAC board, with the caveat that you won't have support for wallwart power, S/PDIF inputs, or the "second" DAC (the WM8501). This would be the γ1 "lighter-than-Lite" config, lol. Anyway, in such a configuration, you still need to populate the JP1D 2-pin header on the γ1 DAC board, the J3 receptacle on γ2, and install a jumper across JP1 on γ2._

 

Haha alright. Well, features are nice but I think I'll keep this next build simple 
	

	
	
		
		

		
		
	


	



 I wish I could join the prototype team, but I don't have any equipment with me now, and as per my experience with the y1 prototype, I didn't really have anything important to contribute anyways other than the fact that I got it working


----------



## MisterX

Nice to hear that you got your prototype working. 
	

	
	
		
		

		
		
	


	



 Chip quik FTW?


----------



## MrSlim

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_I'm glad someone does because I see it as nothing more then a PITA. 

 "Can I get a ready made Gamma 2 DAC in a red, green, blew, silver or gold enclosure?" 
 No. 
	

	
	
		
		

		
		
	


	


_

 

You're just going to have to adopt the Henry Ford view on colors...
 "You can have it in any color, as long as it is black.."


----------



## JamesL

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Nice to hear that you got your prototype working. 
	

	
	
		
		

		
		
	


	



 Chip quik FTW? 
	

	
	
		
		

		
		
	


	


_

 

Lol yeah. Thanks for that suggestion, it came in handy more than once


----------



## UglyJoe

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_UglyJoe, sorry, the answer is no. The opamp actually uses the VADD/2 DC offset from the DAC as a bias, because it's powered by a single supply. We don't want to block the DC there. 
	

	
	
		
		

		
			



_

 

Ahh, I figured there was something I missed for what is happening there. Cool. Thanks, amb.


----------



## cerbie

For getting balanced outputs [size=xx-small](preamp with low-pass filter to be attached internally)[/size], would there be a nicer place to tap the signal grounds than the capacitor leads (C11/C12, C13/C14)?

 Would there little enough risk of interactions between two sets of preamps that the SE output section could also still be used (if not, how unpopulated should the SE section be?)? If so, that would make this quite the bargain [size=xx-small](translation: "_I could afford to make a nice balanced source!_")[/size] for a source+amp [size=xx-small](HP amp, line buffer--what's the difference? 
	

	
	
		
		

		
		
	


	




)[/size].

 [size=xx-small]P.S. I can't believe the sun is coming up and I've been sitting here reading a DAC's datasheet, gamma-2 schematics, and checking out prices of things at Mouser...there's just no hope, is there? At least there's coffee.[/size]


----------



## amb

Quote:


  Originally Posted by *cerbie* /img/forum/go_quote.gif 
_For getting balanced outputs [size=xx-small](preamp with low-pass filter to be attached internally)[/size], would there be a nicer place to tap the signal grounds than the capacitor leads (C11/C12, C13/C14)?_

 

For the next revision of the PCB layout I have added extra ground pads next to the L+/L- and R+/R- pads for this purpose.

  Quote:


 Would there little enough risk of interactions between two sets of preamps that the SE output section could also still be used 
 

You can drive balanced and unbalanced preamps or headphone amps at the same time, there shouldn't be any interaction.

  Quote:


 [size=xx-small]P.S. I can't believe the sun is coming up and I've been sitting here reading a DAC's datasheet, gamma-2 schematics, and checking out prices of things at Mouser...there's just no hope, is there? At least there's coffee.[/size] 
 

That's an almost daily occurrence for MisterX and myself...


----------



## digger945

I spent the whole afternoon yesterday just reading about the upsampling/downsampling capabilities. A lot of reading to do yet. This is gonna be great, really look forward to learning more about these chips.


----------



## cerbie

If balanced will really be that simple, then I'll just plan to go all balanced well before I get a nice SE-only setup going 
	

	
	
		
		

		
		
	


	




. Even adding that, and assuming I'll ruin the most expensive parts as learning experiences [size=xx-small](it's never the $.10 diode that fries)[/size], it still appears affordable to the point of wondering if it's real 
	

	
	
		
		

		
		
	


	




.

 I already have other projects to do [size=xx-small](I can finally afford to build the amp I wanted to back in September, as a Head-fi related one)[/size], so may not be in on the first boards to come out of prototyping. But, as soon as I get them taken care of, a gamma-1 plus gamma-2 it shall be.


----------



## digger945

If the board is populated as it is shown in the pics on the first page, it will have SE outs from the opamp.


----------



## DoYouRight

might throw this in my chassis with my B22 if making it balanced is that easy


----------



## MrSlim

Well, AMB said earlier that if you want to run balanced connections, you are bypassing the 100K low pass filter that is on the SE output. You might have to come up with something like that for the balanced ouptuts, or risk having some high frequency stuff get through.


----------



## cerbie

Quote:


  Originally Posted by *MrSlim* /img/forum/go_quote.gif 
_Well, AMB said earlier that if you want to run balanced connections, you are bypassing the 100K low pass filter that is on the SE output. You might have to come up with something like that for the balanced ouptuts, or risk having some high frequency stuff get through_

 

With a PSU for a HP amp in the case (+12-18V), the opamp options for the job grow by a few orders of magnitude over doing it on +5V [size=xx-small](I'm not sure I'd trust it fully passive before the buffer section)[/size].


----------



## MASantos

AMB, how bad is it using the balanced outs without the filter?

 For instance, TPA's opus dac outputs come directly from the dac's outputs and there are no reports of HF noise. 

 Could you elaborate on this when you have the time?


----------



## digger945

I think I read a post by Beefy the other day that said the I/V is performed on the chip. 
 It may have been in the OPUS thread, like two days ago or something.


----------



## MisterX

Quote:


  Originally Posted by *MASantos* /img/forum/go_quote.gif 
_AMB, how bad is it using the balanced outs without the filter?
_

 

You are going to have to rely on the information provided in the data sheets until we have a chance to measure "it".


----------



## amb

As you could infer from the analog filter's fc of 100KHz, the "noise" is out-of-band and will not be _directly_ audible. Hence you don't hear TPA Opus builders complaining about it. Nevertheless, that noise is undesirable and could (depending on nature and severity, which we do not yet know) cause the amp that the DAC is driving to perform worse.

 FWIW, Wolfson recommends such a filter at the DAC's output. Our design is an enhanced version of one of Wolfson's examples.


----------



## digger945

So we could use the passive filter, or offboard differential filter, with our choice of single or dual rail power supply.
 Or use what's already on the pcb for the single supply SE filter.


----------



## Beefy

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_I think I read a post by Beefy the other day that said the I/V is performed on the chip. 
 It may have been in the OPUS thread, like two days ago or something._

 

Yep, but that is independent of any filtering.

 With the OPUS, you can still use an additional linestage/filter/buffer, either IVY or Ballsie.


----------



## amb

digger945, the passive filter found in the Wolfson PDF is for a DAC with unbalanced outputs. For WM874x you need to use the same filter on both the hot and cold outputs. To make it even simpler, you could connect each of the hot and cold outputs to the 470 ohm resistor as shown, but instead of running a 4.7nF capacitor to ground after that, just run a single 2.2nF cap across. The rest is the same -- coupling caps and drain resistors to ground.

 Note that this passive filter design is 1st order (6dB/octave slope), whereas the active one implemented with the opamp is 2nd order (12dB/octave).


----------



## cerbie

Is the OPA2365 all that cranky of an opamp? The AD8656, FI, warns of impending doom on every other page. If it's not, the datasheet has a nice Butterworth that would just need values tuned for 100kHz [size=xx-small](I would also assume that the phase problems Butterworths are known for are not a big deal at <1/5Fc)[/size]. A shallower passive one would be simpler, though.


----------



## MisterX

Compared to the AD8397 I would consider them both to be non cranky op-amps.


----------



## jar

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_An evolutionary step towards the full featured desktop dac?_

 

 Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_glt, thanks for your comments. There is no room on the γ2 board for a microcontroller, nor is there the power budget for it (the whole thing, γ1 and γ2 combined, must run off USB power). We're trying to keep things simple (i.e., no programming, no firmware, etc), so we run the chip in hardware mode. Also, I don't see a need to upsample to any frequency below 96KHz._

 

I'll definitely build a gamma2, but I second digger's and others' question if the full featured dac is still on the horizon. Microcontroller power consumption seems like it would be a non-issue, but I understand the desire to avoid the complexity. There are plenty of processors that can do what you'd need to configure the DAC for tens of microamps while configuring and tenths of microamps afterward.

 What I'd really like to see eventually is a DAC with the same cost and complexity goals as I perceive in the B22. Make it as good as it can be, but don't throw money away. If you need any help on the micro-controller side, let me know, as it's what I do at my day job.


----------



## hopeless

Quote:


  Originally Posted by *cerbie* /img/forum/go_quote.gif 
_Is the OPA2365 all that cranky of an opamp? The AD8656, FI, warns of impending doom on every other page. If it's not, the datasheet has a nice Butterworth that would just need values tuned for 100kHz [size=xx-small](I would also assume that the phase problems Butterworths are known for are not a big deal at <1/5Fc)[/size]. A shallower passive one would be simpler, though._

 

I've used the OPA2365 in my C&C BOX... no it didn't look crankier than anything else 
	

	
	
		
		

		
			






 Except that it made a big (steep and hard) power on and off pop, so be prepared to that. 
	

	
	
		
		

		
		
	


	




 That is why I suggested the OPA2376 as a real alternative to it, but no one would listen. 
	

	
	
		
		

		
		
	


	




 Pity because the OPA2376 sounded quite good too, just as the OPA2727 (another good choice).


----------



## amb

Quote:


  Originally Posted by *jar* /img/forum/go_quote.gif 
_What I'd really like to see eventually is a DAC with the same cost and complexity goals as I perceive in the B22. Make it as good as it can be, but don't throw money away._

 

That's still down the road, but isn't what the γ2 is.


----------



## jar

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_That's still down the road, but isn't what the γ2 is._

 

That's all I wanted to hear. I'm sure what you learn from the γ2 will make the eventual no holds barred DAC even better. I won't have the time/money for it for a while anyway, which is the only reason I haven't joined the γ2 prototype team.


----------



## MrSlim

I think the concept is brilliant, and for the majority of the people out there, this will be as high end as it needs to get, particularly with the capability to use the WM8741/2. '

 Sure, having access to the software selectable filters, balanced outputs and perhaps a discrete output would be nice, but then it would be a different animal, at a different price point. 

 And what does it all come down to?
 What has to be paid for the extra 3-5% improvement in sound quality? (OK, Im just throwing a number out there, but we all know about the audio laws of diminishing returns, and I'm a big proponent of "bang for the buck". And the y2 is going to have some serious bang.)


----------



## DoYouRight

buffalo goes with b22 I would imagine


----------



## amb

I am still looking to add a few more people to join the γ2 prototyping team. See post #37.
 This is not for the total novice, but you don't need to be an advanced builder either. It will be a bit more challenging to solder than a Mini³. If you're interested, please PM me.


----------



## digger945

I would like to add to what amb said above that there are some extremely helpful online tutorials on smd soldering that made building the Y1 a breeze for me. I will try to find the links and post them.


----------



## MisterX

Curious Inventor - Guides : Surface Mount Soldering


----------



## Lifthanger

and a special hint from someone, that butchered his 100% diy opus and got perfect smd joints on the gamma1: get a pen with liquid no clean flux.. its worth at least three times the price.


----------



## MrSlim

Man, I joined the proto team and how I gotta do homework.. 

 Good thing I've finished real school for now (3 years of Info Sec at night)...

 Is there a thread that has some good info on SMD work and what the best accessories are? 

 How about toaster oven or electric fry pan SMD work?


----------



## digger945

Watch the video MisterX linked, get a flux pen like Lifthanger mentioned(I got Kester #186 and #951). No special accessories required, the correct placement of the devices themselves is the hardest part. Most valuable tool in completing the Y1 for me was a pair of straight tweezers.
 I still remember plugging it into the computer and seeing the balloon pop up stating "Windows is now installing drivers for your device". Toooo cooool. I wanna learn more.


----------



## Beefy

In my experience, albeit limited, you don't have to have a fancy no-clean flux pen. This one worked perfectly for me: Surface Mount Rework Flux Pen - Jaycar Electronics

 I just cleaned the board when i was done with several rinses of 100% isopropyl alcohol and very gentle work with a soft toothbrush.


----------



## JamesL

Quote:


  Originally Posted by *Lifthanger* /img/forum/go_quote.gif 
_and a special hint from someone, that butchered his 100% diy opus and got perfect smd joints on the gamma1: get a pen with liquid no clean flux.. its worth at least three times the price. 
	

	
	
		
		

		
			



_

 

X10

 I butchered the pcm2702 on my first alien dac.. took me maybe 20 minutes, and eventually fried it. I got perfect joints after getting a flux pen.. about 25seconds to solder the pcm onto my first bantam, and 15 seconds for the second and third one. Tweezers and a reasonably fine chisel tip helps as well. 
 I got all three at mouser.


----------



## Billyk

Am in 2000% agreement on the flux and would suggest the bottle with the needle applicator that Tangent has on his site works even better than the pen.


----------



## ShinyFalcon

I grown tired of using my flux pen, I just can't get flux to come out (and I still have a decent amount) and the tip's worn out, often making a massive mess, and is overall a pain to use. But regardless, flux is awesome to have around! I would like to try the one Tangent sells one day...

 Anyways, I wanted to do a point-to-point version of the balanced -> single-ended stage for my Opus, and need to make sure the wiring's okay: clicky. It's probably a lot more trouble than it's worth, but we'll see...


----------



## digger945

Looks like the jist of it. Are you using the circuit on the right? From where did you find it?


----------



## cobaltmute

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_I grown tired of using my flux pen, I just can't get flux to come out (and I still have a decent amount) and the tip's worn out, often making a massive mess, and is overall a pain to use. But regardless, flux is awesome to have around! I would like to try the one Tangent sells one day..._

 

I have used a bottle like the one Tangent sells. It is very nice as you can apply a very limited amount of flux.


----------



## ShinyFalcon

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Looks like the jist of it. Are you using the circuit on the right? From where did you find it?_

 

It's part of the schematics on the first page, second post, I just copy and pasted it so it's easier to compare.


----------



## nattonrice

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_In my experience, albeit limited, you don't have to have a fancy no-clean flux pen. This one worked perfectly for me: Surface Mount Rework Flux Pen - Jaycar Electronics_

 

I use the exact same one! It's very easy to control how much flux you apply.
 Thou I really want a little squeezy bottle like tangent sells as it looks even better... I wonder if you can get a similar product in au?


----------



## amb

Fry's Electronics stores sell liquid flux in bottles with a small brush built-into the cap. I use that now and it works great.

 Flux pens also work well, but only when they're new. The flux tend to dry up at the tip, clogging the flow (even when there is plenty left inside). Working the tip sometimes works to get it started again, sometimes not, or you might suddenly unleash too much flux... making a sticky mess.


----------



## smeggy

I just bought a flux pen from Frys along with a nice Hakko iron. I also have a tub of flux gel stuff. I'll look out for the bottles next time I'm in there along with a needle tip to practice SMD stuff with.


----------



## MisterX

Can't say I have ever left a flux pen unattended long enough for the tip to dry out. 

 As much as I hate to sound ungrateful...I threw the bottle of flux I got from Tangent (for free) away after using less then a quarter of it because the solvent had evaporated to the point where it was a exercise in frustration to try use it.

 Maybe something like one of those "General" pen oilers is a more suitably sized container for novice DIYers?


----------



## smeggy

I think the pens are cheap enough to not worry too much about drying. By the way, where do you get that solder melting stuff from? I'd like to get some for my mista.. erm , chip rolling


----------



## JamesL

Quote:


  Originally Posted by *smeggy* /img/forum/go_quote.gif 
_I think the pens are cheap enough to not worry too much about drying. By the way, where do you get that solder melting stuff from? I'd like to get some for my mista.. erm , chip rolling 
	

	
	
		
		

		
		
	


	


_

 

chipquik? I think mouser stocks them


----------



## MisterX

Digi-key (#SMD1-ND) or maybe at Fry's if you have one near by (# 2644632)

 BTW the flux that comes with that kit is kinda neat because it's tacky but I dunno about the smell.


----------



## amb

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Can't say I have ever left a flux pen unattended long enough for the tip to dry out._

 

I meant over the course of several months, not in a single soldering session...


----------



## amb

Thanks to all those who joined... we now have a good sized prototype team. Over this weekend I will try to tie up any loose ends with the PCB layout, create a BOM, and move forward with the program.


----------



## MisterX

Quote:


 I meant over the course of several months 
 

So I did I.


----------



## digger945

Will we be required to use our existing Y1 boards or can we order the unbroken pcbs and build the whole thing from scratch(this is what I was thinking of doing)?

 Yea I have some trouble getting my solder pen to start flowing sometimes. It says on the side of the pen that they have a shelf life of 2 years. I'm definitely gonna try out the other methods you guys have suggested.


----------



## MisterX

Quote:


 Will we be required to use our existing Y1 boards or can we order the unbroken pcbs and build the whole thing from scratch(this is what I was thinking of doing)? 
 

Either way is fine, there are no "requirements".


----------



## amb

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Will we be required to use our existing Y1 boards or can we order the unbroken pcbs and build the whole thing from scratch(this is what I was thinking of doing)?_

 

You can do as you wish. It would be neater if you don't have to re-join the broken-apart γ1 halves.


----------



## digger945

Actually I would like to do both. 
 Build the Y2 and join the existing Y1(I already have) to give an idea of how it works for those who want to "upgrade", and then assemble a fresh unbroken Y1 board to mate to the new Y2 for a complete assembly to go into the new case you mentioned on the first page(or whatever case we decide to go with).


----------



## MisterX

No need, we already know "how it works". 
	

	
	
		
		

		
		
	


	




 In fact there are pictures of one of the handful of boards I stuck back together posted in the PPA thread. 

http://www.head-fi.org/forums/attach...av2.y1lite.jpg
 (that is how the USB jack ended up on the "inside" of the board )


----------



## oneplustwo

what exactly does "rejoining" broken-apart gamma 1 boards mean?


----------



## amb

Quote:


  Originally Posted by *oneplustwo* /img/forum/go_quote.gif 
_what exactly does "rejoining" broken-apart gamma 1 boards mean?_

 

The γ1 board is really two boards, the USB board and the DAC board, but they are supplied as a single piece with a groove down the middle, so you could break them apart (and then after assembly, plug them into each other to slide into a Hammond 1455C80x case).

 But the γ2 is designed to plug into the one-piece γ1 board (not broken apart), and to fit a Box Enclosures B2-080 case. If you have a γ1 that has already been snapped apart, then they need to be joined back together to work with the γ2. This is necessary because the boards are only supported by their edges in the case slots. Without mechanically joining the γ1, it could "sag" inside the case or otherwise become rattly and misaligned with the panel cutouts.


----------



## oneplustwo

gotcha. i had read the earlier post about rejoining but wanted to make sure there wasn't any signal or ground connections that needed to be made as well.


----------



## amc

Just submitting my order for y1 boards and bits now. This is exciting!


----------



## amb

Post #2 has been updated to v0.12. This will be the version we go to prototype with.


----------



## digger945

I lollered at MisterX's "Gamma extra version 
	

	
	
		
		

		
		
	


	




"

 Can mine be Quadraphonic?


----------



## amb

Boards have been ordered for the prototype team.


----------



## hopeless

Guys and gals, don't use the OPA2365 unless you're ready to perforate your eardrums (especially for headphone users) at every power on and off.


----------



## sergery

Man, this is exciting. Put me on the list for pre-production boards, if you make a revision or get another batch. This would be a fun build and looks pretty potent.


----------



## hopeless

Hm, with a single +5V power supply (and with the subsequent CMOS opamps) ... And with small power supply capacitance too ...


----------



## MASantos

Quote:


  Originally Posted by *hopeless* /img/forum/go_quote.gif 
_Guys and gals, don't use the OPA2365 unless you're ready to perforate your eardrums (especially for headphone users) at every power on and off.
	

	
	
		
		

		
		
	


	


_

 

 Quote:


  Originally Posted by *hopeless* /img/forum/go_quote.gif 
_Hm, with a single +5V power supply (and with the subsequent CMOS opamps) ... And with small power supply capacitance too ..._

 

Dude, these two posts don't bring any useful info to the discussion taking place in this thread.

 If you wish to participate in the thread (and in any other thread FWIW), please do it in a polite and proper manner, which means in this case stating why you think people shouldn't use the OPA2365 and if possible posting or mentioning why. 
 In general, it means supporting your posts and point of view with actual information based on your experience and knowledge (and since you are new around here, sharing your previous experience on the subject would be appropriate) instead of putting a rolleyes smiley, which is saying the least, quite rude...

 Your second post is even worse, as you just mention two of the design characteristics of the project without expressing any kind of opinion... the tone in your posts is quite ironic which isn't much appreciated around here (just letting you know, since you're quite new here).

 AMB is a very well respected member among this comunity which has designed (or participated in the design process) quite a few proven DIY projects and MisterX is also a very well respected member of head-fi, participating in many projects as well, so coming here and just trolling around isn't appreciated and certainly not needed.

 Thank you,

 Manuel Santos


----------



## Billyk

Quote:


 AMB is a very well respected member among this comunity which has designed (or participated in the design process) quite a few proven DIY projects and MisterX is also a very well respected member of head-fi, participating in many projects as well, so coming here and just trolling around isn't appreciated and certainly not needed. 
 

Said what I was thinking!


----------



## hopeless

Quote:


  Originally Posted by *MASantos* /img/forum/go_quote.gif 
_Dude, these two posts don't bring any useful info to the discussion taking place in this thread.

 If you wish to participate in the thread (and in any other thread FWIW), please do it in a polite and proper manner, which means in this case stating why you think people shouldn't use the OPA2365 and if possible posting or mentioning why. 
 In general, it means supporting your posts and point of view with actual information based on your experience and knowledge (and since you are new around here, sharing your previous experience on the subject would be appropriate) instead of putting a rolleyes smiley, which is saying the least, quite rude...

 Your second post is even worse, as you just mention two of the design characteristics of the project without expressing any kind of opinion... the tone in your posts is quite ironic which isn't much appreciated around here (just letting you know, since you're quite new here).

 AMB is a very well respected member among this comunity which has designed (or participated in the design process) quite a few proven DIY projects and MisterX is also a very well respected member of head-fi, participating in many projects as well, so coming here and just trolling around isn't appreciated and certainly not needed.

 Thank you,

 Manuel Santos_

 

Sorry if I was too explicit in saying what I thought or knew.


----------



## Billyk

Quote:


  Originally Posted by *hopeless* /img/forum/go_quote.gif 
_Sorry if I was too explicit in saying what I thought or knew._

 

 From my point of view, learning what I can from these forums, your "..."
 doesn't tell me anything and does not help me to form an opinion. I want to know why you supposedly think these are bad things. All I see of your posts is a lot of part numbers and things like crisp or warm or pop.


----------



## Mr.Duck

Quote:


  Originally Posted by *Billyk* /img/forum/go_quote.gif 
_From my point of view, learning what I can from these forums, your "..."
 doesn't tell me anything and does not help me to form an opinion. I want to know why you supposedly think these are bad things. All I see of your posts is a lot of part numbers and things like crisp or warm or pop. 
	

	
	
		
		

		
		
	


	


_

 

Eh?? 
	

	
	
		
		

		
		
	


	




 Let's just get back and stay on topic can we?


----------



## nattonrice

Indeed ^^

 I just put in my and one other prototyper's order with Ti~
 The gamma2 was going to be a "cheap" distraction untill the b24 decided to tag along for the ride LOL


----------



## UglyJoe

Quote:


  Originally Posted by *nattonrice* /img/forum/go_quote.gif 
_Indeed ^^

 I just put in my and one other prototyper's order with Ti~
 The gamma2 was going to be a "cheap" distraction untill the b24 decided to tag along for the ride LOL_

 

OH WOW. Talk about exponentially increasing your wallet-damage.


----------



## nattonrice

Quote:


  Originally Posted by *UglyJoe* /img/forum/go_quote.gif 
_OH WOW. Talk about exponentially increasing your wallet-damage._

 

Haha yeah well... I'm in holiday mode so my wallet knows no bounds.
 Well, at least till it falls over and curls up into a limp ball... oh dear.


----------



## Filburt

Quote:


  Originally Posted by *hopeless* /img/forum/go_quote.gif 
_Guys and gals, don't use the OPA2365 unless you're ready to perforate your eardrums (especially for headphone users) at every power on and off.
	

	
	
		
		

		
		
	


	


_

 

If you're getting this sort of problem, you may need to check your supply (including bypass) as well as your soldering throughout the signal path. I haven't had this problem except when I used it in an old breadboard that I later discovered had a loose contact and was, regardless, a less than optimal environment for the chip (although I did later get it to work). 

 I've been using this chip for a couple years now, and have used the it in several applications, both in single and dual supply. While it can be a bit finicky in some instances, the performance is exceptionally high. For a low voltage application, it's my first choice. I'm glad to see it finally being specified for a major DIY project.


----------



## Filburt

.


----------



## amb

hopeless, obviously you did not read my earlier post about one of the most important selection critera for this DAC -- due to the low supply voltage, it must swing very close to the rails or we'll encounter clipping at 0dBFS. Not just any rail-to-rail opamp would do. The OPA2132 is simply out of the question for this application, and even the OPA2727 that you suggest is not good enough. It could swing to within 150mV of the rails (with a worse-case of 250mV). Compare this to OPA2365 (10mV typical, 20mV max)., and AD8656 (9mV typical, 30mV max).

 There are other specifications that are also important in our selection process. And trust me, we've lookedf at many opamps and gone over their datasheets with a fine-toothed comb.

 Before we start talking about subjective sound qualities, we must choose opamps that meet all the circuit design requirements first. We narrowed the list down to two, for different uses. The OPA2365 is primary for line-out use only. If you want to drive headphones directly, we recommend AD8656 instead. Not only do our selected opamps meet our technical requirements, we also like their sound very much.

 I would be remiss if I didn't also mention that a very highly regarded commercial portable DAC/amp uses two OPA365s (the single version of the OPA2365) in its DAC's analog output stage...


----------



## Beefy

Quote:


  Originally Posted by *hopeful* /img/forum/go_quote.gif 
_Anyway... what a pain. How much better would be having a socket for normal opamps, and for them an external supply voltage of say 12V ? Oh well, that's just my thinking anyway, no need to go any further in discussing._

 

I can see that you are trying to 'help', and I don't like to chastise people for offering opinions...... but AMB and MisterX are designing a compact DAC predominantly for use with USB power. It seems that they have a very good grasp of what is required for working within these constraints.

 If it doesn't suit your interests, then don't build one. If it doesn't meet your design criteria, then design something for yourself.


----------



## MASantos

Quote:


  Originally Posted by *hopeless* /img/forum/go_quote.gif 
_Sorry if I was too explicit in saying what I thought or knew._

 

You didn't say what you thought or knew, you wrote some nonsence that well.. didn't make much sence at all...

 this continuous BS posting atitute got you banned... so maybe you should rethink your atitude around here...


  Quote:


  Originally Posted by *hopeful* /img/forum/go_quote.gif 
_...How much better would be having a socket for normal opamps, and for them an external supply voltage of say 12V ? Oh well, that's just my thinking anyway, no need to go any further in discussing._

 

It has been said by AMB that using external power ISN'T a design goal of this project!!!! Yes, it would be easier, but it isn't for this project. Can't you understand this? Please go trolling another website!!!


----------



## MrSlim

Hopeful/Hopeless, 
 You are not winning any friends here by attempting to second guess the design choices made by two of the most prominent designers(AMB) and implementers(MISTERX) in the Headfi world. 

 Condesending statements like :

 "I see that this forum's sectarian (or lobbystic) attitudes haven't changed the slightest bit." 

 are not going to help your cause either. 

 Unless you can prove you have a design background equivalent to AMB, then its better to follow the addage:

 "Better to be thought a fool, than to open one's mouth and confirm it.."

 Give it a rest.


----------



## ruZZ.il

Then don't build one.

 How backed is your opinion? 
 Have you ever/even heard a gamma1 DAC for instance? Even when powered off USB, gives some big boys a run for their money.

 Please introduce yourself. I'm intrigued by your background. What have you studied, what have you built, what equipment do you own?


----------



## nattonrice

Quote:


  Originally Posted by *mildclass* /img/forum/go_quote.gif 
_The problem is that this little DAC will be more expensive than the big boys..._

 

I'm usually in agreement that highend diy "can" cost more than the comercial quivilent, depending how extravigent you go with boutique parts. That is the prerogative of the diy'er.

 But, for 2 seconds if you'd stop talking out'ya tooter, you'd see that the gamma2 is slightly cheaper or (possibly) almost the same price as the closest "big boy", the pico dac, and yet manages to use a significantly higher performing Wolfson DAC chip to the pico. This is not to mention the fact that the Pico only has usb input whereas the Gamma2 has usb, coax and optical.
 The Gamma2 also has the possibility to be powered by an ac wall wart.

 I'm not overtly trying to be adversarial but you're spreading erroneous information.

  Quote:


  Originally Posted by *mildclass* /img/forum/go_quote.gif 
_Sure I don't build one._

 

Then what in the hell are you doing here even bothering to comment?


----------



## Lifthanger

I'd like to see a link to something better for less than about 150$ (maybe even less, I didn't do the math). And I'm serious, because if there is, I'll probably build it in the future.

 IIRC the gamma project is only a prelude for a desktop DAC by the design team. Aim was to get in touch with designing DACs in the first place.

 If it'd make you happy, I could try the ballsie as output stage (+-15V) when the gamma2 is running. Don't think this will change much if output goes into an amp.
 These low voltage opamps should be able to drive a (in my case 40cm) interconnect into the amp. 

 on a side note: on most forums I'm on banned members with new accounts get instabanned. I think the courtesy of the mods here should be respected.


----------



## Beefy

Quote:


  Originally Posted by *mildclass* /img/forum/go_quote.gif 
_The problem is that this little DAC will be more expensive than the big boys... much more so (if they're chosen well) maybe._

 

Name them. If I can get something better than the y2 for the price, then I will buy it.


----------



## MASantos

Quote:


  Originally Posted by *mildclass* /img/forum/go_quote.gif 
_I'll say this only - how many big boys (connected to decent transports) have you personally heard?

 The problem is that this little DAC will be more expensive than the big boys... much more so (if they're chosen well) maybe.



 Sure I don't build one. I'm not even interested in going on arguing. Let people be different..._

 

Then please leave this thread. If you wish to participate do it in a polite and educated way, stating your background and DIY experience and plausible reasons to back your opinions.

 And you keep getting banned for your atitude and behaviour, so either change it or leave head-fi for good! 

 people, lets just ignore him and get back to discussing the project.


----------



## ShinyFalcon

Quote:


  Originally Posted by *Lifthanger* /img/forum/go_quote.gif 
_I'd like to see a link to something better for less than about 150$ (maybe even less, I didn't do the math). And I'm serious, because if there is, I'll probably build it in the future.

 IIRC the gamma project is only a prelude for a desktop DAC by the design team. Aim was to get in touch with designing DACs in the first place.

 If it'd make you happy, I could try the ballsie as output stage (+-15V) when the gamma2 is running. Don't think this will change much if output goes into an amp.
 These low voltage opamps should be able to drive a (in my case 40cm) interconnect into the amp. 

 on a side note: on most forums I'm on banned members with new accounts get instabanned. I think the courtesy of the mods here should be respected._

 

A full build y1 parts cost:

 - Mouser ($45 + $11.71 shipping/tax)
 - AMB's lab ($40, minus panels which is additional +$40)

 A full y2 [using prototype BOM]:
 - Digikey ($36 + $10 shipping/tax)
 - Mouser [for WM8741, crystal, etc] (+$17)
 - Allow +$20 for case, ferrite, little bits I may have forgotten
 - Allow for tools, which is usually the bulk of the costs (my iron and tools alone were $150)

 Not bad for $160. What "very high performance" desktop DACs are in the $200 range? My Opus (without Ballsie for balanced->single ended conversion) ended up being $275 (built myself, has Metronome, 4:1 SPDIF Mux, Toslink), but is more flexible in terms of upgradeability and options (XLR, hardware control). Otherwise, the Opus and y2 is very similar to each other with the exception being the output stage and their intended audiences/purpose. Had I known about the y2 a bit earlier, I would definitely have gone with the y2.


----------



## MASantos

Even if you consider the panels or a different kind of casing, or international shipping costs, the price is still amazing for what you get!!


  Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_A full build y1 parts cost:

 - Mouser ($45 + $11.71 shipping/tax)
 - AMB's lab ($40, minus panels which is additional +$40)

 A full y2 [using prototype BOM]:
 - Digikey ($36 + $10 shipping/tax)
 - Mouser [for WM8741, crystal, etc] (+$17)
 - Allow +$20 for case, ferrite, little bits I may have forgotten
 - Allow for tools, which is usually the bulk of the costs (my iron and tools alone were $150)

 Not bad for $160. What "very high performance" desktop DACs are in the $200 range? My Opus (without Ballsie for balanced->single ended conversion) ended up being $275 (built myself, has Metronome, 4:1 SPDIF Mux, Toslink), but is more flexible in terms of upgradeability and options (XLR, hardware control). Otherwise, the Opus and y2 is very similar to each other with the exception being the output stage and their intended audiences/purpose. Had I known about the y2 a bit earlier, I would definitely have gone with the y2._


----------



## Mr.Duck

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_ Had I known about the y2 a bit earlier, I would definitely have gone with the y2._

 

Same with me pretty much. Twisted pear stuff looks good, but when it costs $75 for a USB reciever mounted on a PCB then I'm thinking meh. By them you add up all the bits you need like the ASRC then it starts getting very expensive. Espcially if you go with buffalo then it takes no effort to blow $500+ on all these bits.

 Gamma2 looks like it will be the smallest, neatest, and most affordable way to get a true high end DAC. I'm glad I waited for it. IMO it's been tough and a long time to wait. So many times I was looking on ebay etc for some cheap DAC kit from hong kong, but I'm glad I didn't buy any of them now.


----------



## m1abrams

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_A full build y1 parts cost:

 - Mouser ($45 + $11.71 shipping/tax)
 - AMB's lab ($40, minus panels which is additional +$40)

 A full y2 [using prototype BOM]:
 - Digikey ($36 + $10 shipping/tax)
 - Mouser [for WM8741, crystal, etc] (+$17)
 - Allow +$20 for case, ferrite, little bits I may have forgotten
 - Allow for tools, which is usually the bulk of the costs (my iron and tools alone were $150)
_

 

Also if you want to keep the performance but trim the price even more you can leave off a number of parts in the y1 build like the DAC chip, 3.5mm phono jack, etc. Also if you just need USB DAC then you can trim off many other parts too like the switch, input jacks, power jack and support chips for it. You could probably get a USB lite Y2 build under $100.


----------



## Billyk

I am getting ready to start my y1 and I am not going to split the board and am getting the larger case and am saving for the y2 parts. My timing is good for a change. 
	

	
	
		
		

		
			





 I am looking forward to comparing it to my CAL Alpha DAC with it's 12ax7 output stage.


----------



## m1abrams

Quote:


  Originally Posted by *Billyk* /img/forum/go_quote.gif 
_I am getting ready to start my y1 and I am not going to split the board and am getting the larger case and am saving for the y2 parts. My timing is good for a change. 
	

	
	
		
		

		
		
	


	




 I am looking forward to comparing it to my CAL Alpha DAC with it's 12ax7 output stage._

 

I would recommend you get the case that is spec'd for the y2 for your y1. It should hold the unsplit y1 just fine and you will be able to reuse it when you upgrade to the y2.


----------



## Beefy

Quote:


  Originally Posted by *Mr.Duck* /img/forum/go_quote.gif 
_Same with me pretty much. Twisted pear stuff looks good, but when it costs $75 for a USB reciever mounted on a PCB then I'm thinking meh._

 

Like all commercial products, you have to pay for labour. If you are too scared or hamfisted to do SMD, that $75 is a LOT better prospect than spending the same on a non-functioning y1.

 Me, I'm currently torn between building a y1 for USB to SPDIF duties, and buying the TPA USB module. Not because I can't build the y1, but because the y1 doesn't stack with other TPA modules that I have, which case layout a lot more difficult 
	

	
	
		
		

		
		
	


	




 *

 FWIW, when the y2 is released, I will seriously consider building one to replace/upgrade my existing y1 full build that I use at work. *hint to AMB* A pre-machined panel group buy would certainly help......


----------



## Billyk

Quote:


  Originally Posted by *m1abrams* /img/forum/go_quote.gif 
_I would recommend you get the case that is spec'd for the y2 for your y1. It should hold the unsplit y1 just fine and you will be able to reuse it when you upgrade to the y2._

 

Exactly! 

 I haven't placed my Mouser order yet and the LP2985A-33DBVR LDO regulator is back ordered so my timing isn't that great. Are there any substitutes?


----------



## m1abrams

Quote:


  Originally Posted by *Billyk* /img/forum/go_quote.gif 
_Exactly! 

 I haven't placed my Mouser order yet and the LP2985A-33DBVR LDO regulator is back ordered so my timing isn't that great. Are there any substitutes?_

 

Yep I ran into the same problem and the Toslink receiver is only available at Farnell. Tip - the case and the regulator are also at Farnell, so if you add a couple other items you can meet the $20 min. order at Farnell.


----------



## Billyk

Quote:


  Originally Posted by *m1abrams* /img/forum/go_quote.gif 
_Yep I ran into the same problem and the Toslink receiver is only available at Farnell. Tip - the case and the regulator are also at Farnell, so if you add a couple other items you can meet the $20 min. order at Farnell._

 

 I may be confused... Tried Farnell all prices were in GBP so 20.00 GPB minimum order was $32.40 USD and shipping was like $25.00. A bit more than I can spend at the moment.


----------



## m1abrams

Quote:


  Originally Posted by *Billyk* /img/forum/go_quote.gif 
_I may be confused... Tried Farnell all prices were in GBP so 20.00 GPB minimum order was $32.40 USD and shipping was like $25.00. A bit more than I can spend at the moment._

 

Sorry yeah min. is 20 GPB not dollars, however I did not get $25 shipping. My shipping ended up to be about $5, my total order cost was $37 with shipping.


----------



## amb

Interesting, m1abrams. Good info, I didn't know that one could order directly from Farnell in the US. That's a great solution for both TORX147PL and TOTX147PL.


----------



## ruZZ.il

Group buy them for shipping with boards? 
	

	
	
		
		

		
			




 I haven't seen the BoM yet, but what's the source count on it? Any possibility to drop that count via AMB shop? Would go a long way for us abroad-ers.


----------



## amb

γ2 doesn't use either of these parts, but γ1 does. The optical receiver is not used in the γ1 Lite, and the optical transmitter is only used for USB-to-S/PDIF or full++ configs. This makes it unwieldy for me to include them with boards. Also, the optical receiver shortage is only temporary -- Digikey will restock them by late September.


----------



## luvdunhill

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Interesting, m1abrams. Good info, I didn't know that one could order directly from Farnell in the US. That's a great solution for both TORX147PL and TOTX147PL._

 

Just order them through Newark and pay the Farnell drop ship fee:

TOSHIBA|TOTX147PL|TRANSMITTER, FIBRE OPTIC | Newark.com

 You may have to call to add the TORX147PL, but Newark will allow it to ship from Farnell.


----------



## amb

In case it's not obvious, since γ2 takes I²S as input, it could be used standalone (without γ1) with any source that outputs I²S. Just add a 5V regulated power supply (connect to VCC at either J1 or J5), connect the I²S.lines to either J2 or J4, and then short across JP1.

 This would make an excellent upgrade DAC for CD player transports that output I²S., as an example.

 Just another application idea for γ2...


----------



## Mr.Duck

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_In case it's not obvious, since γ2 takes I²S as input, it could be used standalone (without γ1) with any source that outputs I²S._

 

It's obvious now that you mentioned it 
	

	
	
		
		

		
		
	


	





 It's good if you've got an I2S output already. But if not, would there be any advantage in NOT pairing gamma2 with gamma1?


----------



## amb

Quote:


  Originally Posted by *Mr.Duck* /img/forum/go_quote.gif 
_It's good if you've got an I2S output already. But if not, would there be any advantage in NOT pairing gamma2 with gamma1?_

 

γ2 is designed specifically to pair with γ1, electrically and mechaincally. γ1 provides the 5V power, excellent input receivers for USB, coax and optical S/PDIF, and the whole thing fits neatly into an integrated package. I don't see any reason not to use a γ1 unless you already have an I²S source and a regulated 5V PSU. Since I²S is not usually an external interface, this would be a "specialty" application such as internal to a CDP.


----------



## Lifthanger

about the output caps. Just found some mundorf MKPs but with 3-5uF only.
 It seems that the highpass at the output would have a corner frequency of below 2Hz with 3.3uF. 

 Is this usable, or is the input impedance of the next stage important, too?

 also I'm not sure wether using this caps makes sense in the first place.


----------



## amb

Quote:


  Originally Posted by *Lifthanger* /img/forum/go_quote.gif 
_about the output caps. Just found some mundorf MKPs but with 3-5uF only.
 It seems that the highpass at the output would have a corner frequency of below 2Hz with 3.3uF. 

 Is this usable, or is the input impedance of the next stage important, too?_

 

Yes, the input impedance of the next stage is in parallel with R9/R16 and needs to be taken into account when computing the high-pass corner frequency. 

  Quote:


 also I'm not sure wether using this caps makes sense in the first place. 
 

The issue is not simply capacitance. Space is tight between the boards (when you plug the γ2 into the γ1. Also, parts on the two boards must not physically hit each other. As it stands, using the default/recommended parts, the two boards fit together like a jigsaw puzzle with not much room to spare. I doubt that the Mundorf can fit in there.

 If you don't like electrolytic capacitors as output caps (even though "audio grade" ones are specified), and if your next stage has high input impedance (10K ohms or more), then you could omit C20/C26 and use 3.3uF 50V Wima MKS2 caps for C19/C25. That will fit.


----------



## wiatrob

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_This would make an excellent upgrade DAC for CD player transports that output I²S., as an example._

 

Or a sound card for that matter - I've just been looking at modding two cards I have on the bench for I²S output. In fact, the y2 is compact enough to fit in the computer case - tho' I'd hate to pull the 5V from the computer power supply...

 But I must resist any new projects!


----------



## Lifthanger

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Yes, the input impedance of the next stage is in parallel with R9/R16 and needs to be taken into account when computing the high-pass corner frequency. 


 The issue is not simply capacitance. Space is tight between the boards (when you plug the γ2 into the γ1. Also, parts on the two boards must not physically hit each other. As it stands, using the default/recommended parts, the two boards fit together like a jigsaw puzzle with not much room to spare. I doubt that the Mundorf can fit in there.

 If you don't like electrolytic capacitors as output caps (even though "audio grade" ones are specified), and if your next stage has high input impedance (10K ohms or more), then you could omit C20/C26 and use 3.3uF 50V Wima MKS2 caps for C19/C25. That will fit._

 

thanks amb, really appreciate this. the next stage will (of course 
	

	
	
		
		

		
		
	


	




 ) be one of your amps with 50k impedance on the input, so it should be fine.

 honestly, I haven't got a clue about which caps I like, this was rather an informal question. the standard caps arrived today with the whole gamma2 order and they'll be installed at first. but maybe later I could wire the mundorfs between the output and the rca jacks in a larger case.


----------



## digger945

Just ordered the box enclosures case from Farnell and got a little taste of what it's probably like for those who live outside the US.
 Minimum order requirement, no idea what the shipping will be as it said TBA when I finally checked out. I have no idea if the stuff is located in the US or UK. At any rate I ordered an extra TOTX to have if anyone wants. I was digging around in the parts boxes and came up with one from the Gamma 1 build so I'm set to build one now.

 Is there a minimum voltage rating for C20 and C26?


----------



## amb

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Is there a minimum voltage rating for C20 and C26?_

 

Given that the circuit is powered by a 5V source (and regulated down to 4.5V or 4.75V for the analog supply), and then these caps typically "see" only half that, 6.3V or 10V voltage rating is high enough.


----------



## digger945

That's kinda what I figured but didn't know exactly what kinda output may be coming from the opamp. 

 I finished ordering parts. For enough parts to build two y1's and two y2's with Vishay resistors and a few optional caps and stuff it comes to $203 Mouser and $80 Digikey(neither with shipping included), plus the Farnell case and amb shop stuffs. I think if you just ordered what you need for your specific build you could easily put this in a case for $150 plus shipping.


----------



## komi

Hum, something is strange on Newark ...

TOSHIBA - TOTX147PL - TRANSMITTER, FIBRE OPTIC says there is 688 pieces on stock right now ...

 I place order, but:

 05M1615 - TOSHIBA TOTX147PL - 4 - 4 - $3.03 Each - Back Order - 
 This item is currently on back order with the manufacturer. View Ship Date/Tracking Number field for expected ship date(s). 

 Expected Ship Date - 16 Jul 2009 but - is not shipped yet ...

 Anyone can explane whats goin on there ?



 By the way:

 05M1608 TOSHIBA - TORX147PL - 4 - 4 - $3.33 Each - Complete
 This item has been processed and shipped. 15 Jul 2009


----------



## digger945

I guess you noticed under the "688 pieces" that it says...
 Farnell UK / Direct Ship
 - Non-Cancelable/Non-Returnable 
 Handling Fee $20 per order 
 Delivery within 7 business days 

 If you hover your mouse over the "Farnell UK / Direct Ship" , it says the $20 service charge is in lieu of a Farnell freight charge. That's what made me decide to go ahead and order the Box Enclosure and TOTX both from Farnell UK. I wonder if they charge $20 per item ordered or if it's just one $20 fee for your entire order. 


 That link you gave for Newark shows they also have all the Box Enclosures except the gold color, however it says nothing of the $20 handling fee so they must be in stock here in the states, and nicely priced at $11.10. 

 If you decide to go with Newark we can see what the difference is between yours and mine, parts/shipping/handling, etc. The kicker with Farnell is if you use CC/DC the minimum order is 20 pound.


----------



## komi

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_I guess you noticed under the "688 pieces" that it says...
 Farnell UK / Direct Ship
 - Non-Cancelable/Non-Returnable 
 Handling Fee $20 per order 
 Delivery within 7 business days 

 If you hover your mouse over the "Farnell UK / Direct Ship" , it says the $20 service charge is in lieu of a Farnell freight charge. That's what made me decide to go ahead and order the Box Enclosure and TOTX both from Farnell UK. I wonder if they charge $20 per item ordered or if it's just one $20 fee for your entire order. 


 That link you gave for Newark shows they also have all the Box Enclosures except the gold color, however it says nothing of the $20 handling fee so they must be in stock here in the states, and nicely priced at $11.10. 

 If you decide to go with Newark we can see what the difference is between yours and mine, parts/shipping/handling, etc. The kicker with Farnell is if you use CC/DC the minimum order is 20 pound._

 

I DID order, but - never mind they say 688 pieces is on stock, after order i got shipped just TORX - not TOTX too ... they say TOTX is backordered - even stock says is 688 on stock, never mind where is this stock ... 

 After order i got this in order history:
 -----------------------------------
 05M1608 - TOSHIBA - TORX147PL - 4 - 4 - $3.33 Each - Complete -This item has been processed and shipped 15 Jul 2009
 -----------------------------------
 05M1615 - TOSHIBA - TOTX147PL - 4 - 4 - $3.03 Each - Back Order - This item is currently on back order with the manufacturer. View Ship Date/Tracking Number field for expected ship date(s). Expected Ship Date 16 Jul 2009
 -----------------------------------


 Today is July 19th and TOTX is still not shipped ... Like they say - BACKORDERED ... 


 This is what is confusing to me ... Do they have on stock or not ... And - when they gonna ship ...


----------



## digger945

I don't know why they say BACKORDERED. I am not familiar at all with ordering from Newark/Farnell.
 I ordered from Farnell, and it too says 688 in stock, but no backorder when I checked out.


----------



## amb

Just call them on Monday to find out what' the scoop is.


----------



## komi

I am on short vacation from monday - some traveling around Germany .. will be back in 7 days or something .. will see whats goin on ...


----------



## MisterX

And if you happen to be thinking what I would be thinking after seeing that picture.... this is what the soldering on the top one looks like up close:


----------



## m1abrams

MisterX - Any pics with the board mated with a y1?


----------



## MisterX

Yeah, I have a bunch of pictures with the two boards plugged into each other but there is not a whole lot to see there.


----------



## amb

Here are the top and bottom views of the γ2 prototype PCB (v0.12). These boards will be shipped to the prototype team members tomorrow.

 As seen in the pics posted by MisterX, he has already built three of them, and they work!


----------



## nattonrice

Very excellent


----------



## Beefy

Looks nice! 
	

	
	
		
		

		
		
	


	




 ...... but why all the extra holes on the PCB


----------



## amb

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_...... but why all the extra holes on the PCB 
	

	
	
		
		

		
		
	


	


_

 

The board has double ground planes, one on each side. Those "holes" are a matrix of through-plated vias to stitch the two planes together, to keep them as tightly-coupled as possible even at very high frequencies.


----------



## Beefy

Roger roger


----------



## MisterX

Someone asked me if we could have used a smaller enclosure today...

 The answer was: 
 I don't see how we could fit all the inputs and outputs into a smaller enclosure. 
	

	
	
		
		

		
			










 (yes, the boards are upside down)


----------



## JamesL

Talk about brainfreeze. For the longest time, I kept staring at the board... wondering why the coax input was red.. why the rca outs were spaced so closely together.. and it wasn't until I saw that the coax wasn't no longer next to the optical input that I realized that I was looking at the wrong jacks altogether.

 It looks great though =)
 Count me in for the first batch of production boards


----------



## linuxworks

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_Looks nice! 
	

	
	
		
		

		
		
	


	




 ...... but why all the extra holes on the PCB 
	

	
	
		
		

		
		
	


	


_

 

it reduces shipping weight. duh!


 (I'm kidding)


----------



## dude_500

Nobody seems to have asked, how does it sound? Is it a noticable improvement over just the Y1?


----------



## amb

As of now, only MisterX has heard the γ2, and he appears to be pleased. I should have one up and working within a couple days. We are focused on non-subjective stuff at the moment, such as making various measurements. γ2 is based on some top-tier parts, and I have no reason to doubt that it would perform accordingly.

 Since you're on the prototyping team, and the PCB is on the way to you, build it and hear it for yourself.


----------



## Daveze

Is it the perspective of the shot or is it a little saggy in the middle? Again, I'm really quite amazed at how tidy it is. Starting to wish I had jumped on the proto team...ah well.


----------



## Mr.Duck

Excellent work. Are you expecting v0.12 to be moved up to v1.0 after the beta testers have built them? Or perhaps there will need to be another batch made for testing, such as v0.13 etc?

 BTW, it looks like that case would make an excellent heatsink. Not really needed for this DAC but I was thinking about voltage regs or maybe a beta 22.


----------



## MisterX

Quote:


 Is it the perspective of the shot or is it a little saggy in the middle? 
 

A little of both


----------



## amb

Quote:


  Originally Posted by *Mr.Duck* /img/forum/go_quote.gif 
_Excellent work. Are you expecting v0.12 to be moved up to v1.0 after the beta testers have built them? Or perhaps there will need to be another batch made for testing, such as v0.13 etc?_

 

I don't think we need another proto run. After the current testing phase we will bump the revision to v1.0 and incorporate all changes learned.

  Quote:


 BTW, it looks like that case would make an excellent heatsink. Not really needed for this DAC but I was thinking about voltage regs or maybe a beta 22. 
 

β22 in this little case? I don't think so.


----------



## linuxworks

some initial close-up photos of my solder-in-progress board:





















 I'm waiting on some parts before I can proceed.


----------



## Billyk

Nice work! Can't decide what's better the soldering or the photography!!


----------



## linuxworks

thanks, billy 
	

	
	
		
		

		
		
	


	




 gotta admit, I used the old flood-n-suck method on those 2 so28 chips. but it gets the job done with little hair-pulling


----------



## linuxworks

update:

 IT WORKS!

 for a while, though, I was getting no audio-out. all voltages seemed ok.

 amb suggested I recheck (cough) the extra line between the y1 spdif/receiver board and the y2 board. this is where the i2s data comes from - and I didn't connect that wire 
	

	
	
		
		

		
		
	


	




 2 quick solder connections, replugging and I got music out the rca connectors. both of them, in fact 
	

	
	
		
		

		
		
	


	









 (no, the molex connectors are not part of the standard build. that's my doing.)


----------



## fordgtlover

Nice job - soldering and photos (as always)


----------



## digger945

Yea, as always you seem to have the perfect lighting and all. 
 Are those FM's for output coupling, bypassed with amb shop caps?


----------



## linuxworks

I don't think there are fm's there. nichicon's though.

 the grey box caps are vishay from mouser (1uf). not red, but they were onhand 
	

	
	
		
		

		
			





 re: lighting, I do spend a little time getting it right, but one thing that cures a lot of evils is the 'shadow highlight' tool. it compresses down (either direction) and fixes a LOT of lighting problems.

 also, never use flash. use available light and live-view to point lights off walls. this means a tripod is a must-have and a self-time to trigger itself is also needed.


----------



## digger945

yep that's what I do now, tripod and timer. I bought one of those natural light flourescents for the workbench and it does some better with a pic I took the other day.


----------



## Forte

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_gotta admit, I used the old flood-n-suck method on those 2 so28 chips. but it gets the job done with little hair-pulling 
	

	
	
		
		

		
		
	


	


_

 


 Got to try that method next time I solder one of those chips, always thought that there was a danger of removing to much solder from the joint but your photos show otherwise. Nice work!


----------



## amb

Congrats, linuxworks. That's very clean solderwork. You're the second person to ever hear a γ2, even before I soldered the first joint on mine!


----------



## MisterX

No he's not.


----------



## amb

OK, maybe I should've wrote "second head-fi'er". Significant others or pets don't count.


----------



## MisterX

lol, the cat won't come within 10 feet of my "office" after poking her nose in a CKKIII that I had forgot to put the lid on one night.


----------



## amb

By the way, in case anyone is wondering... The OPA2365 does _not_ have a turn-on pop problem, despite what "hopeless" said.


----------



## linuxworks

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Congrats, linuxworks. That's very clean solderwork. You're the second person to ever hear a γ2, even before I soldered the first joint on mine! 
	

	
	
		
		

		
		
	


	


_

 

I'm no stranger to that phenom. when I was developing the 'volumaster' code for the digital attenuator, another guy I was working with (rwhite) was the first to hear and see it work, even before me. I was writing code, sending to him, getting feedback and debugging until he said 'I hear sound!'. it wasn't until days later that I heard my own unit working


----------



## linuxworks

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_even before I soldered the first joint on mine! 
	

	
	
		
		

		
		
	


	


_

 

if you get to jonesin', you can take a hit off mine.


----------



## MisterX

Quote:


 The OPA2365 does not have a turn-on pop problem 
 

And the white noise when an unused S/PDIF input is selected is minimual...


----------



## linuxworks

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_And the white noise when an unused S/PDIF input is selected is minimual..._

 

confirmed, and then some. this seems to be a well behaved dac. I'm not sure there's any urgent (if any) need for external muting.
 the dac I had just before this one (an ebay china special) had a relay for muting. an actual loud mech relay for when error==true and all that stuff.

 sounds good, in theory, except when I run my media player (popcorn hour) and when you change programs or chapters or even go in/out of pause, you can trigger a mute and the relay starts clicking on you. it gets annoying!

 this dac has no relay and while it has no external muting, it has no harsh problems while doing some video playback tests and while switch to/from audio (audio = 44.1, video = 48k). I downsample all my 5.1 stuff to 2.0 so that I can watch movies with a 'quality dac' and that means a stereo dac (lol).

 so far, music and movies are fine with this dac. its now in place where the previous one used to be. I have a PGA vol control chip following the output of the dac and that works fine, also.

 I had my y1 board build from a long time ago, and I didn't want to deal with making another just to have usb locally. I can convert usb to spdif and from then, spdif is just one of many spdif inputs that can be selected from. keeping it as that half top layer also lets me get access to the line-out jacks and put molex connectors there.

 I was not planning on leaving them sandwiched like that, but I think I will, now. it saved me having to make a cable (lol).


----------



## MisterX

Actually my conclusion is a little hasty, I should have built at least one of the three Gamma 2 boards without the SRC4194 (or AD1896AYRS) to see how much of the white noise is being dealt with by the ASRC. 
 It looks like it would be pretty easy to add the ASRC and associated parts after the fact if one of the participants of the prototype group (with access to a scope) wants to try it. 
 You might save me from ripping all of that stuff back off one of the boards to test it.


----------



## amb

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Actually my conclusion is a little hasty, I should have built at least one of the three Gamma 2 boards without the SRC4194 (or AD1896AYRS) to see how much of the white noise is being dealt with by the ASRC. 
 It looks like it would be pretty easy to add the ASRC and associated parts after the fact if one of the participants of the prototype group (with access to a scope) wants to try it. 
 You might save me from ripping all of that stuff back off one of the boards to test it. 
	

	
	
		
		

		
		
	


	


_

 

I am doing just that on mine. I am leaving off the ASRC chip (along with everything else in the "optional" box as shown in the schematic) and test in that configuration, and then I will add those parts later.


----------



## ruZZ.il

congrats on all the successful builds! It's exciting to see such good progress here


----------



## m1abrams

Glad to see some operational gamma2s. Still waiting for my board. I suspect it will arrive on Monday and of course I am going on a week long vacation on Monday 
	

	
	
		
		

		
			





. So I will have to wait before I can start working on mine.


----------



## amb

My first γ2 now makes sweet music. As I mentioned, this one is currently without the ASRC chip, but I will add it later after some testing. The DAC chip is a WM8742 and the opamp is OPA2365. The γ1 that it mates to is a full++ configuration.

 I am happy to report that this γ2 also produces no hiss when an unused input is selected, so regardless of the presence of ASRC (or not), the DAC is well behaved.

 Here are some pics. You can see how densely everything is packed together.

 γ1 full++ and γ2:






 The γ2 board:






 Mated together:






 Mated together (front):






 Mated together (rear):






 Mated together (side):






 Sliding into case:






 In the case:


----------



## linuxworks

been using the dac for 1 movie and a bunch of ripped 44.1 redbook source.

 so far, so good. dac sounds very good. I hear no major problems (that's about as audiophile as I can speak, sorry) 
	

	
	
		
		

		
		
	


	




 go for it. build it. watch the high density chips. also check and check and check before you power on. look at the board from many angles and even take pics and zoom in on the pics to verify you have no shorts or forgotton solder joints 
	

	
	
		
		

		
		
	


	




 if you follow the bom and connect all the right wires, it *does* seem to work 
	

	
	
		
		

		
		
	


	




 mine did have the SRC chip installed. now that its in, is it possible to jumper around it using that jumper block? any way to turn SRC on/off on the fly?


----------



## Billyk

Brilliant, absolutely brilliant.
 Once again I am awed by the sheer coolness of it all. Can't wait until I am listening to mine.


----------



## linuxworks

ah, I see amb's board is up 
	

	
	
		
		

		
		
	


	




 I notice you left the xtal out.

 I did order both the surface mount and the thruhole versions. I got scared at the last minute and opted to go 'safe' and familiar and used thruhole. the smd version looked like it wasn't as easy to do at home. there is solderable contact area on the side of the xtal chips but the pads underneath don't seem accessible unless you use hot air or something fancy. and once there, again it would be hard to take off. so, is the smd version really worth using for DIYers? I kinda got scared off from just mounting it.


----------



## amb

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_if you follow the bom and connect all the right wires, it *does* seem to work 
	

	
	
		
		

		
		
	


	


_

 

lol.

  Quote:


 mine did have the SRC chip installed. now that its in, is it possible to jumper around it using that jumper block? any way to turn SRC on/off on the fly? 
 

Once the ASRC chip is installed, you can no longer use the JP2 jumpers to bypass it. The ASRC chip has a BYPAS pin (#9), when set to logic "high", it routes the input directly to the output and bypasses the ASRC function. The γ2 PCB hardwires this pin to ground, but if you hack the board you could possibly put in a switch. This is still a bit different than not populating the ASRC, because the master clock would still be provided locally by X1. If you see the schematic, X1 is not installed when the ASRC is also absent, and the master clock is from the CS8416 (full, S/PDIF-only or full++ config) or the PCM2707 (lite config).


----------



## ShinyFalcon

The SMD crystal was easy enough to solder as the pads were directly underneath the crystal. From your description it looks like the pads aren't readily visible?

 How about bridging pin 1 of the crystal (EN) with ground?


----------



## amb

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_I did order both the surface mount and the thruhole versions. I got scared at the last minute and opted to go 'safe' and familiar and used thruhole. the smd version looked like it wasn't as easy to do at home. there is solderable contact area on the side of the xtal chips but the pads underneath don't seem accessible unless you use hot air or something fancy. and once there, again it would be hard to take off. so, is the smd version really worth using for DIYers? I kinda got scared off from just mounting it._

 

The SMD oscillator has somewhat better jitter specs than the through-hole one, but I doubt that it would make a tangible difference. At any rate, it shouldn't be difficult to solder, because the PCB pads are pre-tinned. Just apply some flux and the solder should flow nicely.

 Removing the SMD oscillator might be difficult without special SMD desoldfering tools, but I don't think this part would fail easily. Just make sure you get the orientation right before soldering it down!


----------



## linuxworks

sounds like that could be 2 user config'able options, then; if you want a local clock or not (ie, if you want to use the local clock, src or no-src). and then if you have the src, if you use its function or have it bypass itself, logically, gracefully 
	

	
	
		
		

		
		
	


	




 I would be ok with leaving the clock locally (seems like it would always help and never hurt) and then having the src chip put itself inline or take itself out, all via its pins or serial messages (way later).


----------



## amb

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_The SMD crystal was easy enough to solder as the pads were directly underneath the crystal. From your description it looks like the pads aren't readily visible?_

 

The PCB pads are slightly oversized, so you can solder on the side of the oscillator.

  Quote:


 How about bridging pin 1 of the crystal (EN) with ground? 
 

That would disable the oscillator.


----------



## linuxworks

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Removing the SMD oscillator might be difficult without special SMD desoldfering tools, but I don't think this part would fail easily. Just make sure you get the orientation right before soldering it down! 
	

	
	
		
		

		
		
	


	


_

 

if it doesn't make an earth shattering diff, I'll go with 'easier to swap out' every time 
	

	
	
		
		

		
		
	


	




 so I think I made the right choice. I have extra smd xtals, if anyone runs short 
	

	
	
		
		

		
		
	


	




 it looked cool and small and I wanted to give it a try, but I wanted my board to WORK, first, rather learn about a new smd pkg type. I don't mind smd when things don't get hidden below me, but I don't have hot-air tools or anything at all fancy so I didn't want to venture father than needed. the point was to get a *working* unit, lol.


----------



## linuxworks

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_The SMD crystal was easy enough to solder as the pads were directly underneath the crystal. From your description it looks like the pads aren't readily visible?_

 

the xtal pads were L shaped. the largest area was the foot, where it would be hidden from your soldering iron. the vertical part of the L *could* be touched with a soldering iron, with a slope of solder across this and the pad, below it. 

 there's enough pad space that you could do that slope of solder thing, but I just didn't wanna


----------



## linuxworks

amb, if you have not mounted your SMD and want to try a thruhole first (to get an rmaa run thru it) I have an extra.

 we can unsolder it after the test, go smd and then re-run the test. then we'd see if this even shows up at the rmaa level.

 once smd soldered, it sounds hard to go back and then do tests.


----------



## digger945

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_I am doing just that on mine. I am leaving off the ASRC chip (along with everything else in the "optional" box as shown in the schematic) and test in that configuration, and then I will add those parts later._

 

I'de like to try this also, to see and learn for myself and share with the group. 
 I have the 4192 part here but could place a quick order for the AD1896 so we will have both parts represented.
 My scope is a rather low end 20Mhz Protek P-3502C analog.


----------



## MisterX

Quote:


 I am happy to report that this γ2 also produces no hiss when an unused input is selected, so regardless of the presence of ASRC (or not), the DAC is well behaved. 
 

Good to hear. 
 Will you LMK what the comparative measured "specs" are? 

  Quote:


 Here are some pics. You can see how densely everything is packed together. 
 

The pictures don't really do that gold enclosure much justice do they? 
 (it looks a lot better when you holding it in your hand)


----------



## linuxworks

I have an integration; put it in a box and interfaced a remote control and LCD display to it 
	

	
	
		
		

		
			





 DACmaster is now born:











 I can select a few things, now, with my remote (using a sony DVD remote). I can change the input from coax to opto (I didn't wire a usb card in). I can assign long and short names to the 2 inputs. I can select the 3 filter settings ('Fa' is Filter A'). I can also select the anticlipping features (shows [.] if disabled or [C] if enabled).

 each setting 'steals' a key on the dvd remote control. for example, you can assign keypad keys 1,2,3 for the inputs (coax, opto, usb). you could assign numbers 4,5,6 for the 3 filter settings. you could assign more keys to the clipping on/off. each time you press that button, the mode is selected and the display immediately updates. (todo: save the set of switch positions and recall them, as a group, for each input port (opto, coax, etc). that way you could leave the settings alone on the 'other' port while you play with the ones on this port. switching input ports saves the current settings and then swaps over to the settings from the other input port, when its switched.


 its just an initial take at a GUI (lol) but it does at least show all the status items, all at once, on the display.

 I have the input selector working (that talks to the y1 'red green' switch pads). still to do: run 2 more control wires for the clipping and filter switches (just 1 wire each since you send either a HIGH, LOW or open (highZ) for each of the 2 switches on the y2 board.

 this was kind of fun. I converted some code that I wrote for my spdif switch over to the dac. (code will be released shortly, once things have been tested a bit better).

 edit: if anyone wants to peek, its here:

Index of /dac-master/firmware/arduino

 the pin definitions I picked are in the '#defines' up at the top. that and this code would be enough to build this.


----------



## dude_500

Wow, great job linuxworks, very impressive piece of work


----------



## amb

Here are some RMAA results of my non-ASRC γ2. These are all done with the filter set to "filter C" which gives the widest frequency response in this configuration. The testing chain is as follows:

 computer > M-Audio Firewire Audiophile S/PDIF output > γ1 S/PDIF input > γ2 analog output > M-Audio Firewire Audiophile analog input > computer

 - 16 bit, 44.1KHz
 - 16 bit, 48KHz
 - 32 bit, 96KHz

 I'll say they are quite excellent!

 Some of these results (in particular, noise and stereo crosstalk) are even better than the M-Audio Firewire Audiophile in loopback. I think these measurements are being constrained by the ADC performance within the Firewire Audiophile. γ2's actual performance is probably even better.

 Here are graphs showing the three selectable filter responses at 44.1KHz, 48K and 96KHz sampling rates. Note that this is for the non-ASRC config. With ASRC it would be different, and I'll make those measurements after I add ASRC to my gamma2.

 44.1kHz:





 48kHz:





 96kHz:





 I also observed that the anti-clipping switch, when enabled, reduces the 
 overall level by 2dB.


----------



## linuxworks

the anticlipping just statically drops things by 2db?

 I tried to make sense of their docs but it does not say much. seems to imply they atten 'before doing math' (which is fine) but I still don't understand how even given a 0db signal, how doing math to it would ever bring it over 0db.

 some slop room for math errors is fine, but 2db sounds like a lot. yet, 2db is nothing if they are trying to do real 'headroom'.

 I can't hear any diff with any of the switch positions in any position; the music sounds the same to me no matter what. it must be very very subtle. (its even possible my control circuits aren't working, lol).


----------



## linuxworks

it sure would be nice to get hold of an ESS sabre dac and see how the 2 compare 
	

	
	
		
		

		
		
	


	




 maybe someone could bring one by at the bay area meet that's coming up?


----------



## amb

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_the anticlipping just statically drops things by 2db?_

 

Yes, that's what my measurement indicates. And it's certainly an audible change. I will do more exploratory measurements of this using the oscilloscope later to see what happens with the waveform.

  Quote:


 I can't hear any diff with any of the switch positions in any position; the music sounds the same to me no matter what. it must be very very subtle. (its even possible my control circuits aren't working, lol). 
 

Since you have the ASRC installed, I expect the filter switch changes to be quite subtle because the DAC will always be running at 24/96. But in the non-ASRC config, the early rolloff of the A and B filters are definitely audible at 44.1K and 48K sampling rates.


----------



## linuxworks

I don't know if my clipping switch is working (might be in my code) but I'm pretty sure the filter stuff is being selected (I can see high/low/open as I cycle thru them).

 I guess unless we can gracefully bypass the SRC (for those that install it), there's not much use in the filter settings. at least as far as I can hear.


----------



## amb

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_I guess unless we can gracefully bypass the SRC (for those that install it), there's not much use in the filter settings. at least as far as I can hear._

 

Well, aside from the frequency domain differences between the filters, there are also time domain differences (pre- and post-ringing in impulse response) that aren't shown in the RMAA results. This is a subject of a Wolfson whitepaper and is a hot subject amongst high-end DAC designers, resulting in a new generation of DACs and CD/DVD players with "minimum phase" filters (e.g., Ayre, etc.), as opposed to the traditional "linear phase". It it nice that the WM8741/8742 gives us the ability to select from these filters so we could qualitatively hear these differences. Subtle? Yes, but that's what high-end audio is all about.


----------



## linuxworks

its probably worse in my case, as since you said, the SRC is installed and then the filters mean different things (I guess).

 I'm ok with the fact that none of the 3 filter settings, on my system, change things all that much. it means I can be happy no matter which setting its on


----------



## linuxworks

here's my final mounting for the y2 in a hammond (the same hammond that the PPA and M3 uses):












 labeling is just brother p-touch adhesive labels 
	

	
	
		
		

		
		
	


	




 but at least now everything is marked.


----------



## dude_500

Almost done populating when I dropped my iron on my left hand, so probably out for now (in ice water, typing one hand). One question is BOM says one 8p break apart is necesary for j1,2,3, but it doesn't seem like enough. Am I missing something obvious?


----------



## MisterX

amb sent detailed instructions via email to the members of the group the other day right?


----------



## dude_500

I looked through all the emails and didn't see any reference to there not being enough female receptacles. BOM implies you need 8 total which is what I ordered but it looks like you really need 10p break apart. I'll have to scrounge through my parts box and see if I can pull one out of something else


----------



## MisterX

The Mouser part number given in the last BOM was for an 8 position receptacle but we talked about that when "amc" presented a saved project at Mouser. 
 (I suggested changing it to a 12 pin receptacle in case people ran into issues when separating the sections)

 If worse comes to worse you can always solder pieces of wire between the two boards. 
 It's not the most elegant solution but it does work.


----------



## dude_500

Got it all hooked up, turned it on and got nothing. A slight pop on the right ear when plugging in and a slight pop on the left ear when unplugging, but that is the only sign of life.

 I did voltage checks and 3.3 is fine, but 5V is slightly odd... the 5v check point that is closer to the inside of the board (fed by "VCC" on the feedthrough) is live at 5V, but the one closer to the edge of the board shows no voltage (fed by "VBUS" on the feedthrough). I then checked the continuity across the boards, the VBUS is being passed between boards. I plugged in the Y1 only and checked the VBUS, it shows dead, no voltage.

 Is this a problem with the Y1 and not the Y2? I'm listening to music on the Y1 right now

 EDIT: Just noticed the 4.75 check point, it also checks fine at 4.76V


----------



## amb

dude_500, what power source are you using? USB or wallwart? And what input source? If neither is USB, then VBUS will be 0V. What do you have at y2's 4.5V test point?

 My record shows that you have a full config y1. Did you remember to install the pin header at y1's JP1D pin 2 (to be connected to a matching receptacle at y2's J3)?


----------



## dude_500

Got it to work, it was a bad joint on the crystal (a really awful SMD part). It's sounding great, much more powerful and pronounced bass than the Y1 had and an overall better soundstage.


----------



## amb

Congrats, dude_500!


----------



## MisterX

Do you think moving the SMD pads for the crystal so they stick out further will make it any easier to solder?


----------



## dude_500

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Do you think moving the SMD pads for the crystal so they stick out further will make it any easier to solder?_

 

That might help to extend maybe 2mm on each side, I don't know that that's the primary problem though... it just has a hard time sticking to the edge, and it's tough to get enough solder underneath it to do a bottom-seating. I know one of my pins is BARELY on and I expect it to go silent sometime fairly soon. I'll have to figure out a better way of sticking it on there.

 Another comment I had was I had a really hard time soldering any through-hole that went to ground. I don't understand it, but literally every time there was one it was 10x harder to solder than any other component pin and solder just did not want to stick to the pad. I'm not sure if they treat ground pads differently or something in the quality of them. I also had this issue with the epsilon-27 adapter on my b-22 build.


----------



## nattonrice

The Aussie team's parts arrive 
	

	
	
		
		

		
		
	


	




 @Marshall: I just looked at the g2 board closely and noticed the solder mask "cuts" the thru hole pad off from the smd pad for the X1. Perhaps simply not having that mask "bridge" there would give the extra pad length required?

 Edit: Thou now I think about it that would flood the thru holes... not that that would be a big deal.


----------



## oneplustwo

By no means am I an SMD soldering expert, but I didn't really have an issue with the crystal soldering. I just fluxed the bottom and side of the crystal, put some solder on the iron and touched the side of the crystal and the pad. I dunno... I'm not done with mine yet so maybe it doesn't work?! 
	

	
	
		
		

		
		
	


	




 As for the through holes to ground, I did have problems with some but didn't make the connection that they were all to ground. Maybe there's more thermal inertia to overcome so the pad takes longer to heat up enough to get solder to stick to it?


----------



## nattonrice

Quote:


  Originally Posted by *oneplustwo* /img/forum/go_quote.gif 
_By no means am I an SMD soldering expert, but I didn't really have an issue with the crystal soldering. I just fluxed the bottom and side of the crystal, put some solder on the iron and touched the side of the crystal and the pad._

 

Yeah this is what I planned to do.
 Tis the same technique I used on those little common mode inductors on the tpa lcbps/dps.


----------



## fordgtlover

Quote:


  Originally Posted by *dude_500* /img/forum/go_quote.gif 
_...snip

 Another comment I had was I had a really hard time soldering any through-hole that went to ground. I don't understand it, but literally every time there was one it was 10x harder to solder than any other component pin and solder just did not want to stick to the pad. I'm not sure if they treat ground pads differently or something in the quality of them. I also had this issue with the epsilon-27 adapter on my b-22 build._

 


 I had the same problem when soldering parts connected to the ground plane on the Gamma 1. I ended up swapping soldering iron tips for a larger one that would carry more heat.

  Quote:


  Originally Posted by *nattonrice* /img/forum/go_quote.gif 
_The Aussie team's parts arrive 
	

	
	
		
		

		
		
	


	



 ...snip_


----------



## amb

The double ground planes dissipate the heat from thw soldering iron, so you should turn up the soldering iron's temperature for those pads (that is, assuming you have an adjustable soldering station, which is highly recommended). On my Hakko 936, I set the temp to a bit over 350C for most PCB work except the ground pads, for which I crank it up to 450C+. The Hakko reaches the dialed-in temperature very quickly, and I routinely turn the temperature up and down based on which pads I'm soldering.

 As for the SMD crystal, flux the pads. The PCB pads are pre-tinned with solder, so when you apply heat and solder from the side, the pad should make a nice even bond to the crystal. Making the SMD pads larger is problematic because it would encroach upon the through-hole pads and cause Eagle to fail DRC (design rule check).


----------



## ShinyFalcon

Ground plane joints always gave me problems. I didn't feel comfortable at all with my β22/σ22 build as a lot of the ground joints didn't look good. I always set my iron up to 400-450C when doing those joints. However on the y1 I didn't recall having problems.

 As for the crystal, it did take a while but I tinned the pads on my Metronome (ASRC component for Opus) and attempted to flux the crystal, got a big solder blob, and poked it between them. I think the ground pad once again gave me some trouble.

 I want to order parts for the unbalanced conversion soon, which will more likely be on a breadboard. I hope it won't affect the quality too much/ Any sacrificial γ2 boards that I can cut in half out there?


----------



## MisterX

I did the flux and "sweat" routine for the SMD crystal on my second build. 
 It went without a hitch but I wanted to try something different on the second one so I tinned the pads with some wick that was saturated with solder, cleaned the pads, applied flux, placed the crystal and then touched the iron to the pads until the solder flowed. 
 It worked pretty good but the difference under the microscope is not enough to justify the extra effort so....


----------



## ShinyFalcon

Is there a breadboard-friendly version of the 4.5V regulator? I need to regulate 7.5V from the PSU. 

 Is there a difference between the OPA2365 and the LM4562? It seems like they are pin compatible, and I could probably use it in place of the OPA2365 since power isn't an issue for me, as long as it doesn't exceed my 500mA fuse. The LM4562 does use more power and probably requires a V- source, which I don't have at the moment. (or do I? I noticed V- is attached to ground on the OPA2365) 

 And, I soldered output caps on the balanced output of the WM8741. If I solder a wire to the + lead of the cap, will the signal be affected by the cap? Does DC offset occur when using + and GND of the balanced signal as single ended?


----------



## amb

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Is there a breadboard-friendly version of the 4.5V regulator? I need to regulate 7.5V from the PSU._

 

This is a bit beyond the scope of the γ2, but if you have at least 7.5V, you could use a 78L05 regulator for 5V out. We chose 4.5V or 4.75V because we need to be able to run off a 5V source (USB power or regulated wallwart) before regulation.

  Quote:


 Is there a difference between the OPA2365 and the LM4562? It seems like they are pin compatible
 ... 
 

LM4562 is not rail-to-rail and will clip severely when used in this environment. If you increase the supply voltage or change to a dual-rail supply, then the circuit also needs to change. The γ2 output buffer/filter design assumes that the opamp supply is the same as the DAC's AVDD.

  Quote:


 And, I soldered output caps on the balanced output of the WM8741. If I solder a wire to the + lead of the cap, will the signal be affected by the cap? 
 

Not sure what you're asking here...

  Quote:


 Does DC offset occur when using + and GND of the balanced signal as single ended? 
 

There is AVDD/2 volts DC offset at the DAC's + and - outputs. If AVDD (the analog supply voltage) is 5V, then there will be 2.5V DC offset at each of those points. This is why you need coupling capacitors to block out the DC. This is true whether you use just the + output, or both the + and the -.


----------



## ShinyFalcon

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_ Quote:


 And, I soldered output caps on the balanced output of the WM8741. If I solder a wire to the + lead of the cap, will the signal be affected by the cap? 
 

Not sure what you're asking here..._

 

I have Silmic II caps at the output of the WM8741, and they are between the terminal blocks and the DAC of my Opus DAC. I wanted to bypass the caps when I get to building the unbalanced conversion portion, and there's no easy way to tap the pure balanced signal short of desoldering the caps.

  Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_If you increase the supply voltage or change to a dual-rail supply, then the circuit also needs to change. The γ2 output buffer/filter design assumes that the opamp supply is the same as the DAC's AVDD._

 

Would this mean that the y2 design won't work on the Opus? I do have digital and analog supply on the same PSU at 7.5V, but both can be adjustable. As long as I tap from the analog supply (has a + and GND) it should work, right?

 My apologies for the off-topic...


----------



## Mr.Duck

ShinyFalcon, I'm not sure what your are asking there either.

 The y2 design won't work on the Opus? What does that mean? Opus is a dac designed by twisted pear audio, Y2 is a dac designed by AMB and misterx. How can one dac work on the other? :S


----------



## JamesL

Well, the opus and y2 effectively use the same chip, so I'm guessing that he's asking if it's compatible with the opus boards. 

 I suppose you could take the the signal from the vout pins and use something like the ballsie filter/buffer with a separate psu. 

 Like AMB said, the circuit assumes that the chip's analogue supply is the same as the opamp supplies. 
 My guess is if you want to supply 7.5v to u7, you'll have to cut some traces.


----------



## ShinyFalcon

Yes for the last couple of posts I was primarily talking about the balanced -> unbalanced conversion portion of the y2. I was planning on using it with my Opus, since the Ballsie has not been back in stock for a while. Sorry for the confusion, I probably shouldn't be ambiguous and assume everyone knows what I'm talking about 
	

	
	
		
		

		
			





.

 I suppose I could lower the analog supply down to 5V, because the only thing currently attached to the analog supply on the PSU is the Opus board itself. The only IC on the Opus board are the WM8741 and two voltage regulators for the digital/analog section. 

 Anyways, I don't see anything that is preventing me from using the unbalanced conversion on my Opus, unless there's something that's flying over my head. The only major concern is indeed stability, with this being on a breadboard. I suppose I can go P2P...

 ANd yes, the y2 and the Opus are pretty similar to each other. I'll stop here with my off topic posts, it's probably confusing everyone...


----------



## Beefy

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Yes for the last couple of posts I was primarily talking about the balanced -> unbalanced conversion portion of the y2. I was planning on using it with my Opus, since the Ballsie has not been back in stock for a while._

 

That would be one hell of a hack job.

 Why don't you just use the IVY from TPA? They sell that module in a config specifically for the OPUS, and the manual has all the wiring diagrams......


----------



## linuxworks

also, it seems cetoole is working on some fancy new i/v board. we saw a photo of it a few days ago on the builds/photo thread.

 it looked pretty serious to me


----------



## JamesL

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Yes for the last couple of posts I was primarily talking about the balanced -> unbalanced conversion portion of the y2. I was planning on using it with my Opus, since the Ballsie has not been back in stock for a while._

 

Oh, I see what you're talking about now. You want to use the y2's buffer/se-conversion for your opus board, and not the other way around.

 I don't really see the point though. 
 The benefits of the Opus dac IMO is it's approach to modularity, meaning it can be configured for dual-mono, has a flexible power supply configuration, and can use any number of balanced and unbalanced output stages not limited by the 5v supply.
 The y2's approach to modularity are certainly not without it's benefits either.

 However, if you're using the Opus board on a single 5v rail, and using the y2's output stage on a breadboard, you're kind of losing the benefits of both.. just my 2c


----------



## Beefy

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_also, it seems cetoole is working on some fancy new i/v board. we saw a photo of it a few days ago on the builds/photo thread.

 it looked pretty serious to me 
	

	
	
		
		

		
		
	


	


_

 

Don't forget that the WM8741 is voltage out, and doesn't need external I/V conversion - just a filter and buffer will suffice. Ballsie, IVY, and the y2 all perform very similar roles for this, and I'm not sure how Colin's design would work here.


----------



## linuxworks

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_Don't forget that the WM8741 is voltage out_

 

of course I DID forget that! 
	

	
	
		
		

		
		
	


	




 so, on v-out dacs, there's no WAY to get access to the current-based stage? I guess not (?)

 so technically, the buffer stage on this is a filter but NOT an i/v converter. I missed that detail, I guess.


----------



## ShinyFalcon

Quote:


  Originally Posted by *JamesL* /img/forum/go_quote.gif 
_Oh, I see what you're talking about now. You want to use the y2's buffer/se-conversion for your opus board, and not the other way around.

 I don't really see the point though. 
 The benefits of the Opus dac IMO is it's approach to modularity, meaning it can be configured for dual-mono, has a flexible power supply configuration, and can use any number of balanced and unbalanced output stages not limited by the 5v supply.
 The y2's approach to modularity are certainly not without it's benefits either.

 However, if you're using the Opus board on a single 5v rail, and using the y2's output stage on a breadboard, you're kind of losing the benefits of both.. just my 2c_

 

At the moment I'm not ready to spend $120 more on a Ballsie or IVY and their respective dual rail PSU, and I understand the loss of benefits, but I can indeed wait. I'm planning on building a y1 SPDIF-out and maybe populate another BantamDAC, and I thought this would be a good plan in my part since it only costs a couple of dollars in parts and be under one order. So, do you suggest that I stick with using the Opus' hot signal (+) and GND as my single-ended over the y2's output buffer? I will definitely go for the Ballsie and go balanced in the future, just not immediately.


----------



## Beefy

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_At the moment I'm not ready to spend $120 more on a Ballsie or IVY and their respective dual rail PSU, and I understand the loss of benefits, but I can indeed wait. I'm planning on building a y1 SPDIF-out and maybe populate another BantamDAC, and I thought this would be a good plan in my part since it only costs a couple of dollars in parts and be under one order. So, do you suggest that I stick with using the Opus' hot signal (+) and GND as my single-ended over the y2's output buffer? I will definitely go for the Ballsie and go balanced in the future, just not immediately._

 

Keep in mind that one of the most significant benefits of Ballsie and IVY for unbalanced use is that they negate the DC offset, allowing you to remove the output coupling capacitors.


----------



## nattonrice

Team Australia checking in!!!
 It sounds absolutely fantastic o(^-^)o
 I'm sure fordgtlover will be here soon too~

 I went to the trouble of taking "detailed" photos of building a Gamma1 Full++ and Gamma2 from scratch primarily for my facebook of all things lol.
 Maybe someone will find it useful?

 Things to note:

 - The coin is for reference to the actual size of these smd chips. It is a 5 cent coin, our smallest denomination.

 - The "Travel Ten" card is for an ongoing reference to the size of the components vs the board size. It is the exact same size as a standard VISA credit card.

 - I did somethings in a strange order as I was checking for fit problems (not that it was needed of course o(_ _)O )

 - The amp is a (still) faceless mini3 going to dt880pro... win 
	

	
	
		
		

		
		
	


	




 Here is one I prepared earlier...

































































































 ... and last but not least, MUCH MUCH MUCH gratitude to Ti and Marshall for giving us such a great little (!) project


----------



## oneplustwo

Mine works now too! It's caseless at the moment.


----------



## Lifthanger

I'm so jealous. Don't think customs will let me have fun before next week.

 But thanks for the sexy pics 
	

	
	
		
		

		
		
	


	




.


----------



## MisterX

The image is a "virtual overlay" of the two Gamma DAC boards after some minor adjustment to the part locations. 
 The Gamma 1 parts are red and the Gamma 2 parts are yellow. 
 (I thought it was pretty cool way to visualize how the parts on the two boards fit together so....)


----------



## nattonrice

Quote:


  Originally Posted by *Lifthanger* /img/forum/go_quote.gif 
_But thanks for the sexy pics 
	

	
	
		
		

		
		
	


	




._

 

Not a prob~ ^^

  Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_The image is a "virtual overlay" of the two Gamma DAC boards after some minor adjustment to the part locations. _

 

The fact that only two components really had a problem and even then it was only like 0.5mm is just amazing.
 Great work guys!


----------



## johnwmclean

Well done Tom, that’s some soldering job. It’s great to see the progressive imagery in action as well as the sense of scale.


----------



## nattonrice

Thanks John ^^
 As the other aussie guy and I were discussing, it teaches discipline O.O

 That's exactly right. You see these things in pics but usually until you see it in person you have no idea just how tiny (or HUGE) some of these things are.


----------



## komi

One more is done!

 Tested with old Gamma1, working great ..


----------



## nattonrice

Excellent work!!!

 It was very useful to have another confirmed working gamma1 to test the new Full++ board I built without having to solder the ribbon cables you normally would.

 If someone was to manufacture these in any quantity I can see a ribbon cable pre-terminated with pins on one end and sockets on the other, coming in very handy!


----------



## MisterX

Quote:


 If someone was to manufacture these in any quantity I can see a ribbon cable pre-terminated with pins on one end and sockets on the other, coming in very handy! 
 

I see two problems with that idea. 
 Sourcing "wire mount" connectors that fit in the enclosure and not many people are willing to pay a significant premium for S/PDIF outputs that only service the USB interface.


----------



## amb

Or better yet, use a blank γ2 board with only J1/J2 and J4/J5 populated in lieu of the ribbon cable for the γ1 full++ config.


----------



## Mr.Duck

Regarding PCB dimensions, it seems the gamma2 is 10*1*mm wide (50.48 x 2), but the standard case width such as from Lincoln Binns is 100mm wide... D'oh!

 Is that true? For referance it seems the specified Box Enclosures B2-080 is 108mm wide (4.27 x 25.4).


----------



## amb

The γ2 board is 3.9375" (100.01mm) wide. The Box B2-080 case is 108.5mm wide _externally_, but it's 100.5mm wide internally between slots. The board is intentionally slightly under-sized to allow for manufacturing tolerances of both the board and case.


----------



## MisterX

Redundant...


----------



## Mr.Duck

Ok, I thought 101mm was not going to be correct. But I used gamma1 width after separation and doubled it. So... 1.9875" x 2 x 25.4 = 101.0 mm.

 If it's really 100.01mm then that's fine but I was pretty sure it would have come to 101mm instead. Nevermind.


----------



## TeraHz

Ok, it's about time I post a picture on this forum too...

 Here it is, y1++ upgraded to y2++ 
	

	
	
		
		

		
		
	


	






















 Currently the whole thing has paper panels 
	

	
	
		
		

		
		
	


	




 I don't dare take a picture of that 
	

	
	
		
		

		
		
	


	




 I must say, sounds excellent (at least the 3.5mm out), haven't tried the L,R outs yet, but thing seem to work well


----------



## amc

oh man, every day I hope for that notice that my box of boards and parts is at the post office, but it has yet to clear customs and arrive. I cant wait! Great pictures everyone.


----------



## nattonrice

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Sourcing "wire mount" connectors that fit in the enclosure_

 

Oh I only meant for testing a gamma1 full++ prior to mating it with a gamma2! I never thought of using it it as a permanent solution.

  Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Or better yet, use a blank γ2 board with only J1/J2 and J4/J5 populated in lieu of the ribbon cable for the γ1 full++ config. 
	

	
	
		
		

		
		
	


	


_

 

Hehe now there is a way to sell more boards!


----------



## MisterX

Quote:


 Oh I only meant for testing a gamma1 full++ prior to mating it with a gamma2! 
 

Like the one I have had in my junk parts box for the last 4 months? 
	

	
	
		
		

		
		
	


	




 I think I like plan B better.


----------



## nattonrice

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_I think I like plan B better. 
	

	
	
		
		

		
		
	


	


_

 

hehe witty ^^
 Was that a toner transfer etch? looks pretty sharp eh~


----------



## MisterX

Nope. Just a sharpie, a couple of drafting tools and some enchant is all it took.


----------



## nattonrice

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Nope. Just a sharpie, a couple of drafting tools and some enchant is all it took. 
	

	
	
		
		

		
		
	


	


_

 

Are you serious!? That looks pretty good for just a resist pen O.O
 good work!

 Since I've already annoyed Ti about this I'll get you too... bring on the Gamma22!


----------



## amb

One of the prototype team members won't be able to build his γ2 due to a new job and work/family priorities, so he is looking to pass on his γ2 and γ1 boards, plus a few other parts to someone who would be a worthy prototyper. If you're interested, PM me and I'll put you in touch with him.


----------



## MrSlim

Quote:


  Originally Posted by *amc* /img/forum/go_quote.gif 
_oh man, every day I hope for that notice that my box of boards and parts is at the post office, but it has yet to clear customs and arrive. I cant wait! Great pictures everyone._

 

Good o'l Canada Post.. Slower than the mail to Australia and Europe.. glad I'm not the only one waiting for the gamma2 board.. My one consolation is that I'm sitting in a lovely cottage by the sea for the next 5 days.. I did bring my "kit" in case it's rainy, but so far there seems to be no evidence of that on the horizon...


----------



## digger945

If I jumper JP2D pins 2 and 3 to straight wire usb power, would that let me know if my TPS2115 is bad even if it's still soldered to the board?

 Reason I ask is I have 5V on VBUS with the boards apart, and 4.95V when I plug the two together, but all other test points measure appox. 2.4 or 2.5V when plugged together, including VCC. I pass the y1 usb board initial check steps 1, 2, and 3, with the computer recognizing the dac. I also checked R4U to make sure it was 47k. No cold joints on any regulator on either board, verified with ohmmeter.


----------



## digger945

I went ahead and jumpered it anyway, and now my 3.3's are 3.28, so good there.
 VBUS is 4.75, VCC is 4.73. Led switch changes from red to green when playing a song in iTunes. No sound. I am tired, so I will give it a go tomorrow.


----------



## digger945

A few parts are missing, the coax rcas and optical transmitter, external power jack, rca and mini on the y1.
 The third pic shows the I2S pin missing, but it's in the pics above it.


----------



## MisterX

Your symptoms suggest a marginal short somewhere (jumpering JPD2 effectively removed the current limiting feature of U1D so it's no surprise that the VBUS voltage increased). 
 Try cleaning up that big blob of solder on the supply pin of X1 and see if helps matters any.


----------



## nattonrice

Looks awesome!
 I think that is almost everyone.
 It's great (and amazing) that it went so smoothly~ 
	

	
	
		
		

		
		
	


	




 Edit: I didn't read the reason for posting pics... I'm sure you'll get it fixed ^^


----------



## TeraHz

Here are some more pics from my y2. Took me the good part of today to drill the panels. labels to be added soon (via black on clear ptouch labels)










 BTW I didn't know we can have two active signals running like: usb -> opto out, and opto in -> 3.5mm out.


----------



## digger945

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Your symptoms suggest a marginal short somewhere (jumpering JPD2 effectively removed the current limiting feature of U1D so it's no surprise that the VBUS voltage increased). 
 Try cleaning up that big blob of solder on the supply pin of X1 and see if helps matters any._

 

Thanks, I will try that as soon as I get home. I will figure it out today, I just thought I would post some pics and see if someone noticed something obvoius right off the bat. I think I spent a little too much time on some of the regulator pins maybe, trying to get the joints to look good. And obviously I overlooked some other stuff as you pointed out.


----------



## Beefy

Quote:


  Originally Posted by *TeraHz* /img/forum/go_quote.gif 
_BTW I didn't know we can have two active signals running like: usb -> opto out, and opto in -> 3.5mm out._

 

Yeah, the USB to SPDIF converter is always active if populated and connected to a PC.


----------



## Mr.Duck

I'm impressed with your casework, TeraHz. Even more impressed you managed to drill a square hole lol. How did you do it?


----------



## ruZZ.il

I'm guessing with a dremel + small disc, some drilling maybe, and a lot of filing.


----------



## TeraHz

Quote:


  Originally Posted by *Mr.Duck* /img/forum/go_quote.gif 
_I'm impressed with your casework, TeraHz. Even more impressed you managed to drill a square hole lol. How did you do it?_

 

Thanks 
	

	
	
		
		

		
		
	


	




 Square holes are not any harder than round ones that are much larger than the closest (smaller) bit I have. I just drill small holes around the inner edge of the square and then hammer out the center, the rest is just a little work with the file. For some reason I can't figure out a good way to use the Dremel.


----------



## linuxworks

greenlee punches.

 expensive but sometimes they work well.


----------



## amb

My second γ2 lives! This one has AD1896, WM8741, AD8656 and Nichicon KW 470uF output caps in parallel with Wima 1uF MKS2 caps. The companion γ1 full++ has a WM8759 and also the same Nichicon KW output caps. The large caps and high current opamp make it possible to drive low-Z headphones directly from both outputs.

 For comparison, my first γ2 has SRC4192, WM8742, OPA2365 and Elna Silmic II 22uF caps in parallel with Wima 1uF MKS2s.

 Here are some pics. My γ2 #1 is in the gold enclosure while γ2 #2 is in black.

 γ2 #2 and its buddy γ1:






 Closer view of γ2 #2:





 Cased up (front view):





 Cased up (rear view):





 Closeup of the front panel:





 Closeup of the rear panel:





 Two γ2s and an empty silver γ1 full++ case (I used its board to make γ2 #1):





 Two "art" shots:


----------



## nattonrice

wooooooo you got your front panels!
 They look sweet~
 forgtlover put our order in so it is only a matter of time!


----------



## digger945

Very nice Ti. Looks great.


----------



## jdkJake

So, here is the big question, how do they sound with the new selection of components?


 They look great! Superb packaging!


 jk


----------



## amb

Quote:


  Originally Posted by *jdkJake* /img/forum/go_quote.gif 
_So, here is the big question, how do they sound with the new selection of components?_

 

I'm not big on subjective descriptions, but I'll just say that both of them are superb.


----------



## Mr.Duck

AMB, with all that spare space on the PCB it is easy to forget just how small it is. Someone needs to grab a pic with this DAC hiding under a couple of credit cards to give a sense of scale.


----------



## Mr.Duck

Quote:


  Originally Posted by *TeraHz* /img/forum/go_quote.gif 
_For some reason I can't figure out a good way to use the Dremel._

 

I've tried using a Dremel with a cutting wheel but even on 3mm thick aluminium it's too thick and I end up breaking the wheel. Maybe just use the Dremel to file away at the edges after the round holes have been drilled.


----------



## Lifthanger

the promised pictures. It'll be caseless until I have some time at the workshop.
 This is with the WM8741, the OPA2365AID, the EuroQuartz and small output caps. All went smooth, except for the reclocking chip which was very hard to solder without bridges. The dac with the same package didn't even bridge 2 pins, while soldering. even with my lowly HD595 I appreciate the difference to the gamma1. Also the anticlipping allows me to use the pot on my amp in a better region. Filters make no difference to me, till now 
	

	
	
		
		

		
		
	


	




.










 it is still wet from scrubbing 
	

	
	
		
		

		
		
	


	




 the switches were surprisingly expensive, so I'd advice non prototypers to hardwire anticlipping and any filter (if the reclocking is used).


----------



## rds

Quote:


  Originally Posted by *Mr.Duck* /img/forum/go_quote.gif 
_AMB, with all that spare space on the PCB it is easy to forget just how small it is. Someone needs to grab a pic with this DAC hiding under a couple of credit cards to give a sense of scale._

 

Please make sure to include photos with both sides of the credit cards in case we get confused 
	

	
	
		
		

		
		
	


	




 AMB I take it these great looking panels can be ordered somewhere...


----------



## amb

Quote:


  Originally Posted by *rds* /img/forum/go_quote.gif 
_AMB I take it these great looking panels can be ordered somewhere..._

 

I will offer them when γ2 is released, just like I do for γ1 and Mini³.


----------



## ShinyFalcon

The longer I stare at my Mini³, the more amazed I am at how darn small the γ2 is!


----------



## amb

I ran RMAA testing on my second γ2, which as mentioned before has AD1896 as the ASRC, WM8741 DAC and AD8656 output filter/converter/buffer. The results are as follows:

 - 16 bit, 44.1KHz
 - 16 bit, 48KHz
 - 32 bit, 96KHz

 These tests are all done with γ2's filter switch set to "C" (linear phase). The "32/96" mode is really 24/96 with 24 bits contained in 32 bit words.

 The tests reveal a fundamental flaw with RMAA loopback testing on an upsampling DAC such as the γ2 -- The playback and record bit depths and sampling rates cannot be set independently. Since γ2's DAC always runs at 24/96 (with ASRC), there shouldn't be a noise floor or frequency response difference regardless of the input bit depth and sampling rate. Yet these tests show such differences, because the ADC in the sound card that's used to record the DAC's analog output for measurement is set to the same bit depth and sampling rate as the output stream to the DAC. Thus we're limited by the ADC's performance, and the results do not show the true and full performance of the DAC under test. (see note below)

 Nevertheless, the results we have here are outstanding, easily the equal of (or exceeds) high-end commercial DACs costing $1000 or more (and I have RMAA'ed many such products).

 Regarding the selectable filters, please refer to the following white papers which provides a good overview of what they do and the pros and cons:

 - Ayre's white paper on linear phase vs. minimum phase filters
 - Wolfson's "Ultra High Performance DAC" whitepaper

 Indeed some recent commercial high-end DACs and CD/DVD players are appearing with selectable filters. Many of them use the Wolfson WM8741/42 DACs while others use custom ASICs.

 I was able to measure the frequency and time domain effects of γ2's three selectable filters. Filter C is the traditional "linear phase" brickwall filter, filter B is the "minimum phase" slow rolloff filter, and filter A is a linear phase filter with slow rolloff characteristics.

 First, here is the comparative frequency response graph showing the frequency domain effect of the three filters.






 Here are the time domain impulse response and square wave response oscillograms of the three filters:

 Filter C (linear phase brickwall):








 Filter B (minimum phase slow rolloff):








 Filter A (linear phase slow rolloff):








 You can see that the traditional linear phase brickwall filter exhibits the widest passband frequency response, but produces pre-ringing and post-ringing in the impulse response. This is also reflected in the square wave response's Gibbs Phenomenon pre- and post-ringing on both the rising and falling edges. In the real world, musical instruments, voices and naturally-occuring sounds never produce pre-ringing effect (except for something intentionally concocted on a computer to do that).

 The minimum phase slow rolloff filter trades some phase response deviation for a complete elimination of the pre-ringing effect. Its post-ringing is more severe than the linear phase filters. The downsides of this filter is said to be less audible and more pleasing to the ear than having pre-ringing.

 The linear phase slow rolloff filter is a "compromise" between the two other filters. It has the excellent phase response of the brickwall filter but reduces the pre- and post-ringing to much fewer cycles.

 Note that all three filters roll off well above 20KHz on a γ2 with ASRC. On a γ2 not populated with an ASRC, however, the A and B filters will roll off quite severely at 44K and 48K sampling rates (-3dB at ~15KHz and ~16KHz, respectively).

 Note about RMAA loopback: One way to work around the ADC bit-depth and sample rate limitation in the recording device, is to run two instances of RMAA, one for recording and one for playback. However in practice this causes both RMAA instances to freeze or crash (at least it does for me on Windows XP). Another way to do this is to run RMAA on two computers and two soundcards, one for playback and one for recording. At the moment I do not have an extra Windows machine to do this.


----------



## Mr.Duck

Thanks for the detail about the different filters it is very interesting to compare them. Seems like filter B is best (B for best 
	

	
	
		
		

		
		
	


	




). Maybe Filter C if you don't have the ASRC installed.

 I wouldn't worry about capturing more accurate RMAA results unless you get a much more high performance ADC. I'm sure the M-Audio unit is decent but seems like you could do with somthing like an Apogee Mini Me to get accurate results.

 BTW is there any real difference between AD1896 and SRC4192 or any other compatible device?


----------



## amb

Quote:


  Originally Posted by *Mr.Duck* /img/forum/go_quote.gif 
_Thanks for the detail about the different filters it is very interesting to compare them. Seems like filter B is best (B for best 
	

	
	
		
		

		
		
	


	




). Maybe Filter C if you don't have the ASRC installed._

 

Different people might come to different conclusions about what's "best", perhaps also depends on music program material. Having a switch lets you choose "on the fly".

  Quote:


 BTW is there any real difference between AD1896 and SRC4192 or any other compatible device? 
 

There shouldn't be any difference between AD1896 and SRC4192 as far as I could tell (except the latter is less expensive). I am not aware of any other part that would be pin-compatible.


----------



## Lifthanger

thank you amb 
	

	
	
		
		

		
			





. After some hours of listening I can tell you this is the best my HD595s ever sounded. Not even close. Strange enough this gamma2+mini3 is better than my opus+ballsie+ckk3.
 Don't care, because I'm happy 
	

	
	
		
		

		
		
	


	




.


----------



## amb

My two γ2s will be at today's NorCal/SF Bay Area meet.


----------



## MisterX

I hope you all have a good time.


----------



## oneplustwo

Anyone try using balanced output?


----------



## jnewman

I am a bit late to the party, but as of yesterday I am one of the prototypers, and I'm going to see how fast I can catch up. 
	

	
	
		
		

		
		
	


	



 I ordered all my parts for the gamma1 and gamma2 boards as well as for a couple of new amps, so hopefully I will be able to comment on the build in a few days, and on the finished product a few days after that.


----------



## amc

Quote:


  Originally Posted by *jnewman* /img/forum/go_quote.gif 
_I am a bit late to the party, but as of yesterday I am one of the prototypers, and I'm going to see how fast I can catch up. 
	

	
	
		
		

		
		
	


	


_

 

Welcome to the prototype team - rest assured there are still a few outstanding y2s to be built. I have all parts except the ones from Ti (checked in with the post office today and the lady said a delay like this means they are stuck in customs...). You may very well finish before me


----------



## m1abrams

Quote:


  Originally Posted by *jnewman* /img/forum/go_quote.gif 
_I am a bit late to the party, but as of yesterday I am one of the prototypers, and I'm going to see how fast I can catch up. 
	

	
	
		
		

		
		
	


	



 I ordered all my parts for the gamma1 and gamma2 boards as well as for a couple of new amps, so hopefully I will be able to comment on the build in a few days, and on the finished product a few days after that._

 

Hey I am still one of the ones without a finished y2 
	

	
	
		
		

		
		
	


	




 Between being on vacation (wife would not let me bring the soldering iron) and making a BOM mistake I am sitting next to a y2 missing 2 caps and 1 LDO regulator. My mouser order for those shipped this morning so hopefully I will be up and running soon.


----------



## komi

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_
















 A few parts are missing, the coax rcas and optical transmitter, external power jack, rca and mini on the y1.
 The third pic shows the I2S pin missing, but it's in the pics above it._

 



 I think your pulse transformer [ T1D ] is rotated for 180° ...


----------



## linuxworks

Quote:


  Originally Posted by *komi* /img/forum/go_quote.gif 
_I think your pulse transformer [ T1D ] is rotated for 180° ..._

 

but its a 1:1 trafo. why would this matter?


----------



## komi

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_but its a 1:1 trafo. why would this matter? 
	

	
	
		
		

		
		
	


	


_

 

Right, i just check datasheet - it is 1:1 and You are right ...


----------



## digger945

Thank you both komi and linuxworks. 

 I have had a short setback but now I'm back in form so to pick up where I left off last Thursday....All measurements are taken with the 2115 in place and NO jumpers at JP2D.
 I now have a y1 board that has a solid 5v VBUS on the USB board(not connected to y1 DAC board). When jumpering VBUS and GND over to the y1 DAC board voltage falls to VBUS 4.96v and all 3.3v test points on both USB and DAC boards measure 3.29v(assumed OK), and all 4.5v test points measure 4.75v (assumed OK since I'm using 4.75v reg's).
 VBUS will fall to 4.71v with the y2 board plugged in now, with the y2's 3.3v test point remaining at 3.29v and y2's 4.75v TP falling to 4.68v. I found several mistakes last week like a couple of solder bridges under the pins and in some hard to see places. Also I had good results from using a spray can of Chemtronics Flux-Off

 The next step I think for me is to measure some voltage drops to see what the current is at different points so I can see if I'm on target there and to know if its a short or a device like a regulator that's pulling the voltage down. I had the heat on the 2115 for quite some time and feel like I may have damaged it in the soldering process.

 I appreciate you guys taking a look at it, but this is what you get when you hurry up and try to do something knowing you don't have enough time to complete it correctly, and I knew, but did it anyway. I should have waited until this week to begin. On the plus side, I am becoming quite intimate with the power sections of both boards and, as a result of my mistake, feel like I have a much better grasp of what is going on. I always learn more from my mistakes than successes anyways.


----------



## amb

digger945, seems like your computer USB port's 5V line is weak and sagging with the added load. The VBUS voltage of 4.71V that you measured is lower than the analog rails' regulator voltage (4.75V), therefore they have dropped out of regulation. For best performance, you might want to switch to using LP2985-4.5 regulators to give yourself more dropout headroom, or use a computer with a more robust USB 5V line.


----------



## komi

Build status update !!!

 OK, here we go ...

 Gamma1 + Gamma2 are finished - kinda - LOL !

 I forget to order ONE part from mouser for Gamma1, and - this mean - couple more weeks to finish ...


 How ever, there is Case design update ... [ Ti, sorry for company logo redesign ] 

 Top of the case with laser engraving ...






 Diferent angle ...






 Blue anodized aluminum sheet with laser engraving - a bit overlaping abound the edge, a bit wider for "handles" [ just for fun ] ...






 Original panels with laser engraving ...






 NOW, hold the fingers for me to i put holes on right place, and - to i drill them right ...


 Greets !


----------



## suo

Great work komi! Keep it up.I'm in the market for a better DAC, and the gamma2 looks great.


----------



## digger945

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_digger945, seems like your computer USB port's 5V line is weak and sagging with the added load. The VBUS voltage of 4.71V that you measured is lower than the analog rails' regulator voltage (4.75V), therefore they have dropped out of regulation. For best performance, you might want to switch to using LP2985-4.5 regulators to give yourself more dropout headroom, or use a computer with a more robust USB 5V line._

 

I can use the y1 USB board alone to measure the VBUS and it doesn't vary any at all as I unplug and plug in my camera, 0404usb, cable modem, iPods, etc. I can even unplug everything else from my laptop's usb line and then plug in the mated y1 and y2 and read the exact same voltages as I posted above. I will take some more readings today and possibly short pins 2 and 3 on JP2D to see if there are any differences. It's all good, I like the challenge.

  Quote:


  Originally Posted by *komi* /img/forum/go_quote.gif 
_I forget to order ONE part from mouser for Gamma1, and - this mean - couple more weeks to finish ..._

 

Have you already ordered the part? 

  Quote:


 How ever, there is Case design update ... [ Ti, sorry for company logo redesign ] 

 Top of the case with laser engraving ...






 

Did you have this done by someone locally? I really like the overlapped faceplates. Did you send your case off to someone for the "HiFi Holic" images to be applied?
 My fingers are crossed as you drill LOL!


----------



## komi

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Did you have this done by someone locally? I really like the overlapped faceplates. Did you send your case off to someone for the "HiFi Holic" images to be applied?
 My fingers are crossed as you drill LOL!_

 

I have done by my self, i got access to Laser Engraver !

 "Hi-Fi Holic" image is logo of my web page Hi-Fi Holic, and i engrave that logo to 
	

	
	
		
		

		
			





 Thanx for crossed fingers, was helpfull 
	

	
	
		
		

		
		
	


	




 Front panel is done .. tomorrow will work on rear one !






 Greets !


----------



## linuxworks

very nice and very different looking!

 boxes around the 'groupings' is a nice touch in UI design.

 even the details around the hex bolts (what are those rings?) look good.


----------



## komi

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_very nice and very different looking!

 boxes around the 'groupings' is a nice touch in UI design.

 even the details around the hex bolts (what are those rings?) look good._

 

Thanx 
	

	
	
		
		

		
		
	


	




 Aluminum anodized washers:






 They are made for RC, but i like them and i got them cheapo on eBay ..

 Greets !


----------



## linuxworks

nice touch. details like that do make a diff.


----------



## nightanole

2-3 things.

 1. box enclosures changed there web address to "http://www.boxenclosures.com/category/product_details.html?product__id=179132"

 2. I think i can fit a gamma 1, tread, and mini3 in that enclosure. Ideas ideas

 3. The wolf has digital volume control option. So techinicaly couldnt I make some kind of frankin box that would have the gamma 2 and a nice amp in one box?


----------



## amb

Quote:


  Originally Posted by *nightanole* /img/forum/go_quote.gif 
_2. I think i can fit a gamma 1, tread, and mini3 in that enclosure. Ideas ideas_

 

I don't think so.


----------



## Daveze

Ti, any hints as to when the final version will be released?


----------



## amb

Quote:


  Originally Posted by *Daveze* /img/forum/go_quote.gif 
_Ti, any hints as to when the final version will be released?_

 

Soon, I hope. Just need to wrap up the prototyping phase, do the final touches on the PCB layout and send it out for fabrication.


----------



## nightanole

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_I don't think so._

 

What about a box B3-080? Its the same foot print but 1.77" tall instead of 1.18" of the gamma 2 box.


 I think it would be nice to have a ALL (well you dont make a small power supply) AMB box with amp and dac in 1 spot. 

 Not to highjack the thread but my only question is how to convert the mini3 to desktop use only with no battery to go along with my gamma 1 i built.

Box Enclosures - New Page


----------



## MisterX

A taller enclosure is not going to help. 
	

	
	
		
		

		
		
	


	




 What's the tread for???


----------



## nattonrice

Probably for the mini3 instead of the 9v.


----------



## MisterX

Isn't there a voltage regulator on the Mini3 board for that?


----------



## ruZZ.il

Quote:


  Originally Posted by *nightanole* /img/forum/go_quote.gif 
_.. question is how to convert the mini3 to desktop use only with no battery to go along with my gamma 1 i built..._

 

See how its going here! 
	

	
	
		
		

		
		
	


	




USB-Powered Headphone Amplifier?

 I'm not familiar with all potential complications, though.


----------



## amc

Yes! Got my 2 prototype boards today. Will be breathing flux fumes tonight!


----------



## Mr.Duck

I noticed the modu shop does custom works now. http://www.modushop.biz/ecommerce/cat109_l2.php?n=1

 €30 for drilling without limitations. €4 for engraving per word. How well does that compared to FPE?


----------



## nattonrice

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Isn't there a voltage regulator on the Mini3 board for that?_

 

Yeah~
 I thought perhaps he was doing what n_maher (?) did with his balanced mini3.


----------



## komi

Quote:


  Originally Posted by *Mr.Duck* /img/forum/go_quote.gif 
_I noticed the modu shop does custom works now. modushop.biz

 €30 for drilling without limitations. €4 for engraving per word. How well does that compared to FPE?_

 

Well, i deal with Modu Shop once, and never again [shipping was late and i call Italy to check whats goin' on, and first thing some Italian lady ask me was "What You have against Italian companies" ], thats the first thing, second - 30 for driling, prolly 40-50 for engraving per word, you will be lucky if you get both panels for les then 200 bucks ...

 AVOID !


----------



## Mr.Duck

Sorry to hear you had a bad experience with modu shop. Probably Italy has the worst postal service in the world. But I thought that was for inbound, not outbound. I bought some cases from italy. Not from modu shop, but from Autocostruire. They are very good cases and had no problems with shipping so would buy again. I live in europe though so maybe it's a bit of a nightmare for people in the US?

 BTW, it was €4 per word, not per letter so it seems pretty reasonable if you want that professional finish. But I would just be happy with neatly cut panels.


----------



## komi

Quote:


  Originally Posted by *Mr.Duck* /img/forum/go_quote.gif 
_Sorry to hear you had a bad experience with modu shop. Probably Italy has the worst postal service in the world. But I thought that was for inbound, not outbound. I bought some cases from italy. Not from modu shop, but from Autocostruire. They are very good cases and had no problems with shipping so would buy again. I live in europe though so maybe it's a bit of a nightmare for people in the US?

 BTW, it was €4 per word, not per letter so it seems pretty reasonable if you want that professional finish. But I would just be happy with neatly cut panels._

 

Yes i know .. but if you look @ front and rear panels for Gamma2:
Gamma2 Front and rear Panels
 count the words and multiply by 4 Euros ... - Plus machining for 2 panels - 80 euros - and there you go ... about 200 bucks ...


----------



## MisterX

image removed


----------



## nattonrice

wow the red/orange switches look pretty cool poking thru the black like that =]


----------



## m1abrams

We have one more gamma2 alive and well 
	

	
	
		
		

		
			





 Had a few issues that were solved by a little more heat and love on the X1.


----------



## jnewman

I was going to try to work on mine for some/most of today but I ended up having to go to work - I guess I'll start tomorrow.

 As an aside, when you order parts for a gamma1, gamma2, mini^3, m^3, sigma11, and CK2III all at the same time from Mouser, you end up with a big pink antistatic sack full of about 130 little envelopes. I'm going to be sorting for a while.


----------



## ruZZ.il

custom labels 
	

	
	
		
		

		
		
	


	



 work hard, then play.


----------



## DoubleEs

I don't normally visit the DIY section in this forum so please forgive my ignorance but is this DAC the final version or is it still in the prototype stage and how much would this finished DAC cost?

 I'm currently using the Gamma-1 as my main DAC and it's a fantastic piece of kit. I prefer this to some of the other more expensive DACs I have in my collection.

 Can anyone recommend a DIYer who could build me one of these as I have zero DIY skills. 

 TIA


----------



## Beefy

Still prototyping. I suspect that if you PM MisterX once the final version is done, he can point you in the right direction of a good builder......


----------



## Dougigs

Quote:


  Originally Posted by *Mr.Duck* /img/forum/go_quote.gif 
_I noticed the modu shop does custom works now. modushop.biz

 €30 for drilling without limitations. €4 for engraving per word. How well does that compared to FPE?_

 

I've dealt with Modushop on a number of occasions - - I've ordered half a dozen cases, and on 2 occasions I had them drill various holes and flanges in front panels. I've never had them engrave lettering.

 I've always found them a great deal, and their shipping has been fast and reasonably well packed. Their cases are very nicely crafted - - good Bolognese manufacturing.

 Keep in mind, however, that I'm in Britain. Shipping from Europe to the United States can be tricky and more expensive. However, I've only had good experiences with them.


----------



## linuxworks

Quote:


  Originally Posted by *Dougigs* /img/forum/go_quote.gif 
_I've always found them a great deal, and their shipping has been fast and reasonably well packed. Their cases are very nicely crafted - - good Bolognese manufacturing._

 


 yeah....

 but my metal case still smells like onions!


----------



## jnewman

Quote:


  Originally Posted by *ruZZ.il* /img/forum/go_quote.gif 
_custom labels 
	

	
	
		
		

		
		
	


	



 work hard, then play._

 

I definitely should have put in tags with the parts... but I didn't. Next time.


----------



## jnewman

I am currently building my gamma1. Question: on U6D (TPS93475) I am getting continuity between the two outside pins on the three-pin side, but not between any other pins (including either outside pin and the center pin). Did I burn the chip?


----------



## ShinyFalcon

Pins 1 and 3 are connected probably not within U6D but from the traces on the PCB. You can verify it by looking at the schematics. Chances are, you didn't burn it yet.

 As for pin 2, that is connected to ground.

 If it helps, I once bridged 1 and 2 on a similar voltage regulator, and the chip got hot enough to smoke (maybe it smoked the flux that was stuck nearby), extremely hot to touch. That chip still works properly!


----------



## jnewman

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Pins 1 and 3 are connected probably not within U6D but from the traces on the PCB. You can verify it by looking at the schematics. Chances are, you didn't burn it yet.

 As for pin 2, that is connected to ground.

 If it helps, I once bridged 1 and 2 on a similar voltage regulator, and the chip got hot enough to smoke (maybe it smoked the flux that was stuck nearby), extremely hot to touch. That chip still works properly!_

 

I should have RTFM. 
	

	
	
		
		

		
			





 You're right, the schematic says pins 1 and 3 are connected via PCB.


----------



## MisterX

redundant.


----------



## m1abrams

Question regarding Front Panel Express. Is it possible to get a panel that has the cut edge anodized? If not any other ideas to hide the shiny cut edge? I am using black anodized material.

 Thanks


----------



## jnewman

Quote:


  Originally Posted by *m1abrams* /img/forum/go_quote.gif 
_Question regarding Front Panel Express. Is it possible to get a panel that has the cut edge anodized? If not any other ideas to hide the shiny cut edge? I am using black anodized material.

 Thanks_

 

First question, I don't think so, but maybe. Second question, Birchwood Casey makes a product called "Aluminum Black" that is for applying a relatively permanent black finish to aluminum... you pretty much wipe it on and wipe it off, I think. You might try it, but I've never used it so I can't vouch for the results.


----------



## MisterX

Quote:


 Is it possible to get a panel that has the cut edge anodized? 
 

Yes. 
 There are two ways to do it. You can send them the panels that came with the enclosure and chose the "use customers material" option or ask them to anodize the panels after they have been machined (which is very expensive).


----------



## m1abrams

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Yes. 
 There are two ways to do it. You can send them the panels that came with the enclosure and chose the "use customers material" option or ask them to anodize the panels after they have been machined (which is very expensive)._

 

that part "very expensive" makes it less appealing for a cosmetic feature. Heck the panels are pricey as is if by "very expensive" means doubling the cost then I will probably pass. I do understand the extra cost on FPEs side though.


----------



## dean0

Ordered Gamma Y1+++ Full kit, and reseived my case today ready for the Y2 
	

	
	
		
		

		
		
	


	




. anyone have a template for the Y2 panels? or even better pre-cut? the case is silver btw
 dean0


----------



## jnewman

I think AMB mentioned somewhere that he would be doing panels like his current gamma1 and mini^3 panels for the gamma2 once production starts... I imagine someone could share frontpanel express files for their own, also. I'm planning to do some FPE panels for mine, but it might be a week or two before I get around to it.


----------



## amb

dean0, you're jumping the gun a bit... 
	

	
	
		
		

		
		
	


	



 Production boards have yet to be ordered, and the panels needs to match them. The prototype boards in circulation now are slightly different because I made some tweaks to the locations of panel components.
 I will publish the production panel dimensions when I'm ready.


----------



## amc

I finished my build late last night after seeming endless alcohol scrubs to get all the flux off. I ran through the y1 initial check procedures and am now happily listening via USB. I have tried out both y1 3.5 mini output, and the y2 RCA output. I have not tried the y2 mini output yet.

 Happily it worked the first time. I can not stress enough how important it is to check each SMD part - Visually with magnification, and with your meter for cold joints or solder bridges. It would have been very difficult to find - let alone fix these on a fully populated board.

 Will post pictures of my build progress - hopefully tonight.


----------



## linuxworks

checking BEFORE you power-on saves no only that one part but possibly whole bunches of them, downstream!


----------



## komi

Is finaly done !


















 Sound GREAT, looking good !

 Guys - get soldering irons ready, and stay in line dor boards from AMB LAB !


 Big THANX to Ti and Mister-X for exelent project and help to build THAT one !


----------



## komi

Quote:


  Originally Posted by *dean0* /img/forum/go_quote.gif 
_Ordered Gamma Y1+++ Full kit, and reseived my case today ready for the Y2 
	

	
	
		
		

		
		
	


	




. anyone have a template for the Y2 panels? or even better pre-cut? the case is silver btw
 dean0_

 

I got set of FPE engraved and pre-cut faceplates - black !

 Interested ?


----------



## amb

komi, wow, your panels raises the bar on bling factor! What did you use for the 3.5mm jacks?

 P.S. dean0 is waiting on production boards, which won't work with panels made for the prototypes.


----------



## MisterX

Imputs?


----------



## luvdunhill

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Imputs?_

 

Glmml 2?


----------



## komi

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_komi, wow, your panels raises the bar on bling factor! What did you use for the 3.5mm jacks?

 P.S. dean0 is waiting on production boards, which won't work with panels made for the prototypes._

 

Hey Ti !

 Thanx .. 

 By the way, all connectors are Your "stock" production !

 I was thinking how to do the color coding, and i find out to other sompanies actualy put small plastick rings - in diferent colors on the tip of the RCA jack ...

 All i do is - remove gold plates ground ring - was easy - just slip off the plastic, and then make a plastic part shorter, put color rings - slide gold ground back, and - there is gold plated - color coded RCA jack what will fit in your pcb footprint!

 By the way, i also put small plastic rings in RCA holes on faceplates, to isolate RCA jacks from faceplates, what is - MUST TO DO for coaxial input and output [like you told me for Gamma 1] ...

 3.5 mm are also your "stock" connectors, is just happen to i have some gold plated on some old device in my "basement elec. graveyard" i took them off and i find out to "gold plated" jacks are nothing but 2 small caps to cover the tip of the jack - and - i took them off, and slide on the tips of "stock" 3.5 mm ... nothing but "bling factor" on all mods 

 ONLY thing i would like to see changed [not a biggie really] is USB input ... 

 I would like that one on PCB:






 ... and you know already - TOTX147PL is fu**** hard to find ...


----------



## amb

komi, thanks for the descriptions.

  Quote:


 By the way, i also put small plastic rings in RCA holes on faceplates, to isolate RCA jacks from faceplates, what is - MUST TO DO for coaxial input and output [like you told me for Gamma 1] ... 
 

If the hole is oversized like my panel drawings (and the RCA jack is properly centered in the hole), then the jack will be isolated. No extra padding is necessary.

  Quote:


 ONLY thing i would like to see changed [not a biggie really] is USB input ... 
 

The bigger USB-B jack will not fit the available space on the γ1 board, not only laterally, but also in height. You'll notice that it occupies the same space as the DC power jack when the γ1 USB and DAC boards are plugged into each other, so a low-profile mini-B jack was selected.

  Quote:


 ... and you know already - TOTX147PL is fu**** hard to find ... 
 

This is not a problem any more with the latest γ1 v1.01 PCB, now available. The Sharp GP1FMV31TK0F Toslink transmitter module is now supported and available from Digikey.


----------



## amb

Post #2 of this thread has been updated:
 - Schematic diagram, PCB layout and 3D render updated to v1.0
 - Added BOM

 I expect this to be the production version.


----------



## nattonrice

Awesome work guys!
 I wanna build another :S 
 haha


----------



## MrSlim

Quote:


  Originally Posted by *komi* /img/forum/go_quote.gif 
_I got set of FPE engraved and pre-cut faceplates - black !

 Interested ?_

 

Komi, I'm interested.

 PM sent


----------



## jnewman

AMB, one question that might best be asked here rather than via email as it may be of general interest - you note that gamma2 C20 and C26 may be substituted with 470uF caps to provide for direct headphone output. Also, you note gamma1 C24D and C25D may be substituted with 470uF caps to provide for direct headphone output.

 Obviously these cap choices are better for direct use with headphones or you would not recommend them. Is there any tradeoff or negative impact in using these caps when the DAC is plugged directly into an amp? If so, I'll probably put 470uF caps on the gamma1 and leave the gamma2 alone, if not I'll probably put 470uF caps on both if they will fit.


----------



## amb

jnewman, 470uF is needed for low-Z headphone loads, 22uF will cause severe bass rolloff.

 For connection to an amp, 470uF is more capacitance than necessary, but won "hurt" anything. Some people have a preference for the "sound" of certain lines of capacitors, and since these are directly in the signal path, it is the builder's choice to use the 22uF Elna Silmic II, Nichicon Muse ES, Black Gate NX Hi-Q or the 470uF Nichicon KW or FW. The max size that would fit is 6.3mm diameter, 11mm tall, with lead pitch of 2mm or 2.5mm.


----------



## jnewman

Great, thank you. 
	

	
	
		
		

		
		
	


	




 I hadn't connected the dots, but I do understand about RC complex impedance and rolloff frequencies. I just wanted to make sure it wouldn't have any major effects that I wasn't thinking about.

 I'll probably try it both ways.


----------



## magzcampos

hello im a complete noob and im wondering would i be able to run this off a battery.


----------



## MisterX

The current draw for the Gamma 1 Plus version and a Gamma 2 is roughly 250mA. 
 It would have to be a pretty big battery.


----------



## ShinyFalcon

Is it possible to determine the sampling rate of the incoming data (to CS8416)? The CS8416 has a pin (16) labeled 96kHz, which isn't too useful for what I want to do. I thought of an idea about having four or five LEDs which lights up according to the incoming sampling rate (44, 48, 96, 192kHz, ).

 Actually, Arduino (hifiduino) comes into mind... maybe I should look into that...

 Edit: Doesn't seem like Arduino will be useful... the rate (OSR) would be stuck on 96kHz or 192kHz if I have ASRC installed.


----------



## magzcampos

how big, the size of the dac? a textbook?


----------



## ShinyFalcon

It's about the size of two credit cards.


----------



## amb

Quote:


  Originally Posted by *magzcampos* /img/forum/go_quote.gif 
_how big, the size of the dac? a textbook?_

 

How much run-time are you looking for?
 A good NiMH 9V battery is rated between 200-300mAH, which means that it will run completely dead in less than an hour with the type of current consumption we're talking about.

 Also, since the γ1/γ2 needs a regulated 5V DC power source, and there is no such thing as a 5V battery, you'd have to use a higher-voltage battery (or a bunch of batteries connected in series) to get to something above 5V, then regulate it down to 5V with a voltage regulator circuit. If the circuit is based on a linear regulator, then the extra voltage is thrown away and wasted as heat. Some of the battery capacity will thus not be put to "real" work.

 If you use a 6V 12AH SLA battery, then it willl give you good amount of run-time, but that battery will be at least twice the size of the γ2 and weigh about 5 lbs (not including a low-dropout regulator circuit).

 Why are you looking for battery power anyway? Very few portable media players have S/PDIF outputs that would benefit from an external DAC, so I don't really see the γ1/γ2 too useful as a portable device. If you use a computer as the source, then its USB port will supply the power that the γ1/γ2 needs. If you use a home CD/DVD player or network music player, then you could power the γ1/γ2 with a 5V DC regulated wallwart.


----------



## JamesL

edit: internet problems


----------



## cobaltmute

I can see running of battery if you've got a laptop. The draw for the DAC is just an increased draw on the laptop battery which just means a faster dead laptop. I notice the draw with a γ1, I hate to think about a γ2.

 I'll admit to not having the looked at the project in a bit, but if you use the National regs, instead of the TI regs, you have a higher input voltage range. I would build a 5xAA 2500mAH pack and just plug that into the wall wart jack. Quick and simple.


----------



## natrix

Quote:


  Originally Posted by *cobaltmute* /img/forum/go_quote.gif 
_I can see running of battery if you've got a The draw for the DAC is just an increased draw on the laptop battery which just means a faster dead laptop._

 

In a minimal "E" config (coaxial only, no illuminated switches), I measured the γ1 at 5V, 12mA. My laptop battery (Asus netbook) is 3420mAh, which would run the DAC for almost 12 days. However, I'm not sure how much current it needs in other configurations.


----------



## amb

Quote:


  Originally Posted by *natrix* /img/forum/go_quote.gif 
_In a minimal "E" config (coaxial only, no illuminated switches), I measured the γ1 at 5V, 12mA._

 

That sounds low. The WM8501 DAC will draw about 13.5mA idling (9mA digital, 4.5mA analog), driving no load just by itself, and then the CS8416 draws about 18mA total on all its supply pins at 44KHz sampling rate, and more at higher rates), so you're looking at a minimum of ~32mA just on those two chips alone.


----------



## amb

γ2 v1.0 production boards have been ordered. ETA is about 4 weeks.


----------



## dean0

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_γ2 v1.0 production boards have been ordered. ETA is about 4 weeks._

 







 Great News, I cannot wait!


----------



## cobaltmute

Quote:


  Originally Posted by *natrix* /img/forum/go_quote.gif 
_In a minimal "E" config (coaxial only, no illuminated switches), I measured the γ1 at 5V, 12mA. My laptop battery (Asus netbook) is 3420mAh, which would run the DAC for almost 12 days. However, I'm not sure how much current it needs in other configurations._

 

And your processor, screen, fans, hard drive, memory and all the supporting chips would be running on what for those 12 days?


----------



## Mr.Duck

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_γ2 v1.0 production boards have been ordered. ETA is about 4 weeks._

 

Congrats, guys! v1.0 is a great milestone to reach


----------



## TeraHz

I have been using the usb-> spdif, optical -> 3.5mm (y2), usb->3.5mm(y1) and usb -> RCA(y2) paths in various setups and let me tell you, this thing is amazing. It handles everything without a sweat. 

 The signal out is always dead silent (when analog) and I cannot detect any degradation from jitter on the spdif part.

 I have also used both usb->spdif and optical->RCA(y2) simultaneously and it didn't make a difference. Performance stayed top notch.

 Add to that the satisfaction of DIY and you get an amazing DIY audio project!

 Thanks Ti and Marshall for this great project and thanks for having me on the prototyping team.


----------



## Robinson34

Is it prudent to try to put 2 beta22 boards, 2 sigma22 boards and 2 gamma2 boards in the same enclosure? This would be for use as a speaker amp only. I am wondering if it is good practice to place digital boards in along with analog boards. 
 I am primarily a mechanical guy and am working on the logistics of the enclosure and heat sinking but would like to know if electronically I should not even try to do this. The two toroids would be in a separate enclosure. Thanks for all of you guy's input.


----------



## amb

Robinson34, it's all in the details of how it's done, but trying to put too much into the same case complicates things. If done right, it could work well, but Uncle Erik mentioned a number of reasons to avoid doing so and I concur.


----------



## amc

I posted some build notes and pictures of my y1 build for the y2 prototype in the y1 thread. Check it out 

here


----------



## Robinson34

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Robinson34, it's all in the details of how it's done, but trying to put too much into the same case complicates things. If done right, it could work well, but Uncle Erik mentioned a number of reasons to avoid doing so and I concur._

 

Thanks AMB, I think that the DAC will remain separate. And thanks for all of your knowledge and input here. I am looking forward to getting started.


----------



## jnewman

I received my few last parts yesterday and the day before, and added them during my lunch break today - it looks like I caught all the solder bridges while I was making them, because my Gamma1 (which has been working for almost a week) and my Gamma2 (which has been working for ten minutes) sound absolutely fantastic! I did a quick DC offset check and started listening.

 I posted this already in the Gamma1 thread, but I'll say it here, too - I have never had a standalone DAC or even a particularly fancy CD player or turntable, and I had no idea music could sound this good for so little cash! This DAC is miles ahead of any of the other source equipment I have used (including an Auzentech Forte sound card and an M-Audio USB recording interface).

 AMB and MisterX, thank you for spending so much of your time contributing such great designs to the DIY community! This little box is a marvel, and I couldn't be happier with it.

 Aside from the few little fitment issues mentioned earlier, everything went together pretty painlessly for me and fit in the Box Enclosures B2-080 case is perfect. No rattling up and down or side to side and the length is spot on. I need to get my FPE panels made.


----------



## amb

Excellent, jnewman. The box might be small and the build cost moderate, this little DAC uses top-tier stuff and could run with big-$$$$ commercial DACs.


----------



## DoYouRight

I cant wait for the pcbs to be ready for the final release


----------



## MrSlim

I'm seeing the light at the end of the tunnel on my proto gamma2 build also. I thought my last Digikey order would do it but discovered a couple of more parts missing last night... So hopefully I'll be firing it up on friday night after I get the last of the parts tomorrow. The SMD parts were not as hard to solder as I expected after watching the video, the worst were the the little regulators. I hope I'm done before the production boards show up..


----------



## bada bing

My second γ1 is up and "burning in". This one is a ++ BOM intended for a γ2 build.
 I'm ordering parts for stuffing a γ2 board. I haven't seen it discussed, what are the relative merits between the WM8741 & WM8742 Wolfson DAC chip?
 They are about the same price. Is one preferred ?

 As I listen to my second γ1, I have to say thanks to AMB and Mr X . I have built at least one of every AMB published project (except the β24 but I'm gathering the parts). For some reason, to me this little DAC is the most impressive project so far. I'm not a golden ear, but I hear very little wrong with the γ1. I can't wait for the γ2 board.
 Thanks


----------



## m1abrams

The 8741 is the slighlty better chip. 8742 is meant as a low cost version.


----------



## fordgtlover

Quote:


  Originally Posted by *bada bing* /img/forum/go_quote.gif 
_snip...

 For some reason, to me this little DAC is the most impressive project so far. I'm not a golden ear, but I hear very little wrong with the γ1. I can't wait for the γ2 board.
 Thanks 
	

	
	
		
		

		
		
	


	


_

 

You are in for a treat with the y2


----------



## MrSlim

I finally finished my Gamma2 prototype a couple of days ago and did a very thorough inspection of the joints, looking for bridges, and the smd connections all look good (via a 7X loupe). I did the initial checks and all the voltages are good. I'm using a full Gamma1 to mate with the G2, and get audio out of the G1(input via USB), but nothing out of the G2 so far.. I had installed U6 by mistake (I'm using a 8741), but I have removed it, but that didn't help. The 3.3 and 4.5 v test points are also fine on the G2. I'll post a picture of the board tomorrow morning, and I guess I'll have to drive out to my storage locker (20KM away) to get my o'scope, but I thought I would ask for ideas in the mean time.. Like I said, all the connections look good under magnification.
 I suspect its something simple but so far it has eluded me..


----------



## amb

MrSlim, make sure you didn't forget to install the one-pin header at γ1's JP1D pin 2, to mate with the receptacle at γ2's J3 pin 2. I had previously sent instructions and pictures to the prototype team about this.

 Other than that, check and re-check your solder joints by measuring with a DMM. 90% of all problems with the γ DACs are soldering-related.


----------



## m1abrams

MrSlim - if you are using one of the SMD crystals reflow the solder joints on it. I had a similar problem with my G2 and that solved my issue.


----------



## MrSlim

Thanks guys, it looks like redoing some of the joints did the trick. m1, I saw your message and I had another look at at the crystal and there was one joint that might have had a gap. I also reflowed the pins on one side of the ASRC chip. I could swear that they looked good when I did a final review after doing all the SMD but they just looked a little "barren". 

 Anyway, all is good with the world and it sounds excellent. The first track I listened to was from a Beasty Boys Jazz-Funk disk a friend gave me and I was hearing some noise, and then I realized that it might be tape hiss, so there is a LOT of resolving power in this baby.. Having a quick listen to a couple of my "reference" tracks confirmed that all was well... 

 At least I got the major construction done before the production boards started showing up..
	

	
	
		
		

		
		
	


	




 I just have to do the cross board cable connection on the Lite gamma 1 I built and then I can get on with casing..


----------



## linuxworks

Quote:


 and I was hearing some noise, and then I realized that it might be tape hiss, so there is a LOT of resolving power in this baby 
 

this dac is probably better than many (most?) of the so-called 'pro studio' created audio content.

 I hear multiple levels of noise as a track begins. you can hear how they mixed things. you can hear other flaws, too.

 today's decent playback equipment *exceeds* the specs of the equip used to *make* the recordings. at least that's what I'm finding. my system is no longer the weakest link. the recording guys now have to upgrade their gear (lol).


----------



## strid3r

Quote:


  Originally Posted by *MrSlim* /img/forum/go_quote.gif 
_Anyway, all is good with the world and it sounds excellent. The first track I listened to was from a Beasty Boys Jazz-Funk disk a friend gave me and I was hearing some noise, and then I realized that it might be tape hiss, so there is a LOT of resolving power in this baby.. Having a quick listen to a couple of my "reference" tracks confirmed that all was well... _

 

I'll just echo your opinion...had the same experience with a couple of tracks. Definitely a great piece of gear.


----------



## TeraHz

linuxworks: I totally agree. I've found that almost all recordings that are done 10 or more years ago have plenty of 'detail' (noise, clicks and what not). Nothing from the music I have compares to a cd/flac of Norah Jones in terms of clean sound (that's probably one of the newest recording I have). And this dac does a very good job bringing out all aspects of a recording.


----------



## DoYouRight

im hoping for the production boards sometime soon!


----------



## amb

Quote:


  Originally Posted by *DoYouRight* /img/forum/go_quote.gif 
_im hoping for the production boards sometime soon!_

 

A couple more weeks...


----------



## LingLing1337

Look forward to more impressions of this, sounds like a real giant-killer!


----------



## Mr.Duck

I'd be interested in a comparison between gamma2 and the twisted pear opus. Just out of interest. Still, I would expect the gamma2 to be better overall. Hence I will be building one soon I hope.


----------



## linuxworks

Quote:


  Originally Posted by *TeraHz* /img/forum/go_quote.gif 
_linuxworks: I totally agree. I've found that almost all recordings that are done 10 or more years ago have plenty of 'detail' (noise, clicks and what not)._

 

there's a cd that I've been listening to (a celtic sampler) that has some kind of 'bump' when the artist hit the mic or the table or something with a thud sound.

 what was funny is that when I listen (even with headphones on) I still think there's someone banging on the wall or someone running in the hallway. its quite uncanny 
	

	
	
		
		

		
			





 this is a case of having TOO much detail (lol). when you hear the mistakes in the recording, its not always a good thing.

 I should send mail to that performer, "you should re-record that song. and don't bump into the desk next time, ok? just sing, no banging needed please."


----------



## Dougigs

I have a CD by the great jazz pianist Randy Weston, recorded digitally during this decade, in which on good sound equipment and headphones with good low bass you can feel his feet tapping (hard) on the floorboards - - not as percussive sounds, but as sub-bass whoomps shaking the microphone stand and pushing on the diaphragms at extremely low frequencies. It actually makes it almost unlistenable, because it feels like your headphone is being moved around on your head; I have to switch from HD650s to Grados for it.

 I never had that problem until I started using nice headphone amps and good DACS.


----------



## Mr.Duck

For sure I will need to get a new iron for that surface mount stuff. Hakko 936 is far too expensive for me. I need some recommendations / advice since my last cheap iron was almost useless.

 I was looking at a Xytronic 253 (20W). It is more much more the kind of thing I am looking for...






 What do you think?


----------



## Billyk

I got the Hakko clone Aoyue 936 for under $50.00 shipped. I love it and have done a Bantam, Mini-3, and a Y-1 one with it so far as SMD goes.
 I got it here on ebay. Very reliable seller from Ma.


----------



## Billyk

BTW, I found that I just love SMD soldering! The resistors and caps are a bit fussy but those bigger chips like the DACS and even the little regulators are so cool to solder, and it looks so fine, clean, and neat when you finish it. It is also very fast!


----------



## funch

Quote:


  Originally Posted by *Mr.Duck* /img/forum/go_quote.gif 
_For sure I will need to get a new iron for that surface mount stuff. Hakko 936 is far too expensive for me. I need some recommendations / advice since my last cheap iron was almost useless.

 I was looking at a Xytronic 253 (20W). It is more much more the kind of thing I am looking for...






 What do you think?_

 

How about one of these? I use the Station 1A. 

Circuit Specialists Inc. - Soldering Stations

 The handle for the Blackjack looks just like the pic you posted.


----------



## srserl

Circuit Specialists seem to have moved their web site. It is Circuit Specialists - Data Acquisition - Industrial Computers - Fluke Test Equipment - Components & Supplies.... The soldering station page is here.


----------



## funch

That's odd?! The link worked fine when I tried it in the post preview.

 May be a temporary glitch. Anyway, thanks for finding a better link.


----------



## tally3tally

Hi
 ive gone through plenty of written material on the gamma1&2 i have a question for the gurus here
 is the gamma series just a headphone DAC or can it be used with my home AV equipment too, i have a integrated stereo Amp and two mission m34i floorstanders, will this DAC bring a great change to music when substituted for say my computer/ipod as an audio source.


----------



## dude_500

Quote:


  Originally Posted by *tally3tally* /img/forum/go_quote.gif 
_Hi
 ive gone through plenty of written material on the gamma1&2 i have a question for the gurus here
 is the gamma series just a headphone DAC or can it be used with my home AV equipment too, i have a integrated stereo Amp and two mission m34i floorstanders, will this DAC bring a great change to music when substituted for say my computer/ipod as an audio source._

 

You don't have to use headphones, you can use it with any digital source that is compatible with the input protocols and plug in an amp to the output. It wouldn't be of use for an ipod since there isn't a digital output on the ipod (unless there is some digital mod that I'm not aware of), but other than that yes you can use it as your DAC.


----------



## akcrusier

Quote:


  Originally Posted by *tally3tally* /img/forum/go_quote.gif 
_Hi
 ive gone through plenty of written material on the gamma1&2 i have a question for the gurus here
 is the gamma series just a headphone DAC or can it be used with my home AV equipment too, i have a integrated stereo Amp and two mission m34i floorstanders, will this DAC bring a great change to music when substituted for say my computer/ipod as an audio source._

 

 As long as your AV system has a free pair of RCA line level inputs (it should) this dac will work fine with it. This is a quality DAC and is certainty much better than the line out of an ipod or computer so you will hear a difference.


----------



## amb

Quote:


  Originally Posted by *tally3tally* /img/forum/go_quote.gif 
_is the gamma series just a headphone DAC or can it be used with my home AV equipment too, i have a integrated stereo Amp and two mission m34i floorstanders, will this DAC bring a great change to music when substituted for say my computer/ipod as an audio source._

 

It's the other way around -- the γ1/γ2 are primarily designed to be line-out DACs for use with an amp (headphone amp, integrated amp, or receiver, etc.). The fact that they are also capable of driving headphones directly is a bonus.


----------



## tally3tally

@amb
 @akcrusier
 @dude_500
 thanks for taking time and clearing my doubt...


----------



## Mr.Duck

Quote:


  Originally Posted by *Billyk* /img/forum/go_quote.gif 
_I got the Hakko clone Aoyue 936 for under $50.00 shipped. I love it and have done a Bantam, Mini-3, and a Y-1 one with it so far as SMD goes._

 

Yar that's more like it. Also the CSI Station 1A looks good. I can get it for around $55 in my country (a fair bit cheaper than the Aoyue 936). It is interesting that the iron looks almost the same as the one I posted.

 The one I posted, the Xytronic type 253, is only around $25 so I'm really tempted. So is a soldering station really necessary? The type 253 looks like it is temperature controlled (lots of clues hint at this from reading the description and a user post at head-fi).


----------



## digger945

Well I finally got my amp put back together so I could listen to this OPA2365/blackgate Full++ Gamma 2. It sounds pretty good. I can hear a lot more trash and dubbed parts in the tunes. Guess I gotta find a really good track to see what this dac is fully capable of.

 Thus far I've listened to two of my all time favs and heard something musical in both tracks that I have never heard before. Lots more echo from the instruments. I gotta play around with the filters and stuff and give it more time, but thus far I am liking it a lot.


----------



## bellahsu

What is the output voltage peak-to-peak when OPA2365 is used for Gamma 2 ? (1v p-p or 2v p-p). 

 I plan to use Musical Fidelity X10D tube buffer with Gamma 2. The input impedance of X10D is 1m but it does not work well with DAC capable of 2v p-p.


----------



## amb

1.4Vrms @ 0dBFS (about 4Vpp). This is true for both OPA2365 or AD8656.
 Most DACs are rated with Vrms, not Vpp.


----------



## Billyk

Quote:


 Guess I gotta find a really good track to see what this dac is fully capable of. 
 

I have some very tasty live electric and acoustic blues shows. I would be happy to do a B&P if anyone is interested. I use them to show off.


----------



## bellahsu

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_1.4Vrms @ 0dBFS (about 4Vpp). This is true for both OPA2365 or AD8656.
 Most DACs are rated with Vrms, not Vpp._

 

According to WM8741's datasheet it has ~1Vrms analog outputs (10k load, 0dbDSD input). Would it be possible to keep OPA2365 (for filtering purpose) and have the output of Gamma2 be close to 1Vrms for my tube buffer ? Or will I be better off just taking the outputs directly from WM8741 to drive the buffer ?


----------



## amb

Quote:


  Originally Posted by *bellahsu* /img/forum/go_quote.gif 
_According to WM8741's datasheet it has ~1Vrms analog outputs (10k load, 0dbDSD input). Would it be possible to keep OPA2365 (for filtering purpose) and have the output of Gamma2 be close to 1Vrms for my tube buffer ? Or will I be better off just taking the outputs directly from WM8741 to drive the buffer ?_

 

Look on WM8741's datasheet, page 12. PCM full scale differential output is 2Vrms. The ~1Vrms figure you quote is for DSD, which is not applicable in this case.

 We actually operate the opamp at below unity gain to drop the output down to 1.4Vrms, in order to prevent clipping. Why is 1.4Vrms a problem for your tube buffer? 1.4V is only 2.9dB higher than 1V. You can set the anti-clipping switch to "on" and get 2dB of attenuation, which will make the output only 0.9dB higher than 1Vrms.


----------



## bellahsu

1.4Vrms output maybe OK for my tube buffer. Setting the anti-clipping switch to "on" and attenuate the output by 2dB might be the ticket for me. Now I'm really anxious to build a Gamma 2. Thanks!


----------



## nightanole

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_1.4Vrms @ 0dBFS (about 4Vpp). This is true for both OPA2365 or AD8656.
 Most DACs are rated with Vrms, not Vpp._

 

so 1.4v / .707 x2 = 4vpp? The Bantam PCM2702 is only rated vpp of 3.1v, not rms. I just wanted to compare levels and didnt know how to convert. guess that would make the bantam 1.1vrms...


----------



## amb

Quote:


  Originally Posted by *nightanole* /img/forum/go_quote.gif 
_so 1.4v / .707 x2 = 4vpp? The Bantam PCM2702 is only rated vpp of 3.1v, not rms. I just wanted to compare levels and didnt know how to convert. guess that would make the bantam 1.1vrms..._

 

Vpp = Vrms * 2 * √2

 The PCM2702 is rated to output Vpp = 62% * Vcc at 0dBFS. That would be 3.1Vpp if Vcc was 5V. But Bantam and Alien both have voltage regulators that drop the analog supply voltage down to 4.5V or 4.75V, the Vpp output would be 2.8Vpp or 2.95Vpp, respectively, corresponding to 0.99Vrms or 1.04Vrms.


----------



## Midnighttown

anyone here i can pre order an ready build gamma 2? im interested on one message me


----------



## Daveze

A good segue into a question that's been bugging me: What's the ETA on the boards?


----------



## amb

The boards are on their way to me. It should be just a matter of days now.


----------



## TzeYang

<3.

 I shall be buying from your store in a few more days.

 What about the group buy for the faceplates?


----------



## Daveze

Oh goody.


----------



## amb

Quote:


  Originally Posted by *TzeYang* /img/forum/go_quote.gif 
_What about the group buy for the faceplates?_

 

Instead of a group-buy, I will simply offer them. I have pre-ordered a small number of sets which should also be arriving in a week or so. They are black with silver engraving, and assumes full-functionality (i.e., all features installed on γ2, to be mated to a γ1 full++ config).


----------



## amb

The full-content γ2 website is now up. Some sections still need work, but it's good enough to go live.


----------



## n_maher

That is a heck of an impressive project, Ti. Kudos to you and Marshall for a job well done.


----------



## Beefy

*rubs hands together with glee*

 Well, I know what I'm doing today instead of writing grants......


----------



## ivanrocks321

Is there any chance of buy a completed one. Ive been waiting for a while to try this one.


----------



## Beefy

The answer is _right there_ on the very front page of the y2 website.


----------



## nightanole

Would this be a "worth it" upgrade from a gamma lite fed 256k-320k mp3's amplified via a high performance mini3? Or is my source amb too under rated and i wont see much difference?


----------



## amb

Quote:


  Originally Posted by *nightanole* /img/forum/go_quote.gif 
_Would this be a "worth it" upgrade from a gamma lite fed 256k-320k mp3's amplified via a high performance mini3? Or is my source amb too under rated and i wont see much difference?_

 

I think only you could answer that... because what's "worth it" or not involves value judgements.


----------



## PJPro

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_The full-content γ2 website is now up. Some sections still need work, but it's good enough to go live._

 

Any idea when the boards and panels will be available?

 EDIT...Ooops. In a week or so?


----------



## amb

I should have both by this Friday or next Monday.


----------



## m1abrams

Quote:


  Originally Posted by *nightanole* /img/forum/go_quote.gif 
_Would this be a "worth it" upgrade from a gamma lite fed 256k-320k mp3's amplified via a high performance mini3? Or is my source amb too under rated and i wont see much difference?_

 

I have a hp mini3 also and a gamma1 and a gamma2. I did notice an improvement of the gamma2 over the gamma1 when using it with the mini3 and lossless source files. Now I am not one to say it is a night and day difference, but I can easily tell the 2 apart with just listening. Biggest difference I notice right off is the noise floor is much lower on the gamma2.

 But as Ti stated it is a personal judgment call on your part as to wether it is "worth it". My future plan is to use my gamma2 with the M3 that is in process of being built and the gamma1 with the mini3.


----------



## PJPro

Can someone confirm that I need all the G1 parts to make a G2 (except the case). I want the G2 to have all the available inputs/outputs.

 And, is there a reason why the S11 isn't mentioned as a possible power supply for the G2? Overkill?


----------



## m1abrams

Quote:


  Originally Posted by *PJPro* /img/forum/go_quote.gif 
_Can someone confirm that I need all the G1 parts to make a G2 (except the case). I want the G2 to have all the available inputs/outputs._

 

Well if you want ALL of the inputs and outputs then you will need all the parts for a gamma1 Full++ config.


----------



## PJPro

OK. Thanks. Understand that. But do I also need the DAC chip on the G1 for example?


----------



## yzriver

how gamma 2 compares to twistpearaudio's DAC? Is it reasonable to have two differential output from gamma 2?
 thanks


----------



## MisterX

Quote:


  Originally Posted by *PJPro* /img/forum/go_quote.gif 
_OK. Thanks. Understand that. But do I also need the DAC chip on the G1 for example?_

 



 You did say all of the inputs and outputs


----------



## m1abrams

Quote:


  Originally Posted by *PJPro* /img/forum/go_quote.gif 
_OK. Thanks. Understand that. But do I also need the DAC chip on the G1 for example?_

 

If you want that front panel audio output you need the DAC. But if you do not want that extra audio output then no.


----------



## PJPro

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_You did say all of the inputs and outputs_

 

Errrr?


----------



## jnewman

Quote:


  Originally Posted by *PJPro* /img/forum/go_quote.gif 
_Errrr?_

 

The Gamma2 has two analog outputs. One (the minijack on the front panel) comes from the Gamma1 DAC chip. The other (the minijack and RCAs on the back panel) comes from the Gamma2 DAC chip. If you want all the plugs to work, you need the Gamma1 DAC chip.


----------



## PJPro

Quote:


  Originally Posted by *jnewman* /img/forum/go_quote.gif 
_The Gamma2 has two analog outputs. One (the minijack on the front panel) comes from the Gamma1 DAC chip. The other (the minijack and RCAs on the back panel) comes from the Gamma2 DAC chip. If you want all the plugs to work, you need the Gamma1 DAC chip._

 

OK. Thanks. A full G1 it is then.


----------



## CodeToad

Quote:


  Originally Posted by *m1abrams* /img/forum/go_quote.gif 
_I have a hp mini3 also and a gamma1 and a gamma2. I did notice an improvement of the gamma2 over the gamma1 when using it with the mini3 and lossless source files. Now I am not one to say it is a night and day difference, but I can easily tell the 2 apart with just listening. Biggest difference I notice right off is the noise floor is much lower on the gamma2.

 But as Ti stated it is a personal judgment call on your part as to wether it is "worth it". My future plan is to use my gamma2 with the M3 that is in process of being built and the gamma1 with the mini3._

 

Thanks for sharing that, I was wondering the same thing. I am much more inclined to believe what I read from people in here in the DIY forums than elsewhere on the forums.


----------



## MrSlim

Quote:


  Originally Posted by *yzriver* /img/forum/go_quote.gif 
_how gamma 2 compares to twistpearaudio's DAC? Is it reasonable to have two differential output from gamma 2?
 thanks_

 

AMB has provided connection points on the Gamma2 board for differential outputs directly from the WM8741, but you will be bypassing the output buffer and it's 100Khz low pass filter. You would also have to use some other kind of casing that would have room for differential connectors. 

 We need someone with an Opus to do a comparison to the Gamma2..

 The Opus is a very modular approach whereas the Gamma2 is very integrated approach (and much better bang for the buck). Some people want modular, others like integrated (I love bang for the buck myself..)


----------



## Mr.Duck

Quote:


  Originally Posted by *MrSlim* /img/forum/go_quote.gif 
_The Opus is a very modular approach whereas the Gamma2 is very integrated approach (and much better bang for the buck). Some people want modular, others like integrated (I love bang for the buck myself..)_

 

Opus just houses all the bits on different boards. It is more flexible approach for the builder. Gamma2 is more like a fixed design that would be more difficult to deviate from. It also has the reclocking on board where as an Opus build may leave that off as it requires buying yet another module. Overall, I think the Gamma2 is the better design. Maybe opus can be made into a better performing dac but it would be difficult and expensive. Gamma2 has all the hard work done, you just have to put it together.


----------



## nightanole

I just went over the build, they only have 1 version? I want to make a lite version as my only input will be usb ,and my only out will be analog. On that note i think i only need half a gamma 1 for this setup.


----------



## m1abrams

Quote:


  Originally Posted by *nightanole* /img/forum/go_quote.gif 
_I just went over the build, they only have 1 version? I want to make a lite version as my only input will be usb ,and my only out will be analog. On that note i think i only need half a gamma 1 for this setup._

 

Double check this info, but I believe you can just do a USB lite gamma1 build and leave out the DAC chip and maybe a few other of its supporting pieces if you do not want the front panel audio output.


----------



## jnewman

Quote:


  Originally Posted by *nightanole* /img/forum/go_quote.gif 
_I just went over the build, they only have 1 version? I want to make a lite version as my only input will be usb ,and my only out will be analog. On that note i think i only need half a gamma 1 for this setup._

 

You actually need a minimum of both Gamma1 halves - one board half of the Gamma1 is an SPDIF to analog DAC and the other board half is a USB to SPDIF converter. You need the one to have a DAC and the other to use it with USB.

 If you mean you only need one half of the Gamma1 for use with the Gamma2, the Gamma1 DAC board has all the power supply stuff on it that powers the Gamma2 board, so you at least need that board half even if you don't install the Gamma1 DAC chip itself.


----------



## luvdunhill

Quote:


  Originally Posted by *Mr.Duck* /img/forum/go_quote.gif 
_Opus just houses all the bits on different boards. It is more flexible approach for the builder. Gamma2 is more like a fixed design that would be more difficult to deviate from. It also has the reclocking on board where as an Opus build may leave that off as it requires buying yet another module. Overall, I think the Gamma2 is the better design. Maybe opus can be made into a better performing dac but it would be difficult and expensive. Gamma2 has all the hard work done, you just have to put it together._

 

Perhaps the Buffalo would be the better comparison to the y2.


----------



## nightanole

Quote:


  Originally Posted by *jnewman* /img/forum/go_quote.gif 
_You actually need a minimum of both Gamma1 halves - one board half of the Gamma1 is an SPDIF to analog DAC and the other board half is a USB to SPDIF converter. You need the one to have a DAC and the other to use it with USB.

 If you mean you only need one half of the Gamma1 for use with the Gamma2, the Gamma1 DAC board has all the power supply stuff on it that powers the Gamma2 board, so you at least need that board half even if you don't install the Gamma1 DAC chip itself._

 

On the usb side of gamma 1 it supplies i2s and power to the dac board. This being the case why would i need the dac board of the gamma 1 to get the gamma 2 working? The only thing i see the dac section feeding is the 5v external power, or is the gamma 2 unable to be bus powered?


----------



## m1abrams

Quote:


  Originally Posted by *nightanole* /img/forum/go_quote.gif 
_On the usb side of gamma 1 it supplies i2s and power to the dac board. This being the case why would i need the dac board of the gamma 1 to get the gamma 2 working? The only thing i see the dac section feeding is the 5v external power, or is the gamma 2 unable to be bus powered?_

 

No the gamma2 can be powered via bus, you may not need the DAC board if you do not need external power which why would you if you only have usb input. I think linuxworks might have even done what you suggest during prototyping.


----------



## jnewman

Quote:


  Originally Posted by *m1abrams* /img/forum/go_quote.gif 
_No the gamma2 can be powered via bus, you may not need the DAC board if you do not need external power which why would you if you only have usb input. I think linuxworks might have even done what you suggest during prototyping._

 

Maybe I misunderstood the schematic. It looks to me like the Gamma 2 runs off of power from Pin 2 of Gamma 1 J2U and J4D. It only connects Pin 3 between J2U and J4D but doesn't actually use it for anything. On the USB board, J2U Pin 2 is used as a voltage source for U3U and is not a supply. On the DAC board, J4D Pin 2 is the voltage output of U1D. This appears to be the only voltage supply to J2U/J4D Pin 2 and therefore the Gamma 2.

 I understand the Gamma2 can be bus-powered, that's the way I've been using mine most of the time, but it looks from the schematic like the TPS2115 (U1D) on the DAC board is required for the Gamma 2 to run off of bus power.

 I imagine that you could do something with jumpers or airwiring, but it wouldn't be a part of the normal schematic (it seems to me).


----------



## MisterX

Quote:


 I just went over the build, they only have 1 version? 
 

There is only going to be 1 version of the prefabricated end panels available but otherwise the only configuration "restriction" is the USB to S/PDIF converter (Gamma 1 config "C") will not work with the Gamma 2 because it does not produce an I2S output. 


  Quote:


 On that note i think i only need half a gamma 1 for this setup. 
 

You only need U1U plus the associated components and U1D plus it's associated components to build a Gamma 1 section for use with a Gamma 2 that will only have a USB input. 
 I had taken a picture of a similarly configured Gamma 1 section a while back but the glare on the board rendered it pretty useless so here is a simplified schematic instead.


  Quote:


 This being the case why would i need the dac board of the gamma 1 to get the gamma 2 working? 
 

Among other things...U1D also provides current limiting which will help ensure that you do not damage your computer if you happen to make a mistake.

 The Gamma 1 parts list sez: 

  Quote:


 1.This part may be omitted if the USB board will never be attached to the DAC board, or if you want to hardwire for external DC power or USB power only (See jumper settings in the instructions section). Omitting these parts is not recommended. U1D provides controlled voltage ramp-up during turn-on and current limiting protection that would be defeated if it's not used.


----------



## MrSlim

Quote:


  Originally Posted by *luvdunhill* /img/forum/go_quote.gif 
_Perhaps the Buffalo would be the better comparison to the y2._

 

Since the Opus and Gamma2 use the same DAC chip, it would be interesting to compare the "implementation" parts of each. The Buffalo uses a different DAC (the ES9018), so you would be comparing two different animals. It still might be nice to compare, just to see what you get for 3X the price (my estimate considering all the extras you need to buy for the Buffalo such as casing, connectors, etc to make it the equiv of a Gamma2 build). 

 Since the Buffalo is only available as a completed/tested module, the Gamma2 is actually a more difficult build (although not as bad as some might think after studying up on SMD soldering).


----------



## amb

Quote:


  Originally Posted by *PJPro* /img/forum/go_quote.gif 
_And, is there a reason why the S11 isn't mentioned as a possible power supply for the G2? Overkill?_

 

γ2 taps its power from the γ1 board, so the power supply is sort of beyond the scope of the γ2 website. For the γ1, you could use USB power, or you could use an external regulated 5V DC wallwart. Of course that "wallwart" could instead be a 5V σ11, if you wish. Overkill? Not really, since a fully-populated γ1+γ2 combo would draw more current than a PPA (and a bit less than M³). If you want very clean DC power, then σ11 would serve it up just fine!


----------



## amb

I see that some people are confused about γ2 variations. There is no "full" vs. "lite" as far as the γ2 board itself goes. The only major option is whether to have upsampling or not (U4 and associated parts).

 All the γ1 board configs (except USB-to-S/PDIF (C)) will work with γ2 and _that_ basically determines what inputs and outputs you'd have. The only remaining question is whether to populate the WM8501 DAC and its surrounding parts on the γ1 for the front panel analog output. It only adds a few dollars to the cost but makes the unit more fun and flexible...


----------



## yzriver

For me, I like the gamma 2 integrating receiver and DAC in one board, but it would better to have seperated buffer stage or interconnection to outboard buffer.


----------



## amb

Quote:


  Originally Posted by *yzriver* /img/forum/go_quote.gif 
_For me, I like the gamma 2 integrating receiver and DAC in one board, but it would better to have seperated buffer stage or interconnection to outboard buffer._

 

lol, what was the first sentence on the γ2 website, under "Overview"?


----------



## yzriver

allright, how about make a gamma 3.


----------



## nightanole

You have no idea how happy i was when i looked back 6 months ago to a small email when i built my gamma lite...


 TPS2115APW power multiplexer 1 1.90 1.90



 Looks like im ready to go any time.


----------



## linuxworks

Quote:


  Originally Posted by *MrSlim* /img/forum/go_quote.gif 
_Since the Buffalo is only available as a completed/tested module, the Gamma2 is actually a more difficult build (although not as bad as some might think after studying up on SMD soldering)._

 

as we say in the computer business 'the whole BOARD is the FRU' (field replaceable unit). I didn't like that. I want to be able to get individual parts. the ESS chip is special sourced and regular mortals (lol) can't get them or get them easily.


----------



## MrSlim

I agree with you there Linuxworks.. The Buffalo is a different kind of DIY from the Gamma2. And the whole business of (un)availability of the ESS DAC is really a turnoff..


----------



## CodeToad

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_γ2 taps its power from the γ1 board, so the power supply is sort of beyond the scope of the γ2 website. For the γ1, you could use USB power, or you could use an external regulated 5V DC wallwart. Of course that "wallwart" could instead be a 5V σ11, if you wish. Overkill? Not really, since a fully-populated γ1+γ2 combo would draw more current than a PPA (and a bit less than M³). If you want very clean DC power, then σ11 would serve it up just fine! 
	

	
	
		
		

		
		
	


	


_

 

Would it be possible to run both an M3 and a Gamma2 from one S11? I ask because this is the path to uber-anal audiophile nirvana-dom-ness-osity. I already know my usb power sucks and a wallwart is an audiophile abomination.


----------



## linuxworks

m3 is 24v (and higher) single rail; the gamma2 is 5v single rail.

 how you gonna burn off the diff? pretty big diff, don't you think?


----------



## CodeToad

Just run it through a magic cable.


  Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_m3 is 24v (and higher) single rail; the gamma2 is 5v single rail.

 how you gonna burn off the diff? pretty big diff, don't you think?




_


----------



## linuxworks

Quote:


  Originally Posted by *CodeToad* /img/forum/go_quote.gif 
_ a wallwart is an audiophile abomination._

 

ac wallwarts are fine; they simply 'defer the problem' (lol) to a local ac-to-dc converter. that's fine.

 linear wallwarts are 2nd best. they can be fine, too.

 switching ones: those you want to avoid.


----------



## CodeToad

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_ac wallwarts are fine; they simply 'defer the problem' (lol) to a local ac-to-dc converter. that's fine.

 linear wallwarts are 2nd best. they can be fine, too.

 switching ones: those you want to avoid._

 

Ok cool. It's no secret I don't know nuthin'. 

 Speaking of magic cables I love my Gamma1 so much I splurged on a Cardas interconnect (it's short with both ends at right angles). I'm sorry to report I don't hear any difference over the 1 strand 100 guage POS cable that came with my FIIO amp.


----------



## tacitapproval

OPA2365 seems to be backordered for the next month or so at the usual sources. How much of a trade-off is it to use AD8656 as a line-level source?


----------



## amb

Quote:


  Originally Posted by *CodeToad* /img/forum/go_quote.gif 
_Would it be possible to run both an M3 and a Gamma2 from one S11?_

 

Aside from the voltage difference that Linuxworks mentioned, there is also the issue of real ground vs. virtual ground. When you connect a σ11 to a M³, the TLE2426 on the M³ splits it into a dual-rail supply and creates a virtual ground. When you connect the same σ11 to the γ1/γ2, the "ground" is actually M³'s negative rail. When you then connect the two together, you've created a short circuit and the result would be instant TLE2426-death.

 Keep the DAC and the amp separate, running on separate supplies, and it will save you from all these hassles.


----------



## amb

Quote:


  Originally Posted by *tacitapproval* /img/forum/go_quote.gif 
_OPA2365 seems to be backordered for the next month or so at the usual sources. How much of a trade-off is it to use AD8656 as a line-level source?_

 

IMHO not much tradeoff, both are excellent, with the slight nod going toward the OPA2365.

 At any rate, Allied seems to have OPA2365 in stock, but you have to buy in multiples of 5:
Texas Instruments - OPA2365AIDG4 - Allied Electronics


----------



## R4ABigman

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Aside from the voltage difference that Linuxworks mentioned, there is also the issue of real ground vs. virtual ground. When you connect a σ11 to a M³, the TLE2426 on the M³ splits it into a dual-rail supply and creates a virtual ground. When you connect the same σ11 to the γ1/γ2, the "ground" is actually M³'s negative rail. When you then connect the two together, you've created a short circuit and the result would be instant TLE2426-death.

 Keep the DAC and the amp separate, running on separate supplies, and it will save you from all these hassles._

 

I'm glad to see the y2 out -- once I've got my y1 working then I forsee some additional components on order!

 From the y1 thread (http://www.head-fi.org/forums/f6/y1-...ml#post6011452), would it not be possible to regulate the power for the y1/2 from the o11+m3 combo as such:






 I know everyone says its a bit of a faff and everything should be in separate boxes etc etc, but I'm really keen to get this working in a single box.

 Alternatively, I'm considering the idea of two transformers within the same box, one for the o11 and one + regulator for the y1/2. Just wondering how clean the power supply actually needs to be to get good performance (I understand there is some on-board regulation)?


----------



## TzeYang

what about 2x regulators?

 drop to 12V --> 5V.


----------



## Beefy

Quote:


  Originally Posted by *TzeYang* /img/forum/go_quote.gif 
_what about 2x regulators?

 drop to 12V --> 5V._

 

The first regulator would still be dropping 12V at up to 0.3A, for 3.6W. Not to mention the increased current output and thus heat production from the S11 for no particularly good reason.

 It would make much more sense to run a small 6-9VAC transformer and a Tread.


----------



## linuxworks

stepping back a bit; this is high end audio (pretty much). you WANT to have independant power supplies for 'important parts', so to speak. pushing the 'isolation' all the way back to the trafo level (ie, adding a separate trafo and regulator stage after that) would only help specs and improve the quality of the overall implementation.

 what this world needs is an easy source of multi-winding trafos 
	

	
	
		
		

		
		
	


	







 one big trafo with all our desired secondaries would solve SO much of the world's problems.

 ok, well, at least our audio power supply problems (lol).

 I just can't find good selections of anything over than dual 'same' windings on secondaries. I often need a 5v winding for digital things, a 10 or 12v winding for things and maybe a dual rail 12 or 15 for analog things. can't find such toroids very easily. so I end up with multiple smaller ones, which I admit is less elegant.


----------



## dumbears

I'm interested in making one for myself, however, I've a lot of questions to bother you guys. Thanks in advance for your patience and help.

 May I ask if the SQ of audio socket in gamma-1 is the same as that of the audio socket in gamma-2? The other question is whether it's possible to have one audio socket for amp and the other for headphones/earphones? If it's possible, which is which?

 Moreover, if I'm to use BG NX Hi-Q 47uF/6.3V, should I add 1uF film cap parallel to it? I personally prefer Roederstein, may I use KP1830 series for both the 100pF and 220pF caps?

 Thanks!


----------



## Beefy

You should price up some custom options. So long as it doesn't have a huge power rating, it might be cost effective. SumR would be a good place to start to ask for that sort of thing.


----------



## Beefy

Quote:


  Originally Posted by *dumbears* /img/forum/go_quote.gif 
_May I ask if the SQ of audio socket in gamma-1 is the same as that of the audio socket in gamma-2?_

 

If they were the same, then nobody would bother building the gamma2, would they?


----------



## Billyk

I am sure the output sockets on the y2 will be superior to the one on the y1. This is an upgrade after all.
  Quote:


 Both RCA phono jacks and 3.5mm stereo mini jacks are provided for the analog output. You may use either depending on which cables you have, or use both simultaneously to drive two amplifiers 
 

Powering headphones (low impedance) requires a specific op-amp, it is noted in the parts list.


----------



## MisterX

Quote:


 I personally prefer Roederstein, may I use KP1830 series for both the 100pF and 220pF caps? 
 

http://www.vishay.com/docs/26016/kp1830.pdf

 The dimensions for the 100pF and 220pF caps are listed in the datasheet linked above as: 
 5mm pitch. 4.5mm wide. 7.2mm long. 6mm tall. 

 From the Gamma 2 part list page:

  Quote:


 C15-C18 and C21-C24 are through-hole, radial-lead metallized polypropylene or polypropylene film capacitors for the analog low-pass filter. Their lead spacing is 5mm and the footprint should be no larger than 7.5mm x 4.5mm, with a maximum height of 6mm. 5% tolerance or better is recommended for accurate filter response.


----------



## linuxworks

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_If they were the same, then nobody would bother building the gamma2, would they? 
	

	
	
		
		

		
		
	


	


_

 

the BIGGEST thing about the y2 is the ASRC chip.

 that turns it into something entirely different, in terms of class.

 the new wolfson chip is also more 'tweaky' in that you can play with various filter settings (via a switch). I never bother, myself; as I can't hear any major diffs between them. they seem like splitting hairs, to me; but some people really like to experiment with tweaks like this.

 the asrc is the #1 reason to go with the y2, imo. its claimed to have a good effect on jitter. how can you NOT want that?


----------



## Cankin

Are there any differences (measurement or audit) between SRC4192 and AD1896?


----------



## jnewman

Quote:


  Originally Posted by *Cankin* /img/forum/go_quote.gif 
_Are there any differences (measurement or audit) between SRC4192 and AD1896?_

 

A quick perusal of the relevant datasheets shows that SRC4192 has significantly lower THD+N (total harmonic distortion plus noise), but both are so low I can't see it making much a difference. Depending on input and output frequencies, SRC4192 THD+N is at -141 to -137 dB and AD1896 THD+N is at -133 to -120 dB.


----------



## Beefy

Handy, because SRC4192 is just over half the price.....


----------



## MrSlim

Quote:


  Originally Posted by *dumbears* /img/forum/go_quote.gif 
_I'm interested in making one for myself, however, I've a lot of questions to bother you guys. Thanks in advance for your patience and help.

 May I ask if the SQ of audio socket in gamma-1 is the same as that of the audio socket in gamma-2? The other question is whether it's possible to have one audio socket for amp and the other for headphones/earphones? If it's possible, which is which?

 Moreover, if I'm to use BG NX Hi-Q 47uF/6.3V, should I add 1uF film cap parallel to it? I personally prefer Roederstein, may I use KP1830 series for both the 100pF and 220pF caps?

 Thanks!_

 

It is important to understand that the audio socket on the gamma-1 is the output of the WM8501 DAC, and the audio socket(s) on the Gamma-2 are the output of the WM8740/1/2(chose your poison, with the 8741 being the best, since it takes advantage of the ASRC chip, and the fancy filtering or the 8742, which is just a cost-reduced version of the 8741 with a slightly lower S/N ratio). 

 All things being equal, the 8741 output should have a noticeably better sound quality (otherwise the gamma-2 would be a waste of time/money) than the 8501 output. 

 That said, you can use both outputs simultaneously, one for Headphones and one for an amp. The question becomes: which output should have the better converter. I could say myself that my CTH/K601's are probably much better than any amp/speaker combo I have around the house, so I might choose the 8741 output for them.. Rather than making the choice, why not build an 1 into 2 output selector so that you can use the best output for both..


----------



## Beefy

I would have thought you would drive the headphones from the y2 because of its dedicated output stage, which specifically designed to run a decent amount of current.


----------



## m1abrams

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_I would have thought you would drive the headphones from the y2 because of its dedicated output stage, which specifically designed to run a decent amount of current._

 

Well you certainly can drive headphones from the y2 directly if you use the larger output caps. However keep in mind the output stage has a pretty limited voltage swing so that maybe an issue for some headphones.


----------



## oneplustwo

Hey folks,

 My gamma 2 seems to have developed an issue. I can still get a lock on USB and optical but don't get any sound out of the gamma 2 headphone jack. I still get sound out of the gamma 1 jack though.

 Thoughts?


----------



## m1abrams

Quote:


  Originally Posted by *oneplustwo* /img/forum/go_quote.gif 
_Hey folks,

 My gamma 2 seems to have developed an issue. I can still get a lock on USB and optical but don't get any sound out of the gamma 2 headphone jack. I still get sound out of the gamma 1 jack though.

 Thoughts?_

 

Well I had the same symptoms on mine when I first built it and it was a bad solder joint on the SMB crystal on the y2 board.


----------



## MrSlim

Check the ASRC joints too.. I had the same problem and I re-flowed both the crystal and the ASRC pins..


----------



## fault151

very excited about the y2 upgrade, can't wait to build this.


----------



## rds

It seems that all the parts for the complete y1 and y2 builds can be ordered from Mouser and AMB Parts Shop combined.

 Has anyone posted importable Mouser BOMs for the complete y1 and y2 builds? It would be really handy for many of us, and it does seem kind of inefficient for each builder to copy and paste all the part numbers over to Mouser.


----------



## Billyk

I'll put mine up, I need to through them to make sure I did not add or subtract anything. I got the y1 from MisterX but I know I have modified them.
Gamma 1
Gamma 2
 Please save these for yourselves and TRIPLE check them.
 Forgot to mention, I got the case from Newark, cost $11.10 $17.44 with tax and shipping


----------



## grcassidy

Thanks Billyk, you've saved my brain a whole heap of hurt.


----------



## rds

Quote:


  Originally Posted by *grcassidy* /img/forum/go_quote.gif 
_Thanks Billyk, you've saved my brain a whole heap of hurt.
	

	
	
		
		

		
		
	


	


_

 

x2 
	

	
	
		
		

		
		
	


	




 I've been ordering way too many parts lately. I just can't deal with the copy and pasting right now


----------



## Nebby

Well I saw his post after I copy and pasted all of the gamma1's parts...thanks for saving me from copy and pasting all of the gamma2 parts


----------



## MisterX

Nice try but....

 A few comments about the link to the saved project at Mouser that was posted above: 

 You do not need a dual row 4 position pin header when U4 is populated. 
 You do not need U6 when either the WM8741 or WM8742 DAC chips are used. 
 You need more then 8 positions for the female pin headers when connecting a Gamma 1 full or Gamma 1 Plus version to the Gamma 2 and little birdie suggested you may be better not ordering them from Mouser. 
	

	
	
		
		

		
		
	


	



 The specified part number for the .1uF ceramic caps is: 80-C320C104K5R. 
 Why pay 10 cents extra per part for tape and reel packaged parts when you have to mess with them instead of plugging them right into the board? 
 The specified part number for the .01uF ceramic caps is 80-C315C103K5R. 
 The price is the same this time but the rest of the question remains? 
 (not like the $ total of those parts is a major problem but you may wish to consider revising your project)


----------



## grenert

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_I just can't find good selections of anything over than dual 'same' windings on secondaries. I often need a 5v winding for digital things, a 10 or 12v winding for things and maybe a dual rail 12 or 15 for analog things. can't find such toroids very easily. so I end up with multiple smaller ones, which I admit is less elegant._

 

Here's a link to some pretty versatile off-the-shelf trannies:
Mci Transformer Corporation

 They'll do either 5V and dual 12V, or 5V and dual 15V. Note that these are EI, rather than toroid, but the split bobbin design means less mains noise will make it into your supply.


----------



## Billyk

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Nice try but....

 A few comments about the link to the saved project at Mouser that was posted above: 

 You do not need a dual row 4 position pin header when U4 is populated. 
 You do not need U6 when either the WM8741 or WM8742 DAC chips are used. 
 You need more then 8 positions for the female pin headers when connecting a Gamma 1 full or Gamma 1 Plus version to the Gamma 2 and little birdie suggested you may be better not ordering them from Mouser. 
	

	
	
		
		

		
			




 The specified part number for the .1uF ceramic caps is: 80-C320C104K5R. 
 Why pay 10 cents extra per part for tape and reel packaged parts when you have to mess with them instead of plugging them right into the board? 
 The specified part number for the .01uF ceramic caps is 80-C315C103K5R. 
 The price is the same this time but the rest of the question remains? 
 (not like the $ total of those parts is a major problem but you may wish to consider revising your project)_

 

Thanks for the input.
 Please note I did say they needed to be checked and folks needed to triple check. I posted them as a convenience. 
 I had to go back to the office last night and did not have the time to double check them until this morning....
 Whatever


----------



## LingLing1337

So, I haven't read through this whole thread yet (getting to it), but would one be able to mate an already-populated y1 "Full" to a y2?


----------



## m1abrams

Quote:


  Originally Posted by *LingLing1337* /img/forum/go_quote.gif 
_So, I haven't read through this whole thread yet (getting to it), but would one be able to mate an already-populated y1 "Full" to a y2?_

 

Yes however if you split the PCB of the y1 you will need to come up with some way to physically secure the two y1 boards. You will need to add a header pin to the y1 which should be easy. Depending on how you jumpered some of the pads you may have to redo those for clearance issues however that may have only been for the prototype boards not sure if it is still required for y2.

 But with little effort you should be able to make your y1 work.

 Edit: Check AMB's gamma2 website he has a whole writeup on upgrading a y1 
	

	
	
		
		

		
		
	


	


http://www.amb.org/audio/gamma2/


----------



## LingLing1337

Thanks for the link, comrade.


----------



## amb

γ2 production boards and front/rear panels are here!


----------



## funch

Hot dang! 

 Ah dun ordurd mine. How 'bout ch'all?


----------



## digger945

Quote:


  Originally Posted by *funch* /img/forum/go_quote.gif 
_ How 'bout ch'all?_

 

Yep, you betcha.
 What a steal.
 The more I listen to the y2, the more I like it.
 Many thanks to Marshall and Ti.


----------



## LingLing1337

Bah, the more I read about the y2, the more I look at my TC7520 in contempt. Thanks to AMB labs for making all of this incredible DIY kit available.


----------



## nightanole

Im $33 poorer now...

 I hope this $15 dac sounds better then my $2.50 dac...


 Now i guess i should jb weld my gamma lite back together...

 While down here, what do i need to order to pop in a digital in for my gamma lite?


----------



## jnewman

I built one of the prototype boards and I'm going to build one or two of the production version, too. (One for home computer, one for PS3, one for work...) It's a seriously nice DAC.


----------



## sochee

There wouldn't be any problem with saaay, sticking 2 x RCA outputs in there and putting a rotary switch in between them, would there? I'm looking to build a y1 with SPDIF in only, and then stick a y2 on top of it with 2 x RCA outputs that I can choose between..


----------



## amb




----------



## amb

Quote:


  Originally Posted by *nightanole* 
_While down here, what do i need to order to pop in a digital in for my gamma lite?_

 

You'd need to convert your γ1 from a Lite config to a Full config. The γ1 website has all that you need to know.

  Quote:


  Originally Posted by *sochee* 
_There wouldn't be any problem with saaay, sticking 2 x RCA outputs in there and putting a rotary switch in between them, would there? I'm looking to build a y1 with SPDIF in only, and then stick a y2 on top of it with 2 x RCA outputs that I can choose between.._

 

No problem with that in concept, but there is no room in the default case for such a thing.


----------



## sergery

Anyone wanna split a Farnell order? Tryin' to meet the 20£ minimum, all I need is U7 and X1 (OPA2365AID opamp and EuroQuartz or Aker oscillator). seems Farnell is indeed - as Ti suggests, one of the only distribution options for the nicer Euroquartz and Aker crystal's. Opamp shortage at mouser too, if you haven't noticed

 I am only at 6.51!

 C'mon I know somone else needs an oscillator!!


----------



## dean0

just ordered, pcb and faceplates


----------



## grego9198

Ordered the y1 & y2 pcbs (along with a mini3). I'm excited to build this, but still need to source an AD8656ARZ opamp for th y2 since mouser was out of stock until October 19th. Hopefully one of these electronic suppliers near my work will have one.

 This will be my first amp build. I've been soldering for a few years though so I don't think it should be very difficult and it gives me a reason to upgrade some of my equipment.


----------



## Nebby

Ordered the boards and a few other parts from amb 
	

	
	
		
		

		
		
	


	




 My Box enclosure came in today, I'm a bit surprised how sturdy the little case is! It's rather rigid for it's size.


----------



## nightanole

Im starting my BOM and are confused. What do C11, C13 and there bypass caps c12, c14 do and why do they need to be audio quality? They are also not mentioned in the build up when it comes to parts selection. I have 2 black gates for the outputs c20 and c26 but i would need one more to pop them in the c11,c13 slots.


----------



## MisterX

<deleted the redundant part now that parts list page has been updated>

 C11, C12, C13 and C14 are described in the WM8740 datasheet as "reference de-coupling capacitors for VMIDR and VMIDL"

 "Audio grade" caps are suggested because many people (myself included) feel they effect the sound of the DAC just as much as the output capacitors do. 


 And...

 If I have 2 of something I would need 2 more to have 4.


----------



## rds

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Nice try but....

 A few comments about the link to the saved project at Mouser that was posted above: 

 You do not need a dual row 4 position pin header when U4 is populated. 
 You do not need U6 when either the WM8741 or WM8742 DAC chips are used. 
 You need more then 8 positions for the female pin headers when connecting a Gamma 1 full or Gamma 1 Plus version to the Gamma 2 and little birdie suggested you may be better not ordering them from Mouser. 
	

	
	
		
		

		
		
	


	



 The specified part number for the .1uF ceramic caps is: 80-C320C104K5R. 
 Why pay 10 cents extra per part for tape and reel packaged parts when you have to mess with them instead of plugging them right into the board? 
 The specified part number for the .01uF ceramic caps is 80-C315C103K5R. 
 The price is the same this time but the rest of the question remains? 
 (not like the $ total of those parts is a major problem but you may wish to consider revising your project)_

 

If you want to post your own y1 and y2 projects I won't stop you


----------



## amb

I updated the y2 website to improve the C11, C13, C20 and C26 descriptions. Thanks for the head-up.


----------



## CodeToad

From the Gamma2 site:

 "U7 should be either a OPA2365AID or AD8656ARZ. These two were chosen for their stringent rail-to-rail swing characteristics, low-noise, low distortion and high CMRR performance. Do not substitute with other opamps. OPA2365 is recommended for line-level use while AD8656 is recommended if you plan to drive headphones directly. "

 I'm not entirely clear about the outputs.

 1. The jack on the y1 board is the one on the front panel and it only runs from the y1 boards dac and not the y2?

 2. The jack in between the rca's on the back panel comes from the y2?

 3. If I run the AD8656 on the back panel jack from the y2 can I still use it at line level to a HP amp?


----------



## MisterX

1. Yes. 
 2. Yes. 
 3. Yes.


----------



## CodeToad

Are the rca's affected by the opamp or only the mini jack?


----------



## MisterX

The audio output jacks on the Gamma 2 board are connected in parallel.


----------



## fordgtlover

Quote:


  Originally Posted by *nightanole* /img/forum/go_quote.gif 
_Im starting my BOM and are confused. What do C11, C13 and there bypass caps c12, c14 do and why do they need to be audio quality? They are also not mentioned in the build up when it comes to parts selection. I have 2 black gates for the outputs c20 and c26 but i would need one more to pop them in the c11,c13 slots._

 


 I used Panasonic FMs for C20 & C26 and Silmics for C11 & C13. 

 I'm very happy with the sound.


----------



## nightanole

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_<deleted the redundant part now that parts list page has been updated>

 C11, C12, C13 and C14 are described in the WM8740 datasheet as "reference de-coupling capacitors for VMIDR and VMIDL"

 "Audio grade" caps are suggested because many people (myself included) feel they effect the sound of the DAC just as much as the output capacitors do. 


 And...

 If I have 2 of something I would need 2 more to have 4. 
	

	
	
		
		

		
		
	


	


_

 

I have 3 thanks to a generous donation from you
	

	
	
		
		

		
		
	


	



 I just havent used them yet.


----------



## Mr.Duck

Trying to understand the output filter design. I know it is a low pass filter to loose the high frequency junk from the DAC outputs. But why fc = 100 KHz? Why not 40 KHz for example? I realize to have a corner freq at 20 KHz would be too low because it will be at -3dB.

 Is the filter a 2nd order one? 12dB / octave?

 Oversampling pushes the high freq junk to very high freq range, yes? Do you know what kind of frequency the audio junk will be at for the gamma2? How much will be getting through the filter? For example, the audio junk could be at -80dB, -90dB, etc.

 How does the digital filter fit in to all of this? Or is it not really related to the analog filter?


 Think that is all. I've been playing with FilterLab and have a rough idea in my head for my own output filter for the gamma2 (not better, just different).


----------



## dumbears

About the audio grade caps, shouldn't we pick non-polar/bi-polar caps than polarized caps?


----------



## nightanole

So would it sound odd to use my black gates in C11 & C13 and use only poly film caps for the output caps? I wanted to try that this time but the C11 & C13 caps threw me off.


 As for the polar output caps. The caps are just there to get rid of the dc off set, every dac ive seen uses polar caps. Your free to use non polar ones if you wish.


----------



## fillemon

congratz AMB and mister X for the fine product. 

 i got two simple questions

 1)i have a gamma 1 on usb, but does anyone know how i can have a smooth playback while typing (i don't use usb keyboard). the sound has hickups while typing. 

 2)does anyone know how much the gamma 2 costs (full blown) in parts ? 

 thanks, looking forward to build one. 
 (or buy one from mister X, if i can't find time enough)
 greetz


----------



## Billyk

I was having an issue with the USB and ASIO4all. I found increasing the buffer size took care of my issues.


----------



## MisterX

Quote:


 2)does anyone know how much the gamma 2 costs (full blown) in parts ? 
 

The parts cost is roughly $230 not including tax and shipping from Mouser, Digi-key or Allied.

 The parts cost drops to roughly $190 if you eliminate the USB to S/PDIF outputs, the filter select switch, the anti clipping switch and the Gamma 1 DAC section. 
 The caveat is you will have to design your own custom panels or make them by hand (which is a major PITA but would save you another $45 to $50).


----------



## nightanole

I can beleive it. Figure $25-30 from amb, $100 mouser, $30 case. Then its end panels, and thats if you want to make a lite one. Now if you all ready have a gamma 1....


----------



## Wizik

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_The parts cost is roughly $230 not including tax and shipping from Mouser, Digi-key or Allied.

 The parts cost drops to roughly $190 if you eliminate the USB to S/PDIF outputs, the filter select switch, the anti clipping switch and the Gamma 1 DAC section. 
 The caveat is you will have to design your own custom panels or make them by hand (which is a major PITA but would save you another $45 to $50)._

 

That $230 is including full++ y1 parts and all y2 parts ?


----------



## nightanole

yes


 Ill just leave this here


http://www.drillspot.com/products/35...80BK_Enclosure




MOUSER bom

 I went with muses and didn't splurge the 8 bucks to upgrade 14 resistors...


----------



## grenert

Quote:


  Originally Posted by *nightanole* /img/forum/go_quote.gif 
_Ill just leave this here

Box Enclosures B2-080BK Enclosure_

 

Nice deal on the enclosure! Thanks for the link.


----------



## CodeToad

So using usb as input the y2 board doesn't get used at all and the output is the front panel jack?

 In order for the y2 to kick in you must use either coaxial or optical and the analog outputs are either the mini or RCA jacks on back panel?


----------



## Lifthanger

the gamma2 can use all three input options. 
 maybe both the rca and mini can be used when driving high impedance loads.
 but that's a thing I'd like to know myself, for other projects.


----------



## m1abrams

Quote:


  Originally Posted by *CodeToad* /img/forum/go_quote.gif 
_So using usb as input the y2 board doesn't get used at all and the output is the front panel jack?

 In order for the y2 to kick in you must use either coaxial or optical and the analog outputs are either the mini or RCA jacks on back panel?_

 

No


----------



## Billyk

From the circuit description on page one of this thread:

  Quote:


 γ2 leverages γ1's USB and S/PDIF receiver sections and taps the I²S datastream. Then, an (optional, jumper bypass-able) SRC4192 or AD1892 ASRC chip upsamples to 96KHz. The resultant data stream is then sent to the top-of-the-line Wolfson WM8741 or WM8742 DAC chip (WM8740 also supported).


----------



## CodeToad

Quote:


  Originally Posted by *Billyk* /img/forum/go_quote.gif 
_From the circuit description on page one of this thread:

 Quote:
 γ2 leverages γ1's USB and S/PDIF receiver sections and taps the I²S datastream. Then, an (optional, jumper bypass-able) SRC4192 or AD1892 ASRC chip upsamples to 96KHz. The resultant data stream is then sent to the top-of-the-line Wolfson WM8741 or WM8742 DAC chip (WM8740 also supported). 
_

 

OK. I really want to get this straight in my head.

 I can use usb input and it gets the full monty from the y2? But only from the rear jacks?

 The front mini jack is only output from the y1?


----------



## m1abrams

Quote:


  Originally Posted by *CodeToad* /img/forum/go_quote.gif 
_OK. I really want to get this straight in my head.

 I can use usb input and it gets the full monty from the y2? But only from the rear jacks?

 The front mini jack is only output from the y1?_

 

ALL inputs feed both DACs, the y2 "full" has 2 DACs. 1 from the y1 and one from the y2. The front jack is connected to the y1 DAC and the rear jacks to the y2.


----------



## CodeToad

Ok. I know I asked the same question yesterday but something I read threw me off today.

 Pretty much I gather that all the inputs (including usb) are upsampled the same in the y2 and output through the rear panel jacks. The front panel mini jack is really just a y1 usb "lite" like I have now.....so I can do without that front panel jack as well as those spdif outputs and clean the front panel up real nice.

 So I guess the question is what parts can I leave out of the full build to eliminate the front mini jack and the spdif outputs and their functionality? All I want is the full y2 upsampling output from all the inputs (tos, coax, usb).


----------



## fordgtlover

So, to clarify, you don't want Y1 DAC output at all?

 If that's so, you could leave out everything from R7D through to J3D and everything in the 'optional' area on the Y1 schematic, and 
 by the look of it U9D. And finally U6D and associated parts; the WM8501 appears to be the only thing using 4.5v.

 This would leave you with only the Y1 inputs and the Y2 outputs.

 You would want Mister X or AMB to confirm this though.

 And, if you only want USB power you could also remove everything from J1D to U1D inclusive.

 EDIT: Removed reference to U4D


----------



## ShinyFalcon

Just a warning for those who uses Mouser's project functionality... If you put y1 and y2 parts in separate projects, note that if they share components, like

  Code:


```
[left]270-47K-RC 11 (MISSING 2)P47.0KCACT-ND 80-C320C104K5R 22 (MISSING 9)399-4264-ND 80-C315C103K5R 10 (MISSING 2)399-4148-ND 661-PSA10VB47M 5 (MISSING 2)565-3051-ND 647-UKW1H220MDD (MISSING 7) 604-1051-ND 579-MCP101-300DI/TO (MISSING 1)MCP101-315DI/TO-ND 595-TPS793475DBVR 2 (MISSING 1)LP2985AIM5-4.5CT-ND[/left]
```

those particular parts will not be additive when you add both projects to your shopping cart. In my case, I added y2, then y1, and ended up missing parts above for y2.

 Now, what's the internal height on the Box Enclosure case? Will an RK27 fit in there?


----------



## JamesL

datasheet

 You don't need the datasheet to know that it won't fit in the default chassis with the dac.
 It won't fit in a extended chassis either...


----------



## MisterX

Here is the other datasheet----> 

http://www.alps.com/products/WebObje...K271/RK271.PDF

 a 27mm pot will not fit in a 26mm space.


----------



## jtostenr

Quote:


  Originally Posted by *oneplustwo* /img/forum/go_quote.gif 
_Anyone try using balanced output?_

 

I really wish this had balanced outputs....what would be the easiest way to add these? I know it's tight on space...

 Jeff


----------



## MisterX

Quote:


 what would be the easiest way to add these? 
 

Dual panel mount mini-jacks instead of RCA jacks? 
 Sounds kinda silly at first but mini to XLR adapters are pretty common. 


 And just in case anybody is wondering.... you can just pull the "pin" out of the 3 pin receptacles amb is offering in his shop and trim the extra plastic off with an X-acto knife, which I find is a little easier then breaking the strips from Mouser apart.


----------



## amb

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_And just in case anybody is wondering.... you can just pull the "pin" out of the 3 pin receptacles amb is offering in his shop and trim the extra plastic off with an X-acto knife, which I find is a little easier then breaking the strips from Mouser apart. 
	

	
	
		
		

		
		
	


	


_

 

In case anyone is confused, MisterX is referring to modifying the 3P receptacle to make it 2P (for use as J3), needed when the matching γ1 is a Full (A), S/PDIF only (E) or Full++(F) configuration.


----------



## amb

Quote:


  Originally Posted by *fordgtlover* /img/forum/go_quote.gif 
_So, to clarify, you don't want Y1 DAC output at all?

 If that's so, you could leave out everything from R7D through to J3D and everything in the 'optional' area on the Y1 schematic, and 
 by the look of it U4D and U9D. And finally U6D and associated parts; the WM8501 appears to be the only thing using 4.5v.

 This would leave you with only the Y1 inputs and the Y2 outputs._

 

You still need U4D because U2D (CS8416) needs it.


----------



## fordgtlover

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_You still need U4D because U2D (CS8416) needs it._

 

I see it now. Thanks. I've corrected my previous post.


----------



## tacitapproval

I got my board and parts yesterday to upgrade my y1 to y2. Unfortunately, it's not working on my first go round. The first problem I can report is that I am getting 4.72v at both the 5v and the 4.5v test points. I do get 3.27v at the 3.3v point, which I believe is ok. 

 I have reflowed all the joints that looked in anyway dodgy. I am concerned that I fried the arsc, as I was a little careless when I first tried to solder it and I needed to desolder a few pins and start again. The dac chip went a bit smoother.

 This is a full (not ++ and known working) y1 to upsampling (hopefully) y2. 

 Anything jump out from this?


----------



## amb

tacitapproval, if you're using USB power, it's possible that the computer's USB power voltage is a bit low. This is what you're measuring at the 5V test points. If you're using the TPS793475DBVR regulator for the 4.5 rail, then it has dropped out of regulation.

 Have you tried simply to connect it and see if it makes music?


----------



## Beefy

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_tacitapproval, if you're using USB power, it's possible that the computer's USB power voltage is a bit low. This is what you're measuring at the 5V test points. If you're using the TPS793475DBVR regulator for the 4.5 rail, then it has dropped out of regulation._

 

This seems to be coming up as a common problem. Would you be inclined to recommend people use the 4.5V regulators rather than the 4.75V options if they can?


----------



## tacitapproval

I am using TPS793475DBVR. I am a little confused when you say it has dropped out of regulation. I thought it is supposed to to put out 4.75 (in this 4.72)v? 

 I measured my usb output, and it is indeed low at 4.80v. 

 No, no music, unfortunately.


----------



## nightanole

Quote:


  Originally Posted by *tacitapproval* /img/forum/go_quote.gif 
_I am using TPS793475DBVR. I am a little confused when you say it has dropped out of regulation. I thought it is supposed to to put out 4.75 (in this 4.72)v? 

 I measured my usb output, and it is indeed low at 4.80v. 

 No, no music, unfortunately._

 

Mr 4.75v regulator cann't regulate with just 4.8v in. It needs 5v in to start regulating. Just like if you had a 12v regulator, it wont start regulating till you put 14v on it. What people are saying is swap out the 4.75v regulator for the 4.5v regulator. It will regulate at 4.8v in.

 Pc usb voltages are 4.75-5.1v on average.


----------



## linuxworks

also the pc usb voltage CAN vary if you have a somewhat long/thin usb cable. also if you are running off a usb hub that is not locally powered.

 try using a direct motherboard connection and not a hub (for those that are seeing regulation issues). also try using a better cable (its only a matter of VERY cheap vs acceptable cables; nothing more than that).

 a to-spec usb2.0 cable that is about 2' long seems to work fine for me. once I extend it or 'hub it' I see lower voltage, in general, from that usb port.

 perhaps 4.5 is a good idea instead of 4.75.


----------



## Beefy

Quote:


  Originally Posted by *nightanole* /img/forum/go_quote.gif 
_Mr 4.75v regulator cann't regulate with just 4.8v in. It needs 5v in to start regulating. Just like if you had a 12v regulator, it wont start regulating till you put 14v on it. What people are saying is swap out the 4.75v regulator for the 4.5v regulator. It will regulate at 4.8v in.

 Pc usb voltages are 4.75-5.1v on average._

 

Indeed. I'm not 100% sure I am reading it right, but Mr Datasheet says your dropout voltage might be as high as 125mV at 200mA. So if your USB is less than 4.875 you might hit trouble.


----------



## tacitapproval

Thanks all for the clarification. It makes sense. I will see if I can find another actual 5v source and retest.


----------



## jtostenr

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Dual panel mount mini-jacks instead of RCA jacks? 
 Sounds kinda silly at first but mini to XLR adapters are pretty common. _

 

Never thought about doing that....do you think there would be space in the standard enclosure?

 I think I may have to build one of these before I get back to the B22 
	

	
	
		
		

		
			





 Thanks,
 Jeff


----------



## MisterX

It looks like cylindrical style mini jacks (digikey # CP-43502PM-ND as an example) would fit in the default enclosure but I dunno if you would be able to fit an air-wired passive balanced output stage in there as well.


----------



## grego9198

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Just a warning for those who uses Mouser's project functionality... If you put y1 and y2 parts in separate projects, note that if they share components, like

 those particular parts will not be additive when you add both projects to your shopping cart. In my case, I added y2, then y1, and ended up missing parts above for y2._

 

Same thing happened to me, I didn't notice the error until I received my parts yesterday. I gave their customer service a call an hour ago and had them ship out the missing products while waiving the shipping fee. They said it would be here tomorrow (gotta love their quick shipping).

 Still waiting on Canadian customs to release my amb.org package. Once that arrives I'm good to go. Looks like it'll be a weekend project for me. The only part I couldn't find online was the mini-B usb jack. I picked up another one that I thought would work, but turns out it doesn't have through hole connections, but rather surface mount legs. Not sure whether I can make it work?


----------



## ShinyFalcon

It probably will, but if you subject it to a lot of connections/disconnections it'll wear out fast. Maybe hardwiring your USB cable is an option.

 Mouser has the USB mini-B connectors back in stock now.


----------



## jtostenr

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_It looks like cylindrical style mini jacks (digikey # CP-43502PM-ND as an example) would fit in the default enclosure but I dunno if you would be able to fit an air-wired passive balanced output stage in there as well._

 

Couldn't you just take the balanced outputs right off the DAC? Or would there not be enough gain, or high output impedance, or something else?

 I assume you wouldn't need a balanced/se switch if you only have one set of outputs connected at a time.

 Jeff


----------



## Beefy

Quote:


  Originally Posted by *jtostenr* /img/forum/go_quote.gif 
_Couldn't you just take the balanced outputs right off the DAC? Or would there not be enough gain, or high output impedance, or something else?

 I assume you wouldn't need a balanced/se switch if you only have one set of outputs connected at a time._

 

Honestly, if you or anyone else wants balanced outputs, then build a DAC that was designed specifically with balanced outputs in mind. Trying to draw balanced outputs from the y2 just doesn't make sense considering its design goals and physical footprint.


----------



## jtostenr

Actually, the gamma-2 meets all of my basic requirements:

 - good DAC chip
 - relatively inexpensive
 - small
 - balanced outputs (right off DAC chip)

 All I'm looking for is something that I can use to drive the balanced inputs on my B22 once it is finished. My next project will be either a Buffalo DAC or hopefully a new DAC designed by AMB to complement the B22 (hint, hint 
	

	
	
		
		

		
		
	


	




). Once that is done, I'd like to be able to use this as my portable DAC.

 If all I have to do is add a couple of jacks to give me balanced outs then I think this is the perfect DAC for my needs. The only issue I see is if I need an output stage or buffer or something, then I may be SOL.

 Jeff


----------



## linuxworks

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_Honestly, if you or anyone else wants balanced outputs, then build a DAC that was designed specifically with balanced outputs in mind._

 

or, use the SSM2142 or THAT1646. those do a good job of converting SE to balanced; and pro audio guys use these quite often.

 nothing 'wrong' with good SE/B conversion on a single chip. or 2 chips, as the dip8 is only single channel. and I think you do want to have a buffer BEFORE the SSM chips; but its also possible the dac chip can be buffer enough to 'boot' the SSM chips into operation


----------



## jtostenr

But the WM8742 already has balanced outputs, so there would be no need for the SE/B converter. I just wonder if the balanced outputs right off the dac chip would be appropriate to drive a preamp/amp with.

 Jeff


----------



## m1abrams

Quote:


  Originally Posted by *jtostenr* /img/forum/go_quote.gif 
_But the WM8742 already has balanced outputs, so there would be no need for the SE/B converter. I just wonder if the balanced outputs right off the dac chip would be appropriate to drive a preamp/amp with.

 Jeff_

 

See AMB post on this in this thread 
	

	
	
		
		

		
		
	


	


http://www.head-fi.org/forums/f6/gam...3/#post5785408


----------



## jtostenr

Ahh there it is...thanks m1abrams. I read through this thread a couple months ago and thought I had seen something on this subject.

 Thanks for everyone's input, now I'll just have to see if I can find the time and $$$ to start working on this.

 Jeff


----------



## Beefy

Quote:


  Originally Posted by *jtostenr* /img/forum/go_quote.gif 
_Actually, the gamma-2 meets all of my basic requirements:

 - good DAC chip
 - relatively inexpensive
 - small
 - balanced outputs (right off DAC chip)_

 

Yes, but even though the DAC chip itself is balanced, the doesn't offer balanced outputs. You still need balanced filtering, buffering and line driving, and the y2 just isn't set up for that.

  Quote:


  Originally Posted by *jtostenr* /img/forum/go_quote.gif 
_Ahh there it is...thanks m1abrams. I read through this thread a couple months ago and thought I had seen something on this subject._

 

I don't see that it helps, for the reasons I said above. If you want balanced outputs, I earnestly believe you would be better served waiting for a DAC specifically designed with balanced outputs in mind.


----------



## amb

tacitapproval, even if your 4.5V rail measures a tid bit low it should still work. There is still another problem that you need to fix. First of all, make sure you're starting with a known, working γ1. (What configuration is it?) And then make sure γ2's J3 is (or is not) installed to match. Is there a solder joint problem? As I said before, 90%+ of the time, problems with γ1/γ2 are related to bad solder joints.


----------



## jtostenr

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_Yes, but even though the DAC chip itself is balanced, the doesn't offer balanced outputs. You still need balanced filtering, buffering and line driving, and the y2 just isn't set up for that._

 

Yes, that was my question, are all those things you mentioned necessary in this application. I think it was answered adequately with AMB's post.

  Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_I don't see that it helps, for the reasons I said above. If you want balanced outputs, I earnestly believe you would be better served waiting for a DAC specifically designed with balanced outputs in mind._

 

I see your point, but this is just a temporary solution, so I'm not too worried about it. Just as long as I'm not going to blow anything up 
	

	
	
		
		

		
		
	


	




 I assure you, when I go to build a dac for the long-term it will be something like the Buffalo.

 Jeff


----------



## Beefy

Quote:


  Originally Posted by *jtostenr* /img/forum/go_quote.gif 
_I see your point, but this is just a temporary solution, so I'm not too worried about it. Just as long as I'm not going to blow anything up 
	

	
	
		
		

		
			



_

 

Cool bananas


----------



## Nebby

Got my stuff today from AMB; great shipping/packaging as usual Ti


----------



## nightanole

why are people getting missing items with their mouser orders when combining projects? When i add several projects it just says they are combining lines, not ordering only some from one project.


----------



## tacitapproval

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_tacitapproval, even if your 4.5V rail measures a tid bit low it should still work. There is still another problem that you need to fix. First of all, make sure you're starting with a known, working γ1. (What configuration is it?) And then make sure γ2's J3 is (or is not) installed to match. Is there a solder joint problem? As I said before, 90%+ of the time, problems with γ1/γ2 are related to bad solder joints._

 

The regulator problem is solved. This was a bad joint and the 4.8v measurement from my usb was wrong--it was being pulled down. It is actually around 4.95v. 

 I'm still not getting music though. 

 The y1(full) definitely works, I've been using it for months. I have the J3 DI going to JP1D on the y1 (although, I had to use a SIP and a clipped lead, because I missed the dual receiver on my order). I have been over the joints pretty carefully. 

 As I said, I am worried I fried the src4192, as the install of that chip did not go smoothly. Is there any way of checking this specifically?


----------



## bada bing

My γ2 board arrived yesterday and I stuffed the board last night. About 2 hours work with very little head scratchin. The music came right out when I plugged in the γ1++ built a few weeks ago in anticipation of the board release. The γ series deserves to be the biggest collaborative success yet. I've built 3 γ1 and now a γ2 without a single hitch. I'm pretty sure I'll end up stuffing a few more γ1~2 combos after this is heard by my friends. Thanks a bunch AMB & MrX for the work so far and now get to cracking on the γ3 (just kidding....or not 
	

	
	
		
		

		
		
	


	




 )

 Early impressions: Definitely a step up from the γ1, which was already a stellar performer. I'm a fan of wolfson DAC chips and the γ2 seems a pretty polished implementation of the current flagship. It has the slightly euphoric sound signature shared by other wolfson powered DACs I've spent time with. Without getting into premature γ2 comparisons, my preference between Opus and Buffalo DACs has always been slightly towards the Opus (wolfson) sound. So far, I'm not hearing anything in the γ2 that is giving anything away to my favorite Opus. 

 Thanks again for another homerun project.


----------



## amb

Quote:


  Originally Posted by *tacitapproval* /img/forum/go_quote.gif 
_As I said, I am worried I fried the src4192, as the install of that chip did not go smoothly. Is there any way of checking this specifically?_

 

Only way I could think of is to scope the output I2S bus to see if it looks reasonable. That, of course, requires that you have a scope and know what to look for.

  Quote:


 The y1(full) definitely works, I've been using it for months. 
 

OK, so it should still be working with the y2 mated, so do you now get sound from the front panel 3.5mm jack? This would at least isolate the problem to the board.


----------



## tacitapproval

No, no scope or know how.

 Yes, I get sound out of the y1 with the boards mated. The y2 yields only noise.


----------



## amb

Last check before you should attempt to replace anything, are all chips soldered in the proper orientation?


----------



## tacitapproval

Check on proper orientation.


----------



## tacitapproval

I need to amend my earlier statement that I get music out of the y1 when mated to the y2. I get some music followed by some terrible noise, then music again and so on. This does not happen when I re-mate the two y1 boards together.


----------



## amb

Are the pin and sockets between the y1/y2 boards making good, reliable contact? You can check their continuity with your DMM in ohms mode (while powered off, of course).
 If so, then maybe your ASRC chip really did get damaged and is somehow affecting the I2S bus.


----------



## tacitapproval

Continuity between the mating pins checks out okay. I guess I will have to try a new ARSC. I am a little concerned about the pads for the chip making it through the replacement. I guess I will try to work as slowly and carefully as I can.


----------



## grego9198

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Mouser has the USB mini-B connectors back in stock now. 
	

	
	
		
		

		
		
	


	


_

 

I managed to contact mouser before they shipped out my package to add 2 of the USB connectors. I believe I only need one for between the y1 & y2 boards, so if you need one I can mail it off to you when I receive it.

  Quote:


 why are people getting missing items with their mouser orders when combining projects? When i add several projects it just says they are combining lines, not ordering only some from one project. 
 

The window would pop up telling me that it was adding the lines, but it never actually did. I used both IE8 and Safari but both had the same problem. I would just double check the whole order before submitting it.


----------



## hansel_ng

Hello,

 Am I correct to say that analog output 1 was retained by the designers because the y2 is an upgrade from the y1, and that in all situations analog output 2 will be the superior?

 Will you lose anything if you leave out analog output 1 (itself excepting)? 

 If so, will there be any chance that the quoted configuration can be added to the amb.org website for those who are building the y2 from scratch and so might want to leave this out to save some money? 

 thanks

  Quote:


  Originally Posted by *fordgtlover* /img/forum/go_quote.gif 
_So, to clarify, you don't want Y1 DAC output at all?

 If that's so, you could leave out everything from R7D through to J3D and everything in the 'optional' area on the Y1 schematic, and 
 by the look of it U9D. And finally U6D and associated parts; the WM8501 appears to be the only thing using 4.5v.

 This would leave you with only the Y1 inputs and the Y2 outputs.

 You would want Mister X or AMB to confirm this though.

 And, if you only want USB power you could also remove everything from J1D to U1D inclusive.

 EDIT: Removed reference to U4D_


----------



## tacitapproval

In experimenting some more with it, I actually caught a small snippet of music in the midst of a lot of noise on the y2 output. I the y1 output produces louder noise, but more music. I don't know if this helps narrow it down to the ARSC, but it was actually heartening to hear a tiny chirp of life within the electrical chaos.


----------



## nightanole

Quote:


  Originally Posted by *hansel_ng* /img/forum/go_quote.gif 
_Hello,

 Am I correct to say that analog output 1 was retained by the designers because the y2 is an upgrade from the y1, and that in all situations analog output 2 will be the superior?

 Will you lose anything if you leave out analog output 1 (itself excepting)? 

 If so, will there be any chance that the quoted configuration can be added to the amb.org website for those who are building the y2 from scratch and so might want to leave this out to save some money? 

 thanks_

 

Ok this is what you should do. Build up the gamma 1 input section anyway you want it other then usb to spidf mode. Then look in this thread and find Mr. X's bar bones build of the gamma 1 needed for just usb. Build up the dac of the gamma 1 like he lists. thats all you need.

 Mr. X has posted a bar bones build of the gamma 1 if you want only usb. In all reality the cost of omitting the gamma 1 dac might save 5 bucks. Whats the dac, $2.50?


----------



## MisterX

Quote:


  Originally Posted by *tacitapproval* /img/forum/go_quote.gif 
_In experimenting some more with it, I actually caught a small snippet of music in the midst of a lot of noise on the y2 output. I the y1 output produces louder noise, but more music. I don't know if this helps narrow it down to the ARSC, but it was actually heartening to hear a tiny chirp of life within the electrical chaos._

 

I dunno if it does either. 
 Do you have any pictures?


----------



## tacitapproval

Assuming I remove it, if I want to test it out without the ARSC, do I need to also remove U3, X1, R1, C7and C8?


----------



## m1abrams

What happened to the board around U4?


----------



## m1abrams

Also check u1, hard to tell from the photo but you may have a bridge on it. If you can get a more infocus shot that would help.


----------



## MisterX

Quote:


 

 Assuming I remove it, if I want to test it out without the ARSC, do I need to also remove U3, X1, R1, C7and C8? 
 

The image resolved any doubt I had about the resistors networks....
 Removing U4 and X1 is enough but I would also remove L4 and L5. 
 maybe even try removing the beads first (because they are easy to put back) and see if not powering the clock and ASRC has any effect on the noise from the Gamma 1 output


----------



## tacitapproval

Depowering the ARSC cleared up the problem on the y1 output. I guess this confirms the problem. Any advice on removing the X1? Chipquick, right, but I don't have any of course.

 m1abrams - I had to desolder pins on that side of U4, which is what led me to assume the ARSC was at fault in the first place. 

 U1 is ok.


----------



## MisterX

Yeah, chipquik may be the best solution but I dunno if I would worry about removing the clock yet. 
 I would remove the ASRC, see how the pads look then maybe jumper the JP2 positions to see if it works first. 
 (if the solder pads for U4 end up being a problem I would just cut the trace from the clock and call it a day)


----------



## tacitapproval

So, it seems I am mistaken that removing the power from the ASRC and clock fixed the noise on the y1 output. It's still there ro came back. Sometimes music, sometimes noise. 

 I removed the U4 and jumpered the JP2 locations. No music on y2, not suprisingly.

 I am rather confused at this point.


----------



## amb

Quote:


  Originally Posted by *tacitapproval* /img/forum/go_quote.gif 
_I removed the U4 and jumpered the JP2 locations. No music on y2, not suprisingly.

 I am rather confused at this point._

 

Did you also remove X1? You need to do that to bypass the ASRC.


----------



## tacitapproval

I removed X1 (using two soldering irons, actually not that hard). Condition is unchanged; intermittent music and noise on y1 and quieter noise on y2.

 Stumped.


----------



## linuxworks

so, you get mixed music and noise? any pattern? is it somewhat regular (like low freq oscillation)?

 perhaps its at your receiver chip side? if that was 'wonky' it could go in and out of receive mode.

 if you get music AT ALL then the dac side of things is probably functional and maybe something upstream (the receiver or media blocks; opto or coax) is flakey.

 does it matter if you use coax or opto in? any change at all?


----------



## ShinyFalcon

Did you install JP1D (1P on pin 2) on your y1? Can you get sound if you tap L+ and G (use a 22uF cap across L+, don't need to solder)? Does your WM8741 get warm/hot after a while?


----------



## tacitapproval

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Did you install JP1D (1P on pin 2) on your y1? Can you get sound if you tap L+ and G (use a 22uF cap across L+, don't need to solder)? Does your WM8741 get warm/hot after a while?_

 

Yes on JP1D. 
 Tapping those lines yields the same sort of noise as the output.
 It doesn't get hot.

  Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_so, you get mixed music and noise? any pattern? is it somewhat regular (like low freq oscillation)?

 perhaps its at your receiver chip side? if that was 'wonky' it could go in and out of receive mode.

 if you get music AT ALL then the dac side of things is probably functional and maybe something upstream (the receiver or media blocks; opto or coax) is flakey.

 does it matter if you use coax or opto in? any change at all?_

 

The sporadic noise on the y1 output may be a mechanical connection problem. I messed with the pins within the receptacles and now I seem to be getting unadulturated music out of the y1 with the boards mated. 

 I still don't get music on the y2 out. The one time I heard a brief snippet of music on the y2 out was before I removed the ARSC and crystal, which now seems to not have been the problem , or at least the only problem.

 This has all been with usb as power and source. I just tried coax and the results are unchanged. Music only on y1 out.


----------



## Beefy

Quick'n'dirty screencaps of planned panels for my y2 build. They come out about $6 more expensive than AMB's panels, but I get all that back and more on the parts that won't be populated.

 Suggestions? Comments?











 [EDIT] Ooops, font on back panel is still DIN, and will be changed to the same as the front panel. Need coffee


----------



## linuxworks

one thing I never quite understood; why does anyone need a walkman style jack when you have (on the 5v/usb side of the box) 2 perfectly fine rca male jacks there? 
	

	
	
		
		

		
			





 if it was me, I'd omit the 1/8" jack and just use the 2 rca's.


----------



## m1abrams

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_one thing I never quite understood; why does anyone need a walkman style jack when you have (on the 5v/usb side of the box) 2 perfectly fine rca male jacks there? 
	

	
	
		
		

		
		
	


	




 if it was me, I'd omit the 1/8" jack and just use the 2 rca's._

 

I agree with you , however I put the 1/8" jack in after much inner thought. Why you ask, because I currently only have the mini3 for an amp and already have a 1/8" IC cable and wanted to continue to use that until I finish my MMM build. Yes I could have made/bought another cable but that would have only been used until I finish the MMM and then would have the mini3 back hooked up to my gamma1 via 1/8" IC.


----------



## Beefy

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_one thing I never quite understood; why does anyone need a walkman style jack when you have (on the 5v/usb side of the box) 2 perfectly fine rca male jacks there? 
	

	
	
		
		

		
		
	


	




 if it was me, I'd omit the 1/8" jack and just use the 2 rca's._

 

I was going to continue using my BJC mini-to-RCA cable. Its a good length and the cable is low on the bulk.

 On the front, the connector is already there on my y1, and I hate desoldering


----------



## amb

For the price of one 3.5mm jack, you gain a bunch of convenience. Not only could you use whatever cable you have at hand and interconnect with home or portable amplifiers, you could also use them to drive two amps at the same time. This is ultra-useful, say, at a meet or something.


----------



## tacitapproval

Is it possible if the U4 was bad it took out the DAC with it? 

 I should not need to remove the other upsampling components (R1, C7 & 8) beyond U4 and X1 to have it produce sound, right?

 I'm not sure what else to try now.


----------



## linuxworks

I hate 1/8" jacks and plugs with a passion, though. so the dual rca (which does not bounce or spin and stays put pretty well) is my consumer line-level jack of choice.


----------



## MisterX

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_Quick'n'dirty screencaps of planned panels for my y2 build. They come out about $6 more expensive than AMB's panels, but I get all that back and more on the parts that won't be populated._

 

Yeah, in-filled engravings add quite a bit to the price don't they? 


  Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_Suggestions? Comments?
_

 

Bigger text maybe? 

 I was gonna suggest wiring in one of those little alpha rotary switches and using a "standard" LED but your comment about desoldering kinda killed that. 
	

	
	
		
		

		
		
	


	




 (as an example...the image below is one of the panel options I was considering during prototyping)


----------



## Beefy

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Yeah, in-filled engravings add quite a bit to the price don't they?_

 

And no bulk discount 
	

	
	
		
		

		
		
	


	




  Quote:


 Bigger text maybe? 
 

Good point. After switching to Helvetica the text does seem a bit small. Fixing, fixing......

 And a critical new addition......


----------



## nightanole

Aw man the opamps from mouser got pushed back to 10-19-09.


----------



## tacitapproval

I guess I am beyond help. This is disconcerting.


----------



## amb

tacitapproval, ok, so you've established that the γ1 board is working fine. So you can focus on the γ2 board. Since you've already bypassed the ASRC, and you've also jumpered around the opamp, so you've narrowed down to only a few components.

 1. Make absolutely sure that the inter-board pin headers and sockets are all making good contact. You mentioned some problems with this on the γ1 itself, perhaps something is also amiss between the γ1 and γ2.
 2. Go through the whole board carefully again to make sure all parts are oriented correctly and soldered well. Check for solder bridges too. As I said, solder joint problems account for most of the problems in these projects.
 3. Test the supply rail voltages (again).
 4. If you still can't find anything, perhaps the DAC chip has been damaged. There is really not much else there.


----------



## Beefy

I just BOM'ed it all out, and all parts (excluding the panels) to upgrade my y1 to my desired configuration (with ASRC, WM8741, no filter/clip switches) will set me back less than $100...... brilliant!


----------



## Clutz

Quote:


  Originally Posted by *tacitapproval* /img/forum/go_quote.gif 
_I guess I am beyond help. This is disconcerting. 
	

	
	
		
		

		
		
	


	


_

 

You'll get it to work. I can relate to how frustrating it can be, but you will get it to work. Just have some faith that you'll get it to work in the end.


----------



## linuxworks

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_I just BOM'ed it all out, and all parts (excluding the panels) to upgrade my y1 to my desired configuration (with ASRC, WM8741, no filter/clip switches) will set me back less than $100...... brilliant! 
	

	
	
		
		

		
		
	


	


_

 

I never installed the filter/clip switches either.

 with the asrc, its not obvious that one -needs- to change filters. I understand on the non-asrc version it matters audibly; but on asrc I could not tell any diff worth wiring a switch and drilling a hole, for 
	

	
	
		
		

		
		
	


	




 to this day, I still don't understand wolfson's intention with 'anti clip'. it sounds like its a dynamic feature but it appears (?) that its JUST a constant attenuation. not sure why that belongs in a dac. 

 what I wish the dac chips would offer us (consumers/users) is the word depth and samplerate in some led-friendly way! people ask for that all the time (they want to see 44.1 and 16 on their display, etc) but dacs and even receiver chips don't offer direct reading pins to show this kind of status. pity.


----------



## Beefy

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_with the asrc, its not obvious that one -needs- to change filters._

 

Precisely.

  Quote:


 to this day, I still don't understand wolfson's intention with 'anti clip'. it sounds like its a dynamic feature but it appears (?) that its JUST a constant attenuation. not sure why that belongs in a dac. 
 

I'm actually going to hard wire anti-clipping on. Perhaps it will let me get past the one 'hour' of rotation with my y1 and Mini Max for a bit better volume control......


----------



## linuxworks

you're not able to listen for more than an hour at a time? huh?

 (I'm kidding)


----------



## tacitapproval

So, I have music on the right side of the y2. Looking further into the mechanical connection between the boards, I tried hard soldering a lead to replace the socket I was using on J3. This exposed a connection problem there. Unfortunately, the left side is silent. Closer, but ughhh, I made a mess of things.


----------



## linuxworks

don't be afraid to start over with a new board.

 sometimes it happens. and sometimes its best to start fresh.


----------



## tacitapproval

Yes, that may be where I am headed.


----------



## ShinyFalcon

Now, it could be your opamp, your DAC, or the soldering of your components (resistors, caps, etc) from the DAC to output. Judging from your solder joints, it may simply be a bad connection. Reflow your legs one last time, maybe it's just a contact issue.

 What solder/flux did you use? They all seem cold and corroded.


----------



## linuxworks

Quote:


  Originally Posted by *tacitapproval* /img/forum/go_quote.gif 
_Yes, that may be where I am headed._

 

boards are still around; parts are still around; and you've been thru one before 
	

	
	
		
		

		
		
	


	




 so its not a big deal to just restart fresh.


----------



## tacitapproval

The solder is just Radio Shack rosin core and I'm using Goot liquid flux. I think the picture I posted is not the best quality. It doesn't look that bad in person (except for the mess around U4, but that is now gone). I will though go through everything one more time, just to make sure one more time. 

 If that doesn't resolve it. I guess I will take linuxworks advice. I suppose I can salvage all the through-hole parts and start fresh on the smt.


----------



## m1abrams

Quote:


  Originally Posted by *tacitapproval* /img/forum/go_quote.gif 
_The solder is just Radio Shack rosin core and I'm using Goot liquid flux. I think the picture I posted is not the best quality. It doesn't look that bad in person (except for the mess around U4, but that is now gone). I will though go through everything one more time, just to make sure one more time. 

 If that doesn't resolve it. I guess I will take linuxworks advice. I suppose I can salvage all the through-hole parts and start fresh on the smt._

 

You did a pretty good number to U4 and the pads near the opamp looks like they took some damage to.

 Most of the through hole parts (resistors, and cheaper caps) are not worth the effort to salvage. The higher priced caps and switches, jacks, do salvage though.


----------



## jnewman

I have been working on Frontpanel Express panels for my Gamma 2 prototype. I will send the Frontpanel Express files to anyone who wants them once I have gotten my order and made sure everything fits, but obviously I will not guarantee that everything is correct and you use them at your own risk. I have posted my design so far below for comments and concerns - anything look grossly wrong? Anything missing? Any ideas as to what to put in the space below all the business on the back panel?

 The two panels together come to $52.11 plus shipping at the moment. I didn't do any kind of engraving infill because it adds $18 to the cost and it's easy enough to do myself with Testors paint.

 Also, to echo AMB's comments above, this will ONLY work for the prototype Y2, not the production boards. Among other things, it looks like the filter select and anti clipping switches have switched places.

 As a side note, I set up the Gamma 1 output to drive headphones and left the Gamma 2 output as standard, so that's why they're labeled that way - if anyone wants the files and wants to change that, it's as easy as double-clicking on the text and writing something else in.


----------



## amb

Quote:


  Originally Posted by *jnewman* /img/forum/go_quote.gif 
_Also, to echo AMB's comments above, this will ONLY work for the prototype Y2, not the production boards. Among other things, it looks like the filter select and anti clipping switches have switched places._

 

Not only did the two switches swap places, their toggle directions have also been reversed in the production version. Also, the locations of the switches and the rear output jacks have shifted a bit.


----------



## Henrik Nordberg

Quote:


  Originally Posted by *jnewman* /img/forum/go_quote.gif 
_



_

 

You have "SPDIF" on the front and "S/PDIF" on the back. Minor but I would change the front one to "S/PDIF".

 Cheers,
 - Henrik


----------



## ShinyFalcon

For the Crystek crystal, is the top metal housing supposed to have a connection to pin 2/GND?


----------



## amb

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_For the Crystek crystal, is the top metal housing supposed to have a connection to pin 2/GND?_

 

Yes.


----------



## tacitapproval

It turns out that I do have sound on the left side as well. It is just much quieter than the right side. 

 Would this indicate the opamp, or does it not narrow it down between it and the DAC?

 Edit: Actually, it is a mono signal that comes through both channels, but is louder on the right. It may be time to start afresh.


----------



## nightanole

Has anyone tested the current draw (average and peak) of the gamma2 with the non headphone opamp setup?


----------



## ShinyFalcon

Why must U1 be so darn close to C3... Both regulators on the y2 gave bad voltages, but managed to get the 3.3V one working. What does pin 4 do? I feel that it may not be making contact with the board, that or pin 5...

 Edit: I'll probably bypass it for the time being... when I fix my desoldering pump I'll have a go at desoldering C3.

 #2: I think the leg for pin 5 disappeared or was never there in the first place... I hope it didn't melt inside... 

 #3: Nothing will happen if I leave y2.U1 out but leave the power for the ASRC intact, right? I desoldered U1 already but stopped short of tapping y1's 4.5V regulator.


----------



## jnewman

Quote:


  Originally Posted by *Henrik Nordberg* /img/forum/go_quote.gif 
_You have "SPDIF" on the front and "S/PDIF" on the back. Minor but I would change the front one to "S/PDIF".

 Cheers,
 - Henrik_

 

I told myself to go change that and promptly forgot about it. Thank you for reminding me - I'd have been pretty incensed with myself if I'd ordered the panels with an inconsistency like that.


----------



## MisterX

Quote:


 What does pin 4 do? I feel that it may not be making contact with the board, that or pin 5.... 
 

Pin 4 is the noise reduction or Bypass pin, in either case the pin is connected to an external capacitor which helps improve the performance of the regulator. 
 Pin 5 is the output. 


  Quote:


 #3: Nothing will happen if I leave y2.U1 out but leave the power for the ASRC intact, right? I desoldered U1 already but stopped short of tapping y1's 4.5V regulator. 
 

U1 is the 4.5 or 4.75 volt regulator.....


----------



## ShinyFalcon

Pin 5 is missing from one of my 4.5V regulator (I can only think of that time where one of the regulators got stuck on my iron tip, or me trying to reflow with C3 in the way and melted the plastic off wiping the pin sideways). As such I can't exactly fix it. I was somehow getting 0.7V out of the 4.5V particular test point, but I couldn't see the output pin. The 3.3V regulator also outputted odd voltage, read about 0.3V but I reflowed the pins on that one and got 3.29V out of that. So, I don't know what happened to the poor regulator, and a new order is heading my way... This paragraph talks about y2's regulators.

 What I wanted to do was hardwire y1's 4.5V regulator output (after the cap and ferrite) to y2's 4.5V test point, and cut before the WM8501 supply as to not overload the regulator. I didn't want to go through the hassle so I stopped there.

 Edit: massive proofreading


----------



## MisterX

Yeah, would have been a pain to undo....


----------



## FOXY

Any impression of Gamma2 compared with Buffalo32s or another good dac?


----------



## nightanole

Hey to all the usb powered people. The computer only sees the pcm2704 right? and PSEL is grounded right? Doesnt that tell the usb to use low power 100ma mode and not 500ma bus power mode if PSEL was high? 

 If this was the case how would one tell since the gamma 2 sucks more then 100ma? Would simply lifting the pin (well its not a pin but you get the idea) be enough to send it into 500ma bus power mode?


 From AMB "The only thing worthy of note is that the PSEL pin, which normally selects self-powered or bus-powered mode, is hardwired to self-powered mode in this circuit. This is because of the fact that we allow on-the-fly switching between the two modes, and that we don't use the PCM2707's built-in 5V-to-3.3V regulator. "


----------



## amb

nightanole, first, it's a PCM2707, not PCM2704. Anyway, the PSEL pin is used as info during USB enumeration so that the host can arbitrate high current devices. Yes, we have it set to low because we also have an external power option. In reality, unless you have a really old computer, you can draw more than 100mA safely (up to 500mA steady state, and even more in short durations). There are plenty of "pseudo-USB" devices (from battery chargers to computer cooling fans, even coffee warmers) that perform no enumeration at all and draw more than 100mA of current.


----------



## fordgtlover

Quote:


  Originally Posted by *FOXY* /img/forum/go_quote.gif 
_Any impression of Gamma2 compared with Buffalo32s or another good dac?_

 

See post #620 in this thread.


----------



## tacitapproval

I'm not sure if I should post this here or in the y1 thread, but since it is a continuation of the comedy of errors I have been having with my y2 build, I will post this here for continuity. 

 My y1 is not putting out sound now. Again, I have been using this daily for at least six months, so I know it was a working build. Since my last go round troubleshooting the y2 build, I remated the y1 boards with each other. It is recognized by the computer, power test points check out, switch led goes from red to green with music, but I don't get any output. Previously, it was working fine when mated to the y2. I had also rejoined the y1 boards more than once while working on the y2, and it worked every time. I can only assume that the faulty y2 has harmed the y1 in some way. But in what way?

 I had already resigned myself to starting over with the y2 build. But, this is depressing...


----------



## ShinyFalcon

If you're getting data, the switch goes on, 4.5V works, then that would lead to the WM8501 being fried somehow, or the data/clocks not reaching the WM8501. Check and see if optical/coaxial works, and check the mating pins and make sure they're continuous. If you remate the y2 and the y1 makes sound again, it would imply connection problem.


----------



## Beefy

It might even be something as simple as the output jack is dodgy...?


----------



## tacitapproval

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_It might even be something as simple as the output jack is dodgy...?_

 

It's not the jack. Again, the y1 has been my daily use DAC for some time.

  Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_If you're getting data, the switch goes on, 4.5V works, then that would lead to the WM8501 being fried somehow, or the data/clocks not reaching the WM8501. Check and see if optical/coaxial works, and check the mating pins and make sure they're continuous. If you remate the y2 and the y1 makes sound again, it would imply connection problem._

 

Coax or usb makes no difference. The connection is solid. I guess I will order another WM8501 with the y2 parts. Anyone want to second this plan or suggest other parts?

 Edit: Uh, nevermind. I rejoined the y1 to the y2 board and the y1 is outputing music. I guess there was a connection problem. I think I will just leave it connected to the y2 until I get the new y2 parts and board. 

 Sorry to waste people's time and thanks for indulging my foolishness.


----------



## Billyk

Ordered the board and other bits form AMB and was disappointed to find that the WM8742GEDS-V is still back ordered at Mouser. Are there any other sources?


----------



## tacitapproval

Why not get the WM8741?


----------



## Billyk

Quote:


  Originally Posted by *tacitapproval* /img/forum/go_quote.gif 
_Why not get the WM8741?_

 

Good question! I did not have an answer, did some research, now I know, no reason, I think I will do just that.
 Thank you very much!


----------



## digger945

Quote:


  Originally Posted by *Billyk* /img/forum/go_quote.gif 
_Good question! I did not have an answer, did some research, now I know, no reason, I think I will do just that.
 Thank you very much!_

 

*EDIT: See amb's post below*
 The 8741 would allow you to take advantage of the switching between filters and such that are designed into the Y2 board, and are built into the 8741 and not the 8742. It's a pretty neat feature with noticable(audible) differences.


----------



## amb

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_The 8741 would allow you to take advantage of the switching between filters and such that are designed into the Y2 board, and are built into the 8741 and not the 8742. It's a pretty neat feature with noticable(audible) differences._

 

Actually, both WM8741 and WM8742 have the switchable digital filter and anti-clipping features. It's the WM8740 that doesn't. Nevertheless, WM8741 is the slightly better chip than WM8742.


----------



## userlander

These look great. Are DIY-challenged head-fiers going to be able to get them somehow?


----------



## penger

The website lists MisterX as a contact.


----------



## nightanole

Since the opamps are backordered for weeks, Is there any harm in running partial build and just using the gamma1 output? I Just have the ics,resistors, and some caps mounted, and the gamma 1 is back to the uncracked condition.


----------



## userlander

Quote:


  Originally Posted by *penger* /img/forum/go_quote.gif 
_The website lists MisterX as a contact._

 

And that means he builds them for people on request? Sorry, I'm not really sure what you mean by that, or even if you were responding to me.


----------



## Beefy

Quote:


  Originally Posted by *userlander* /img/forum/go_quote.gif 
_And that means he builds them for people on request? Sorry, I'm not really sure what you mean by that, or even if you were responding to me. 
	

	
	
		
		

		
		
	


	


_

 

Why don't you email MisterX and ask?


----------



## userlander

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_Why don't you email MisterX and ask? 
	

	
	
		
		

		
		
	


	


_

 

Because normally I don't go around bothering people by randomly emailing them with stupid questions just because I can't get a clear answer on a forum.


----------



## Beefy

Quote:


 Originally Posted by *y2 website*
_Inquire with the follow professional builder if they would build you a completed γ2 DAC, in case you cannot build one yourself.

 * MisterX (Marshall Wyant)_ 
 

Doesn't sound like it would be a random email to me......


----------



## userlander

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_Doesn't sound like it would be a random email to me...... 
	

	
	
		
		

		
		
	


	








_

 

Okay, thanks for pointing that out. I didn't see that buried at the bottom of the page.


----------



## nightanole

Quote:


  Originally Posted by *userlander* /img/forum/go_quote.gif 
_Because normally I don't go around bothering people by randomly emailing them with stupid questions just because I can't get a clear answer on a forum. 
	

	
	
		
		

		
		
	


	


_

 

That is like so epic. It needs to be in a interwebs faq or something.


----------



## userlander

Quote:


  Originally Posted by *nightanole* /img/forum/go_quote.gif 
_That is like so epic. It needs to be in a interwebs faq or something._

 

That's "epic?" You don't get out much, huh?


----------



## amb

Quote:


  Originally Posted by *nightanole* /img/forum/go_quote.gif 
_Since the opamps are backordered for weeks, Is there any harm in running partial build and just using the gamma1 output? I Just have the ics,resistors, and some caps mounted, and the gamma 1 is back to the uncracked condition._

 

No harm at all.


----------



## nightanole

Do i have to attach both ground planes back together or can i just solder 1 plane together on the gamma 1?


----------



## grego9198

I just finished building my y1 Full, I've tested the USB side and it checks out, now I need to test the other side. But since I'm building a y2 to go with it I don't want to break them apart to plug them into each other. Can I just populate the headers on the y2 board and plug it into y1? I read in the thread it'll work for full++ I assume it's the same for just the Full config? Or is my better option to use wiring and connect the two together ala y1 full++ on amb.org?


----------



## MisterX

Yes, soldering the connectors onto the Gamma 2 and plugging it into the Gamma 1 will work.


----------



## MisterX

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_And just in case anybody is wondering.... you can just pull the "pin" out of the 3 pin receptacles amb is offering in his shop and trim the extra plastic off with an X-acto knife, which I find is a little easier then breaking the strips from Mouser apart. 
	

	
	
		
		

		
			





  Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
In case anyone is confused, MisterX is referring to modifying the 3P receptacle to make it 2P (for use as J3), needed when the matching γ1 is a Full (A), S/PDIF only (E) or Full++(F) configuration.

 

_

 

Trimming the extra plastic off is indeed optional. 
	

	
	
		
		

		
		
	


	



 (just pulling out the extra pin is enough)

 And... 
 Since the Box enclosures do not come with them, do you think it would be a good idea to add some stick on feet to the parts list? 
 (Mouser # 517-SJ-5312CL for example)


----------



## ShinyFalcon

I say yes. I was lucky to have extra 3M bumpons from Radioshack lying around. Don't want the bottom all scratched up, especially since the cases are packaged so nicely.

 What would happen if the ASRC receives a 192KHz stream? Does it get downsampled to 96KHz?


----------



## pixeljedi

Anyone have a US source for the "Mini-B USB connector, PCB-mount". Looks to be sold out everywhere except Farnell. Has to be the only part I need too eh?!? haha


----------



## ShinyFalcon

You'll find your answer in post 875 of the y1 thread


----------



## pixeljedi

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_You'll find your answer in post 875 of the y1 thread 
	

	
	
		
		

		
		
	


	


_

 

Thanks!!!


----------



## amb

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_What would happen if the ASRC receives a 192KHz stream? Does it get downsampled to 96KHz?_

 

Yes, it would. That's actually not as bad as it seems. We could have made the upsampling to 192KHz but the DAC's digital filters perform better at 256*fs than at lower master clock rates, but 256*fs isn't available for 192KHz (see WM8741 datasheet).


----------



## pixeljedi

Hi All,

 Is there any sacrifice in quality/features by going with the AD8656? I think it's a cool feature to have the unit drive headphones, but definitely not if it's going to compromise the sound in any way for my line-level stuff.

 Is there a consensus out there for which of the two op-amps delivers the best sound?

 Thanks in advance!


----------



## amb

Quote:


  Originally Posted by *pixeljedi* /img/forum/go_quote.gif 
_Is there any sacrifice in quality/features by going with the AD8656? I think it's a cool feature to have the unit drive headphones, but definitely not if it's going to compromise the sound in any way for my line-level stuff._

 

IMO there is no sacrifice going with either. Their measured performance are very similar and both sound great. Like all things opamp, it all boils down to preference (of course, direct low-Z headphone drive capability tilts the choice toward AD8656).

 To drive low-Z headphones you'd need to use 470uF output caps, which restricts your choice to just the Nichicon KW or FW. I think this factor far outweighs the opamp choice. I happen to think that the KW sounds pretty good, but YMMV.

  Quote:


 Is there a consensus out there for which of the two op-amps delivers the best sound? 
 

Consensus on "opamp sound"? Not likely...


----------



## pixeljedi

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_IMO there is no sacrifice going with either. Their measured performance are very similar and both sound great._

 

Thanks amb!


----------



## dg3f

hi,

 i want to make the analog output level a little bit higher,but i don't know how to change the gain,could anyone tell me ? i also want to know will changing gain affect performance very much if power supply voltage is not taken into account?

 thanks,


----------



## Mr.Duck

Quote:


  Originally Posted by *dg3f* /img/forum/go_quote.gif 
_i want to make the analog output level a little bit higher,but i don't know how to change the gain,could anyone tell me ? i also want to know will changing gain affect performance very much if power supply voltage is not taken into account?_

 

I don't think you can do that. It already swings rail to rail so I'm sure you will get clipping if you increased the gain.

 Can I ask why you want to? Unless you are running your volume controls at zero attenuation, then you should be able to get enough volume shouldn't you?


----------



## dg3f

Quote:


  Originally Posted by *Mr.Duck* /img/forum/go_quote.gif 
_I don't think you can do that. It already swings rail to rail so I'm sure you will get clipping if you increased the gain.

 Can I ask why you want to? Unless you are running your volume controls at zero attenuation, then you should be able to get enough volume shouldn't you?_

 

i want to build a my own modified desktop version gamma-2 with higher supply voltage and use some other opamp that can be powered with about +-12v as filter and analog output along with diamond buffer so that can drive both low and high impendance headphones


----------



## Beefy

Good luck with that. The whole y2 is designed around using USB power.

 Perhaps you should look into other designs that better suit your needs?


----------



## nightanole

Do any inputs/outputs of the gamma2/mini3 need to be isolated from the chassis like with the ckIII? I wanted to panel mount all the inputs/outputs to make them hold up better. Ive always hated pcb mount connectors, they always seem to get bad joints after a few years.


----------



## ShinyFalcon

Quote:


  Originally Posted by *dg3f* /img/forum/go_quote.gif 
_i want to build a my own modified desktop version gamma-2 with higher supply voltage and use some other opamp that can be powered with about +-12v as filter and analog output along with diamond buffer so that can drive both low and high impendance headphones_

 

Note that the WM8741 has an absolute maximum voltage input of 4.5V for digital and 7V for analog. You can use LP2985AIM5-5.0CT-ND and LP2985AIM5-3.3CT-ND voltage regulators to regulate 12V down to 5V and 3.3V respectively. The choice of opamp for the y2's output stage will be difficult. But since you say you'll be using a different output stage (maybe IVY or Ballsie or Zapfilter?) then that won't matter.

 nightanole, judging from the panels amb sells, everything needs to be isolated.


----------



## JamesL

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_nightanole, judging from the panels amb sells, everything needs to be isolated._

 

I may be wrong, but the board's ground-plane is connected to signal-output ground so I'm under the impression that isolated outputs are not necessary.


----------



## Beefy

Coax input should be isolated, otherwise it defeats the galvanic isolation benefit of the transformer coupling.


----------



## amb

The S/PDIF coax jack(s) should be isolated so it doesn't defeat the pulse transformer's galvanic isolation. The output jacks should be also be isolated if you're going to be driving headphones, so that the return current from the headphones don't travel through the case.


----------



## grego9198

Sweet! Got my y2 up and running this evening. Appears tho I have some clipping. Not sure if it's attributed by having to use cheap caps in lieu of the ones in C11/C13. Going to order proper Nichicons tonight along with a zener diode for my mini3 (it blew up when I put the battery in...not sure why but I'll post that in the relevant thread.) Other than the clipping it sounds very good, I'm super psyched that it worked on the first go.


----------



## amb

If you used all the specified parts in the BOM, and the rail voltages are within spec, then you shouldn't encounter any clipping, unless the program material was already clipped in the first place (not unusual these days in the "loudness wars" -- load your ripped songs in a wave editor and prepare to be shocked).


----------



## nightanole

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_The S/PDIF coax jack(s) should be isolated so it doesn't defeat the pulse transformer's galvanic isolation. The output jacks should be also be isolated if you're going to be driving headphones, so that the return current from the headphones don't travel through the case._

 

the grounds on both the rca's and the 3.5mm out are connected directly to the ground plane, which is connected to the chassis. 

 If i use panel mount connectors can i just connect the connectors ground to the original rca's ground point, and not isolate them from the chassis? It seems impossible to isolate them from chassis since they connect directly to the ground plane in stock form.

 The only ground i see i need to isolate is the usb connector since it goes thru a bead.


----------



## amb

Quote:


  Originally Posted by *nightanole* /img/forum/go_quote.gif 
_the grounds on both the rca's and the 3.5mm out are connected directly to the ground plane, which is connected to the chassis. 

 If i use panel mount connectors can i just connect the connectors ground to the original rca's ground point, and not isolate them from the chassis? It seems impossible to isolate them from chassis since they connect directly to the ground plane in stock form._

 

While they're all connected, if you use un-isolated jacks, then there will be multiple paths of "ground" (through the wiring, and through the case) for ground, which creates mini ground loops. It may or may not matter, but generally it's best to avoid such a scenario.


----------



## Fuzzy OneThree

Would this be too ambitious of a project for someone who has only made a few cMoys and a Millet Starving Student?


----------



## linuxworks

good soldering is really all that is needed to assemble these kinds of projects.

 no new design work is needed. just soldering, really


----------



## Billyk

Quote:


  Originally Posted by *Fuzzy OneThree* /img/forum/go_quote.gif 
_Would this be too ambitious of a project for someone who has only made a few cMoys and a Millet Starving Student?_

 

It is a question of your soldering skills. The layouts are compact but not difficult. There is a fair amount of Surface Mount involved, here is a link to an excellent tutorial. The Bantam Dac has a good tutorial on it as well, I actually prefer the method there, YMMV. 
 I was surprised by how much I enjoy the SMT work. All it takes is a steady hand, focus and a good magnifier. Not to mention the soldering tools and flux.


----------



## dumbears

While there is a question on SMT soldering, I do have another novice question on soldering on the ground plane. How to get the solder flow? Do I need a higher power solder or I should heat the area longer? I myself don't think the latter one is a good idea, since the heat will damage the component, and the ground plate may actually dispenses heat faster.


----------



## grego9198

Quote:


  Originally Posted by *Fuzzy OneThree* /img/forum/go_quote.gif 
_Would this be too ambitious of a project for someone who has only made a few cMoys and a Millet Starving Student?_

 

I'd imagine you'd be fine. The gamma1/2 were my first soldering projects involving surface mount components and the only part I found semi difficult was the U5 IC because the leg pitch was small and I didn't want to screw it up being a fairly pricey chip. 

 Once you get the technique down (that tutorial video is very good) it doesn't take too long to propagate the board. Just make sure you have the right equipment (flux pen, fine tip for your iron, magnifier) and watch the polarity on parts that require it.

 Overall I think it took me like 6 hours for both pieces. I'm curious as to how long it takes the more experienced builders to build these.


----------



## amb

Quote:


  Originally Posted by *dumbears* /img/forum/go_quote.gif 
_While there is a question on SMT soldering, I do have another novice question on soldering on the ground plane. How to get the solder flow?_

 

If you have an adjustable temperature soldering station, crank the heat way up to solder the ground pads, a bit of additional liquid flux helps too. This let's you get the pads hot enough to do the job quickly.

 Fortunately, most of the pads that have ground plane connections on both sides of the board are passive parts, and those are not easily damaged by heat.


----------



## CodeToad

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_good soldering is really all that is needed to assemble these kinds of projects.

 no new design work is needed. just soldering, really 
	

	
	
		
		

		
			



_

 

Anybody use this technique?

http://www.youtube.com/watch?v=t06ma...om=PL&index=35


----------



## nightanole

ya i have to crank my tip up to 365c on the ground connections. The rest of the board i can get away with 315-325c. I highly recommend some liquid flux, its like liquid gold when it comes to making shinny joints. Alot of the solder like kester "44" rma doesnt even need to be cleaned other then for cosmetic reasons. I use kester 1455 flux which is RA so i need to clean it off with some rubbing alcohol.


----------



## tacitapproval

I ended up with 595-TPS79333DBVREP for U2, rather than 595-TPS79333DBVR. The chip is marked PHUE, instead of PHUI. The data sheets list pin 4 as Bypass and Noise Reduction, respectively. Although, I would think this is the same thing. Other than this, I don't see too much difference between them. Nonetheless, I am having a power supply problem on round 2 of my y2 build (maybe I am just not fated to have this upgrade) and I am wondering if this is the culprit. 

 I think one of the regs may have burned up, because I had power at first although I was getting as I recall @4.75v at all test points. Then the led started to fade. Now I read @.5v at the 5v points. 
	

	
	
		
		

		
		
	


	




 Again, the y1 boards work fine together.


----------



## Lazerboy2000

Is it possible to use a Gamma 1 lite (USB>>headphone jack) for the Gamma-2 upgrade?


----------



## Beefy

Yes. Details are all on the y2 website.


----------



## tacitapproval

I swapped both regulators with the ones off my first y2 board, which were working on it. I am now getting 5.08v(using a wall wart) at all four test points. So no regulation is being done.


----------



## amb

Quote:


  Originally Posted by *tacitapproval* /img/forum/go_quote.gif 
_I swapped both regulators with the ones off my first y2 board, which were working on it. I am now getting 5.08v(using a wall wart) at all four test points. So no regulation is being done._

 

Sounds like bad solder joints on the regulators' ground pin. But strange that it would happen on both. Try reflowing. If that doesn't work, then the regulators are probably bad.

 The TPS79333DBVREP is equivalent - has tighter specs (see datasheet).


----------



## tacitapproval

U2 is working now, I'm getting 3.39v. U1 continues to be problem, so I was going to swap it out. Unfortunately, pad 3 got lifted in the removal. Can I jumper it to pin 1, or is there something else I must do?


----------



## digger945

Quote:


  Originally Posted by *tacitapproval* /img/forum/go_quote.gif 
_U2 is working now, I'm getting 3.39v. U1 continues to be problem, so I was going to swap it out. Unfortunately, pad 3 got lifted in the removal. Can I jumper it to pin 1, or is there something else I must do?_

 

If your referring to U1(TPS793475DBVR or LP2985AIM5-4.5) then yes, pin 1(IN) must be connected to pin 3(EN) to turn the regulator "on". I suppose you could fashion a small resistor lead into a U shape and solder it to both pins after you have the regulator soldered to the pcb.

 EDIT: There is ground plane all around U1 so I would be careful not to let the connection even touch the pcb as it will probably get hot enough to penetrate the solder mask during soldering.


----------



## tacitapproval

Yes, that's it. Thanks. 

 Fingers crossed...


----------



## digger945

Thinking about it now, maybe you could toss the idea around and see whatcha think.
 You might be able to solder a lead to the top of pin 3 before you solder the reg to the board, and if it turns out to be a big pain to solder the other end to pin one then maybe you could solder it to the leg of C3D where the trace from pin 1 connects. I don't know how this would work out for ya, you may have very steady hands and good eyes so no problems. Just an idea or two.
 Also something I've done before is to leave the lead long so you can manipulate it better, then after everything is soldered together and tests good you can trim the excess.


----------



## tacitapproval

Well, that did something, but it still ain't right. After joining pins 1 & 3, voltage on it now is bouncing around between 3v and 3.40v(It is a 4.75v, in case you were wondering), . This was a new reg. U2 is stable at 3.28v (although it seems to start a little higher, like <3.50v and climb down in few seconds.) and VCC is 5.10v.


----------



## digger945

Quote:


  Originally Posted by *tacitapproval* /img/forum/go_quote.gif 
_Well, that did something, but it still ain't right. After joining pins 1 & 3, voltage on it now is bouncing around between 3v and 3.40v(It is a 4.75v, in case you were wondering)_

 

Pin 4 on U1 is reading between 3 and 3.4V?

  Quote:


 This was a new reg. U2 is stable at 3.28v (although it seems to start a little higher, like <3.50v and climb down in few seconds.) and VCC is 5.10v. 
 

Pin 1 on U1 is indeed 5.10V?
 Are you still using the wallwort and if so what is the unloaded voltage?


----------



## tacitapproval

Yes, I am measuring from the test points. I get <3v at the 4.5v test point. 3.28v at 3.3v and 5.10v at the two 5v test points. This is a wallwart that puts out 5.13v unloaded. 

 U1 is doing something, but not what it should.


----------



## digger945

The test points won't do. You will have to measure the voltage at pin 1 on U1, up on the pin right where it goes into the package. Also to verify the connection it wouldn't be a bad idea to power everything down and measure the resistance from the same point up high on pin 1 of U1 to Vcc, and while your at it measure the resistance from pin 1 to pin 3. There should be almost zero resistance between Vcc and pin 1 and pin 3, any way you measure it.


----------



## tacitapproval

Measuring from the pins is about the same. 5.09v on pin 1. Pin 4 put out 3.7v when I first measured, this fell slowly to @3.1v with some fluctuation inbetween. Continuity checks out at @.8ohms anywhere between pin 1 and 3 and VCC.


----------



## funch

Good news: I finished my y2 today.

 Bad news: when I did my initial check, the 5V and 3.3V readings
 were spot on, but only 0.4V at the 4.5V point. 

 When I checked U1, I found pin 3 almost burned in half. Looked 
 like something had shorted it to ground, and the corner of the 
 plastic was gone. Dunno what happened. My y1 Full +++ went 
 smooth as a babie's butt. Now i gotta order a new reg. I used
 the TPS, but this time I'll try the LP. 

 BTW, the parts page on amb's site lists U1 as TPS793475, but 
 the Initial Check page says TPS493475. I know. I'm being anal.
 Again!!


----------



## amb

tacitapproval and funch, check all your chips for proper mounting orientation, including X1 (the oscillator). A reversed chip could do weird things and load down the voltage regulator, not to mention possibly destroying the chip too. While you're at it also inspect carefully for solder bridges on the entire board. Use the schematic as a guide and measure resistances between pins.

 I'll fix the typo on the web page.


----------



## tacitapproval

I swapped the 4.75v reg for another (my last) and I get right around 3v again, so I don't think it is the reg that is the problem. The chips are oriented correctly and I can't find any bridges in poking around with the meter, or looking through my loupe. Could it be the opamp pulling down the regulator. I did swap this from the previous board since they are hard to come by at the moment, so it could be faulty. It does show @1.5v on each side, so I don't see anything obvious from this. I'm not sure what else to check.


----------



## rhester

Anybody have any mini USB b receivers, since DIgikey and Mosuer are out of stock for 3 months? Or is there another alternative?


----------



## 4season

Quote:


  Originally Posted by *rhester* /img/forum/go_quote.gif 
_Anybody have any mini USB b receivers, since DIgikey and Mosuer are out of stock for 3 months? Or is there another alternative?_

 

I ordered them from Avnet.com, and just received notice that my order has shipped. I should have plenty of spares.


----------



## Billyk

Quote:


  Originally Posted by *rhester* /img/forum/go_quote.gif 
_Anybody have any mini USB b receivers, since DIgikey and Mosuer are out of stock for 3 months? Or is there another alternative?_

 

I have ordered this one for another project. It is a Mini AB style but everything else is the same including pin-out. I would wait until someone here confirms, or corrects, me as I a sure they will.


----------



## funch

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_tacitapproval and funch, check all your chips for proper mounting orientation, including X1 (the oscillator). A reversed chip could do weird things and load down the voltage regulator, not to mention possibly destroying the chip too. While you're at it also inspect carefully for solder bridges on the entire board. Use the schematic as a guide and measure resistances between pins.

 I'll fix the typo on the web page._

 

Thanks amb. I have a Bausch and Lomb binocular magnifier, so I can 
 see very fine detail, and everything looks good. Checks with my multimeter 
 show everything OK as well. To be honest, I'm thinking that somehow (I'm a klutz) I banged something into pin 3 of U1, leading to the problem. I'll report back next week after the new U1's arrive.


----------



## amb

Quote:


  Originally Posted by *Billyk* /img/forum/go_quote.gif 
_I have ordered this one for another project. It is a Mini AB style but everything else is the same including pin-out. I would wait until someone here confirms, or corrects, me as I a sure they will._

 

Yes, that one works too.


----------



## Billyk

Thanks, and while I am at it thanks so much for your projects and your incredible support of them!


----------



## nightanole

51 lucky people will get some OPA2365AID from mouser. After that no more till xmas


----------



## n_maher

Quote:


  Originally Posted by *nightanole* /img/forum/go_quote.gif 
_51 lucky people will get some OPA2365AID from mouser. After that no more till xmas 
	

	
	
		
		

		
		
	


	


_

 

Amplifiers & Comparators | Newark.com

 Avail. = 375


----------



## nightanole

question on the upsampling feature. 
 On high end projectors they take 24frames per second video and then frame interpret it to 120 frames a second. It makes the video much smoother but 75% of your information is non original. 

 When this board is upsampling it to 24bit 96k, is it adding interpreted data via a algorithm to smooth out the ridges , or is it just duplicating original data?

 aka the original is data is 1,3,5,7,9,
 it reinterprets as 1,2,3,4,5,6,7,8,9
 or does it just duplicate 1,1,3,3,5,5,7,7,9,9


----------



## m1abrams

Quote:


  Originally Posted by *nightanole* /img/forum/go_quote.gif 
_question on the upsampling feature. 
 On high end projectors they take 24frames per second video and then frame interpret it to 120 frames a second. It makes the video much smoother but 75% of your information is non original. 

 When this board is upsampling it to 24bit 96k, is it adding interpreted data via a algorithm to smooth out the ridges , or is it just duplicating original data?

 aka the original is data is 1,3,5,7,9,
 it reinterprets as 1,2,3,4,5,6,7,8,9
 or does it just duplicate 1,1,3,3,5,5,7,7,9,9_

 

With your method the video is done as 1,1,1,1,1,3,3,3,3,3,5,5,5,5,5,7,7,7,7,7,9,9,9,9,9, at 120hz.
 Need to understand that with the video method it is to OVERCOME a problem created by trying to display film material that is encoded at 24fps to be displayed on consumer gear that has for ages used 60hz as the timing (in the US). 24 is not an even multiple of 60 so a trick TV makers have done is doubled the timing to 120hz which is an even multiple of 24 and 60. With TVs that do not have this 120hz ability they have to do a messy conversion called the 3:2 pulldown which can introduce a stutter.


----------



## nightanole

Uh ya missed the whole point. Modern tvs have something called frame interpolation. It adds information to the video, it doesnt just do 3:2 pulldown or frame double it as you described.

Is Frame Interpolation Important?


----------



## amb

Quote:


  Originally Posted by *nightanole* /img/forum/go_quote.gif 
_question on the upsampling feature. 
 ..._

 

Rather than rehash some already good info I'll just point you to one that came to mind:
Asynchronous Sample Rate Conversion - diyAudio

 Along with the SRC4192 datasheet you should have a pretty good idea of what the ASRC does.


----------



## m1abrams

Quote:


  Originally Posted by *nightanole* /img/forum/go_quote.gif 
_Uh ya missed the whole point. Modern tvs have something called frame interpolation. It adds information to the video, it doesnt just do 3:2 pulldown or frame double it as you described.

Is Frame Interpolation Important?_

 

Read my post again, that is what I described. Note not all "modern" TVs do this. In fact it is still a feature you must look for. Worse part is even some "120hz" TVs do not actually do this which is sad.


----------



## nightanole

Wow my question is way over my head. Im gonna have to find an idiots guide to this, that thread was way over my head.

 Ya sorry about the tv thing, I know all about frame quadrupling to make a 30hz single fit on a 120hz screen. And the expensive ones that "fill in the blanks" and add interpreted frames to fill in the 120hz.

 I was asking if the upsampler frame doubled or if it "filled in the blanks" with interpeted data. 

 I Guess i dont know enough to even ask the correct question yet. 

 "so we immediately see that the fundamental job of the Asynchronous Sample Rate Converter is to provide output audio samples corresponding to points of time IN BETWEEN the original audio samples. Sometimes only one sample in between, sometimes two ... because the output rate is faster. Make sense?"


 I thought thats what this thing did....

 Then i read this:

 So right away we recognize the job of our ASRC to be one of INTERPOLATION."




 "1. OK, Fs_in at 44.1kHz and Fs_out at 48kHz. No problem, you might say ... simply interpolate the input data by the integer 160, to a rate of 7.056Mhz, and follow that by integer decimation of 147 to the final output rate of 48kHz. Simple, right ?? Nope, wrong."


----------



## sergery

Quote:


  Originally Posted by *nightanole* /img/forum/go_quote.gif 
_"so we immediately see that the fundamental job of the Asynchronous Sample Rate Converter is to provide output audio samples corresponding to points of time IN BETWEEN the original audio samples...."

 So right away we recognize the job of our ASRC to be one of INTERPOLATION."_

 

I think you have it, they are just saying it harder than you would think - compare the prices of the ASRC and the DAC. anyway, from wikipedia, Interpolation:

 In the mathematical subfield of numerical analysis, interpolation is a method of constructing new data points within the range of a discrete set of known data points.

 Exactly the process being described here.

 To answer your question directly, it is filling in the blanks.


----------



## sergery

Can somebody explain the function of the U5 (WM8471) pins 11 and 18 (R & L "midrail decoupling pins"). Just trying to get a feel for the circuit, the data sheet didn't offer much. 

 Thanks


----------



## sergery

Quote:


  Originally Posted by *sergery* /img/forum/go_quote.gif 
_it is filling in the blanks._

 

of course the time scales are different, so essentially all of the new samples will be 'filled in blanks', since they will not line up in time.


----------



## amb

Quote:


  Originally Posted by *sergery* /img/forum/go_quote.gif 
_Can somebody explain the function of the U5 (WM8471) pins 11 and 18 (R & L "midrail decoupling pins"). Just trying to get a feel for the circuit, the data sheet didn't offer much. _

 

Most modern DACs have something similar to this. Basically, there is an internal resistor divider network used to establish the "zero" reference point for the output waveform. That zero reference needs to be extraordinarily "clean" (i.e., free from noise) so that it doesn't introduce noise into the output.

 These DAC chips are single-supply, therefore the "reference" point is usually biased at half the analog supply rail voltage (VADD / 2), instead of 0V (ground). Since the reference voltage is divided down from the analog supply rail, there needs to be a decoupling capacitor there to shunt any rail noise to ground while allowing a DC bias. A large-ish amount of capacitance is required, so it is unfeasible for the capacitor to be on-chip.

 The γ1's WM8501 DAC has a common mid-rail reference pin for both stereo channels while on the γ2, the WM874x has a separate mid-rail reference pin per stereo channel. On both boards we specify a 22uF audio-grade electrolytic cap bypassed by a 0.1uF MLCC to bypass these pins.


----------



## sergery

I think I am getting this. The reference is an internal one for the generated output waveform - the outboard (off-chip) 'midrail decoupling pins' are to offer a convenient way to implement large enough capacitor(s) to shunt rail noise to ground. 

 I was confused thinking they serve as external references, seeing them tied to L+ and R+. In the application note, VMIDR and VIMIDL are decoupled by 2 caps, tied together and shorted to ground. Is there an advantage to tieing them to L+ and R+ as you have done? 

 Thanks for bearing with me, I have no electrical background but I am intrigued.


----------



## amb

Quote:


  Originally Posted by *sergery* /img/forum/go_quote.gif 
_I think I am getting this. The reference is an internal one for the generated output waveform - the outboard (off-chip) 'midrail decoupling pins' are to offer a convenient way to implement large enough capacitor(s) to shunt rail noise to ground. 

 I was confused thinking they serve as external references, seeing them tied to L+ and R+. In the application note, VMIDR and VIMIDL are decoupled by 2 caps, tied together and shorted to ground. Is there an advantage to tieing them to L+ and R+ as you have done? 

 Thanks for bearing with me, I have no electrical background but I am intrigued.






_

 

Those pins' primary purpose is to add external decoupling caps. But in the γ2 I took advantage of the availability of the clean mid-rail reference and played a neat trick with it. If you look at the Wolfson "recommended output filters" doc, their single-supply, differential filter example in figure 11 has input caps and output caps at the opamp. It also uses the "dirty" 5V rail to bias the opamp to mid-rail. My design here makes use of "clean" mid-rail reference to bias the opamp, and eliminates the input caps at the same time.


----------



## sergery

Thanks for your responses. Cheeky, neat trick. 
	

	
	
		
		

		
		
	


	



 I missed that there was an a need to bias the opamp to keep it from swinging around 0V. Now it makes more sense. Thanks for the link.


----------



## funch

I got my new U1 in today, installed it, and everything is A-OK. I'm 
 listening right now to Fourplay on my PPA and it's sounding great.
 I don't hear any real differences between the filter settings, though.

 Thanks again amb for your fabulous designs as well as your continued
 support here.


----------



## rhester

Woo hoo listening to mine now. Just need some groovy faceplates now.


----------



## hedmaster

This would be from scratch, as I don't have a gamma 1. I am trying to find out what people are spending, have spent in order to get theirs from ordering to plugged in and listening. 
	

	
	
		
		

		
		
	


	




 I have the tools needed, so that won't factor in. I have gone to the website and looked at the BOM, but that as far as I have been able to go.

 If someone would please offer up their experiences as far as the BOM, any tips, or tricks that only experience can teach, please feel free to share them with us.

 Thanks,
 Matt


----------



## pixeljedi

I believe mine was around $205 (incl shipping from 5 different places). Not including faceplates, I'm doing those myself.


----------



## digger945

Quote:


  Originally Posted by *hedmaster* /img/forum/go_quote.gif 
_ I have gone to the website and looked at the BOM, but that as far as I have been able to go.

 If someone would please offer up their experiences as far as the BOM, any tips, or tricks that only experience can teach, please feel free to share them with us.

 Thanks,
 Matt 
	

	
	
		
		

		
		
	


	


_

 

First thing I do is to print out the BOM from Amb.org to use as reference and to cross of the parts as they are ordered, and also to check the parts when they arrive. I also use this list to mark off parts as they are installed, and to cross off parts that are not necessary for my particular build.

 When it comes time to order, open up Mouser in one tab, Digikey in another tab, Amb.org in another tab and copy and paste the part numbers from Amb.org to the part search box on Mouser or Digikey one at a time. Doesn't take long. Marking the parts off on the list printed first allows me to be interrupted and then resume where I left off later. Doing one part at a time allows you to deal with "out of stock" parts as they are discovered.


----------



## hedmaster

Quote:


  Originally Posted by *pixeljedi* /img/forum/go_quote.gif 
_I believe mine was around $205 (incl shipping from 5 different places). Not including faceplates, I'm doing those myself._

 

 Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_First thing I do is to print out the BOM from Amb.org to use as reference and to cross of the parts as they are ordered, and also to check the parts when they arrive. I also use this list to mark off parts as they are installed, and to cross off parts that are not necessary for my particular build.

 When it comes time to order, open up Mouser in one tab, Digikey in another tab, Amb.org in another tab and copy and paste the part numbers from Amb.org to the part search box on Mouser or Digikey one at a time. Doesn't take long. Marking the parts off on the list printed first allows me to be interrupted and then resume where I left off later. Doing one part at a time allows you to deal with "out of stock" parts as they are discovered._

 


 Pixeljedi, thanks, that helps a great deal on planning!

 digger945, very good info.! That is a great idea(s). Organizing and ordering in that way will help me a whole bunch. I have the hardest time setting up my BOM with the different stores, then the boutiques, oos, etc. 
 I think your ideas will minimize my confusion, lol!
	

	
	
		
		

		
			





 Thank you both for the quick responses.


----------



## hedmaster

Oh, I also wanted to ask for comparisons to the Keces 131 MKII DAC which I recently purchased. 

 I have read some of the thread, but not all, I must admit. Forgive me if it is already in there, but I didn't see it. 

 I did see someone mention that it could be a contender with the OPUS DAC. Are there any thoughts on that?

 I know it is very subjective. I would define better as cleaner, more detail oriented, with nice bass extension, sparkley highs w/ out harshness, and little to no roll off on either end. Basically transparent, and musical, if that's possible, lol!

 Thanks again guys, this is really going to help me to plan for this build in Nov., if all goes according to plan.

 Blessings to all of you,
 Matt


----------



## dg3f

mr.amb:

 the 4.5v ldo are out of stock here,can i replace it with 3.3v ldo ? will this change introduce some kind of distortion?

 i used wm8740 in my implement

 thanks


----------



## 4season

Hello, hoping that there's an easy fix here...

 Just completed the Gamma 1 + 2 last night, inspected the connections w/a microscope, did preliminary checks and found no short circuits, and reflowed a few suspect connections. Gamma 1 seems to work fine via SPDIF (I have not yet tried optical or USB). Gamma 2 seems to be totally dead. Also, if I switch Anti-Clipping to "off", the light goes from green to red.

 I did voltage checks on both Y1 and Y2 and all looks pretty good to me: 4.5V test points measure closer to 4.7, but otherwise, about what I'd expect.

 Y1 is configured as "Full" or "+++" (what's the diff?) and 470uf output caps. SPDIF jumper is shorted, all others are open.

 Y2 has the upsampling chip and all default ICs save for the opamp, where I used the alternate chip + 22uf output caps. No jumpers and no U6.

 Power is via 5v 800mA Motorola cell phone charger which measures ~5.2v, no-load.


----------



## m1abrams

Quote:


  Originally Posted by *4season* /img/forum/go_quote.gif 
_Hello, hoping that there's an easy fix here...

 Just completed the Gamma 1 + 2 last night, inspected the connections w/a microscope, did preliminary checks and found no short circuits, and reflowed a few suspect connections. Gamma 1 seems to work fine via SPDIF (I have not yet tried optical or USB). Gamma 2 seems to be totally dead. Also, if I switch Anti-Clipping to "off", the light goes from green to red.

 I did voltage checks on both Y1 and Y2 and all looks pretty good to me: 4.5V test points measure closer to 4.7, but otherwise, about what I'd expect.

 Y1 is configured as "Full" or "+++" (what's the diff?) and 470uf output caps. SPDIF jumper is shorted, all others are open.

 Y2 has the upsampling chip and all default ICs save for the opamp, where I used the alternate chip + 22uf output caps. No jumpers and no U6.

 Power is via 5v 800mA Motorola cell phone charger which measures ~5.2v, no-load._

 

Well since you have done a visual inspection, I would probe out all the connections to make sure you have a good connection where you should and no connection where you shouldn't. So using the schematic test from the top of the chip pins to the next component they should connect to on the board.

 NOTE: I had a similiar issue however did not have the Anti-Clipping symptom you mention. My issue was my SMD crystal apparently had a poor solder joint and reflowing it solved my problem. Since that is an easy thing to try, I would try that first.


----------



## amb

dg3f, while 3.3V is at the very bottom of WM8740's recommended operating voltage range, it is outside of γ2's _designed_ range. Using a 3.3V regulator for the analog supply will cause clipping. There are several options for the 4.5V/4.75V regulator. Are they ALL out of stock?

 4season, it's very odd that γ2 anti-clipping switch would affect the γ1 CS8416's operation (the green/red LED indication is derived from the CS8416's pins). Check to make sure all the γ2 parts are mounted in the correct orientation, especially the ASRC and DAC chips, and the oscillator.


----------



## digger945

Quote:


  Originally Posted by *hedmaster* /img/forum/go_quote.gif 
_digger945, very good info.!_

 

I'de like to add one more thing. If you take a few days or even a few hours to build an order with Mouser or Digikey, before you click on the "place order" button, go over the entire list one more time to make sure that nothing you have selected has suddenly been backordered. This has happened to me more than once in the past. Saves you time and trouble and allows you to find a suitable replacement before ordering.


----------



## Billyk

I like to use the Project Manager and the BOM import tools, they really make your life easier.


----------



## hedmaster

Quote:


  Originally Posted by *Billyk* /img/forum/go_quote.gif 
_I like to use the Project Manager and the BOM import tools, they really make your life easier._

 

I tried that, but I couldn't get it to work for some reason.

 I will have to try it again. As I recall, it needs to be put into excel first?

 Thanks for the help,
 Matt


----------



## Billyk

The Project Manager and The BOM import are independent but can be used together. They are not the most intuitive things but easy enough to get used to. For the BOM import tool you only need a text file with the part number the pipe symbol (shifted backslash usually found above the enter key) and then the quantity, Excel not required.


----------



## hedmaster

Quote:


  Originally Posted by *Billyk* /img/forum/go_quote.gif 
_The Project Manager and The BOM import are independent but can be used together. They are not the most intuitive things but easy enough to get used to. For the BOM import tool you only need a text file with the part number the pipe symbol (shifted backslash usually found above the enter key) and then the quantity, Excel not required._

 


 Thanks BillyK, you are the man! Wow, does that ever help! I was trying to figure out the BOM for the Millet Max a while back. Between all the boutique possibilities, the different vendors, and the oos, I was losing my mind.

 Now, it should be a piece of cake!

 Thanks again BillyK,
 Matt


----------



## 4season

Touched up every single solder joint on the Y2, and now the anti-clipping switch doesn't cause the light to go red anymore.

 Still no output from the Y2 though, so I dug out my 100 mhz oscilloscope to see what, if anything, it might tell me. Feeding it signal via the SPDIF coax input.

 X1: I see a pretty nice square wave there.
 R1: Poking around here, I see what looks like signal and clock.
 U3: Delivers a brief burst of 3V at power-up.
 R2: Pretty much flatlined here.

 Would I be right in thinking that the ASRC is likely the problem? And is it kosher for me to remove the ASRC and temporarily jumper around it while leaving U3, X1 et al in place?


----------



## amb

If you remove the ASRC and jumper around it, you'll also need to remove X1.


----------



## mattcalf

I'm very interested in a γ2 and am wondering what the benefits of the γ1 full++ will have over the γ1 full. I know it's the USB-to-S/PDIF converter, however, but will it affect what functions will I lose on the γ2 if I don't go ++?

 Also if anyone could let me know of the rough extra cost of ++ I'd be looking at that'd be great! 
	

	
	
		
		

		
		
	


	




*EDIT: *I'm ordering from Mouser and once you get over AU$200 worth of stock you end up with free postage, a saving of US$40 (alot).
 I'm need to spend another AU$11.50 (buying a proper solder station) so I'm wondering what I should purchase to get to the $200 mark. Whether it be an appropriate new solder tip or some components that are prone to being easy to break/fry that I should get a few just in case?

 Thanks again,
 Matt.


----------



## sergery

Quote:


  Originally Posted by *mattcalf* /img/forum/go_quote.gif 
_I'm very interested in a γ2 and am wondering what the benefits of the γ1 full++ will have over the γ1 full. I know it's the USB-to-S/PDIF converter, however, but will it affect what functions will I lose on the γ2 if I don't go ++?

 Also if anyone could let me know of the rough extra cost of ++ I'd be looking at that'd be great! 
	

	
	
		
		

		
		
	


	


_

 

Like you say, the main difference in functionality is the added USB-to-S/PDIF converter. This won't affect the γ2, it will run while the γ2 is running. The other difference is the specified case, but if you are planning on a γ2 it is the same so this point is moot. 

 Difference in cost will be due to a few parts including optical transmitter, RCA jack, pulse transformer, couple resistors and capacitors. ~5-10$


----------



## mattcalf

Ok, I've checked the γ2 and γ1++ parts list against a Mouser and Farnell order, as well as, nattonrice's BOM. 
	

	
	
		
		

		
			





 AU$201 (total) for my mouser order and AU$68 (total) for my farnell order, mouser includes a $75 soldering station. 
	

	
	
		
		

		
		
	


	




 I've listed everything according to which build they belong to so I feel very organized.

 Will contact AMB about my order from his shop soon.


----------



## nattonrice

Actually it is fordgtlover's bom so all credit goes to him.


----------



## nightanole

Well i just finished upgrading my gamma lite to a gamma 2. 
 Amps are a ckIII and a few commercial pocket amps.
 Cans are grado 60's and q40's

 With tracks with very few instruments and only 1 male voice its hard to tell the diff. However once you get into some female vocals, higher pitched drums and cymbals it really shines. When i built my gamma1 i thought it was revealing how bad my 192k mp3s were. Now with the gamma2 they are not harsh at all. All symbolance (sp) is gone. When i get a track with both male and female, and they are perfectly in sync, i can still tell them easily apart. 

 This is definitely worth the $100 upgrade over the gamma1. My setup was the non headphone amp, Nichicon muse es, Roederstein bypass.

 for the gamma1 it was stock wimas, and Silmic II.


----------



## 4season

I've got the Gamma 2 (mostly) up and running! My ASRC was no good, and until it's replacement arrives, I've got it bypassed. Even so, it seems like quite an improvement over the Gamma 1, or the analog output of my old NAD 502. Even without upsampling or the low-jitter crystal, redbook audio sounds "higher res" to me, individual instruments are easily separated, and easily get in-your-face if they're recorded that way. 

 The switchable filters are pretty interesting, but probably didn't need to be switchable:

 "A" sounds crispest to me, though I thought it also added a recessed, hollowed-out quality to the sonics.

 "B" sounds richest overall. Might also seem like the least-detailed at first, but it's the most coherent and fleshed-out. Set it here and leave it!

 "C" sounds like a compromise between "A" and "B", though it seems to add a "pinched" quality to vocals that I don't much care for. If it were a digital photograph, I'd say it was oversharpened.

 Would love to know how the Y2 compares to today's popular commercial products like the Grace 902, Benchmark, upcoming Wadia i-product etc.


----------



## nightanole

Seems like another person is thinking B stands for BEST
	

	
	
		
		

		
		
	


	




 I should have just saved the 7 bucks and not installed the switches, and just set to B and anticlip.


 In other news, can i have 2 sources on the gamma 2 at the same time as long as they are 50k or so sources each? Im building mine with an internal mini3 with a 50k pot but kinda wanted an out too. My next choice would be to use a switched TRS connector for output, so it goes to the mini3 with nothing plugged in, and goes out if something is plugged in. But that adds resistance vs a direct solder job.


----------



## 4season

Quote:


  Originally Posted by *nightanole* /img/forum/go_quote.gif 
_Seems like another person is thinking B stands for BEST
	

	
	
		
		

		
		
	


	


_

 

It seems that my preferred setting is currently causing a rolloff at around 14 khz! Will have to re-evaluate once I have the new ASRC chip installed.

 For now, mine sounds best with Anti-Clip set to "off": Besides being slightly louder, it's also more forward and seems to have more drive. Will find out of this still holds true with the ASRC in place soon enough.


----------



## amb

Quote:


  Originally Posted by *nightanole* 
_In other news, can i have 2 sources on the gamma 2 at the same time as long as they are 50k or so sources each?
 ..._

 

I think you really meant to have 2 _loads_ on γ2's output. Yes, you can drive 2 or more loads at the same time. γ2 has low output impedance and enough output current capability to do this, as long as they're not all low-Z headphone loads.

  Quote:


  Originally Posted by *4season* 
_It seems that my preferred setting is currently causing a rolloff at around 14 khz! Will have to re-evaluate once I have the new ASRC chip installed._

 

Yep, without ASRC, any filter setting other than "C" will cause a rolloff with -3dB point at around 14KHz if your source material sampling rate is 44.1KHz or 48KHz. See the "tech highlights" section of the γ2 website. With ASRC, however, all filter settings give you extended response to well beyond the audio band.


----------



## CodeToad

The Gamma2 is a definite upgrade from the Gamma1. It's a very "liquid" sound, almost like the headphones disappear. Even paired with a mini3 it's a satisfying setup. I'm not in any real hurry now to heat the room up with a beta22, although I will one day.

 A few pictures of the three amigos.


----------



## mattcalf

Sweet build CodeToad!

 Good to see that you're happy with AMB lineup (Mini3), as I'm hoping to go for a M3+γ2 combo. 
	

	
	
		
		

		
		
	


	




 So excited.


----------



## fordgtlover

Quote:


  Originally Posted by *mattcalf* /img/forum/go_quote.gif 
_Sweet build CodeToad!

 Good to see that you're happy with AMB lineup (Mini3), as *I'm hoping to go for a M3+γ2 combo*. 
	

	
	
		
		

		
		
	


	




 So excited._

 

That is a really good combo (I'm listening to it now)


----------



## MisterX

Quote:


 Yep, without ASRC, any filter setting other than "C" will cause a rolloff with -3dB point at around 14KHz if your source material sampling rate is 44.1KHz or 48KHz. 
 

Image removed. 
 The easy fix is to jumper the OSR pins


----------



## amb

I don't know the full ramifications of mucking with the OSR pin yet. This is something that I wanted to experiment with but had not found a chance to do it yet.


----------



## MisterX

Changing the OSR pin state primarily affects the available filter modes and the switch sequence.


----------



## koto-in

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_I don't know the full ramifications of mucking with the OSR pin yet. This is something that I wanted to experiment with but had not found a chance to do it yet._

 

StageDAC manual


----------



## MisterX

Deleted


----------



## nightanole

Im having trouble finding a 5v supply of good quality. Ive found like 4 from old cell phones that have the right cable end. However they are all like 5.5-5.7v when measured. Would it be easy to just make one? All i want is a normal linear regulated unit. I have a wall wart case and the cable.


----------



## Beefy

Cell phone chargers will all be REALLY cheap switchers. Probably far worse than USB power.

 Why not build a TREAD?


----------



## nightanole

I thought that might be over kill to make a $30 shipped ps for 5v.


----------



## Beefy

If you want something better, that is the price you pay.


----------



## cobaltmute

A σ11 can provide 5V.
	

	
	
		
		

		
			





 Remember in you search that you're dealing with the PSRR of the regulators and then how much noise the regulator itself generates. You could drive yourself nuts to get an ultra quiet supply only to be adding noise with the TPS reg.


----------



## nightanole

Uh what does tps mean? rejection ratio i got.


----------



## Beefy

Cobaltmute means the onboard 4.5 and 3.3V regulators.


----------



## grenert

Quote:


  Originally Posted by *cobaltmute* /img/forum/go_quote.gif 
_Remember in you search that you're dealing with the PSRR of the regulators and then how much noise the regulator itself generates. You could drive yourself nuts to get an ultra quiet supply only to be adding noise with the TPS reg._

 

True, but the regs specified for the DAC have some pretty good noise figures for fixed regulators:
 LP2985AIM5-4.5 30uV
 TPS79333DBVR 32uV
 So, you want to be at least that quiet if you're going to go all out with the PS. The ripple rejection of the regs is not so great at higher frequency, and that is something I think you can improve upon. I use an "optimized" LM317 supply with RC filtering with my gamma-1. You can read about ideas for improving the LM317 at:
Using 3-pin regulators off-piste: part 1
Simple Voltage Regulators Part 1: Noise - [English]
 and in the Bob Pease book "Troubleshooting Analog Circuits" available here:
Amazon.com: Troubleshooting Analog Circuits (EDN Series for Design Engineers) (9780750694995): Robert Pease: Books

 Whether or not you can _hear_ a difference with a better supply is unclear, but DIY is all about overkill, right?


----------



## cobaltmute

Let's use my example:

 The σ11 is very low noise - 12µV per amb. Now take a look at the datasheet for the TPS regs. It only states output noise for the TPS79328 @ full output, but it is spec'ed at 32µV best case. So you are dealing with the fact that the on-board regulators are adding noise to the line.

 So you can supply super clean DC to the board and your ultimate limit on noise is the on-board local regulators.


----------



## cobaltmute

Quote:


  Originally Posted by *grenert* /img/forum/go_quote.gif 
_True, but the regs specified for the DAC have some pretty good noise figures for fixed regulators:
 LP2985AIM5-4.5 30uV
 TPS79333DBVR 32uV
 So, you want to be at least that quiet if you're going to go all out with the PS. The ripple rejection of the regs is not so great at higher frequency, and that is something I think you can improve upon. I use an "optimized" LM317 supply with RC filtering with my gamma-1. You can read about ideas for improving the LM317 at:
Using 3-pin regulators off-piste: part 1
Simple Voltage Regulators Part 1: Noise - [English]
 and in the Bob Pease book "Troubleshooting Analog Circuits" available here:
Amazon.com: Troubleshooting Analog Circuits (EDN Series for Design Engineers) (9780750694995): Robert Pease: Books

 Whether or not you can _hear_ a difference with a better supply is unclear, but DIY is all about overkill, right? 
	

	
	
		
		

		
		
	


	


_

 

When you're building one, overkill is good. 
	

	
	
		
		

		
		
	


	




 The datasheet only spec's noise on the TPS79328, not the TPS79333. We can hypothesize or measure, but it is not on the datasheet.

 Dual secondary transformer with separate regs supplying 3.3V and 5V bypassing the on-board regs?


----------



## amb

Quote:


  Originally Posted by *cobaltmute* /img/forum/go_quote.gif 
_The σ11 is very low noise - 12µV per amb._

 

That was measured on a σ11 with 30V output, which runs its error amp at 2.5x gain. For 5V output, the gain is 1x, so expect even lower noise.


----------



## mattcalf

Just a quick question AMB, how many gamma2 pre-made front panels are left? If you don't mind divulging.


----------



## amb

Not many... 
	

	
	
		
		

		
		
	


	




 But I usually pre-order a few sets at a time to avoid running out completely. This of course doesn't guarantee anything.


----------



## mattcalf

Okay, swell. 
	

	
	
		
		

		
		
	


	




 Probably going to have to wait until December (school holidays) to kick start this build but I'm very excited!

 Cheers,
 Matt.


----------



## Shahrose

Has anyone found SQ differences among the different outputs? ie. coax, optical, usb.


----------



## linuxworks

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_Why not build a TREAD?_

 

second that opinion. lm317 is a perfect match as a front-end to a device that has its own regulators. 7805 is fine but 317 is quieter and slightly better and a tread style setup requires no expensive parts at all. its a good basic design and isn't at all overkill.


----------



## 4season

Still can't get the ASRC chip (SRC4192I) to work! If I bypass it, all is good. As far as I can tell, U3, R1 and X1 are okay, and all voltages are pretty close to spec. I've purchased 2 SRC4192s from Mouser on two different occasions-what are the odds of my actually getting two defective ICs? Is this chip much more delicate than the others?

 Suggestions welcomed. Foil traces on the PCB looked fine, and the only thing I could think of doing was trying a different supplier for the ASRC in hopes of getting a part from a different production run.


----------



## mattcalf

I plan to use the gamma2 almost exclusively with USB so I'm not too concerned about the power supply, however, would something like this be suitable?


----------



## MisterX

Seems like overkill to me. 

 Maybe something like this instead?

LM317 DC In 5~24V Out 2.5~12V Volt Regulator Converter - eBay (item 350264583172 end time Oct-16-09 03:13:37 PDT)

 The caveat is you will need a transformer and rectifier so maybe a tread really is a better option?

 Edit: 

 Plan B? 

http://cgi.ebay.com/Voltage-Regulato...mZ260479385900

 Edit #2: 

 Plan C? 

http://cgi.ebay.com.au/Universal-DC-...mZ200395046712


----------



## amb

4season, it's quite unlikely that two SRC4192s from Mouser would be defective.
 Maybe post some clear photos of your board, top and bottom?


----------



## MisterX

Yeah, seems more likely the SCR4192 was not the problem.... 
 4season, did you check U3 and make sure it's the right part and that it is working as expected?


----------



## Anima87

Hi guys

 New to this Gamma Dac. Would like to try it out.

 I have some questions:

 What is the total price for a gamma 1 + 2 build without casing, and is it possible to do without much experience in this field? - I have been soldering a bit, but not many exotic components tbh. 

 I have written an email to misterx in order to get a qoute on a build, but it seems as if they all go to his spam-filter for some reason - he dosen't reply..

 Thanks for the help!


----------



## MisterX

Are you sure it's not the other way around? 
 Roughly 10% of the inquiries I reply to are refused on the other end or end up in the senders spam folder.


----------



## mattcalf

Thanks MisterX, tread looks like a spanking option. But I'll leave it until I need it.


----------



## Anima87

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Are you sure it's not the other way around? 
 Roughly 10% of the inquiries I reply to are refused on the other end or end up in the senders spam folder. 
	

	
	
		
		

		
		
	


	


_

 

Only mail i have received, that went into the junk folder, was from Lin Jgywypy titled "Lingerie Demons".. I seriously doubt is from you
	

	
	
		
		

		
		
	


	




 If we need to go all private, i have allowed members from this site to write emails to me. You can just contact me via PM or email. 

 Thank you, Marshall.

 Best regards, Troels


----------



## MrSlim

Quote:


  Originally Posted by *Anima87* /img/forum/go_quote.gif 
_Hi guys

 New to this Gamma Dac. Would like to try it out.

 I have some questions:

 What is the total price for a gamma 1 + 2 build without casing, and is it possible to do without much experience in this field? - I have been soldering a bit, but not many exotic components tbh. 

 I have written an email to misterx in order to get a qoute on a build, but it seems as if they all go to his spam-filter for some reason - he dosen't reply..

 Thanks for the help!_

 



 Someone asked before about a price, it's in thread somewhere.. check the last few pages of posts. 

 Also, if you read though the beginning of the thread there is some good info on SMD soldering (including a tutorial) as well as some "must have" tools to do it. I had only done a little SMD stuff before, but once I watched the tutorial, it wasn't so bad. Actually, doing the smaller components is the worst.. and I didn't really have the right tweezers. I had a couple of bad joints, but got them resolved pretty quickly. 

 If you take your time, you'll probably be able to do it yourself..


----------



## Anima87

Quote:


  Originally Posted by *MrSlim* /img/forum/go_quote.gif 
_Someone asked before about a price, it's in thread somewhere.. check the last few pages of posts. 

 Also, if you read though the beginning of the thread there is some good info on SMD soldering (including a tutorial) as well as some "must have" tools to do it. I had only done a little SMD stuff before, but once I watched the tutorial, it wasn't so bad. Actually, doing the smaller components is the worst.. and I didn't really have the right tweezers. I had a couple of bad joints, but got them resolved pretty quickly. 

 If you take your time, you'll probably be able to do it yourself.._

 

Hi Slim

 Thanks for the reply.

 I am much like James May from top gear - i like spending time doing my projects, and don't mind it taking my time. I would just hope that the documentation is a bit better than the schematic, as i don't find it very easy to read. However, the board layout helps somewhat.

 I need to check how to insert each component, as it now something i do often, and i do not work with.. but i like it on a hobby plane.


----------



## amb

Quote:


  Originally Posted by *Anima87* 
_I would just hope that the documentation is a bit better than the schematic, as i don't find it very easy to read._

 

Anima87, have you looked at the official γ2 and γ1 websites?


----------



## fc911c

I just finished my Y2 and I must say I am very happy with the way it sounds. I have it matted with a Y1 full ++, great job guy's thanks for the out standing kits.

 Frank


----------



## amb

FYI. Mouser is currently out of stock of the Wima 505-FKP2100/100/2.5 polypropylene film caps until December. You can use 505-FKP2100/100/5 as substitute. It has 5% tolerance instead of 2.5%, but the difference is negligible (the LPF response is way above audio range anyway).


----------



## 4season

Here's a couple of pics of my Gamma 2, hope you folks can see an easy and obvious fix that I keep missing 
	

	
	
		
		

		
			





 Besides my Weller WPTCN soldering station, I also have a new 850B hot air setup that I'm still learning to use.

 The oscillator seems to be putting out a decent square wave around 25 mhz.

 U3 delivers a split-second 3V pulse to U4 immediately at startup but otherwise sits idle.


----------



## amb

Quote:


  Originally Posted by *4season* 
_U3 delivers a split-second 3V pulse to U4 immediately at startup but otherwise sits idle._

 

Ooh. Sounds like you used the wrong part for U3. It should be a MCP100, you probably installed a MCP101 in there.


----------



## 4season

Ouch, you're right, I had U9D and U3 swapped. Corrected that, and now I get white noise and lots of it. Audio output sounds like white noise, but looks like semi-random square waves pulsing a couple of times a second. 3.3B power supply is also pulsing like that and looks pretty noisy. Maybe I shouldn't have reused those parts?


----------



## amb

4season, I thought that it was working fine without ASRC, so what changed other than installing the ASRC, oscillator, and fixing U3? Don't forget you need to remove all the JP2-_n_ jumpers.


----------



## Anima87

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Anima87, have you looked at the official γ2 and γ1 websites?_

 

Hi

 Yes i have, but only for the y2.. I'm just used to idiot proofed assembly instruction stadign what part goes where. The only thing i see is a sort of connection diagram. But i might just need to spend some time into understanding the schematic. 

 I also found this on page 39:

  Quote:


  Originally Posted by *misterx* 
_
 The parts cost is roughly $230 not including tax and shipping from Mouser, Digi-key or Allied.

 The parts cost drops to roughly $190 if you eliminate the USB to S/PDIF outputs, the filter select switch, the anti clipping switch and the Gamma 1 DAC section.
 The caveat is you will have to design your own custom panels or make them by hand (which is a major PITA but would save you another $45 to $50)_

 

I have a contact who is working for an electronics company, so i might be able to keep price the down. 

 Found this link in the thread (It's a gold mine once you have the keywords 
	

	
	
		
		

		
		
	


	




)

https://dk.mouser.com/ProjectManager...sID=e7373810f7

 MERCHANDISE TOTAL:

 $58.56 (USD)

 Then i would need the boards themselves, a case and i'm good to go?

 Casing: 15 USD

 Boards: 27 USD


 Thanks!


----------



## MisterX

Quote:


 Then i would need the boards themselves, a case and i'm good to go? 
 

You would also need a Gamma 1 board and parts.


----------



## Anima87

hi MisterX

 Thanks, the parts were forgotten (Boards are 12 and 15 USD)


----------



## amb

Anima87, I know you want to be spoon-fed with everything, but you should read the y1 and y2 websites thoroughly before ordering any parts. There are many build options to consider which will affect what parts you'd need. Also, MisterX's Mouser project does not include everything, so you should use the websites' parts lists sections as the _definitive_ guide.

 Yes, it will take some work, but that's the nature of this kind of DIY.


----------



## Anima87

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Anima87, I know you want to be spoon-fed with everything, but you should read the y1 and y2 websites thoroughly before ordering any parts. There are many build options to consider which will affect what parts you'd need. Also, MisterX's Mouser project does not include everything, so you should use the websites' parts lists sections as the definitive guide.

 Yes, it will take some work, but that's the nature of this kind of DIY._

 

Appreciate the honesty. I'll do some more research before jumping at it.

 I'm just pretty excited tbh. Was going to buy a DacMagic for 400 USD, and now find this at roughly 200 USD. I love diy, and believe that i can do this project. 

 Been reading the schematic, and it's fairly simple once you take your time to read it. You can even trace the routes over at the board. 

 Thank you for your comments, it gives food for thought before i jump at it.


----------



## Beefy

Quote:


  Originally Posted by *Anima87* /img/forum/go_quote.gif 
_Been reading the schematic, and it's fairly simple once you take your time to read it. You can even trace the routes over at the board._

 

Once you understand the nature of the optional parts, it is pretty much paint by numbers. Check, double check, and triple check your parts list against AMB's website before you order anything. Check, double check, and triple check every part as you install it on the board. Take your time, be patient and very little can go wrong.


----------



## 4season

Ugh how embarrassing: I've been fussing with electronics since my teens, and here I go making one rookie mistake after another with my DAC 
	

	
	
		
		

		
		
	


	




 Turns out I had a solder bridge on the DAC between pins 1 and 2, which I missed under the microscope because I was only looking straight down onto the board, whereas the bridge was small and on the vertical side. The DAC *had* been fine, but I must've run my soldering iron there by mistake while resoldering the ASRC chip. I'm having fun learning SMD, but it definitely has me feeling a bit like a beginner again! Now all I need are the two missing 22 ohm resistors for the USB port, and I'm done.


----------



## Anima87

Just wondering..

 My source, a laptop (Lenovo T61), only has headphono output, some usb, firewire and some expansion ports. I see the following while reading the overview of the y1:

 # The maximum S/PDIF resolution and sampling rate is limited to 24-bit 96KHz for best digital filter response.
 # The maximum USB resolution and sampling rate is 16-bit 48KHz.

 That way, i see the s/pdif is superior to the usb. Now, does anyone know how to be able to output to the Y1 without the USB? - i see firewire can handle the higher stream of data, but a firewire to s/pdif adapter can't be found on google. Any ideas?

 # Ports: 3 USB 2.0, 1 FireWire, Monitor out, modem, Ethernet, headphone out, microphone in
 # Slots: 1 PC Card Slot, 1 ExpressCard slot (optional media card reader and Smart Card reader)


----------



## Beefy

Quote:


  Originally Posted by *Anima87* /img/forum/go_quote.gif 
_# The maximum S/PDIF resolution and sampling rate is limited to 24-bit 96KHz for best digital filter response.
 # The maximum USB resolution and sampling rate is 16-bit 48KHz.

 That way, i see the s/pdif is superior to the usb._

 

Do you have any music that is higher than standard CD at 16/44.1? If not, then don't worry about it.


----------



## Anima87

Ok, thanks.

 Most music is rips from standard CD's, so thats settles it.


----------



## royewest

Some of the Thinkpad docks have coax SPDIF out ports. Good luck with USB -- I had a heck of a time with it when I was on Thinkpads with USB -- lots of stuttering and drops. With luck the more sophisticated reclocking, etc., on the y2 will work much better for you when connected to the TP via USB.


----------



## amb

If you're running Windows Vista, you may experience poor USB audio behavior. Some people seem not to be affected while others have trouble. My HP Pavilion dv7 laptop with Vista64 Home Premium SP2 has problems with USB audio, but the same machine dual booted to Linux works great, so it's not a hardware problem. I don't know if Windows 7 would fix this. The whole audio architecture in Vista and later seems to be problematic.

 Windows XP works fine, and of course, so does modern releases of Linux and Mac OS X.


----------



## Anima87

I'm using two drives that i swap - one is with XP, and one is with the new Windows 7. Never been a fan on Vista tbh.

 I've got some more research to do, but i think i'm gonna go with the Gamma 1 full (A) option, and then maybe expand to the ++-verision. It's an old laptop, so maybe it's time to see what the markets brings next year..

 amb, have you guys sent out some units for review? - I can't find any reviews on google. I can do with building experiences, but i always read a review of the stuff i buy on the internet before buying..

 Have a nice evening, and thanks to all of you for your help,


----------



## amb

Quote:


  Originally Posted by *Anima87* /img/forum/go_quote.gif 
_amb, have you guys sent out some units for review? - I can't find any reviews on google. I can do with building experiences, but i always read a review of the stuff i buy on the internet before buying.._

 

No, I've not ever done anything like that with my projects. The only time people get to hear them before they build or buy is at meets or other audio events. There are some reviews written in this thread (and others), look for them.


----------



## m1abrams

Subjective reviews are well subjective and only meaningful to the reviewer and maybe to someone who values that reviewers opinions. However in the audio space there are few reviewers that I trust to provide a meaningful subjective review.
 As for technical reviews AMB provides very nice technical review of his products.


----------



## sergery

Amb has built and provided some nice info on the unit with and without the ASRC. Has anyone else had a chance to listen to both? Alternatively can someone give a review or some impressions of the non-ASRC version? Just wondering how much of an improvement it offers in actual listening, not just filter response (that is a clear win).

 cheers

 serge


----------



## 4season

I listened to mine without ASRC for about a week (coax input only, hooked up to my NAD CD player) and it wasn't bad at all. Smoother and more euphonic, I thought. Even when used in the "B" filter setting, with frequency response down at 14 khz, I found it pleasant, and when listening to my brand-new 5 CD set of early Django Reinhardt 78s (JSP Records JSP901), it was no hardship at all 
	

	
	
		
		

		
			





 I've heard very expensive setups which had far less high frequency response.

 But the attacks also seemed soggier than I'd consider ideal.

 ASRC seems to really tighten and brighten things up. More accurate, but perhaps not as "lush".


----------



## sergery

Thanks for the added input - I forgot you just commented on this:rolleyes

  Quote:


 ASRC seems to really tighten and brighten things up. More accurate, but perhaps not as "lush". 
 

So it is a fairly audible benefit to your ears? Assuming tight and bright is good at the expense of lush.

 the other post


----------



## 4season

Quote:


  Originally Posted by *sergery* /img/forum/go_quote.gif 
_So it is a fairly audible benefit to your ears? Assuming tight and bright is good at the expense of lush._

 

Yes, I think so, but it drove me to remove the two small film bypass capacitors at the outputs (C19, C25), and so far I think it sounds better without 'em.


----------



## sergery

Quote:


  Originally Posted by *4season* /img/forum/go_quote.gif 
_Yes, I think so, but it drove me to remove the two small film bypass capacitors at the outputs (C19, C25), and so far I think it sounds better without 'em._

 

Interesting, I have been wondering about the differences in sound with the different cap configurations as well. Could I coerce you to go into further detail? It will help me plan my build, I am sure others are curious as well. Of course I may just have to try both ways.
	

	
	
		
		

		
		
	


	




 thanks


----------



## 4season

Quote:


  Originally Posted by *sergery* /img/forum/go_quote.gif 
_Interesting, I have been wondering about the differences in sound with the different cap configurations as well. Could I coerce you to go into further detail? It will help me plan my build, I am sure others are curious as well. Of course I may just have to try both ways.
	

	
	
		
		

		
		
	


	




 thanks
	

	
	
		
		

		
		
	


	


_

 

For what it's worth, I'm using an AD8656 opamp driving line outputs via 22uf non polarized Nichicon Muse caps: The OPA2365 was out of stock at the time.

 I thought the stock setup of 22uf electrolytic bypassed with 1uf film cap seemed to have plenty of air and top-end sparkle, but maybe not as much lower-frequency weight as I might like. I felt that removing the film cap reduced some of the high frequency energy, giving me a tonal balance that was more to my liking. 20 years ago, I spent way too much time fussing with bypass capacitors, but today's "audio grade" electrolytics sound pretty good to me without any add-ons.


----------



## Shahrose

I think I asked this before but didn't get any replies, but, should there theoretically be a SQ difference between the two different types of inputs (S/PDIF vs USB) in the y2? More specifically, is it possible that USB is inferior than the others? I ask because earlier I saw this finding mentioned by one of the DIY'ers in the y1 thread.


----------



## grenert

Quote:


  Originally Posted by *4season* /img/forum/go_quote.gif 
_I thought the stock setup of 22uf electrolytic bypassed with 1uf film cap seemed to have plenty of air and top-end sparkle, but maybe not as much lower-frequency weight as I might like. I felt that removing the film cap reduced some of the high frequency energy, giving me a tonal balance that was more to my liking. 20 years ago, I spent way too much time fussing with bypass capacitors, but today's "audio grade" electrolytics sound pretty good to me without any add-ons._

 

On the Gamma-1, which uses the same output cap system, I tried 22uF Silmics alone and with a small 0.01uF MKP1837 metallized polypropylene. The film bypasses produced a high frequency graininess that I did not like, so I pulled them out. The Silmics on their own are very nice. I may try some larger bypasses... or I may not.


----------



## amb

Quote:


  Originally Posted by *Shahrose* /img/forum/go_quote.gif 
_I think I asked this before but didn't get any replies, but, should there theoretically be a SQ difference between the two different types of inputs (S/PDIF vs USB) in the y2? More specifically, is it possible that USB is inferior than the others? I ask because earlier I saw this finding mentioned by one of the DIY'ers in the y1 thread._

 

Aside from different maximum resolution and sample rate limitations. if everything is working perfectly then there shouldn't be any audible difference between the two as long as you stay within the limits of each. In reality, though, some versions of Windows (e.g., Vista) don't work well with USB, so you may get better performance via S/PDIF.

 On the other hand, depending on your source device's S/PDIF port implementation, it may or may not be bit-perfect. This is especially true of some computer sound cards. So you may be better off with USB.

 In short, there is no universal answer to this question. It depends on the specifics of your setup.


----------



## 4season

For no particular reason, here are photos of my completed Gamma 2!


----------



## MisterX

Nice to see that you have it all sorted out.


----------



## dean0

finished building my y2, attatched to a working y1 full config, and not working 
	

	
	
		
		

		
			




 The selector switch stays red and there is a highing noise when connected to my amp, any ideas?


----------



## DrGolem

Successfully (kind-of) built gamma2. Everything seems to work fine and it produces a clear high quality audio. In first attempt to assembly I misplaced U4 and U5 chips 
	

	
	
		
		

		
		
	


	



 I build no-ASRC and haven't put any switches for filters and anti-clip.
 One issue I have - ACLIP leg has connection to +3.3V source. I checked legs of chip, tried re-solder few times and can see that there is no visible solder bridges between legs.
 How does it affect DAC performance to have ACLIP connected to 3.3V line? Obviously, I can't put ACLIP switch in, because it will shorten voltage line to ground.


----------



## amb

Quote:


  Originally Posted by *dean0* 
_finished building my y2, attatched to a working y1 full config, and not working 
	

	
	
		
		

		
		
	


	



 The selector switch stays red and there is a highing noise when connected to my amp, any ideas?_

 

Check the basics first -- do the 3.3V and 4.5V test points give the correct voltage reading? Checked for proper mounting orientation of all parts? Checked to make sure you used all the correct parts everywhere? Checked for solder joint issues?

  Quote:


  Originally Posted by *DrGolem* 
_One issue I have - ACLIP leg has connection to +3.3V source. I checked legs of chip, tried re-solder few times and can see that there is no visible solder bridges between legs.
 How does it affect DAC performance to have ACLIP connected to 3.3V line? Obviously, I can't put ACLIP switch in, because it will shorten voltage line to ground._

 

ACLIP is U5 pin 26. Pin 25 (MUTEB) is connected to +3.3V, so there is a high chance that there is a bridge between those two pins. Try to locate and fix that bridge.

 If ACLIP is connected to +3.3V (rather than left to float or switched to ground), the DAC chip will activate its de-emphasis filter which will cause the high frequency response to droop. See the appropriate WM874x datasheet for details.


----------



## dean0

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Check the basics first -- do the 3.3V and 4.5V test points give the correct voltage reading? Checked for proper mounting orientation of all parts? Checked to make sure you used all the correct parts everywhere? Checked for solder joint issues?


 ACLIP is U5 pin 26. Pin 25 (MUTEB) is connected to +3.3V, so there is a high chance that there is a bridge between those two pins. Try to locate and fix that bridge.

 If ACLIP is connected to +3.3V (rather than left to float or switched to ground), the DAC chip will activate its de-emphasis filter which will cause the high frequency response to droop. See the appropriate WM874x datasheet for details._

 


 5v = 2.49v
 4.5v = 2.2v
 3.3v = 0.01v

 Checked solder joints and orientation of parts and all is correct, cannot see any solder bridges under magnifacation, but on the dac chips there are a couple of pins next to each other that my multimetre says are connected.
 Any ideas? 
 Thanks 
 dean0

 btw I havnt connected the clipping/filter switches yet, does this matter? and im powering it through usb


----------



## dean0

Okay re-flowed the solder on both chips and installed the switches, but still no luck. 
 Any help would be appreciated


----------



## digger945

Quote:


  Originally Posted by *dean0* /img/forum/go_quote.gif 
_ on the dac chips there are a couple of pins next to each other that my multimetre says are connected.
 Any ideas? _

 

If you will give the pin numbers and part name or number, or a pic, then I'll look at the schematic and see if those are supposed to be connected.


----------



## amb

dean0, you said that your y1 full config is working. Is it still working when the y2 board is mated? Verify that the 5V test points on the y1 is measuring ok. If so, yet the 5V test points on y2 measures low, then you have a basic contact problem with the pin headers/receptacles between the two boards.

 Also, since your y2 3.3V test point has no voltage, you should reflow U2.


----------



## dean0

Okay problem solved, there was a solder bridge on the dac chip that I missed.
 Testing atm with HD650 
	

	
	
		
		

		
		
	


	



 Thanks for the help
 ps What does the digital filter and anti clipping do?


----------



## amb

Quote:


  Originally Posted by *dean0* /img/forum/go_quote.gif 
_ps What does the digital filter and anti clipping do? 
	

	
	
		
		

		
		
	


	


_

 

See "Tech highlights" at the y2 website.


----------



## DrGolem

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_ACLIP is U5 pin 26. Pin 25 (MUTEB) is connected to +3.3V, so there is a high chance that there is a bridge between those two pins. Try to locate and fix that bridge.

 If ACLIP is connected to +3.3V (rather than left to float or switched to ground), the DAC chip will activate its de-emphasis filter which will cause the high frequency response to droop. See the appropriate WM874x datasheet for details._

 

Thank you! There were indeed a solder bridge somewhere - after cleaning between pins with a sharp knife, connection to V+ line has gone.


----------



## fyleow

I'm getting pretty much the exact same measurements as dean0. Have reflowed U2 as well as the DAC and TI chip several times to no avail.

 Also managed to burn part of a Wima cap in the process. Do I need to replace that?


----------



## amb

fyleow, your board-to-board connector header pins look bent. Are they making good contact with the receptacles on the y1 side?

 The Wima cap does not have to be replaced, but _I would_ because I'd be bothered by the appearance.


----------



## dean0

Quote:


  Originally Posted by *fyleow* /img/forum/go_quote.gif 
_I'm getting pretty much the exact same measurements as dean0. Have reflowed U2 as well as the DAC and TI chip several times to no avail.

 Also managed to burn part of a Wima cap in the process. Do I need to replace that?







_

 

Reflow U4, I bet there is a solder bridge near the top by C7, that was my problem anyway. The method I used, add liquid flux (very important), then add solder to your iron and clean so there is a small coating on the iron, then drag down the pins, you should see the solder reflow clearing any bridges you may have.
 Hope that helps
 dean0

 ps also clean the whole board with a flux cleaner (spray, alcahol etc.) after reflowing the chip. and may be worth reflowing any 'dodgey' looking pads on the bottom, some require a fair amount of heat to flow properley.
 you will also have to remove the switches to solder U4 properley

 off topic; anyone know why my feedback link in my signature appears like that?


----------



## nightanole

<a href="http://www.head-fi.org/forums/f12/dean0-440292/">Feedback</a>


feedback

 "feedback"


----------



## dean0

Quote:


  Originally Posted by *nightanole* /img/forum/go_quote.gif 
_<a href="http://www.head-fi.org/forums/f12/dean0-440292/">Feedback</a>


feedback

 "feedback"_

 

mmm... that didnt help much, what did you change??


----------



## fyleow

I will check the back of the board for cold joints. What's the best way to fix the cold joints? When I flux the area and heat it up with the iron it doesn't come cleanly off and tens to form just a blob of solder still attached to the component lead.

 I had a lot of issues with the y2 and cold joints especially on the ground leads for some resistors and the small caps. The solder just didn't seem to want to stick at all. The pads get oxidized and it gets harder and harder to fix. I'm not sure what the issue is though...I don't think I'm doing anything out of the ordinary based on what I've seen/read on curious inventor as well as soldering in the past.


----------



## amb

If you're not getting a nice joint on the ground pads, your iron is not hot enough.


----------



## fyleow

Hmm ok...I will try bumping up the temperature a bit. I'm using a temp controlled Weller WES50 at 650F and Cardas Quad Eutectic solder. I try not to use too high temps due to fear of damaging components.


----------



## Billyk

Don't forget the flux, lots of flux....


----------



## MrSlim

Quote:


  Originally Posted by *fyleow* /img/forum/go_quote.gif 
_Hmm ok...I will try bumping up the temperature a bit. I'm using a temp controlled Weller WES50 at 650F and Cardas Quad Eutectic solder. I try not to use too high temps due to fear of damaging components._

 

The silver content in the Cardas solder probably needs a higher temp to melt. You might want to try some regular o'l solder.. 

 oops.. egg on my face.. I just looked at the Rat Shack solder Im using and its got 2% solder in it.. and it worked fine


----------



## Sfox7076

Anyone know where I can get two Toshiba optical transmitters? It's the last part I need to build my two DACs. I have never tried to build something so ambitious, so I am excited. Until then, I just have my old Advent Model One to fix.

 Shawn


----------



## CodeToad

I've found 700 works well with Cardas quad. Tap-shimmy-shimmy-Boom you're done.


----------



## fyleow

Thanks for the advice. The flux and 700F temps helped in getting some of the joints I was having trouble with. Still no luck though, the voltages not looking good. I've also resoldered one side of the DAC as the wick from a debridging job soaked up a lot of it. As I looked under magnification I could see that sometimes the wick does get stuck and leave strands which potentially cause shorts so definitely have to be careful there.

 I'm getting pretty good at figuring out if it works without even touching the multimeter! If the LED light glows dimly that means the voltages aren't right and it's not working.

 EDIT: I also straightened the pins a little to make sure the contact between the boards is better. One of the 5v pads on the y2 board measures 5v so at least that connection is good.


----------



## amb

Quote:


  Originally Posted by *Sfox7076* /img/forum/go_quote.gif 
_Anyone know where I can get two Toshiba optical transmitters? It's the last part I need to build my two DACs. I have never tried to build something so ambitious, so I am excited. Until then, I just have my old Advent Model One to fix.

 Shawn_

 

The only source for Toshiba TOTX147PL is Farnell. or through their affiliate Newark in the US with a flat $20 handling charge. If you don't mind a different brand, try this.


----------



## nightanole

Quote:


  Originally Posted by *dean0* /img/forum/go_quote.gif 
_mmm... that didnt help much, what did you change??_

 

I used forum tools and highlighted your http://www.head-fi.org/forums/f12/dean0-440292/ and placed it in a link window, then named it feedback. You are trying to use strait html code...


----------



## Billyk

fyleow, a technique for checking joints on the larger chips that I find useful is to hold the board up to a bright light. I usually see all of the pads clearly through the board itself and that helps me find any bridges. It works well and I have found a few that I could not have found otherwise.


----------



## pixeljedi

Quote:


  Originally Posted by *Billyk* /img/forum/go_quote.gif 
_fyleow, a technique for checking joints on the larger chips that I find useful is to hold the board up to a bright light._

 

That's a good tip Billyk. I use a x30 Jewelers loupe. Helps me see what I may have missed at x4 with my flip-downs.


----------



## fyleow

Quote:


  Originally Posted by *Billyk* /img/forum/go_quote.gif 
_fyleow, a technique for checking joints on the larger chips that I find useful is to hold the board up to a bright light. I usually see all of the pads clearly through the board itself and that helps me find any bridges. It works well and I have found a few that I could not have found otherwise._

 

This is a great tip. Holding it up directly to a table lamp I could only see through the U4 part one on side clearly. I thought I had spotted some bridges under the light but I think they turned out to be just traces. Pins 15,16,17 and 26,27 on U4 which according to the schematic are supposed to be connected.

 I worked on any suspicious joints that I could find and reflowed the SMDs again tonight but I'm still not having any luck. I'm really not sure what to do at this point.


----------



## MisterX

Quote:


 I worked on any suspicious joints that I could find and reflowed the SMDs again tonight but I'm still not having any luck. I'm really not sure what to do at this point. 
 

Did you include the Crystal in the list of suspicious joints? 
 I am asking because they look pretty suspicious from where I am sitting but I only have a picture to work from. 
 If you pile up the solder to high on those pads it can come in contact with the "plate" on the top of the crystal and cause a short circuit (just ohm between the top of the crystal and each of the 4 through hole pads, pin 2 is the only one that should have continuity) .


----------



## fyleow

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Did you include the Crystal in the list of suspicious joints? 
 I am asking because they look pretty suspicious from where I am sitting but I only have a picture to work from. 
 If you pile up the solder to high on those pads it can come in contact with the "plate" on the top of the crystal and cause a short circuit (just ohm between the top of the crystal and each of the 4 through hole pads, pin 2 is the only one that should have continuity) ._

 

That's a good observation. I actually piled up the solder high on the corners because I didn't know about the plate. That may be the issue.

 I was just worried that the crystal wasn't making good contact...what I did was tin the pads with solder first and heated the pads while placing the crystal on it. I don't know if I did it incorrectly or not.


----------



## a1m80t

I have my y2 working great, but I damaged the solder mask in a spot. Is it necessary to cover that the damaged solder mask?


----------



## Nebby

Not necessary imo, if it's cased up. But I would still get some clear nail polish and cover it back up.


----------



## a1m80t

Thanks for the heads up. I’ll go patch it up. On a different note, I found that the y2 to be sound noticeable better than y1.


----------



## fyleow

It's working! Thanks everyone for the help and to Ti and Marshall for creating the DAC.

 I started cleaning up the excess solder on pin 4 of the crystal and found it strange that no matter how clean it looked it still shorted with the ground. Looking at the schematic the pin 4 is the 3.3v so I checked the schematic for all the parts that were supplied with the 3.3v. Turns out that there was a bridge on the Wolfson DAC that I missed.

 It sounds great and looks great! I love the compact form factor, it takes up a fraction of the space my Zhaolu does. The casing work was non existant (perfect for me as I hate drilling) and with the AMB panels it has a really nice look.


----------



## amb

fyleow, I am glad you found the problem. Happy listening!


----------



## pila405

Hey Ti and Marshall, I have seen that you sell the front and rear panel on AMB shop, is it engraved and drilled? and where can I get the rest of the chassis and how much it cost?

 Another thing is: how is this DAC in comparision with other DACs which use the same Wolfson chip - like the Opus? or maybe Pico DAC?


----------



## fordgtlover

Quote:


  Originally Posted by *pila405* /img/forum/go_quote.gif 
_Hey Ti and Marshall, I have seen that you sell the front and rear panel on AMB shop, is it engraved and drilled? and where can I get the rest of the chassis and how much it cost?
 ..snip_

 

The case is listed in the parts list at:
The &gamma;2 Compact High Performance DAC


----------



## pila405

Can someone aswer my comparision question please?


----------



## Billyk

fyleow, that's terrific news! I know you will enjoy it.


----------



## amb

pila405, I don't think many people will answer that because it's inappropriate to pitch one design against another like that around here. Not only that, "Opus" means different things to different people because it's only the DAC core. It does not include the other portions of the circuit (digital input receivers, ASRC, analog output filtering and buffering, etc) that would comprise an equivalence to a fully-equipped γ2 (which has some options of its own).

 Rather than the subjectives, why not read the γ2 website for the technical info? If you're interested in how it "sounds", then you should listen to one with your own ears.


----------



## pila405

You are right. Sorry.
 But unfortunately I can't listen to any until I buy it cause I live in Israel and don't think anyone here owns one...

 I guess I can't fall on the wrong thing. So to the work - I have beta22+sigma22 and gamma2 to build! 


 Thanks.


----------



## Shahrose

Quote:


  Originally Posted by *a1m80t* /img/forum/go_quote.gif 
_I found that the y2 to be sound noticeable better than y1._

 

Good to see. I was wondering how much of an improvement there was. I'd appreciate it if you could elaborate further when you get the chance.


----------



## geezer

OK, I am in the process of building a γ2 and have just reached a "decision stage" regarding the opamp. OPA2365's are not available at the moment, but I do have a AD8656. I will only be using line-out and have no intention of directly driving headphones.

 I have not installed the components surrounding the opamp as yet so I can get the iron to it when I come to fit the chip.

 So. I have two questions for anyone who can help:

 1. Should I go ahead and fit the AD8656 and accept a possible lesser SQ?

 2. If I decide to wait for the OPA2365's to return to stock, how do I test that the DAC is working? I have no 'scope.

 Your comments/recommendations will be much appreciated.

 Ken


----------



## MisterX

Quote:


 1. Should I go ahead and fit the AD8656 and accept a possible lesser SQ? 
 

Here is a link---> 

Gamma-2 (γ2) DAC Thread - Page 48 - Head-Fi: Covering Headphones, Earphones and Portable Audio

  Quote:


 2. If I decide to wait for the OPA2365's to return to stock, how do I test that the DAC is working? I have no 'scope. 
 

Here is another link-----> 

The &gamma;2 Compact High Performance DAC


----------



## geezer

MisterX, Thanks for that - I had already seen those refs. As far as the opamp is concerned, I think I am looking for something subjective - They may test identical, but how do they sound? If I commit to the AD8656, it will be difficult to roll to the OPA2365, so I want to fit the best from the start.

 For example, which would you prefer sonically? - I assume you have compared both opamps.

 Thanks - Ken


----------



## amb

Quote:


  Originally Posted by *geezer* /img/forum/go_quote.gif 
_As far as the opamp is concerned, I think I am looking for something subjective.
 ...
 I want to fit the best from the start._

 

One person's subjective preference does not make it "best" for everyone else. If I tell you I like apples better than oranges, that doesn't make apples the "best" does it?

 One thing you can be certain of, is that both opamps will provide excellent sound. You can't go wrong with either one.


----------



## geezer

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_One person's subjective preference does not make it "best" for everyone else. If I tell you I like apples better than oranges, that doesn't make apples the "best" does it?

 One thing you can be certain of, is that both opamps will provide excellent sound. You can't go wrong with either one._

 

It does if you are comparing apples... 
	

	
	
		
		

		
			





 Thanks for that - I'll go with the AD8656 - I have a bit of a soft spot for Analog Devices.

 Cheers - Ken


----------



## geezer

I just thought I'd post to thank AMB and MisterX for their help and advise - I fitted the AD8656 opamp. The γ2 is now working - And sounding superb. I have it playing as I type through my M³ into AKG K701's 
	

	
	
		
		

		
		
	


	




 and I am in audio heaven.

 So, for anyone in a similar position of being unsure which opamp to choose - Don't think the AD8656 is second best.

 BTW - I found that a thin bead of solder along the ground plane edges of both γ1 and γ2 help to make a nice snug fit in the case slots, so you get a really good ground connection with the case.

 Cheers - Ken


----------



## amb

Good to hear! (double entendre, lol)


----------



## MisterX

No pics? 
	

	
	
		
		

		
		
	


	



 What a jip....


----------



## geezer

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_No pics? 
	

	
	
		
		

		
		
	


	



 What a jip.... 
	

	
	
		
		

		
		
	


	


_

 

OK, can do that - Just give me a little while to crank up the camera and I'll post a few snaps.

 Ken


----------



## geezer

OK, as promised - Here are a few pics of my completed γ2. I have also included the γ1 which I build some time ago.

 Here is the γ1 re-joined using pieces of copper wire soldered on the joint line. It may not look pretty, but it does the job.






 The γ2 ready to be connected to the γ1






 A couple of shots of the final build. I really like the red case. I wont be needing digital out, so the front can be minimalist.






 I isolated the phono jacks with a thin strip of tape to make sure they don't come into contact with the case.






 Thanks for looking - Comments will be appreciated...

 Cheers - Ken


----------



## pila405

The pics. are very very small. Can see none.


----------



## geezer

Quote:


  Originally Posted by *pila405* /img/forum/go_quote.gif 
_The pics. are very very small. Can see none._

 

Yeh, sorry about that I posted the thumbnails - Should be OK now, I have re-loaded images.

 Ken


----------



## MisterX

Nice job.


----------



## tally3tally

hi im following this for a long time now but am confused between the parts lists for a gamma2 a gamma1 partslists is also required and am mixing things up
 can someone please point me to a fully populated BOM so i can compare my partslist


 kindly disregard the above

 these are now my questions

 my setup
 itunes- airport express-- Gamma2 optical in --output to my Amp

*Gamma2 setup*

 Gamma1 in *E: S/PDIF DAC only* config (coax and optical inputs, selectable with front panel switch, no USB board).
 and 
 Gamma2 board mated to it

 external power

*Questions*

 1) Is this the right way to go??

 1) later if and when i feel the need of a Usb interface *can i add the usb board* *???*
 lemme know if im going terribly wrong in understanding the working concept....


----------



## pila405

GREAT WORK geezer! Looks awsome!!!
 I realy like this metalic red.


----------



## deerinheadlights

I want to use Sigma11 configured for 5 volts to power the y1y2 full++. I don't know what VA toroidal to get. Y236001 (9v+9v, 15VA) or Y236101 (9v+9v, 30VA) would be more than enough or too much?


----------



## amb

30VA is more than enough for y1/y2, but if you want to make something that could also power other more current-hungry devices, then it won't hurt to over-rate the transformer a bit.


----------



## m1abrams

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_30VA is more than enough for y1/y2, but if you want to make something that could also power other more current-hungry devices, then it won't hurt to over-rate the transformer a bit._

 

Maybe like a micro-controller that someone has in the prototype stages


----------



## 4season

This is probably really old news to everyone else, but changing my AC brick had more effect on the sonics than expected: The Motorola cell phone charger (5V, 800 mA, switch-mode) sounded the worst, giving me a rather lean tonal balance. My Apple iPhone charger (via USB) seemed to give me somewhat warmer sonics, but the real surprise was the CUI Inc 5v 300mA regulated linear PS: Loads of bass energy there. I had previously removed the .1 uf film bypass caps from the outputs, thinking they overemphasized the high frequencies, but now I'm thinking of trying them again!

 Wondering if there's any point in trying an even quieter power supply, or whether things are right where they need to be?


----------



## ShinyFalcon

Interesting findings 4season. I always wanted to make (or rather modify the one I already have...) a TREAD for my y1/y2 but never got to it. I have a charger for my cell phone, but I really don't want to plug it in... Are you powering your y2 using USB or the DC jack?

 A question, will there be a problem if one of the ferrites (the one closest to the edge on the y1's USB board) was chipped/scraped in the process? This particular ferrite is very very close to the case wall but at the moment isn't making contact, and I'm hoping the outer ferrite core isn't conductive. I really wasn't expecting to have to sand down the y1 boards, and had to resort to my lead clipper... and you can guess the rest.

 Another question, if the y1 lost ground contact with the case (ie, the connection to the case via the ground strips wasn't strong in the first place), would that cause problems? I recall a builder having shocked his y1 with static merely by touching the case, and that got me wondering whether I should bother scraping my case's slots, for isolation.

 I'm hoping that some slight rearrangements for the next version of the y1/y2 boards (particularly the ferrites, the voltage regulators' caps and making access to the regulators more removal/reflow-friendly) is possible; I just feel uneasy with the parts very close to the edge, but maybe doing so would make it worse


----------



## amb

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Interesting findings 4season. I always wanted to make (or rather modify the one I already have...) a TREAD for my y1/y2 but never got to it. I have a charger for my cell phone, but I really don't want to plug it in..._

 

The σ25 Regulated power supply





  Quote:


 A question, will there be a problem if one of the ferrites (the one closest to the edge on the y1's USB board) was chipped/scraped in the process? This particular ferrite is very very close to the case wall but at the moment isn't making contact, and I'm hoping the outer ferrite core isn't conductive. I really wasn't expecting to have to sand down the y1 boards, and had to resort to my lead clipper... and you can guess the rest. 
 

As long as the ferrite isn't actually broken, then don't worry about it.

  Quote:


 Another question, if the y1 lost ground contact with the case (ie, the connection to the case via the ground strips wasn't strong in the first place), would that cause problems? I recall a builder having shocked his y1 with static merely by touching the case, and that got me wondering whether I should bother scraping my case's slots, for isolation. 
 

Grounding the case provides RFI shielding, potentially reducing interference. It may or may not make a difference depending on how "noisy" your environment is.


----------



## Beefy

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_The σ25 Regulated power supply



_

 

Sneaky bugger! 
	

	
	
		
		

		
		
	


	




 Does this mean that you will always have supplies of S24 boards? They are always listed as 'limited quantities', and I dread the day that they actually disappear......


----------



## amb

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_Sneaky bugger! 
	

	
	
		
		

		
		
	


	




 Does this mean that you will always have supplies of S24 boards? They are always listed as 'limited quantities', and I dread the day that they actually disappear...... 
	

	
	
		
		

		
		
	


	


_

 

Yeah, aside from the obvious utility of a small and simple PSU, σ25 is also a new way to justify the continued availability of σ24.


----------



## hansel_ng

Hello. instead of 5V at VCC i'm getting about 4.83V. Everything else reads correctly (exactly 3.3V and 4.75V at the other points). Is this normal? I'm using the y2 straight from usb. thanks!


----------



## 4season

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Are you powering your y2 using USB or the DC jack?_

 

Yes.

 I use whichever one happens to be handiest at the moment.


----------



## amb

Quote:


  Originally Posted by *hansel_ng* /img/forum/go_quote.gif 
_Hello. instead of 5V at VCC i'm getting about 4.83V. Everything else reads correctly (exactly 3.3V and 4.75V at the other points). Is this normal? I'm using the y2 straight from usb. thanks!_

 

It just means that your computer's USB port 5V power is a little low.


----------



## wirewiggler

Just finished and tested, sounds great on usb from my computer to my M3. Will have to move it into listening room and see how it compares to the Meridian. 

 thanks Ti for great design.

 Bill


----------



## K3cT

I've searched the thread here but found no information so please bear with me.

 Is it possible to build a USB-only version?


----------



## Beefy

Sure. Just build the y1 part of it as a 'Lite' or USB-I2S converter.


----------



## K3cT

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_Sure. Just build the y1 part of it as a 'Lite' or USB-I2S converter._

 

OK. Then would it be possible to add the other outputs should the need arise in the future? 

 I think ideally I want to work with the F++ configuration but only populating the parts necessary for USB operation but I'm not sure that's possible or not.


----------



## Beefy

........ its all there on the y1 website.


----------



## K3cT

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_........ its all there on the y1 website._

 

OK, it's clear that I still have a lot of homework to do. 
	

	
	
		
		

		
		
	


	




 Thanks anyway Beefy. Always the reliable guy when it comes to DIY!


----------



## mattcalf

Getting excitingly close to my monster mouser order purchase. 

 Not that I'm getting the fuses from Mouser but I'm just wondering what kinda fuse is recommended for the σ24 and σ25 combo?

 Thanks again,
 Can't wait!


----------



## amb

Quote:


  Originally Posted by *mattcalf* /img/forum/go_quote.gif 
_Not that I'm getting the fuses from Mouser but I'm just wondering what kinda fuse is recommended for the σ24 and σ25 combo?_

 

The fuse style entirely up to you -- as long as the rating is appropriate for the application.


----------



## johnwmclean

AMB, is there any viable preference for slow blow vs fast blow?


----------



## amb

Slow blow fuses are primarily used in applications where there might be a very large turn-on current surge (large toroid + large bulk capacitors). If you were to use a fast blow fuse that would actually provide sensible overload protection in such a circuit, chances are it would blow out at turn-on time. Hence you need slow blow fuses to allow large turn-on transients without blowing fuses all the time, yet when there is a sustained overload condition the fuse would blow.

 For a small PSU with a limited amount of turn-on surge, a fast blow fuse will provide better protection.

 Anyway, this stuff should be in its own thread rather than the γ2 thread.


----------



## johnwmclean

Thanks Ti, back to topic then.


----------



## mattcalf

Appropriate?


----------



## amb

Is this just for the γ1/γ2? If so, 3A is way too high. I would use a 0.25A-0.5A fuse on the AC mains side of the transformer.


----------



## mattcalf

Ok thanks for that.


----------



## Robinson34

With regard to tally3tally's question 
http://www.head-fi.org/forums/f6/gam...ml#post6128708, 
 I also want to build a y1,y2 that gets it's input from an Apple Airport Express optical s/pdif signal. There seem to be several parts on the y1 E:s/pdif DAC only, configuration that would not be necessary including among others the DAC itself. 
 My question is what can be eliminated from the y1 E:s/pdif configuration knowing that it is only going to be used with a y2?


----------



## ShinyFalcon

With E, basically the USB portion (about 2 hours of work out of ~6 hours) is gone. On the y1 DAC board, U1 can be omitted. Maybe U3, U6, U9 (not sure about U4), C8-11, C22-27, R7-10, L3D, if you're not using the WM8501. Look at the parts list under the E column to find out what you can omit.


----------



## MisterX

Removed.


----------



## Robinson34

Thanks guys! This helps a lot. Should this configuration be added to the y1 or y2 website as another choice?


----------



## amb

Quote:


  Originally Posted by *Robinson34* /img/forum/go_quote.gif 
_Thanks guys! This helps a lot. Should this configuration be added to the y1 or y2 website as another choice?_

 

No, I consider that to be a sub-configuration. There are many such possibilities under the main configurations and if I were to document all of them, it would clutter up the site and make it more confusing.


----------



## Robinson34

I understand, I guess that's why we have these forums. Thanks again


----------



## mattcalf

I'd just like to echo the sentiments of many DIYers before me:
 Check, recheck and then check again your various orders (Mouser + Farnell etc) against the AMB BOM!!!!

 Last night after I'd been through it once I thought I was all good. After ordering and printing off my 60+ part order and checking it once more in bed I realised I had ordered one less resistor in two value classes, under-ordered some ceramic capacitor by 17(!!!) and ordered extra micro switches.

 In my haste I got in communication with Mouser and was lucky enough to be able to modify my order.

 Also thanks to Ti Kan who had my back luckily.

 I'm really excited to order my AMB lot as soon as Ti has the sigma 24 and 25 in stock and get building in the school holidays.


----------



## ShinyFalcon

Another victim 
	

	
	
		
		

		
		
	


	




. 

 Rather on depending on Mouser's project manager, spreadsheets are the way to go, along with Mouser's Easy BOM functionality.

 For the giggles I could build a σ25 using a TREAD board...


----------



## amb

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_For the giggles I could build a σ25 using a TREAD board..._

 

lol. But that won't integrate with the σ24...


----------



## MisterX

Would be a real easy PCB to etch.


----------



## a1m80t

Does anyone know what kind of torx screws are normaly included in the box enclosure? I ruined four torx screws tapping the enclosure (I used a flat screw driver)


----------



## amb

a1m80t,the Box Enclosures come with self-tapping philips head screws, not torx. You don't have to tap the enclosure if you use the stock screws. If you want to use nicer socket cap screws, then you should tap the holes with actual taps, not with another screw.

 EDIT: oops, I answered wrongly -- was thinking of the Hammond. Box Enclosures come with torx "tapping" screws and philips head screws. Sorry about that.


----------



## MisterX

I have a couple extras floating around....


 PM me your address info an I will drop a bunch of them in the mail in the morning.


----------



## glt

Is the OSR pin selectable to match input sampling rate? or is it always set to high? I was looking at the response curves for the DAC and with input sampling rate of 44.1/48K, you can set OSR to 0, Z or 1, According to information elsewhere, setting OSR to 1 turns off the internal upsampler and setting the OSR pin to low tells the DAC to apply maximum (internal) upsampling.


----------



## MisterX

Quote:


 Is the OSR pin selectable to match input sampling rate? or is it always set to high? 
 

http://www.amb.org/audio/gamma2/gamma2_v100_pcb_top.jpg

 Notice the text next to U6?


----------



## glt

Thanks. I was looking at the filter response curves for 44/48 in the website. Thus the response for 44/48 will be different depending on the OSR setting wouldn't it?


----------



## MisterX

With or without the ASRC installed?


----------



## glt

Without the ASRC. I suppose the graphs in the website for 44.1/48 material without the ASRC are for OSR=1? (bypass the internal oversampling)


----------



## MisterX

http://www.head-fi.org/forums/6079734-post810.html

 Edit:

 Yes, reconfiguring the OSR pin (by installing a jumper across the corresponding U6 positions) changes the "filter response curve" when a 44.1 or 48K "sample" is fed to the DAC when the ASRC is not installed but it also changes the behavior of the filter mode switch.


----------



## Wizik

Hello, I have one question, when I´m going to solder SMD on Gamma2, solder iron MUST BE grounded ? Because my soldering iron isn´t now.


----------



## MisterX

You should be fine with an "ungrounded iron"


----------



## Wizik

Are you sure ? Lot of people, who are soldering SMD told me, that I need grounded soldering iron and some told me that I need cuprextit desk under y1/y2 PCB conected to soldering iron and to me (for example to metal watch).


----------



## amb

Some parts are ESD-sensitive, but it just depends on your comfort level. I don't use such things as a grounded wrist strap or work surface and have not blown any parts yet... In a lab or production environment those things may be required by the company, but I think most of us get by without them and it's fine. Just observe some basic common sense when handling the parts, such as keeping them in the anti-static bags until you're ready to solder them, don't walk around while holding the bare parts, and touch the grounded case of a computer or other equipment before you touch the parts. That should be good enough.


----------



## Wizik

So I can use only my ungrounded soldering iron and it´s okay ? I´m going to build it in home conditions, so I don´t have any special table or other thinks. Realy i can sold it without grounding ?


----------



## m1abrams

I have a working y1 and y2 that was built with an ungrounded iron. They work great.


----------



## Beefy

I built 2 y1's with an ungrounded iron. No problems.


----------



## Shahrose

Just received my MisterX y2. The build quality is excellent (better than expected) and it sounds quite good, but I have some practical issues with it. 

 First of all, the windows volume doesn't work with it (it's position has no effect on volume). This is my main problem because it's really inconvenient as my amp and speakers are far enough from me that I'd have to get up and a few paces to change the volume.

 Secondly, when scrolling through songs or switching to the next track/previous track there is a delay of about 500ms before it registers. It's quite annoying when scrolling within a song. I've tried using WASAPI, KS and DS and out of the 3, DS has the least amount of delay, but then it's not bit-perfect. Reducing the buffer in foobar alleviated it a bit, but not enough to get rid of the problem.

 Any help would be appreciated.


----------



## Beefy

Quote:


  Originally Posted by *Shahrose* /img/forum/go_quote.gif 
_First of all, the windows volume doesn't work with it (it's position has no effect on volume).....

 .....DS has the least amount of delay, but then it's not bit-perfect._

 

If you use the Windows volume control it isn't bit-perfect either.


----------



## m1abrams

Quote:


  Originally Posted by *Shahrose* /img/forum/go_quote.gif 
_Just received my MisterX y2. The build quality is excellent (better than expected) and it sounds quite good, but I have some practical issues with it. 

 First of all, the windows volume doesn't work with it (it's position has no effect on volume). This is my main problem because it's really inconvenient as my amp and speakers are far enough from me that I'd have to get up and a few paces to change the volume.

 Secondly, when scrolling through songs or switching to the next track/previous track there is a delay of about 500ms before it registers. It's quite annoying when scrolling within a song. I've tried using WASAPI, KS and DS and out of the 3, DS has the least amount of delay, but then it's not bit-perfect. Reducing the buffer in foobar alleviated it a bit, but not enough to get rid of the problem.

 Any help would be appreciated._

 

1st off if you plan to control volume from the computer you can through the idea of "bit-perfect" out the window. Since it can not transmit bit-perfect from the computer to the DAC AND adjust the volume at the same time. Keep in mind the most important thing you want to avoid is resampling. I.E. 44.1khz sample rate converted to 48khz.

 Now then all the problems you describe are not due to the gamma2 but in your computers setup. I suspect your volume issue is due to using ASAPI driver. The delay issue probably can be traced back to the delay/buffer settings, again these have zero to do with the DAC but with your software.

 How are you connecting the gamma2? USB or SPDIF?


----------



## Shahrose

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_If you use the Windows volume control it isn't bit-perfect either._

 

 Quote:


  Originally Posted by *m1abrams* /img/forum/go_quote.gif 
_1st off if you plan to control volume from the computer you can through the idea of "bit-perfect" out the window. Since it can not transmit bit-perfect from the computer to the DAC AND adjust the volume at the same time. Keep in mind the most important thing you want to avoid is resampling. I.E. 44.1khz sample rate converted to 48khz.

 Now then all the problems you describe are not due to the gamma2 but in your computers setup. I suspect your volume issue is due to using ASAPI driver. The delay issue probably can be traced back to the delay/buffer settings, again these have zero to do with the DAC but with your software.

 How are you connecting the gamma2? USB or SPDIF?_

 

Thanks for the quick responses.

 I'm running Windows 7 Ultimate and using foobar2000 0.9.6.9 WASAPI connected to the DAC via USB and feeding it into the M^3 + Sigma 11. I'm also using an external PSU for the y2. All my other computer specs can be found under my profile.
 The delay is present with KS as well as WASAPI. With DS, the delay is absent.
 I see your point about the problem of changing volume with bit-perfect output. That being said, is there a way to change the volume from my computer? (let's forget about it being bit-perfect or not for now).


----------



## Beefy

You should be able to change the volume when using Direct Sound.

 If you can't, it is your software that is screwy - not the DAC.


----------



## MisterX

image remove


----------



## MisterX

Simple enough?


----------



## Shahrose

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_You should be able to change the volume when using Direct Sound.

 If you can't, it is your software that is screwy - not the DAC._

 

I can't change volume with DS either. BTW, I never said it's the DAC's fault...

 I'm sure someone presented the same issue as me before but I can't locate the post and see if he found a way to change volume through Windows (regardless of it being bit-perfect or not). 

 As a temporary solution, I'm using the built-in volume control of foobar, but if someone knows what can be done to enable volume-control through Windows, please feel free to PM me or post here (so everyone can know).


----------



## Shahrose

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Simple enough?_

 

Yep, that's what I'm doing for now. I tried what you showed in the Mixer tab as well, and that works but it doesn't work when I change the main "Speakers" tab which is what my keyboard is linked to. Strange.

 Let me also take this chance to thank you for your excellent work Marshall. The DAC is honestly better than I thought it would be both in terms of build and SQ.


----------



## m1abrams

Quote:


  Originally Posted by *Shahrose* /img/forum/go_quote.gif 
_Yep, that's what I'm doing for now. I tried what you showed in the Mixer tab as well, and that works but it doesn't work when I change the main "Speakers" tab which is what my keyboard is linked to. Strange.

 Let me also take this chance to thank you for your excellent work Marshall. The DAC is honestly better than I thought it would be both in terms of build and SQ._

 

You know that is interesting little issue. I never change the volume in windows so never noticed it. But mine does the same thing. I am not using WASAPI either. It seems that changing the Master Vol. does not affect the Application volume even though the Mixer shows the levels changing. If I manually adjust the Application volume it does change the volume. Odd

 P.S. Nice setup, that is pretty much my exact setup except I am connected to the DAC via spdif coax from my X-Fi. I love my recently completed M3/Sigma11 combo with Gamma2


----------



## Shahrose

Quote:


  Originally Posted by *m1abrams* /img/forum/go_quote.gif 
_You know that is interesting little issue. I never change the volume in windows so never noticed it. But mine does the same thing. I am not using WASAPI either. It seems that changing the Master Vol. does not affect the Application volume even though the Mixer shows the levels changing. If I manually adjust the Application volume it does change the volume. Odd_

 

Exactly what I mean. It's just a little inconvenient since it renders my keyboard volume control useless.

  Quote:


  Originally Posted by *m1abrams* /img/forum/go_quote.gif 
_P.S. Nice setup, that is pretty much my exact setup except I am connected to the DAC via spdif coax from my X-Fi. I love my recently completed M3/Sigma11 combo with Gamma2 
	

	
	
		
		

		
		
	


	


_

 

Thanks. This combo is producing the best SQ I've ever heard from the HD650s.


----------



## tally3tally

Hi
 i just ordered all the parts at mouser and farnell 
 ive hit a roadblock
 this part U2U in the Gamma 1 parts list has turned out to be on mouser's backorder list
 and my friend is getting the stuff along with her to India so i cant wait... 
	

	
	
		
		

		
		
	


	



 can someone nerdy enough suggest a replacement
 there are many listed at the mouser website but im not sure ill be able to pick the right one
 here are the details
 A replacement at Mouser itself would be most useful 
	

	
	
		
		

		
		
	


	



Mouser Part #: 595-SN74AHC1G08DBVR
 Manufacturer Part #: SN74AHC1G08DBVR
 Manufacturer: Texas Instruments
 Description: Gates (AND / NAND / OR / NOR) Single 2-Input


----------



## MisterX

Someone already has. 
	

	
	
		
		

		
			





74AHC1G08GV,125 NXP Semiconductors Gates (AND / NAND / OR / NOR)


----------



## tally3tally

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Someone already has. 
	

	
	
		
		

		
		
	


	




74AHC1G08GV,125 NXP Semiconductors Gates (AND / NAND / OR / NOR)_

 

thanks a ton


----------



## pixeljedi

Front panels arrived today.

 All said and done, these are remarkable units and an incredible value for the performance you get out of them. Hats off to AMB and Mister X - well done. For my non-headphone setup, I use a PS Audio DL-III (a Cullen Stage IV mod) and when we switched between it and the Gamma 2, they were very similar in performance. I have to pick up the parts for a third soon, as the two I've built are already going to friends.


----------



## mattcalf

Sweet build pixeljedi, the custom front panels are really sweet! 
	

	
	
		
		

		
		
	


	




 Itching to get mine going.


----------



## pixeljedi

Thanks mattcalf, I had a good time with these. Only had a snag with the second one. Had to reflow the oscillator a few times, but then she started singing. Talk about building your smd skills, these are awesome for that. I used to hate it, but now it's almost meditative - haha 
	

	
	
		
		

		
		
	


	




 I'm listening through it right now and man do I ever love this thing.


----------



## amb

Just FYI, if you're planning to build a σ25 PSU with a σ24 transformer mounting board for use with a γ1+γ2, a 2.8VA 9V EI-30 transformer should work well. The σ25 should be configured to output 5V DC.

 Part numbers:

 Digi-Key: 567-1040-5-ND (115V primary) or 567-1042-5-ND (230V primary)
 Farnell: 1689068 (230V primary)

 Mouser does not stock any EI-30 transformers with the needed specs . However, if you're going to be powering a γ1 only (no γ2), you can use Mouser 673-030-7151-0

 Alternatively, you can use an Amveco TE62011 (Digi-Key TE62011-ND) or TE62021 (TE62021-ND) toroidal transformer, and skip the σ24 PCB. These transformers have two 9V secondary windings which should be wired in parallel. They also have two primary windings which should be wired in parallel for 115V AC mains, or in series for 230V.

 You could also use an AC or DC wallwart (unregulated) rated at 9V 300mA or above instead of a transformer.


----------



## mattcalf

Just placed my AMB order. 
	

	
	
		
		

		
		
	


	







 Really excited now, checked off all my parts physically against a BOM and I'm ready to roll.

 Can't wait to get building.

 Thanks Ti. 

  Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Just FYI, if you're planning to build a σ25 PSU with a σ24 transformer mounting board for use with a γ1+γ2, a 2.8VA 9V EI-30 transformer should work well. The σ25 should be configured to output 5V DC._

 

Just added to my cart at Farnell.


----------



## ShinyFalcon

Has anyone looked into cases suitable for stacking the σ24 and σ25? I came up with 563-CU-791 which I think is spacious enough and maybe allows for a switch as well. Add a 1.3mm cable assembly and something to attach to AC mains and I'm set...


----------



## m1abrams

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Has anyone looked into cases suitable for stacking the σ24 and σ25? I came up with 563-CU-791 which I think is spacious enough and maybe allows for a switch as well. Add a 1.3mm cable assembly and something to attach to AC mains and I'm set..._

 

Do not forget a fuse! - course you can just get an IEC that has a switch and fuse builtin for max use of space and also a bit safer since you have less Mains wiring that could be exposed.


----------



## ShinyFalcon

I was hoping to keep my adapter small and cute, but I guess it's inevitable eh? 
	

	
	
		
		

		
		
	


	




 I think I have 500mA fuses left over from my Opus... maybe not. I do have a certain metal case 2.75" X 2.1" X 1.60" in mind, and that allows me to put the boards side by side (there is no thickness/strange slots to worry about) but it still won't allow for a fuse/switch unless I leave everything external, which makes me cringe.


----------



## amb

You _could_ just wire the fuse with an inline fuse holder and no switch (plug it in and it turns on), and use a strain-relieved AC power cord without IEC -- basically a home-made wallwart that doesn't actually hang on the wall. I would suggest a case with ventilation though, the transformer and the regulator will both get hot.


----------



## Conte Zero

First of all, hi everybody, while it's been a while following this forum this is kinda my first post, and sadly for a troubleshooting advice.
 Actually the trouble is with a gamma1 full, originally to be paired to a gamma2 once working, but the original thread on headwize, as the whole forum, is currently under maintenance and in read only mode.
 So, hoping I can still pose my technical question here in the meanwhile (lot of photos for a reward 
	

	
	
		
		

		
		
	


	




 )... I built a gamma1 full, tested voltages and shortcircuits as standard initial testing showed, checked for cold joints with a lens and so on, then I turned it on, connecting to USB for both power and data.
 The DAC sounded very well, tested it on a pair of AKG KSC-75, just some little scratches and noise at the maximum iTunes volume, but seemed to dissipate in a few seconds at least for the most. The switch light also lit red to become green when audio was playing to blink red then green again while playing. Then I tried to move the input switch, which of course silenced the headphones, yet, and there it is the problem, when switched back to USB it barely stayed green for a few moments then turned red and no more sound from it from then, like there was no data input. I of course disconnected and reconnected the USB cable, just to be sure restarted the mac, reflowed nearly all SMD components on board, checked again for burned components or toasted smell (both none), cold joints (seems none) and wrong parts (seems none too).
 I have to say that I have some experience in SMT soldering and one source of the problem MAY be that I cleaned in isopropolic alcohol spray the boards, which there MAY have been some slight residues under some chip, maybe shortcircuiting it.
 I'd hope you can help me at least restrict the possible broken or malfunctioning part with your experience, I followed that schematics and tried to check or reflow anything that may be part, but before replacing al of the components I'd like to have at least a few to try first.
 I repeat that voltages where, while powered from USB, perfect from both boards and when mated togheter and sadly I'm not able right now to both try to power the gamma1 from a wall plugged transformer, nor to check for any other input (optical or coaxial), the latter I may be able to try tomorrow.
 As this little jewel is surely form a very good pair with my PPAv2 I hope to get it back working again very soon... can't actually wait for it to blossom to a full gamma2 too eh eh...

 Thanks anyway for any help, sorry again for not posting in the most right topic, yet can't find or use one more specific.

 Ric


----------



## ShinyFalcon

The mating pins are probably the most problematic. However if your light switch isn't turning off (just blinking red and green) we can probably rule out a connection problem. The problem is most likely located on the USB board. Is your build the full++ or config A?

 What's your operating system? Can you try messing with the buffer length in foobar2000 (press stop and then play after every buffer length change), and maybe try ASIO or WASAPI?


----------



## Conte Zero

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_The mating pins are probably the most problematic. However if your light switch isn't turning off (just blinking red and green) we can probably rule out a connection problem. The problem is most likely located on the USB board. Is your build the full++ or config A?

 What's your operating system? Can you try messing with the buffer length in foobar2000 (press stop and then play after every buffer length change), and maybe try ASIO or WASAPI?_

 

I tought mating pins too, I tried to bend the males a little to force a little more contact while pushing them in yet no change.
 Also the switch light isn't turning red and green, it stay solid red always, just blinked, actually like a faulty jumping connection for a few moments before just turning solid red, no matter what.
 My build is the A profile, full one, not full++.
 I tried it on MacOSX and linux (so Core Audio and PulseAudio over ALSA respectively), haven't tried changing the buffer sizes, but on both systems are dinamically set based on latency and system load, also I'm not so sure it is a software problem... kinda fear is a faulty hardware one... :/


----------



## Conte Zero

Some more informations: after a very engaging saturday morning with me, a multimeter and the gamma1 I found that U5D middle gnd pin was lifted and I reflowed it, checking for correct connection.
 Yet same results, no sound and red light only. But I've noticed another strange behaviour, the DAC is always powered by USB, when the switch is in the middle position is always a bright, firm red, when I select the coaxial setting it becomes nearly visible, only to become redder and redder in a three-four seconds, like some capacitor charging or something like that...


----------



## amb

Conte Zero, try reflowing the U1U, U2U and U2D solder joints.


----------



## Conte Zero

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Conte Zero, try reflowing the U1U, U2U and U2D solder joints._

 

Ok, thanks, trying now, I'll let you know in a few!


----------



## amb

... and also U8D which controls the switch illumination.


----------



## Conte Zero

Reflowed them, quick multimeter checked for shortcircuits and false joints... connecting... and voila green light...
 Never mentioned you have just a won a free week in Italy if you come nearby? 
	

	
	
		
		

		
			





 The problem seemed to be a defective U2D joint... I don't know how I kept missing it before... well, again thanks, I'll test the DAC for a while and I'll be sure to post photos later.

 Ric

 EDIT: Actually the red switch problem manifested again while inserted into to case, I tried moving the pcb a little and so on, looking again at the mating connector, then I realized that the mating connector soldered tips were left uncutted as they were very short, but they, once inserted in the case, were sometimes touching the aluminum... cut them and as predicted all is again working perfectly (actually, due to the faulty joint a lot better than before).

 Thanks again Ti and ShinyFalcon, offer for the trip to Italy is still valid!


----------



## ShinyFalcon

U2D is the biggest thing on the board, how could you. 
	

	
	
		
		

		
		
	


	




 Don't feel bad, I missed a joint on my second CS8416... Hope your γ2 build goes well


----------



## dsavitsk

Can someone measure the voltage on pins 11 and 18 (VMIDR and VMIDL) on the WM8741? Are they at the same DC potential as the VOUT pins (12, 13, 16, 17) or at 1/2 voltage?


----------



## amb

They are _all_ at 1/2 AVDD.


----------



## Wizik

Hi all, please, I need to know, if I can change U4D on y1 (Microchip Technology MCP100-315DI/TO or Maxim/Dallas DS1818 reset manager TO-92) for something else, because I can´t found it, maybe I lost it. Please help, I can´t buy it anywhere in my country.


----------



## amb

Quote:


  Originally Posted by *Wizik* /img/forum/go_quote.gif 
_Hi all, please, I need to know, if I can change U4D on y1 (Microchip Technology MCP100-315DI/TO or Maxim/Dallas DS1818 reset manager TO-92) for something else, because I can´t found it, maybe I lost it. Please help, I can´t buy it anywhere in my country._

 

Sorry, those are the only pin-compatible devices I know of . Farnell is your closest source, the part number is listed on the γ1 website parts list.


----------



## PScal

Hey look, a picture!






 Waiting for my forgotten u2 before I go any further... Any obvious errors so far? This is my first ever surface mount build (and 2nd build ever). Those voltage regulators are so tiny. One of them could be mistaken for a flea. I made sure all of the grounds were continuous and there were no bridges, but maybe I got something backwards...


----------



## pidesd

Quote:


  Originally Posted by *Conte Zero* /img/forum/go_quote.gif 
_
 Thanks again Ti and ShinyFalcon, offer for the trip to Italy is still valid! 
	

	
	
		
		

		
		
	


	


_

 

i d be careful guys, i heard italians had lots of venereal diseases.


----------



## Conte Zero

First of all, that's not true, we kinda have low statistical averages about sexual diseases, second... well I offered to host them, not hump them.


----------



## mattcalf

Pictures do not do it justice how tiny these things actually are, my AMB order arrived today in an package. I opened it up expecting bags of stuff to fill the envelope, however, I had to pull our a DVD brace which contained the parts.

 The PCB's are things of beauty, I can't begin to imagine how long it would've taken to plan the design and layout.

 Can't wait for my Dealextreme order (flux, tweezers, lead clippers) to come in so I can start building this DAC. :

 Thanks Ti.


----------



## ujamerstand

grr, they ran out of 1.5K resistors at mouser, and there is no other equivalent in terms of size... RN55's are too big. Digikey has them but thats another 20 dollars of shipping, I can get it along with the enclosure at Newark, but there's a 20 dollars handling fee PLUS shipping as well. Would it be okay if I go one value up or down? Or tombstone a larger RN55 in the R16D, R2U and R5U positions? If there's any other way I can go to save that cash, I would. But I don't really want to derail from the schematics if I can help it. I've already decided to use 270-221-RC at R11D and R8U positions since those are out too. Any input would be helpful!

 Edit: Well, it seems after a bit of research I might as well order directly from fernell for the enclosure and missing resistors. Thanks for viewing!


----------



## amb

ujamerstand, 1.5K is the value shown in the PCM2707 datasheet for R2U and R5U, I think you can get away with using the next step up or down, but I would replace them with the proper 1.5K resistors when you can get some. For R16D, you can go down a step in value which will raise the TPS2115A's current limit protection threshold a bit.


----------



## cobaltmute

RN50 are equivalent size, aren't they? Bit more pricey, but some are in stock.

 Last I checked Digikey was $8 shipping to Toronto for UPS next day


----------



## amb

Yes, Vishay-Dale RN50 and CMF50 can also be used.


----------



## MrSlim

Quote:


  Originally Posted by *ujamerstand* /img/forum/go_quote.gif 
_ Digikey has them but thats another 20 dollars of shipping,_

 

What method are you using for shipping? I pay $8 for overnight to Ottawa, via UPS with Digikey I wish they had more of the parts I need because it burns me to pay $20 for the faster shipping from Mouser. Mouser only charges $8 for the slow shipping (a week) as long as you aren't in a rush..


----------



## mattcalf

Would this be suitable for cleaning the board of flux after finished building?

 Thanks,
 Matt.


----------



## Beefy

Quote:


  Originally Posted by *mattcalf* /img/forum/go_quote.gif 
_Would this be suitable for cleaning the board of flux after finished building?

 Thanks,
 Matt._

 

No, not even close. Try Cat # N0049 at Dick Smith. I'm pretty sure that is the stuff I used to use, and should be 99% isopropanol.

 A _soft_ toothbrush can help too.


----------



## mattcalf

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_No, not even close. Try Cat # N0049 at Dick Smith. I'm pretty sure that is the stuff I used to use, and should be 99% isopropanol.

 A soft toothbrush can help too._

 

Thanks beefy, will swing by DSE and grab that stuff when the time comes.


----------



## ujamerstand

Well, I think I might have confused digikey's 8 dollar shipping with mouser's. Mouser's 8 dollar shipping has yet to arrive on me. It's been over a month, and I'm still waiting... It's good to know a cheaper, faster option! 

 Final question before I go, what is the minimum power rating for the resistors in gamma-2? I was afraid to use the 1/20 watt RN50 resistors when the ones listed on the BOM was 1/8 watt.

 Oh, and thanks for answering my questions!


----------



## amb

Quote:


  Originally Posted by *ujamerstand* /img/forum/go_quote.gif 
_Final question before I go, what is the minimum power rating for the resistors in gamma-2? I was afraid to use the 1/20 watt RN50 resistors when the ones listed on the BOM was 1/8 watt._

 

Don't worry about the power rating of resistors on these boards. None of them would dissipate enough power to come close to these ratings. Also bear in mind the ratings between the RN50s and the others are not directly comparable, because RN50 is rated using Mil-spec and are at least "derated" by a factor of two.


----------



## ujamerstand

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Don't worry about the power rating of resistors on these boards. None of them would dissipate enough power to come close to these ratings. Also bear in mind the ratings between the RN50s and the others are not directly comparable, because RN50 is rated using Mil-spec and are at least "derated" by a factor of two._

 

Great, that means I just need to double check my BOM to make sure I have all the parts before making the purchase.


----------



## PScal

I could use some troubleshooting help. I finished the gamma 1 and gamma 2 (yay!) and the initial tests passed. The gamma 1 works, but when I plug in the gamma 2, it does not work. I get an 'unrecognized usb device' error on the PC. 

 I noticed that the 4.5v and 3.3v test points were measuring equal voltages when powered on (about 2.5 volts) despite reading a large ohm value when powered off. I also measured resistance when powered on and it seems they are shorted (<1 ohm resistance)... but as soon as I unplug it, the resistance goes up (5k ohm and greater). Has anyone experienced this before?

 Edit. it appears I do have a short. The 3.3v and 4.5v are continuous with ground even when disconnected. The hunt begins...


----------



## mattcalf

Quote:


  Originally Posted by *ujamerstand* /img/forum/go_quote.gif 
_Great, that means I just need to double check my BOM to make sure I have all the parts before making the purchase._

 

Please triple, you may not be as stupid as I am. But I made a few mistakes that almost resulted in me paying alot more to do another mouser order!


----------



## nattonrice

mattcalf, another alternative is a liter of this:

Isopropyl Alcohol 100% : Adelaide Moulding & Casting Supplies


----------



## mattcalf

Quote:


  Originally Posted by *nattonrice* /img/forum/go_quote.gif 
_mattcalf, another alternative is a liter of this:

Isopropyl Alcohol 100% : Adelaide Moulding & Casting Supplies_

 

Thanks, looks perfect but I don't wanna fork out too much money for postage when I can walk down to a DSE.


----------



## K3cT

OK. Just making sure, if I want to convert the y1 Lite to y2 I would need to make it accept external 5V DC power and short JP1 no?


----------



## amb

Quote:


  Originally Posted by *K3cT* /img/forum/go_quote.gif 
_OK. Just making sure, if I want to convert the y1 Lite to y2 I would need to make it accept external 5V DC power and short JP1 no?_

 

No, γ2 can run on whatever power source option(s) you choose to use on the γ1. JP2U should be used only if you don't have U1D installed, and want to hard-wire the power source to USB or external _only_. Please see the jumper settings table on the "Instructions" section of the γ1 website. JP1D should be shorted with a jumper.

 EDIT, if you're referring to JP1 on the γ2 board, and your γ1 is a "Lite" config, then yes, you need to install a jumper there. The γ2 website has detailed info on this. This is completely unrelated to USB vs. external power.


----------



## K3cT

OK, I thought γ2 needs external power to perform its best and since my γ1 Lite is USB bus-powered, I'm thinking of populating the parts required for that at γ1 DAC board.


----------



## amb

A good/clean _linear_ regulated external supply should be better than USB power, but the difference is not night and day. My measurements show that USB power causes some minor noise floor spikes/hash, whereas it's absolutely clean and spike-free running on a σ25 PSU (or a CUI 5VDC linear regulated wallwart I have on hand that's no longer available). If you'd like a little overkill, you could also use a σ11 and know that the PSU will never be a performance bottleneck.

 Of course, different computers may have different levels of USB power noise, so one can't really conclude that USB power will _always_ be audibly worse.


----------



## K3cT

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_A good/clean linear regulated external supply should be better than USB power, but the difference is not night and day. My measurements show that USB power causes some minor noise floor spikes/hash, whereas it's absolutely clean and spike-free running on a σ25 PSU (or a CUI 5VDC linear regulated wallwart I have on hand that's no longer available). If you'd like a little overkill, you could also use a σ11 and know that the PSU will never be a performance bottleneck.

 Of course, different computers may have different levels of USB power noise, so one can't really conclude that USB power will always be audibly worse._

 

Gotcha. I guess why not since any improvement is good in my book. 
	

	
	
		
		

		
			





 I've studied the schematics and documentations in the γ1 site. These locations ie. J1D, L4D, C1D, U1D, R14D, R15D, R16D, and U1D (I don't have the U1D installed) are all that are required to be populated for the external 5V DC PS no? Please correct me if I'm wrong somewhere. 

 That should be all that are required to prep the γ1 for γ2 conversion am I correct? JP1U is empty in my γ1 so that shouldn't be a problem. 

 Thanks, ti.


----------



## amb

Quote:


  Originally Posted by *K3cT* /img/forum/go_quote.gif 
_I've studied the schematics and documentations in the γ1 site. These locations ie. J1D, L4D, C1D, U1D, R14D, R15D, R16D, and U1D (I don't have the U1D installed) are all that are required to be populated for the external 5V DC PS no?_

 

Correct.

  Quote:


 That should be all that are required to prep the γ1 for γ2 conversion am I correct? JP1U is empty in my γ1 so that shouldn't be a problem. 
 

You should have a wire shunt across JP1U pins 2-3 if you have a γ1 Lite (B) configuration. This selects I2S output from the PCM2707. JP1D should also be shorted with a jumper.


----------



## PScal

Quote:


  Originally Posted by *PScal* /img/forum/go_quote.gif 
_I could use some troubleshooting help. I finished the gamma 1 and gamma 2 (yay!) and the initial tests passed. The gamma 1 works, but when I plug in the gamma 2, it does not work. I get an 'unrecognized usb device' error on the PC. 

 I noticed that the 4.5v and 3.3v test points were measuring equal voltages when powered on (about 2.5 volts) despite reading a large ohm value when powered off. I also measured resistance when powered on and it seems they are shorted (<1 ohm resistance)... but as soon as I unplug it, the resistance goes up (5k ohm and greater). Has anyone experienced this before?

 Edit. it appears I do have a short. The 3.3v and 4.5v are continuous with ground even when disconnected. The hunt begins..._

 

So, weird stuff is happening over here. I noticed that the 3.3v and 4.5v are only shorted after the gamma 2 has been plugged in. First thing when I plug it in, everything works. Then after a couple seconds, the voltages go crazy. My multimeter shows this, and the LED switch also comes on rock solid (red, green, red), then starts to flicker (red) after a 2-ish seconds.

 After I unplug the USB, the 3.3v and 4.5v are continuous for a few minutes on the gamma 2 board. Over time, the resistance between them increases. I assumed the problem was with the DAC, as it seems to be the only thing that touches both 3.3v and 4.5v, but I can't figure out why the resistance seems to be changing over time. Any advice on this? 
	

	
	
		
		

		
		
	


	







 PS - the gamma 1 sounds very nice


----------



## MisterX

Quote:


 I also measured resistance when powered on and it seems they are shorted (<1 ohm resistance)... but as soon as I unplug it, the resistance goes up (5k ohm and greater). 
 

You cannot measure resistance when the circuit is powered on. 

How to Measure Resistance with a Multimeter :: Electronics and Radio Today

  Quote:


 *Remember to ensure the circuit under test is not powered on. Under some circumstances it is necessary to measure resistance values actually on a circuit. When doing this it is very important to ensure the circuit is not powered on. Not only will any current flowing in the circuit invalidate any readings, but should the voltage be high enough, the current resulting could damage the multimeter*. 
 

 Quote:


 I can't figure out why the resistance seems to be changing over time. 
 

You're charging the capacitors. 

  Quote:


 *Ensure capacitors in a circuit under test are discharged. Again when measuring resistance values in a circuit, it is necessary to ensure that any capacitors in the circuit are discharged. Any current that flows as a result of them will cause the meter reading to be altered. Also any capacitors in the circuit that are discharged may charge up as a result of the current from the multimeter and as a result it may take a short while for the reading to settle*.


----------



## ShinyFalcon

Try looking at WM8741's pins 8 and 9, if those are bridged then it will short 3.3V and 4.5V. Heat may cause whatever bridge there is to expand, shorting those two. See if these two voltage points are shorted to ground as well, they shouldn't be.


----------



## PScal

Thanks for the information. I will continue troubleshooting


----------



## PScal

Well still no luck. I am certain pins 8 and 9 are not bridged (via multimeter). The circuit seems to be stable for a few seconds (until the caps charge is my guess) then the voltages plummet. Here's a picture of my board... including melted plastic film cap. Any sore thumbs sticking out?


----------



## mattcalf

If I'm using Cardas Quadeutectic (activated rosin core flux) on my Gamma1+2 should I wait until I have flux or will I be fine soldering with it?


----------



## PScal

Quote:


  Originally Posted by *PScal* /img/forum/go_quote.gif 
_Well still no luck. I am certain pins 8 and 9 are not bridged (via multimeter). The circuit seems to be stable for a few seconds (until the caps charge is my guess) then the voltages plummet. Here's a picture of my board... including melted plastic film cap. Any sore thumbs sticking out?
_

 

Scratch that... cleaned off a little flux from between the pins and she's singing now. Yeah!


----------



## MisterX

Quote:


 If I'm using Cardas Quadeutectic (activated rosin core flux) on my Gamma1+2 should I wait until I have flux or will I be fine soldering with it? 
 

I would suggest waiting.
 It makes it all a lot lot lot lot more easier when you have flux for the SMDs. 

  Quote:


 Scratch that... cleaned off a little flux from between the pins and she's singing now. 
 

Pins 13 and 14 of U4 by chance? 
 They look pretty close in the picture and it fits the symptoms you had described. 
 Nice assembly job.


----------



## mattcalf

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_I would suggest waiting.
 It makes it all a lot lot lot lot more easier when you have flux for the SMDs. _

 

Ok thanks for that. 
	

	
	
		
		

		
		
	


	




 Damn DealExtreme, they need to get their sh!t together.


----------



## Beefy

Quote:


  Originally Posted by *mattcalf* /img/forum/go_quote.gif 
_Damn DealExtreme, they need to get their sh!t together. 
	

	
	
		
		

		
		
	


	


_

 

You really need to stop looking to the internet, when a trip to your local store is so much easier...... Solder Flux Pen 12ml - Jaycar Electronics

 I built two y1's with this pen, and it works perfectly.


----------



## mattcalf

Thanks beefy, I thought I had already searched the Jaycar site for such a solution, however, on second glance I only searched for 'flux remover'.

 Should've known better, Jaycar hasn't disappointed so far. 
	

	
	
		
		

		
		
	


	




 Cheers,
 Matt.


----------



## nattonrice

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_I built two y1's with this pen, and it works perfectly._

 

The one I have sitting here has done every joint in the b22/s22, buff32, two mini3's, two gamma1's and a gamma1/2~
 Amazing the thing is still going O.o


----------



## Beefy

Quote:


  Originally Posted by *nattonrice* /img/forum/go_quote.gif 
_The one I have sitting here has done every joint in the b22/s22, buff32, two mini3's, two gamma1's and a gamma1/2~
 Amazing the thing is still going O.o_

 

Yowza, I had no idea they would last so long!


----------



## nattonrice

Should have seen the look on my face when I picked it up last week for a fix job... crazy good value that pen, provided you look after it.


----------



## mattcalf

Good to hear, providing like most people I catch the DIY bug after this job. 
	

	
	
		
		

		
		
	


	




 My phone is full of Jaycar and DSE Cat. numbers, can't wait to be able to get into town to purchase them!


----------



## K3cT

Does anyone have a personal recommendation for the best WM874x to be used in the Gamma2? As far as I know, the WM8741 is essentially the same chip with different voltage requirement ie. 3 to 5.5V for 8740, 4.5 to 5.5V for 8741 with support for DSP and SACD?


----------



## MisterX

Best is very subjective. 
	

	
	
		
		

		
		
	


	



 If you do not want the filter select or anti clipping mode switches I do not see a reason to pay the premium for the WM8741. 
 And.. I do not see the price difference between the WM8742 and WM8741 as being significant enough to even consider the WM8742.


----------



## K3cT

Not to mention its crappy availability to my location...

 I guess I'll go for the WM8740, thanks Marshall,


----------



## aj-kun

Quote:


  Originally Posted by *mattcalf* /img/forum/go_quote.gif 
_Ok thanks for that. 
	

	
	
		
		

		
		
	


	




 Damn DealExtreme, they need to get their sh!t together. 
	

	
	
		
		

		
		
	


	


_

 

haha i ordered a whole bunch of tools and stuff from deal extreme too... i am waiting :|

 that jaycar stuff is like $1 per ml, wish there was some diy flux i could make =D


----------



## Beefy

Quote:


  Originally Posted by *aj-kun* /img/forum/go_quote.gif 
_that jaycar stuff is like $1 per ml, wish there was some diy flux i could make =D_

 

...... how much do you think you are going to use?!?


----------



## grenert

Well, after a stupid, stupid mistake (frying my WM8741 by soldering it in the wrong orientation 
	

	
	
		
		

		
		
	


	




 ), my gamma-2 is alive and well. To satisfy the DIYer need to "make it my own," I decided to change a few of the capacitors. I have some through-hole 0.1 uF C0G ceramic caps that are small enough to work in some places, and also some surface-mount 0.1 uF C0G caps as well. So, on the gamma-1 and gamma-2 boards, I replaced a number of the X7R caps with C0G ones (bypass on the DACs, opamp, SRC, CS8416 and crystal). I went with LP2985 regulators, since the datasheet specifically states that they are designed to work with low-ESR output caps, which the organic polymer caps certainly are (couldn't find a similar statement in the TPS793xx datasheet, though they do say you can put a ceramic on the output). The datasheet says to use a 1 uF or greater input cap. I have some tiny 2.2 uF Blackgate PK caps, and these have lower ESR than the 1 uF X7R ceramic caps I was considering, so I went with them. For the noise bypass cap on the LP2985, they suggest C0G or PP/PC film caps . I didn't have any in 10 nF size, but I was able to find some PPS surface mount caps for that role. On the Wolfson application notes (WAN-0129), they suggest low ESR caps for the AVDD, DVDD and VMID, so I went with the same organic polymer caps used on the regulator outputs, rather than audio-type capacitors. For the DC blocking caps, I used Silmics on the Gamma-1, and Blackgate NX Hi-Q for the Gamma-2; no film bypass. Here are a few pics:

 Gamma-1





 Gamma-2





 DAC bypassing





 Regulator caps





 Tight fit with the PK caps! (note that in the second photo, I had to situate cap C6U a little off-center to clear the polymer cap)









 I have no idea if these changes made anything better, worse, or different at all. It was just fun to try. Thank you, AMB and MisterX for a great project!


----------



## aj-kun

nice man - in my eyes it looks clean (n00by eyes)
 @beefy, i didnt know that 11mL was alot, i bought like 2 20mL ones from deal extreme - i think they are 20 mL


----------



## rds

I'm a little confused on u4d for the y1. On AMB's website the mouser part listed is 579-MCP100-300DI/TO and yet for digikey it is MCP100-*315*DI/TO
 Is this a mistake or is the 579-MCP100-300DI/TO the prefered part? The reset voltages are slightly different for these two parts.
 Thanks


----------



## MisterX

The answers are a lot easier to find if you search in the right thread. 
	

	
	
		
		

		
		
	


	




http://www.head-fi.org/forums/f6/y1-...ml#post5705915


----------



## rds

thanks =)


----------



## Beefy

Quote:


  Originally Posted by *rds* /img/forum/go_quote.gif 
_I'm a little confused on u4d for the y1. On AMB's website the mouser part listed is 579-MCP100-300DI/TO and yet for digikey it is MCP100-*315*DI/TO
 Is this a mistake or is the 579-MCP100-300DI/TO the prefered part? The reset voltages are slightly different for these two parts.
 Thanks_

 

I answered that for somebody else here


----------



## AudioCats

is buying PCB then all the loose parts the only option? or is there a place I can buy complete Gamma1/2 kits?

 thanks


----------



## ShinyFalcon

Indeed it is so. AMB's shop (required stuff and hard-to-find parts), Mouser (the tiny parts, IC's), Digikey (out-of-stock-at-Mouser-parts, output capacitors, TOSLINK), and Newark (enclosure) are places where you can source your own parts. It shouldn't be too difficult to make kits, but it would depend on the demand for them.


----------



## amb

With the exception of the enclosure, you can obtain all needed parts from me and Mouser. Those out-of-stock items at Mouser all have good substitutes (see recent posts in both gamma threads here).


----------



## MisterX

Quite a few of the "out of stock items" are currently in stock at Newark... but.....

 picture deleted


----------



## ujamerstand

ouch, Looking at that, I kinda realized I should've ordered from newark instead of farnell UK... I wonder how much are they going to charge for shipping now


----------



## ShinyFalcon

Did your order from Farnell ship yet? Call them as soon as possible. What did you order from them?


----------



## ujamerstand

I've ordered the enclosure and 1:1 pulse transformers from them. The shipping was around 13 dollars in the end for UPS saver. Not too bad considering the shipping cost for mouser is 20 dollars for the same service. If only there are no minimum order from them!
	

	
	
		
		

		
		
	


	




(it was 20 dollars for credit card payment)


----------



## K3cT

If I use 22uF caps for C20 and C26, can the γ2 still be used to drive headphones directly?


----------



## Beefy

The bass levels will be in the toilet. You really need something bigger.

 [EDIT] Corner frequency at 300ohms is ~24Hz, but for 32ohms phones it would be 226Hz.


----------



## K3cT

I'm just curious as I have another amplifier for that. If the γ2 is not meant to drive headphones directly, is there any advantage using those 470uF caps?


----------



## Beefy

Quote:


  Originally Posted by *K3cT* /img/forum/go_quote.gif 
_I'm just curious as I have another amplifier for that. If the γ2 is not meant to drive headphones directly, is there any advantage using those 470uF caps?_

 

I can't imagine so. You are moving _down_ the audiophile cap ladder in order to get those large capacitances in such a small size.


----------



## Wizik

Hi, I´m building y2, y1 desk is already complete, I was checking it, but resistors R2D,R3D,R14D and R20D is showing only something between 35-38KΩ instead of 47KΩ, I need to change it, yeah ?


----------



## amb

Quote:


  Originally Posted by *Wizik* /img/forum/go_quote.gif 
_Hi, I´m building y2, y1 desk is already complete, I was checking it, but resistors R2D,R3D,R14D and R20D is showing only something between 35-38KΩ instead of 47KΩ, I need to change it, yeah ?_

 

If you're measuring the resistors after they've been soldered to the board, then the results include paralleled resistances of other parts in the circuit, so you'll read less than the resistor's value. This is normal and you don't need to replace them.


----------



## Wizik

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_If you're measuring the resistors after they've been soldered to the board, then the results include paralleled resistances of other parts in the circuit, so you'll read less than the resistor's value. This is normal and you don't need to replace them._

 

Thanks for reply, but I found that R1D (75Ω) have very low impedance, something about 1-5Ω and R9U (110Ω) the same, so this must be replaced I think, or not ? All other values are good. And one more question, if I make a fault for example in some SMD part like U1U and destroy it when soldering it and I don´t know about that, so when I then plug adapter to y1 board, can it destroy because of this more parts ?

 I hope you can understand my bad English.


----------



## MisterX

Quote:


 Thanks for reply, but I found that R1D (75Ω) have very low impedance, something about 1-5Ω and R9U (110Ω) the same, so this must be replaced I think, or not ? All other values are good. 
 

They are both OK. 
 You are measuring the in-circuit combined resistance of the resistor and a parrelled component (in the case of R9U and R1D that component is a transformer with very low DC resistance) but expecting to see just the value of the resistor.


  Quote:


 And one more question, if I make a fault for example in some SMD part like U1U and destroy it when soldering it and I don´t know about that, so when I then plug adapter to y1 board, can it destroy because of this more parts ? 
 

Doubtful but that is one of the reasons why you are instructed to test the USB section separately.


----------



## amb

R1D is in parallel with T1D transformer's winding, and R9U is in parallel with the T1U's winding. The tranformer windings have low resistance.

 EDIT: MisterX beat me to it.


----------



## Wizik

So I´ll test first the DAC board, then USB board and after that, if will be everything OK, than wire USB and DAC board together and test the sound ?


----------



## amb

The γ1 test procedures are all at the γ1 website "initial check" section. The only difference for γ2 is that since the γ1 board is not snapped apart, you cannot plug the two halves together to test them together. But you can use the γ2 board to do that (populate only J1-J5 first if you want).


----------



## Wizik

Ok thanks, I already read it. I checked everythink, but I´m scared plug it in the DC wallwart :-D


----------



## Wizik

Sorry for stupid questions, but can I use for example these adapter ? It´s 5V, 20W, 4A

MW-SYS1319-2005 2.1 (751-545) - GM Electronic


----------



## ShinyFalcon

The plug is too big. While it can work, it's a switching supply, and might add noise to the DAC.

 I recommend testing the USB portion first. I do not think bad will happen 
	

	
	
		
		

		
		
	


	




. The DAC board and the USB board will still receive power from the USB. Even if the USB portion does not work, the DAC portion might.

 Edit: I think you're trying to follow the initial check step by step, if you don't have a DC wallwart, you can skip the steps involving it, no need to have one if you're using it with a PC. I think you're building this for educational purposes, is that correct?


----------



## Wizik

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_The plug is too big. While it can work, it's a switching supply, and might add noise to the DAC.

 I recommend testing the USB portion first. I do not think bad will happen 
	

	
	
		
		

		
		
	


	




. The DAC board and the USB board will still receive power from the USB. Even if the USB portion does not work, the DAC portion might.

 Edit: I think you're trying to follow the initial check step by step, if you don't have a DC wallwart, you can skip the steps involving it, no need to have one if you're using it with a PC. I think you're building this for educational purposes, is that correct?_

 

Yes, too, this DAC is for my school leaving exam, but then I want using it for my amp and akg K701. I don´t want using it with DC wallwalrt, only with USB connection, but I thinked from amb initial check that I need to first test it with wallwart, then with USB. So I will plug it into USB for first test ? It´s safe ?


----------



## ShinyFalcon

Yes, you can skip the first step involving the DC wallwart and go to the next step. That first step tests the functionality of U1D. If U1D fails to work for whatever reason, we can easily bypass it.


----------



## Wizik

So when I plug it into the USB port and nothing happen, then I need to do short 2-3 on JP2D yeah ?


----------



## ShinyFalcon

I didn't mean skip directly to the USB step, I meant to follow these steps next:

  Quote:


 2. With your multimeter set to Ohms mode (use the lowest resistance range on a manual-ranging meter), check for short circuits between the points listed below. If you read less than a few Ohms for any of these, then there is a short circuit. Carefully locate the short (such as a solder bridge) and fix it. You may use the exposed strips along each edge of the board as the GND contact.

 DAC board:

 * JP2D pin 1 and GND
 * JP2D pin 2 and GND
 * JP2D pin 3 and GND
 * +3.3V test pad and GND
 * +4.5V test pad and GND


 USB board:

 * +5V test pads(s) and GND
 * +3.3V test pads and GND

 and so on... 
 

until you get to the USB test. 

 First, since you're building a y2 as well, are the y1 halves broken apart and plugged into each other? If the y1 is not broken apart yet, you will need to install the y2 board on top of the y1, but you can just install J1-J5 of the y2 board.


----------



## Wizik

I check all that points, on every from that points was high impedance (from 30KΩ to 100KΩ). So can I plug USB now?

 And i don´t have y2 already finished, first I want to test y1 before completing y2. y1 is not broken apart. I wired it with 5 wires, like is in instruction.


----------



## Shahrose

remove: accidental post...


----------



## amb

Wizik, you don't need the 5 wires if you're going to use a y2. The blank y2 board with only J1-J5 installed will act as the bridge between the two y1 halves.


----------



## Wizik

I already wire it with wires, it doesn´t matter now, I plug it into USB, and everythink looks fine ! On USB board is 5V = 4,96V and 3,3V=3,29V and on DAC board 3,3V = 3,28V and 4,5V = 4,74V, looks great, I try only direct playing on my ety ER-4P and it plays  Now I´m going to build y2, hold fingers for me


----------



## Billyk

Wizik, way to go!!
 Hope everything turns out great for you, I was thinking about you and your school exam the other day. Let us know.


----------



## Wizik

Ok, I builded y2 already, but on one 5V I have 4,84V and on other 4,8V it is okey ? On 3,3V I have 3,28V and on 4,5V I have 4,73V, that´s okay, but what with that 5V ?


----------



## amb

Yes, that is ok. Many computers' USB power voltage is not exactly 5V, and yours is a little low, but within specifications. If you used TPS793475DBVR for your "4.5V" voltage regulator, it will read ~4.75V.


----------



## Wizik

Yes, it´s okay, I already test it, it´s great. Good work AMB ! Only the digital filters is all the same for me, and anticliping not change tone too for my ears.


----------



## Nebby

Finally placed my mouser and digikey orders, I had a couple of backordered goods, but they'll be in stock within a week. I must say thanks to amb and all for finding alternatives for items that were OOS everywhere, it certainly came in very handy.


----------



## ujamerstand

One of your backordered items was the opa2635 op-amp, wasn't it? It was suppose to ship today at mouser, but they delayed it till the 29th.


----------



## Beefy

Quote:


  Originally Posted by *ujamerstand* /img/forum/go_quote.gif 
_One of your backordered items was the opa2635 op-amp, wasn't it? It was suppose to ship today at mouser, but they delayed it till the 29th. 
	

	
	
		
		

		
		
	


	


_

 

I've got them on backorder, and the 2.5% caps that are OOS as well. Have to wait until well after Christmas now 
	

	
	
		
		

		
		
	


	




 I suppose I should know better than to trust shipping during the holiday season.


----------



## Nebby

Quote:


  Originally Posted by *ujamerstand* /img/forum/go_quote.gif 
_One of your backordered items was the opa2635 op-amp, wasn't it? It was suppose to ship today at mouser, but they delayed it till the 29th. 
	

	
	
		
		

		
		
	


	


_

 

The opamp on mouser showed a backorder ship date of 1/18/2010 for me 
	

	
	
		
		

		
		
	


	




 so I picked it up from avnet which has an estimated ship date of the 28th. Digikey has an est. ship date of 20th for the ad8656 part, so I picked that up as a backup.


----------



## ujamerstand

Well, Newark do have them in stock, but considering the shipping for a 5 dollar chip...

 Edit: wow, they are not in stock any more, They were last time I checked!


----------



## Beefy

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_The opamp on mouser showed a backorder ship date of 1/18/2010 for me 
	

	
	
		
		

		
		
	


	


_

 

They have had a shipment coming in mid-December for a long time, but that all sold out before it even arrived......


----------



## amb

Newark also has some AD8656ARZ in stock now, since they are also a source for the Box B2-080 series enclosures, you can buy them together.


----------



## nattonrice

After some half-assed trace repair and replacing the power multiplexer my y2 lives again =D


----------



## Wizik

On my Gamma2 is not working ASIO, where is the problem ? I´m using latest foobar and asio4all, but I don´t see Gamma2 in ASIO virtual devices in foobar.


----------



## mattcalf

Is it best to clean off flux as soon as possible (within reason) or is it alright if I don't clean it until I have completely finished soldering which might be over a 2-4 day period, as long as I clean it up before initial testing?


----------



## nattonrice

Solder all the SMD stuff first and then scrub both sides with isopropyl.
 Then you can wait till everything else is mounted to clean up the solder side.


----------



## ShinyFalcon

Quote:


  Originally Posted by *Wizik* /img/forum/go_quote.gif 
_On my Gamma2 is not working ASIO, where is the problem ? I´m using latest foobar and asio4all, but I don´t see Gamma2 in ASIO virtual devices in foobar._

 

When you install ASIO4All, install the "offline" portion. That way you can easily access the stuff for the y2. 

 Alternatively, you can use ASIO4All with your regular sound card, and when you play music, in your taskbar on the bottom right you'll see a green arrow, you can double click there.

 mattcalf, I'm sure you can wait, but as the flux dries (maybe if you wait weeks) it will be a bit harder to come off, but not impossible. I have always done initial checks right after I have finished my soldering/casework without any adverse effects. And of course, the β22 was a different story, I took forever and great care with that one.


----------



## Wizik

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_When you install ASIO4All, install the "offline" portion. That way you can easily access the stuff for the y2. 

 Alternatively, you can use ASIO4All with your regular sound card, and when you play music, in your taskbar on the bottom right you'll see a green arrow, you can double click there.

 mattcalf, I'm sure you can wait, but as the flux dries (maybe if you wait weeks) it will be a bit harder to come off, but not impossible. I have always done initial checks right after I have finished my soldering/casework without any adverse effects. And of course, the β22 was a different story, I took forever and great care with that one._

 

I instaled already the off-line settings too, I see there Gamma2, but when I start to play music from foobar, there is shown that USB Audio DAC is unavaible, what´s that ?


----------



## ShinyFalcon

Try the following steps: http://i108.photobucket.com/albums/n...lcon/aesfd.png


----------



## mattcalf

Thanks to both of you, I'll begin SMD stuff tomorrow hopefully and see whether or not I get carried away and marathon the whole board out. Friday I'll endeavor to get some Isopropyl and give it a clean.


----------



## linuxworks

Quote:


  Originally Posted by *mattcalf* /img/forum/go_quote.gif 
_Is it best to clean off flux as soon as possible (within reason) or is it alright if I don't clean it until I have completely finished soldering which might be over a 2-4 day period, as long as I clean it up before initial testing?_

 

you can wait months.

 in fact, I just did. finally bought some 99% iso alc. (kept forgetting to get this but been meaning to). the made-for specialty can spray removers work very well but are $15 a can! drug store alc. is cheap and I finally tried it. works very well (I rinse the whole board under hot water and then air-dry with compressed canned air so that no water is left on the board, even under chip legs).

 the board looks brand new, now. and it had been 'fluxed up' for half a year, now


----------



## Wizik

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Try the following steps: http://i108.photobucket.com/albums/n...lcon/aesfd.png_

 

Yes, I can add it like you show me, but then when I want click to play, nothing happen, song don´t start


----------



## m1abrams

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_you can wait months.

 in fact, I just did. finally bought some 99% iso alc. (kept forgetting to get this but been meaning to). the made-for specialty can spray removers work very well but are $15 a can! drug store alc. is cheap and I finally tried it. works very well (I rinse the whole board under hot water and then air-dry with compressed canned air so that no water is left on the board, even under chip legs).

 the board looks brand new, now. and it had been 'fluxed up' for half a year, now 
	

	
	
		
		

		
		
	


	


_

 

How long do you let it air-dry before applying power. I have wanted to wash the boards as you describe but with smd devices I am just a little worried about trapped water. I guess if you use compressed air and let it sit for a day it should be fine.


----------



## ShinyFalcon

I used a hairdryer after dousing in alcohol. Not the best combo, but I got very clean boards and burnt fingers as a result.

 As for Wizik, let's see a screenshot of your output devices (where you choose DS, ASIO, etc). Also take a screenshot of your ASIO4All window. You have used ASIO4All before, right? Do you have the foo_out_asio.dll in your components folder?


----------



## linuxworks

sit for a day? you kidding me?

 I spray it with canned air and its dry right then and there! if you LEAVE any water there, THAT is the problem. better to get it dry in the first 5 minutes, if you can.

 I also avoid putting trimmer pots on the board if I'm going to alc/water clean it. same for screw terminals and things where there is metal to metal.

 one of my first jobs, as a kid, was working at a hand-built pc board shop (early 80's). our *standard procedure* was to use acid flux (some liquid red stuff), do board touch-up (first process was a wave solder conveyor) and you had BETTER scrub off acid flux or it will eat thru things. we used soap and hot water and a scrub brush. just like a kitchen sink (similar setup). we had a drain rack (didn't use canned air back then) and once the boards were dry, we did some test and then shipped them onto the next manuf stage. it blew me away seeing circuit boards being washed and dried like dishes in a sink but apparently it worked for that guy, back then. and the boards were nice and clean when we were done with them.

 after that, I got over my fear of water and circuit boards. just dry them well but its not hard to do nor should it take a long time.


----------



## Beefy

I can't understand why you would use water at all 
	

	
	
		
		

		
		
	


	




 My cleaning regime is a soft toothbrush and >99% isopropanol, with very gentle scrubbing. I keep it 'wet' with isopropanol to make sure everything stays dissolved, and slowly increase the amount that I splash on with the toothbrush. Excess is gently shaken off, I wipe everything down gently with a Kimpwipe, then air dry a few minutes. If there is still a white residue, I re-wash with more isopropanol.

 Isopropanol has a much lower evaporation temperature than water, and will dry off very quickly in air. It is relatively non-conductive, and sufficiently pure stuff has low levels of salt contaminants that will absorb water from the air further down the track. Drying water is much more likely to leave stuff behind IMHO, unless you have access to really good double de-ionised stuff.


----------



## linuxworks

I was never able to get all the residue off the board with just alcohol. but a hot stream of running water made quick work of it once the alc. loosened the debris.

 as long as I shoot a lot of canned air at things, the result looks good enough to me.


----------



## linuxworks

(dp)


----------



## m1abrams

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_I was never able to get all the residue off the board with just alcohol. but a hot stream of running water made quick work of it once the alc. loosened the debris.

 as long as I shoot a lot of canned air at things, the result looks good enough to me._

 

Yeah my method is basically what Beefy does and I have never been able to get ALL the residue off and usually just say F@#$ it after a few washes, no will see it and I doubt I will have this part long enough for any problems to arise.


----------



## Beefy

The secret is making sure things stay dissolved - a tip I got from TomB. Don't just slap some on and let it dry, but make sure it stays 'wet' with isopropanol. Rinse a lot once everything is dissolved, then get as much excess off before it dries.


----------



## Wizik

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_I used a hairdryer after dousing in alcohol. Not the best combo, but I got very clean boards and burnt fingers as a result.

 As for Wizik, let's see a screenshot of your output devices (where you choose DS, ASIO, etc). Also take a screenshot of your ASIO4All window. You have used ASIO4All before, right? Do you have the foo_out_asio.dll in your components folder?_

 

Here is screenshot, everything looks OK, but when I click on play, nothing happens.

http://img37.imageshack.us/img37/2381/gammaq.jpg


----------



## dean0

My y2 is connected via optical and Iam using usb input from my pc for power, but when I connect usb Iam getting noise, bearly audioable but its anoying between tracks.
 Would using this help; Emerson Network Power | Power Supplies | Power Supplies, Inverters, DC/DC Converters & Generators | External Power Supplies | Switch Mode - Emerson |DCH3-050UK-0001 , as I wouldnt be relying on my pc for power source, or any other better powersupply options?
 thanks
 dean0


----------



## Beefy

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_I used a hairdryer after dousing in alcohol. Not the best combo, but I got very clean boards and burnt fingers as a result._

 

I missed this on the first pass......

 You've got to be really careful when using hairdryers or vacuum cleaners for cleaning electronics, computers etc. They can generate a LOT of static from the air movement through the hairdryer/vacuum itself.

 Canned compressed air is MUCH better.


----------



## dean0

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_I missed this on the first pass......

 You've got to be really careful when using hairdryers or vacuum cleaners for cleaning electronics, computers etc. They can generate a LOT of static from the air movement through the hairdryer itself.

 Canned compressed air is MUCH better._

 

or a lighter


----------



## amb

dean0, how about this?


----------



## padam

May I ask: later on, will there be a standalone y2 at a lower cost?


----------



## amb

Quote:


  Originally Posted by *padam* /img/forum/go_quote.gif 
_May I ask: later on, will there be a standalone y2 at a lower cost?_

 

No, there is enough flexibility in the existing design to make a very bare-bones y2 already.


----------



## MisterX

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_dean0, how about this?_

 

I prolly should bite my tongue until I verify one of the transformers I ordered the other day fits but...






 It is a little better looking then a run of the mill wall wart.


----------



## dean0

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_dean0, how about this?_

 

thanks, looks like the best route for 'clean' power source, this may sound stupid, but what size dc-jack do I need?
 MisterX I may have to copy you on that!


----------



## Nebby

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_I prolly should bite my tongue until I verify one of the transformers I ordered the other day fits but...

 It is a little better looking then a run of the mill wall wart. 
	

	
	
		
		

		
		
	


	


_

 

what case did you use for that? is it the box enclosure that's 1.77" tall?


----------



## amb

Quote:


  Originally Posted by *dean0* /img/forum/go_quote.gif 
_thanks, looks like the best route for 'clean' power source, this may sound stupid, but what size dc-jack do I need?
 MisterX I may have to copy you on that! 
	

	
	
		
		

		
		
	


	


_

 

The DC jack on the DAC side is 1.3mm as specified in the γ1 BOM. On the 
 PSU side, you could use any panel-mount jack you want, or no jack at all (just a strain-relieved pigtail with plug, a la wallwart).


----------



## mattcalf

Just got out of the solder-cave, with a few things/points/conclusions: 
 1. Surface mount soldering is HARD!!

 2. I don't think I received L3U, which was meant to come from AMB. An honest mistake I'm sure, Ti, what are the specifics (rating/part number) so I can go about sourcing a substitute in Australia. 
	

	
	
		
		

		
		
	


	




 [_would this work?_]

 3. My U2U (Texas Instruments SN74AHC1G08 (SOT23-5)) sourced from Farnell (#1105918), if I'm correct, does not have the correct 'leggings'. Instead of 3 pins on one side and 2 on the other to match the solder screen on the board, it only has 1 on one side and 2 on the other. What do I do?

 Thanks in advance and thanks to all who made the project possible, I'm having great fun,
 Matt


----------



## Beefy

Quote:


  Originally Posted by *mattcalf* /img/forum/go_quote.gif 
_1. Surface mount soldering is HARD!!_

 

I find SMD soldering to be very inconsistent...... I had no problems at all PCM2707 chips on three y1's, but the SRC and DAC on the y2 were absolute hell to get right.


----------



## amb

Quote:


  Originally Posted by *mattcalf* /img/forum/go_quote.gif 
_2. I don't think I received L3U, which was meant to come from AMB. An honest mistake I'm sure, Ti, what are the specifics (rating/part number) so I can go about sourcing a substitute in Australia. 
	

	
	
		
		

		
		
	


	




 [would this work?]_

 

It looks like a small resistor, please check your packaging. Anyway, the 78F series inductor you list is too big to fit the board. The correct part is the 79F series. If the inductor is truly missing, contact me offline.

  Quote:


 3. My U2U (Texas Instruments SN74AHC1G08 (SOT23-5)) sourced from Farnell (#1105918), if I'm correct, does not have the correct 'leggings'. Instead of 3 pins on one side and 2 on the other to match the solder screen on the board, it only has 1 on one side and 2 on the other. What do I do? 
 

Looks like Farnell sent you the wrong part.


----------



## Wizik

Is someone who can help me with that ASIO ? I already add Gamma2 to asio virtual devices in foobar, but when I want click play, nothing happens.


----------



## ShinyFalcon

Does it work when using DirectSound? All I can think of is to delete that virtual device, make a new one, and make sure it looks like this:


----------



## mattcalf

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Looks like Farnell sent you the wrong part._

 

Yeah I figured, time for another Farnell order. 
	

	
	
		
		

		
		
	


	




 Also realised I'm missing a RCJ-041, that's my mistake though. And I don't foresee myself using Coaxial anytime soon.


----------



## MisterX

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_what case did you use for that? is it the box enclosure that's 1.77" tall?_

 

Yep, B3-080.


----------



## Nebby

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Yep, B3-080. 
	

	
	
		
		

		
		
	


	


_

 

Very cool. I was contemplating the sigma 25/24 combo in that case. Looks like it'll be a very close fit with the transformer? On the other hand it seems the amveco low profile transformer would fit in the case easily, so that might be a better route than the sigma24.

 </stream of consciousness>


----------



## MisterX

Easy until you account for the wires. 

http://i23.photobucket.com/albums/b3...side/wires.jpg

 I guess it would be a lot easier if you omit the IEC and power switch.....


----------



## ShinyFalcon

Wow, Mouser had around 1000 or so OPA2365 in stock yesterday, and now this morning they're all gone. I should've bought an extra or two 
	

	
	
		
		

		
		
	


	




.


----------



## Beefy

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Wow, Mouser had around 1000 or so OPA2365 in stock yesterday, and now this morning they're all gone. I should've bought an extra or two 
	

	
	
		
		

		
		
	


	




._

 

I'm pretty sure they were just filling backorders. They were never actually available to ship to new buyers


----------



## ShinyFalcon

I estimated 1000 because when I visited the page there were 92x in stock, and was thinking that 80 had the backorders fulfilled. I ordered from Mouser just yesterday and one of the chips is coming my way. I kind of doubt that 900 were rushing to buy one for their y2, unless the demand for the y2 is that high. Only Ti knows 
	

	
	
		
		

		
		
	


	




.

 Edit: Seems like Newark has 700 in stock. They were out yesterday.


----------



## Nebby

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Easy until you account for the wires. 

http://i23.photobucket.com/albums/b3...side/wires.jpg

 I guess it would be a lot easier if you omit the IEC and power switch....._

 

True, I hadn't given the wiring too much thought as I was worried about getting a transformer that would actually fit. Very neat wiring there MisterX, I'll give mine a shot as looking nearly as neat and organized that is


----------



## Wizik

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Does it work when using DirectSound? All I can think of is to delete that virtual device, make a new one, and make sure it looks like this: 




_

 

It works now, thank you !


----------



## dean0

Finished! Went together with no issue's. Testing atm, and no smoke, yet! This little p/s is outputting 5v (5.01v to be exact) no sweat, and the interferance noise from my pc has completley gone! 
 happy times 
	

	
	
		
		

		
		
	


	



 The chassis is the same as the y2 DAC, but 1.5cm taller, which was need to fit the trafo. think the led looks awesome...


----------



## MisterX

Pretty cool, we don't see hand etched boards around here very often. 
	

	
	
		
		

		
		
	


	




 Which gets hotter, the transformer or the Heatsink?


----------



## dean0

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Pretty cool, we don't see hand etched boards around here very often. 
	

	
	
		
		

		
		
	


	




 Which gets hotter, the transformer or the Heatsink?_

 

both are pretty warm, I am going to use a larger heatsink on V.reg, which will help. The case itself becomes warm when closed up, ventilation hole above the trafo may also be a good idea, for long term reliabilty.
 edit. just tested dc out and it has fallen from 5.01v to 4.98 after 1 hours use, is this a heat issue?


----------



## amb

Quote:


  Originally Posted by *dean0* /img/forum/go_quote.gif 
_edit. just tested dc out and it has fallen from 5.01v to 4.98 after 1 hours use, is this a heat issue?_

 

The voltage regulator does have some temperature coeffient, but I wouldn't worry about a slow 0.03V change over time.


----------



## dean0

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_The voltage regulator does have some temperature coeffient, but I wouldn't worry about a slow 0.03V change over time._

 

Thanks, is it the heat that is causing the 0.03v change?


----------



## amb

By "temperature coefficient", that's what I inferred.


----------



## dean0

okay thanks 
	

	
	
		
		

		
		
	


	




 How much current does the y2+y1 draw? I understand the y2 draws 150mA, is that for both? 
 Thanks Again
 dean0


----------



## amb

The current draw depends on the specific configurations and operating conditions, but it's anywhere from mid-100mA to low-200mA combined.


----------



## Billyk

Looks great! Congrats on a fine looking build. I am pretty excited myself, we had enough left over after family gifts that the wife is gifting me the parts for my Gamma 2 and I just placed the order with Mouser!!


----------



## vixr

got my order from AMB Labs today!!! The panels are perfect, Merry Chistmas Ti...I hope you get everything you want this year.


----------



## tacitapproval

I just got a y2 up and running, but have found a strange problem. USB and coaxial inputs are clear and sound great, but optical puts out a stuttering version of the music. It sort of pulses rapidly in and out. The optical works fine on the y1 output. It only occurs on the y2. Any ideas?


----------



## Beefy

Did the optical module get dirty with flux fumes or flux cleaner?


----------



## tacitapproval

I suppose that is possible, but then why would the y1 output continue to function properly?


----------



## amb

tacitapproval, your problem doesn't make sense indeed. All three input types (USB, coax and optical) gets routed through the CS8416 mux chip and gets converted into I2S, which then feeds both DACs (γ1's WM8501 and γ2's SRC4192/WM874x). If all inputs work on your γ1, then everything up to the I2S bus is working fine, as well as the WM8501. Since your coax and USB inputs also work fine on the γ2, then it shows that everything downstream of the I2S (including the SRC4192/WM874x) also works fine. There is nothing specific to the optical input that could fail from that point on.

 I can't offer an explanation, other than perhaps when the toslink connection is causing physical stresses and purturbing a marginal solder joint somewhere between the γ1/ γ2 interconnect headers, or on the γ2 board itself...


----------



## tacitapproval

Very strange, indeed. I will keep poking around. There must be an iffy joint somewhere, because I have had to restart the dac a few times after locking up while playing for a bit. The optical results have been consistent this way though.


----------



## tacitapproval

I found yet more strange behavior with the optical input. If I run asio the music is nearly intact, but with split second dropouts every second or two, whereas directsound produces more stutter than music. And, again, I can immediately switch the plug to the y1 out and everything is clear. I obviously haven't found the problem contact yet. I could live without the toslink, but the dac drops out sporadically on USB after playing flawlessly for a while. Arghh.


----------



## m1abrams

Quote:


  Originally Posted by *tacitapproval* /img/forum/go_quote.gif 
_I found yet more strange behavior with the optical input. If I run asio the music is nearly intact, but with split second dropouts every second or two, whereas directsound produces more stutter than music. And, again, I can immediately switch the plug to the y1 out and everything is clear. I obviously haven't found the problem contact yet. I could live without the toslink, but the dac drops out sporadically on USB after playing flawlessly for a while. Arghh._

 

I would look at JP1D pin. I bet that connection is iffy.


----------



## MisterX

Patch the optical output into the optical input and make sure it's not the source?


----------



## tacitapproval

Quote:


  Originally Posted by *m1abrams* /img/forum/go_quote.gif 
_I would look at JP1D pin. I bet that connection is iffy._

 

Nope, no luck with that one.

  Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Patch the optical output into the optical input and make sure it's not the source?_

 

I don't have optical in/out on the source, but as I said, the optical works fine on the y1 out at the same time as it is hiccuping on the y2.


----------



## fishski13

Quote:


  Originally Posted by *vixr* /img/forum/go_quote.gif 
_got my order from AMB Labs today!!! The panels are perfect, Merry Chistmas Ti...I hope you get everything you want this year._

 

x2. the FPE panels look much better in the flesh than the pics - perfect! as usual, super-duper speedy shipping and service. i can't wait to get started.


----------



## Billyk

Another one lives! A y1++ and Y2. Boy this thing sounds swell. Thank you Ti and Marshal, and proto testers for a wonderful little device. Everything works all input and outputs. Can't stop listening to it!!
 Thanks again and Happy New Year everyone!


----------



## TzeYang

don't you hate it when you are in the middle of completing the BOM and the site tells you the item is out of stock 
	

	
	
		
		

		
			





 -NATIONAL SEMICONDUCTOR - LP2985AIM5-4.5

 Alternative, guys?

 Farnell is the only distributor in my country so anything from there is appreciated.


----------



## TzeYang

NATIONAL SEMICONDUCTOR|LP2985IM5-4.5/NOPB|LDO REG | Farnell Malaysia

 Did some searching and ended up with this. Is the STD version that much worse than the A version?


----------



## TzeYang

Okay sorry, I found it.

NATIONAL SEMICONDUCTOR|LP2985AIM5-4.5/NOPB|LDO REG | Farnell Malaysia

 The part number on Amb's site is a bit outdated and i know how much fail farnell is when it comes to parts number consistency.


----------



## Billyk

Boy don't I know it. Seems like a fact of life at mouser. I finally went to order the parts for my y2 only to find they were out of two of the metal film resistors. Ordered about 50 carbon film and matched them instead. Sounds swell.
 AMB lists an alternative op amp, I used that one.
 Good luck.


----------



## ShaneP

Finished building a y1 and y2 a couple weeks back. I never realized I was listening to total crap coming out of my sound blaster card. Bass is much stronger now and I can't hear any static when I turn the volume all the way up with no music playing.

 Only hitch was one of the screws supplied with the enclosure decided to shear off at the head after I screwed it in about a centimeter. Oh, and everything from Texas Instruments was out of stock


----------



## francisdemarte

Having some problems with my y2 mated to a y1 full. I'm not getting any output on either the mini-jack or RCA jacks. The output jack on the front is just outputting static.

 I've double checked all solder joints and voltages they appear normal. Switch light turn solid green when I connect via USB and music is played.

 I've also tried by passing up sampling by shorting JP2-1/4 this results in no output.

 Y1 worked perfectly when both halves were mated together.


----------



## amb

francisdemarte, someone else experienced a similar problem, try looking through earlier parts of this thread to see if it helps you.


----------



## francisdemarte

EDIT: *It's Working!* Still not sure what was wrong. 

 To re-hash for anyone else having this issue:

 Symptoms: No sound from RCA and Mini on Y2. Just static white noise on front Y1 mini. 

 I'm suspecting it was X1 crystal. Basically I put a larger flat screw driver tip on my iron and ran a clean tip across all the IC's and tried to reflow the solder under the crystal. So either this eliminated a small bridge or bad connection under the crystal.


----------



## amb

Did you mount the 1P header/socket at y1-JP1D to y2-J3? Does the y1 still work now when plugged into each other? If it does, but doesn't work when mated to the y2 (i.e., the WM8501 output at the front jack doesn't work any more), then check for connectivity problems at the board pin headers and sockets. Definitely check for solder joint problems on the y2 as well, and make sure all parts are mounted in the correct orientation.


----------



## Masterrer

I've been reading quite a lot on these forums the last several weeks.

 Right now my brain is in overload mode from all the dac's opamp's cap's and their impact on sound quality.

 I really need to choose a good dac for my PC. I'm quite into DIY and can do stuff like swap ram chips on wireless routers...

 At this point I can't decide between the Musiland Monitor 02 and the Gamma-2
 my budget for a DAC is about 200$.

 If anyone can comment on which one may sound better, I would highly appreciate it!

 P.S. The dac will be driving a Pioneer A400 stereo amp and JPW ML510 speakers. Probably will buy something like SENNHEISER HD555 later on.


----------



## Beefy

Quote:


  Originally Posted by *Masterrer* /img/forum/go_quote.gif 
_P.S. The dac will be driving a Pioneer A400 stereo amp and JPW ML510 speakers. Probably will buy something like SENNHEISER HD555 later on._

 

I can't help you with your DAC questions because I haven't heard the Musliand...... but IMHO the HD555 are just plain awful. There are MUCH better headphones in the same price range.


----------



## luvdunhill

amb:

 on the y1 usb to SPDIF conversion circuit, isn't the result inverted from the incoming data? I'd expect a single hex inverter feeding the three paralleled gates I suppose.

 Incidentally, it's hard to read some of the values on the schematic. For example, the reference designator of the inductor connected to pin 14 of the hex inverter.


----------



## amb

Quote:


  Originally Posted by *luvdunhill* 
_on the y1 usb to SPDIF conversion circuit, isn't the result inverted from the incoming data? I'd expect a single hex inverter feeding the three paralleled gates I suppose._

 

S/PDIF uses biphase mark encoding which makes it phase-insensitive. In fact some of the pulse trafos used for S/PDIF coax galvanic isolation are itself inverting, while others aren't, but it doesn't matter.

  Quote:


 it's hard to read some of the values on the schematic. For example, the reference designator of the inductor connected to pin 14 of the hex inverter. 
 

L3U.


----------



## luvdunhill

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_S/PDIF uses biphase mark encoding which makes it phase-insensitive. In fact some of the pulse trafos used for S/PDIF coax galvanic isolation are itself inverting, while others aren't, but it doesn't matter._

 

ah, right. Looking at the datasheet, I notice that there isn't a minimum propagation delay specified between the gates. Couldn't this be a problem for a usage such as this? If not (which I'm not convinced), why not just parallel all 6 together?

 Also, what is the effective bandwidth of SPDIF? I'd think 10Mhz+? Again, aren't logic gates too slow for this use?

 I'm thinking about doing the same thing roughly as you've done, but these questions are still nagging me a bit.


----------



## amb

I don't know which datasheet you're looking at, but TI's SN74HCU04 datasheet lists 7nS as the "typical" propagation delay. S/PDIF bandwidth is 2.8MHz (44.1K), 3.1MHz (48K).

 At 3.1MHz the time period is 322nS which is 46x the typical 7nS propagation delay, thus it is more than good enough.


----------



## linuxworks

Quote:


  Originally Posted by *luvdunhill* /img/forum/go_quote.gif 
_Also, what is the effective bandwidth of SPDIF? I'd think 10Mhz+? Again, aren't logic gates too slow for this use?
_

 

well, my 'low end' spdif switch uses a variety of semi-low speed devices (rs422 buffers and cmos switches). I've used ttl, as well. spdif fits inside that just fine.

 the 74hcu04 buffer is classic (at least 15 yrs old if not more). it passes the test of time if nothing else.


----------



## luvdunhill

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_S/PDIF bandwidth is 2.8MHz (44.1K), 3.1MHz (48K)._

 

Thanks again Ti. I thought the 44.1K/48K was the data rate before the BMC encoding? Wouldn't the resultant encoded stream be of higher bandwidth?


----------



## amb

A raw (un-encoded) 16b/44.1KHz stereo stream would be 44100 * 16 * 2 = 1.4MHz.


----------



## francisdemarte

Anyone have their y2 in a larger enclosure? I don't like the look of the little enclosure in my component stack.


----------



## tacitapproval

I need some troubleshooting help.

 I was working on reconfiguring a tread to power a previously working y2 and I briefly, accidentally shorted positve to ground on the y1 dc jack with an errant probe. Now the y1 continues to function, but the y2 does not. I get 1.7v on the 3.3v reg and only .3v on the 4.5v one. Would this have taken out the 4.5v reg? I do hope I didn't wipe out the wm8741...


----------



## linuxworks

my guess is that the chips are ok but the regs are blown. your voltage measurements show that, to me.

 shorting + to - should not hurt the chips. in fact, you are now sending 0v thru the chips, which should be harmless, right? 
	

	
	
		
		

		
			





 but NOT harmless to the v-regs


----------



## linuxworks

Quote:


  Originally Posted by *francisdemarte* /img/forum/go_quote.gif 
_Anyone have their y2 in a larger enclosure? I don't like the look of the little enclosure in my component stack._

 

I'll snap a pic of mine, later on. its inside a hammond case and also has an lcd controlling it (and an spdif switch board, as well).

 I'm not a big fan of the small designed-in case and so I allowed myself some freedom in not using rca jacks and instead using molex offboard connectors. works just fine that way and gives more freedom in the box selection.

 next up is to mount a tread and sigma25 in the box (dual vregs for the 2 devices I use; digital and analog).


----------



## tacitapproval

I will see if swapping the regs solves it. I wonder why it damaged the y2, but not the y1?


----------



## MisterX

I would power the Gamma 2 board direct and make sure the regulators still have a problem before replacing them.

 Edit: And I would check the current draw while I was at it.....


----------



## tacitapproval

Forgive my ignorance, but can you explain what powing the y2 separately would show? Both y2 regs are getting 5v on their inputs. 

 I will check the current draw.


----------



## MisterX

If you eliminate all of the other stuff by applying the supply voltage directly to the Gamma 2 board and the regs still have low voltage problems and the current draw is within a reasonable range you have verified the regulators are cooked. 
 That's all.

 Edit:
 Another double check is to measure the voltage on the noise reduction pin.


----------



## linuxworks

Quote:


  Originally Posted by *tacitapproval* /img/forum/go_quote.gif 
_I will see if swapping the regs solves it. I wonder why it damaged the y2, but not the y1?_

 

I recently had a y2 'die' also. not sure which part of actually died (hmm, might have been the regs, I didn't check mine). and yet my y1 continues to live. I built another y2 and that is working ok, now, but I can't explain why my y2 died and y1 lived. I might have been messing with plugging/unplugging the power a lot (my dac was a demo dac taken to a few road shows and was handled more than it should, maybe).

 I've heard that tps regs are very very static sensitive. maybe I had a problem with that.


----------



## Beefy

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_I might have been messing with plugging/unplugging the power a lot (my dac was a demo dac taken to a few road shows and was handled more than it should, maybe)._

 

I managed to get my y2 oscillating in the audible region (mid bass, perhaps?) by switching the 3.5mm audio output back and forth from the y1 to the y2 while music was playing. Stopping the music did nothing, but a power cycle and it was OK again.


----------



## tacitapproval

The reason I ask about powering the y2 separately is because I had some contact problems with the pins and headers, so I ended up wiring the the boards together. Therefore, I would rather eliminate other things before desoldering the wiring.


----------



## tacitapproval

Current draw is 20.2mV without music and 21mV with. This is low, no?

 U1 is 4.98v going in, and .29v out and .93v on the NR. U2 is 4.98v in, 1.7v out and .98 on NR. Does this reveal anything?


----------



## linuxworks

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_I managed to get my y2 oscillating in the audible region (mid bass, perhaps?) by switching the 3.5mm audio output back and forth from the y1 to the y2 while music was playing. Stopping the music did nothing, but a power cycle and it was OK again._

 

tried the power cycle a few times on mine. no dice. reflowed solder joints and still nothing. tapped into the line-out pins on the dac and still nothing. I did 'press on' the op amp with my finger (while looking for overheating chips) and some noise (white noise) went down a lot, so I thought it might be the opamp but not having audio from the dac chip, itself, made me think the problem was deeper.

 I did not buy any chipquick or try fixing the board; I guess I just ditched it and went with a new one (non-beta board since my only board was one of the beta tester ones).

 speaking of blowing parts, lately I'm ruining some IR detector modules for my remote controls. they also seem static sensitive or maybe my PSU is spiking when I plug and unplug things. I've ruined a good number of the vishay IR modules. very annoying! guess we have to be more careful with our parts (some are bullet proof but not all are)


----------



## Beefy

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_tried the power cycle a few times on mine. no dice. reflowed solder joints and still nothing. tapped into the line-out pins on the dac and still nothing._

 

I wonder whether the WM874* are a bit more sensitive as well. Its a pretty complicated chip, and for some reason was a LOT more difficult for me to solder than the PCM2707.


----------



## linuxworks

just to keep things really simple (for now) I've decided my 2nd build will not have the SRC chip onboard. one less thing to fail or worry about or debug later.

 what I DO want to have is a 2nd board JUST for the src. that way its truly defeatable. too bad the current design did not allow true defeating of the src, that would have been a lot of fun to play around with 
	

	
	
		
		

		
			





 what I'm thinking about is using an existing src board (one from the ebay/hk upsampling dac kit) and then just tapping into the 5 lines and giving it pwr/gnd. once the y1 deocodes to i2s, you can use some other board that has the SRC to upconvert, THEN feed that output (as if it came natively from the y1) to the y2. I think that should work as long as I keep the cabling 'exact'.

 then, if my src fails, I can truly remove it. not that I assume it will fail but I do like keeping things modular whenever possible.


----------



## tacitapproval

Quote:


  Originally Posted by *tacitapproval* /img/forum/go_quote.gif 
_Current draw is 20.2mV without music and 21mV with. This is low, no?

 U1 is 4.98v going in, and .29v out and .93v on the NR. U2 is 4.98v in, 1.7v out and .98 on NR. Does this reveal anything?_

 

Mister X (or others) can you tell me if these numbers show anything? I am not quite sure how to interpret them for my problem.


----------



## linuxworks

I would just simply replace both regs as a matter of course. sounds like stuff goes in but nothing much comes out. replace them and then retest.

 alternately, if you happen to have a variable voltage supply around, you COULD inject that proper voltage to the output of the vreg in question (once you unsolder it).

 at least they're easy enough to unsolder and just try new ones. I'd do that.


----------



## OliverK

Hi to everyone, my first post here.

 Just ordered gamma 1 and 2 a few days ago.
 I read most of the posts, but havent found a reference if anyone used wm8740 instead of wm8741/2. Ive got 2 of 8740 lying around so i thought if anyone compared those two chips? 8740 has a bit lower distortion while 8741 has a bit higher S/N.


----------



## linuxworks

I have not tried 'last years chip' (the odd one out; the $5 chip version) but I have tried both of the 41/42 chips. I can't tell them apart. the s/n is only a few db apart and even that sounds questionable to me (perhaps its just marketing). looking at the data sheets, there seems to be no diff. every word and paragraph other than a few db numbers are identical. beats me, what the diff is!

 you'd also have to have some serious test gear to be able to actually see any diff between those 2 top end chips.


----------



## OliverK

8740 are used in cambridge audio CD players, in dual differential configuration mostly. 
 I bought them 2 years ago but had no opportunity to use them till now. Dont know if the digital filter features on 8741/2 are worth it to get new chips instead of old. Thats why i thought of checking out first.


----------



## CodeToad

Quote:


  Originally Posted by *OliverK* /img/forum/go_quote.gif 
_Dont know if the digital filter features on 8741/2 are worth it to get new chips instead of old. Thats why i thought of checking out first._

 

In my opinion, no. If I built another G2 I would leave the anti clipping and filters off as well as the G1 output and digital outputs on the front panel leaving only the input selector.


----------



## linuxworks

both switches (clipping and filters) do nothing, really, for me. the last build, I just left both switches off and have not even tested which filter I'd want to leave in all the time. I'll pick the better filter setting, jumper it and leave it from then on.


----------



## francisdemarte

I concur. I think the y2 would look much cleaner with less clutter in the front of the unit. I'm debating the usefulness of the front mini-jack also. Does anyone use it?

 Not to thread jack, but does anyone have panels for the y2 without the switches or the front coax and toslink outputs? Or just an extra set of AMB front and rear panels I can take off your hands?


----------



## ShinyFalcon

I was going to ask MisterX if he still has the FPE files for such panels. He did a very nice front panel without the SPDIF outs. I believe pictures are somewhere in this thread.


----------



## linuxworks

Quote:


  Originally Posted by *francisdemarte* /img/forum/go_quote.gif 
_Not to thread jack, but does anyone have panels for the y2 without the switches or the front coax and toslink outputs?_

 

I don't have 'panels' but I did make an alternate chassis for it:






http://www.head-fi.org/forums/f6/pos...ml#post6295441


----------



## tacitapproval

It was the ldo's. With new ones in she is singing again!
 Thanks everyone.

 Edit: It was working fine for a few minutes. Now the regs are gone again. Maybe it wasn't a dmm probe that caused this, after all. Thoughts?

 Edit Two: I think I found the problem. Shoddy wiring on my part, suprise, suprise. Unfortunately, I need to order more regs to test my hypothesis.


----------



## francisdemarte

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_I don't have 'panels' but I did make an alternate chassis for it:






http://www.head-fi.org/forums/f6/pos...ml#post6295441_

 

That's an amazing build! What enclosure is that and what are the extra resisters/caps on the RCA's?


----------



## linuxworks

Quote:


  Originally Posted by *francisdemarte* /img/forum/go_quote.gif 
_That's an amazing build! What enclosure is that and what are the extra resisters on the RCA's?_

 

thanks 
	

	
	
		
		

		
		
	


	




 on the 2 rca jacks in the back, those are coax-in ports. the standard config that I use is:

 port - .01uf cap - pulse_trafo - 75ohm R in parallel






 if you look close you can see blue caps on the center lead. that goes to the trafo and the rca ground goes to the other input leg of the trafo. 75ohm R's are soldered to the secondary and that is supposed to give a nice 75ohm 'view' into the rest of the downstream circuit. from there it goes to a differential rs422 receiver chip. that chip receives the trafo 'data' and TTL'izes it so that it can be sent to the analog mux switch chip.


----------



## ksnider1

Ladies and Gentlemen here it is, my first DIY working y2 DAC 

Y2DAC

 Thank you for this fine device.

 It's connected to xbox via S/PDIF. I'm using XBMC to play my flac collection. Also I tested usb input connected to my d610 laptop with mplayer and it works great. 
 Y2 is connected to marantz pm8003 with aperion 6T speakers. I will post more info after I will listen more music. So far I like it very much, maybe more than my cd5003. It's hard to tell right now.

 Thank you !!!


----------



## Volkum

Quote:


  Originally Posted by *ksnider1* /img/forum/go_quote.gif 
_Ladies and Gentlemen here it is, my first DIY working y2 DAC_

 

A word of warning: it's a bad idea to put bare electronics on carpet due to the possibility of electrostatic discharge damaging components!

 Anyways, grats on the build!


----------



## ksnider1

Quote:


  Originally Posted by *Volkum* /img/forum/go_quote.gif 
_A word of warning: it's a bad idea to put bare electronics on carpet due to the possibility of electrostatic discharge damaging components!

 Anyways, grats on the build!_

 

Thanks, I moved from carpet. Case should arrive sometime next week.


----------



## fishski13

my sigma11 is putting out 4.837V. too low? i have a bunch of extra 5.1V zeners.


----------



## m1abrams

Quote:


  Originally Posted by *fishski13* /img/forum/go_quote.gif 
_my sigma11 is putting out 4.837V. too low? i have a bunch of extra 5.1V zeners._

 

Sorry can not answer your ? but when you do get that sigma11 will you do a comparison between it and usb power and/or basic switching supply. So the rest of us know wether it is worth the effort


----------



## ShinyFalcon

I think it should be fine, the voltage should not fluctuate.

 And yes, comparisons please


----------



## fishski13

i ripped out the zener and socketed the pads, but i have to take off to help a buddy suss the electrical on his 40 year old rebuilt snowmobile.

 i should have the y-2 up and running tomorrow. i ohmed all the chips out and found one solder bridge. i want to re-ohm everything once more before i power-up. i'll report my finding between my switching wallwart and the o-11.


----------



## JazzVinyl

Quote:


  Originally Posted by *ksnider1* /img/forum/go_quote.gif 
_Ladies and Gentlemen here it is, my first DIY working y2 DAC 

Y2DAC

 Thank you for this fine device.

 It's connected to xbox via S/PDIF. I'm using XBMC to play my flac collection. Also I tested usb input connected to my d610 laptop with mplayer and it works great. 
 Y2 is connected to marantz pm8003 with aperion 6T speakers. I will post more info after I will listen more music. So far I like it very much, maybe more than my cd5003. It's hard to tell right now.

 Thank you !!!_

 

Wow, they look great! Good job...

 And I see two JARRE CD's in the photo, you have great taste in music, too!!

 Double congrats!!


----------



## rds

Quote:


  Originally Posted by *fishski13* /img/forum/go_quote.gif 
_my sigma11 is putting out 4.837V. too low? i have a bunch of extra 5.1V zeners._

 

I'm wondering a similar thing since my sigma 11 is outputting 4.75V. Unfortunately I only have the one zener on hand.


----------



## Beefy

Quote:


  Originally Posted by *rds* /img/forum/go_quote.gif 
_I'm wondering a similar thing since my sigma 11 is outputting 4.75V. Unfortunately I only have the one zener on hand._

 

You could change the feedback resistor as well.

 [EDIT] Ooops, the resistor not used at low voltages


----------



## fishski13

Quote:


  Originally Posted by *rds* /img/forum/go_quote.gif 
_I'm wondering a similar thing since my sigma 11 is outputting 4.75V. Unfortunately I only have the one zener on hand._

 

i threw in another zener and am getting 4.91V. let me know if you need any. i can test them in situ for you and shoot you one FOC.


----------



## pila405

Deleted


----------



## amb

Measure the voltage across σ11's D5 zener. If it's low, then the output vltage will also be low. If accurate voltage is required, it's always a good idea to order a small handful and test them. They are cheap.


----------



## ShinyFalcon

Can I place the output caps after R9/R16? I thought about air-wiring the output and bypass caps for easy removal/addition. (external case, of course)

 Also, on the schematics, at J6, the output is directly shorted to ground. Is it supposed to be that way? Or is it referring to the shell of the RCA?


----------



## MisterX

Quote:


 Also, on the schematics, at J6, the output is directly shorted to ground. Is it supposed to be that way? Or is it referring to the shell of the RCA? 
 

Yes to the second part.....

 Edit: here is a link that will explain the symbol on the schematic for you: http://www.dumall.com/en/manuals/ele...ls/index.shtml


----------



## amb

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Can I place the output caps after R9/R16? I thought about air-wiring the output and bypass caps for easy removal/addition. (external case, of course)_

 

The purpose of R9/R16 is to provide a charge/discharge path to ground for the output coupling caps, and they should be _after]_ the coupling caps.


----------



## fishski13

i measured 2.7V at the 3.3V test point. i hooked up the y-2 and no love. i re-ohmed all the SMD and found a leg on both U2 and U7 with solder but intermittent measurement depending on hard i pushed with my DVM probe. this was my 3rd time ohming out the SMDs - they were fine with previous checks. right now i'm listening to Serge Gainsbourg via the y-2/Oppo/B22/K271 and celebrating with some beer and tequila 
	

	
	
		
		

		
			





.

 a huge kudos to Ti and Marshall for their generous gift to the DIY community
	

	
	
		
		

		
		
	


	




!!!


----------



## rjkdivin

I just completed two Gamma 2s using the Full++ configuration of the Gamma 1 boards and using the AD8656 Opamp at U7 and 450uF caps at C20 and C26 on the Gamma 2 board and C24D and C25D on the Gamma 1 board to allow direct headphone driving at both analog outputs. The volume when driving headphones directly is indeed a bit too high with my test bench CD player....perhaps an in line attenuator could be fashioned.

 The sound is very very good and to my ears provides a fuller, or expanded sound compared to the Gamma 1 alone when using the SPDIF inputs. I have not compared it to my Benchmark DAC-1 yet, but I will post some comments after I do.

 As usual, the build guidance from AMB’s website is phenomenally good and complete. I really had no issues during the build. I used a small pair of wiring harnesses for the testing of the Gamma 1 boards in ‘mated’ configuration.










































 Sorry for the large photos, but they illustrate how neat the IC soldering can be by using a flux pen on the solder pads and only minimal solder on the iron tip. I actually use a microscope to do the soldering, and I keep the iron very hot...680 to 700 deg. F. so the contact time is very short.


----------



## fordgtlover

^ Nice job


----------



## pila405

Amazing job! Looks very clean and neat!


----------



## fishski13

rjkdivin,
 i'm interested in your impressions between the y-2 and DAC1. i'm going to leave my y-2 hooked up for awhile before plugging in my DAC1. so far, the y-2 is a bit more warmer and smoother sounding. i'm also prefering the A filter. i'm also getting occaisional dropouts via SPDIF, maybe a half a second or so. my Oppo has been freezing up on me though from time to time.


----------



## BoogieWoogie

I'm collection info for a DAC to work with a RS-1 ,HD650, 701 + MiniMAX and this appears to be a good DAC from your impressions . 
 Who are the direct rivals, any way near the DAC19MK3 ? How much is it already built?


----------



## fishski13

this is a honey of a DAC. very liquid sounding. i'm still adjusting to the treble response though, compared to the DAC1. right now, i wish i had a brighter phone to throw into the mix, something like a K701. oddly enough i'm prefering the K271 over the DT990/600ohm with the B22. i'm going to throw the M3 and Bijou into the mix in the next few days. 

 i won't be able to make any comparisons with a switching wallwart until i can order a smaller plug to fit the DC-in plug along with parts for another build sometime next week.

 i'm currently on a 5 week paternal LOA. my second child is the younger brother of my 2.5 year old daughter, born healthy on 1/6/10 20:33. i can't think of a better way to celebrate than with music. btw, my daughter is a huge Otis Redding and Jack Johnson fan.


----------



## GWorlDofSPACE

Quote:


  Originally Posted by *fishski13* /img/forum/go_quote.gif 
_this is a honey of a DAC. very liquid sounding. i'm still adjusting to the treble response though, compared to the DAC1. right now, i wish i had a brighter phone to throw into the mix, something like a K701. oddly enough i'm prefering the K271 over the DT990/600ohm with the B22. i'm going to throw the M3 and Bijou into the mix in the next few days. 

 i won't be able to make any comparisons with a switching wallwart until i can order a smaller plug to fit the DC-in plug along with parts for another build sometime next week.

 i'm currently on a 5 week paternal LOA. my second child is the younger brother of my 2.5 year old daughter, born healthy on 1/6/10 20:33. i can't think of a better way to celebrate than with music. btw, my daughter is a huge Otis Redding and Jack Johnson fan._

 

That would be interesting to compare it whit your DAC1. What I noticed about the A,B,C filters is that when you switch it to each other, there is no difference. Funny is I prefer B whit B22 and C whit Bijou. I think its something in subconscious.


----------



## WesrFegT

The parts from AMB arrived after being held by customs for almost 2 weeks. Bit like christmas all over again. Am most impressed with the engraved face plates, first not entirely sure whether to get them, but having them in my hands i'm really glad I did.

 Just waiting for some final supplies from Farnell and i can start putting it together (if school didn't mess things up). Ohh well just have to wait a little longer, though it will be difficult with all those parts within arms reach.

 This (and the mini3) would be my first DIY audio projects, looking forward putting them together and really curious how they will sound.


----------



## fishski13

Quote:


  Originally Posted by *GWorlDofSPACE* /img/forum/go_quote.gif 
_That would be interesting to compare it whit your DAC1. What I noticed about the A,B,C filters is that when you switch it to each other, there is no difference. Funny is I prefer B whit B22 and C whit Bijou. I think its something in subconscious._

 

depending on the recording i can here immediate differences when i switch between the filters, but the differences are subtle. 

 i'm going to plug in the Bijou tonight.


----------



## fishski13

Quote:


  Originally Posted by *WesrFegT* /img/forum/go_quote.gif 
_The parts from AMB arrived after being held by customs for almost 2 weeks. Bit like christmas all over again. Am most impressed with the engraved face plates, first not entirely sure whether to get them, but having them in my hands i'm really glad I did.

 Just waiting for some final supplies from Farnell and i can start putting it together (if school didn't mess things up). Ohh well just have to wait a little longer, though it will be difficult with all those parts within arms reach.

 This (and the mini3) would be my first DIY audio projects, looking forward putting them together and really curious how they will sound._

 

even though Ti has detailed drawings, i've done enough DIY face-plates as well as FPE to know that i had no interest in the effort involved to build/design my own. yes, the face-plates are beautiful and worth every penny. what a PITA it must have been for Ti to measure them. i would also recommend that you seat each face-plate component and only tag a single pin so that adjusting to fit the face-plate will be easier.


----------



## GWorlDofSPACE

Quote:


  Originally Posted by *fishski13* /img/forum/go_quote.gif 
_depending on the recording i can here immediate differences when i switch between the filters, but the differences are subtle. 

 i'm going to plug in the Bijou tonight._

 

You will be surprised how well the Y2 fits to Bijou.


----------



## BoogieWoogie

So many guys bulding this DAC but there is a lac of impressions, care to make one on the impressions thread ?


----------



## GWorlDofSPACE

Quote:


  Originally Posted by *BoogieWoogie* /img/forum/go_quote.gif 
_So many guys bulding this DAC but there is a lac of impressions, care to make one on the impressions thread ?_

 

Yes, agree. You could make one. I will make a short review of my impressions also.


----------



## BoogieWoogie

I would if I had one, right now I'm undecided between y1 and y2 or pico dac and some impressions would help.


----------



## m1abrams

Quote:


  Originally Posted by *BoogieWoogie* /img/forum/go_quote.gif 
_I would if I had one, right now I'm undecided between y1 and y2 or pico dac and some impressions would help._

 

As I stated in the other thread the reason you do not see many "impressions" is because most DIYers probably do not see much value in it. Ti does an excellent job documenting the design and providing test results. What else needs to be done?


----------



## BoogieWoogie

Documenting the design? and test results ?
 Please correct me but what those have to do with the real sound quality impression ?


----------



## m1abrams

Quote:


  Originally Posted by *BoogieWoogie* /img/forum/go_quote.gif 
_Documenting the design? and test results ?
 Please correct me but what those have to do with the real sound quality impression ?_

 

I could argue the same about some random persons 2 dollar words about what they hear.


----------



## BoogieWoogie

Well then you don't see the point of this forum I guess, excluding diy and sales section though.


----------



## m1abrams

Quote:


  Originally Posted by *BoogieWoogie* /img/forum/go_quote.gif 
_Well then you don't see the point of this forum I guess, excluding diy and sales section though._

 

Yep I am here mostly for the DIY.


----------



## K3cT

If you want to play safe then go for the Pico DAC. If you want to explore into the unknown (with potentially very satisfying result) then go for the γ2.


----------



## GWorlDofSPACE

Y2 is a great sound source and for that little money there is no alternative. 
 I can not imagine the DIY would not see big value in it. Its a great neutral sounding DAC what else you want to have.


----------



## Shahrose

FWIW, when I heard the Pico, it was no better than the STX, but had a different sound signature (ie. warmer and smoother). When I got the y2, I thought it was a big upgrade to the STX. 

 The only problem in this comparison is the fact that the Pico was a DAC/amp and not the standalone DAC, so the tiny amp could very well have been limiting the SQ.


----------



## GWorlDofSPACE

Its true. I noticed the same improvement. But I am using Y2 whit sigma11 PSU. I do not use my essence anymore so huge is the difference.


----------



## Shahrose

Quote:


  Originally Posted by *fishski13* /img/forum/go_quote.gif 
_rjkdivin,
 i'm interested in your impressions between the y-2 and DAC1. i'm going to leave my y-2 hooked up for awhile before plugging in my DAC1. so far, the y-2 is a bit more warmer and smoother sounding. i'm also prefering the A filter. i'm also getting occaisional dropouts via SPDIF, maybe a half a second or so. my Oppo has been freezing up on me though from time to time._

 

Congrats on the newborn 
	

	
	
		
		

		
			





 Immediately switching among the 3 filter settings will yield very subtle differences that may not be noticeable at first listen. But, overtime you should be able to pick out a couple key changes. I tried each filter for a few weeks and I found filter B to be the best in my system. It's definitely doing something to the treble because it's less harsh and more natural. You can notice it with any kind of treble-centric percussive effects, and it's even more pronounced with electronic music. I also think there is a subtle increase in wetness/soundstaging but this needs to be investigated further.

 I'm anxiously awaiting your comparisons to other DACs in your system BTW.


----------



## Shahrose

Quote:


  Originally Posted by *GWorlDofSPACE* /img/forum/go_quote.gif 
_Its true. I noticed the same improvement. But I am using Y2 whit sigma11 PSU. I do not use my essence anymore so huge is the difference._

 

Hey GWorld, I'm wondering if you've had the chance to compare the effects of a regular wallwart against that of the Sigma-11 for the y2. I'd like to get a Sigma-25 built for the y2 and I want to see if it would improve the sound at all.


----------



## GWorlDofSPACE

The B filter I think has more natural sound. The instruments and vocals have wonderful swings as I would say in real life. But as I said I prefer B for B22 and C for Bijou. I would also be happy if someone compares it other DACs not only in the same price range.


----------



## GWorlDofSPACE

Quote:


  Originally Posted by *Shahrose* /img/forum/go_quote.gif 
_Hey GWorld, I'm wondering if you've had the chance to compare the effects of a regular wallwart against that of the Sigma-11 for the y2. I'd like to get a Sigma-25 built for the y2 and I want to see if it would improve the sound at all. According to an email I got from MisterX, the Sigma-11 doesn't really do anything for the y2 over the wallwart, but I've come to distrust the hard science-based DIY'ers for sound impressions. 
	

	
	
		
		

		
		
	


	


_

 

What can I say! No, I have not. But if you have clean PSU, then this is only good for the sound I think. Maybe the q11 over wallwart in this case does not make such difference. But I can tell, my essence card inside the computer is using switching psu and it sounds flat, not interesting.


----------



## wuaffiliate

I am excited to build one of these, i have been in need of a usb dac and one i do not want to upgrade for some time. Luckly my father is skilled in electronics so i can learn a ton and have it done right!


----------



## GWorlDofSPACE

This is great for you. I suggest you to build it on your own. Than you will love it more.)


----------



## fishski13

Quote:


  Originally Posted by *Shahrose* /img/forum/go_quote.gif 
_Congrats on the newborn 
	

	
	
		
		

		
			





 Immediately switching among the 3 filter settings will yield very subtle differences that may not be noticeable at first listen. But, overtime you should be able to pick out a couple key changes. I tried each filter for a few weeks and I found filter B to be the best in my system. It's definitely doing something to the treble because it's less harsh and more natural. You can notice it with any kind of treble-centric percussive effects, and it's even more pronounced with electronic music. I also think there is a subtle increase in wetness/soundstaging but this needs to be investigated further.

 I'm anxiously awaiting your comparisons to other DACs in your system BTW._

 

thanks!

 i have just been sticking with A because this is my preference thus far. it has a little more treble than the others. i have owned the DAC1 for nearly 3 years now and need some time to adjust to the different sound sig. i will definitely report my impressions between the two after the y-2 has some more time in my kit. it's easily on the same level of the DAC1, but definitely a different flavor.


----------



## fishski13

Quote:


  Originally Posted by *BoogieWoogie* /img/forum/go_quote.gif 
_I would if I had one, right now I'm undecided between y1 and y2 or pico dac and some impressions would help._

 

before deciding to build this DAC i searched and found very little info. i have no idea how many people have a y-2 and another high quality DAC to compare with, but my guess would be not many. compound this with the reluctance of DIYers to write prose about sonic sigs and you have the resultant dearth of reviews of the y-2.


----------



## fishski13

Quote:


  Originally Posted by *GWorlDofSPACE* /img/forum/go_quote.gif 
_You will be surprised how well the Y2 fits to Bijou._

 

i've been listening to the y-2/Bijou for the past 2 days. very nice...
	

	
	
		
		

		
		
	


	




. btw, i have Regal's mod and Mundorf output caps.


----------



## WesrFegT

Quote:


  Originally Posted by *fishski13* /img/forum/go_quote.gif 
_i have no idea how many people have a y-2 and another high quality DAC to compare with, but my guess would be not many._

 

I'm new to hifi and really at the beginning of getting a nice audio setup together. I'm a bit guessing here, but i think i'd sooner get a 2nd amp or pair of cans later on then a 2nd DAC when i have the means to improve my setup later on.

 Although that all depends on how this build will work out.


----------



## K3cT

Cans are always the most important. That's where you choose what kind of sonic signature that you want and the rest of your components are just a matter of synergy with your headphone.


----------



## Shahrose

If anyone is looking for further sound impressions of the y2 DAC, they can be found here:

http://www.head-fi.org/forums/f7/amb...ssions-454445/


----------



## fishski13

Quote:


  Originally Posted by *K3cT* /img/forum/go_quote.gif 
_Cans are always the most important. That's where you choose what kind of sonic signature that you want and the rest of your components are just a matter of synergy with your headphone._

 

x2. the amp requirements for a lower impedance/easier to drive HP will be less as well.


----------



## fishski13

i need a USB cable to connect my y-2 and 'puter with a standard USB hub. is the mini-B on this cable correct? Newnex USB 2.0 A plug to Mini-B plug 5 Meters - Industrial Component


----------



## Volkum

Quote:


  Originally Posted by *fishski13* /img/forum/go_quote.gif 
_i need a USB cable to connect my y-2 and 'puter with a standard USB hub. is the mini-B on this cable correct? Newnex USB 2.0 A plug to Mini-B plug 5 Meters - Industrial Component_

 

Mini-b is it.


----------



## MisterX

$25? 
 Ouch, here I though $8.73 at Digi-Key was bad.


----------



## Volkum

Monoprice has super cheap USB cables.


----------



## vixr

just finished mine...fabulous.


----------



## vixr

Quote:


  Originally Posted by *fishski13* /img/forum/go_quote.gif 
_i need a USB cable to connect my y-2 and 'puter with a standard USB hub. is the mini-B on this cable correct? Newnex USB 2.0 A plug to Mini-B plug 5 Meters - Industrial Component_

 

I've been using the one that came with my digital camera...


----------



## fishski13

Quote:


  Originally Posted by *vixr* /img/forum/go_quote.gif 
_I've been using the one that came with my digital camera..._

 

i need 12-15ft and running the the USB cable across a lot of computer cables and other junk to reach the y-2.

 i just switched out my Oppo DVD player for my trusty 10 yr old Pioneer. the illuminated switch on the y-2 turned from green to a very faint red and no music with the Oppo. the Oppo has been acting up over the past month and i've been experiencing drop outs with the y-2. i'm hoping it's just the Oppo. it's not even 3 yrs old.


----------



## fishski13

congrats Vixr 
	

	
	
		
		

		
			





!!! i love the red anodized.


----------



## fishski13

well...with the Pioneer, the y-2 illuminated switch went from normal brightness Green to a very dim Red - no music. powered down the y-2 and now working fine powered back up.


----------



## fishski13

Quote:


  Originally Posted by *fishski13* /img/forum/go_quote.gif 
_well...with the Pioneer, the y-2 illuminated switch went from normal brightness Green to a very dim Red - no music. powered down the y-2 and now working fine powered back up._

 

somethings not right with the y-2. i have just the y-1 board hooked up to see if the problem is the the y-1 or the y-2 board. btw, i was measuring 3.15V at the 3.3V on the y-2 board.


----------



## fishski13

the y-2 has been running continuously without issue for the past 12 hrs - nude with y-1 only, then added y-2 board, and finally mounted in the chassis. i have a 1500W space heater with a thermostat that switches on and off plugged into the same AC mains ring as the hi-fi along with my computer . i turned it off this morning suspecting it was creating some voodoo. 

 i still have another 4 weeks off of work but i guess i will need to run a dedicated mains from the breaker-box for the hi-fi sooner than later. at least we're experiencing a balmy Jan thaw in MN at the moment 
	

	
	
		
		

		
		
	


	




.

 as far as transports go, i'm preferring my ancient Pioneer to the Oppo. before building the y-2, i preferred the Oppo with the DAC1. the little y-2 continues to impress.


----------



## fishski13

WOW!

 the y-2/B22/DT990 and K271 sound amazing with:






 pretty dull sounding on the DAC1.


----------



## K3cT

So it was some weird groundloop issue? It's nice to see that you managed to sort it out, fishski13.


----------



## oneplustwo

I too continue to be more and more impressed with the gamma 1 and 2 as I listen to more and more of the competition. Now, there just needs to be a balanced version.


----------



## jc9394

I have commissioned a builder to build me one but I have a question, is the analog out drive JH13 well?


----------



## m1abrams

Quote:


  Originally Posted by *jc9394* /img/forum/go_quote.gif 
_I have commissioned a builder to build me one but I have a question, is the analog out drive JH13 well?_

 

I do not know about the JH13 phones, but regardless of the phone make sure your building is using the larger capacitors for C20 & C26 and use the Analog Devices AD8656ARZ for U7 opamp.


----------



## pixeljedi

Quote:


  Originally Posted by *m1abrams* /img/forum/go_quote.gif 
_I do not know about the JH13 phones, but regardless of the phone make sure your building is using the larger capacitors for C20 & C26_

 

Speaking of larger caps 
	

	
	
		
		

		
		
	


	









 I had some extra from the sohaII I'm building and decided to give them a whirl since I have the extra room. I also threw some KZ's in for C11,C13 (the blurry ones in the back). The sound is really really really nice. Subjective, but I believe better than the two previous ones I built. I'm not a fan of caps installed like this, so I may do something to cover up those leads.

 Thanks again Ti and Marshall!


----------



## fishski13

i ran 40ft of 12awg Romex this morning for a dedicated hi-fi mains off a 20A breaker for the new man-cave. the sound has noticeably improved since isolating the hi-fi from the computer, fluorescent lights, and dimmer switch that was on the same mains. 

 i now have heat and hi-fi 
	

	
	
		
		

		
		
	


	




.


----------



## fishski13

i decided to hook up my DAC1 for some comparisons. i've owned the DAC1 for 3 years now. i also know that a lot of people dislike it, saying it's cold, sterile, and lifeless. i've never felt the DAC1 was a limiting component with my M3 or Bijou - the combos sound great. listening via the B22 seeded an itch to scratch though...

 o.k. i don't DBT and ABXYZ or whatever they're called, but did roughly volume match with my Rat Shack analog SLM. i spent a few hours last night and today switching back and forth between the two DACs and my Pioneer and Oppo DVD players as transports, with the B22 and DT990/600ohm downstream.

 keeping in mind that we have different tastes and listening habits, i prefer my hifi to reproduce the performance with prescence and drama. "hi-fi" artifacts like soundstaging, imagining, air etc are all subservient to the _music_. is it too much to ask for tone and timbre as well? 

 with the B22/DT990, the DAC1 is in comparison to the y-2:
 -cooler, brighter, and analytical sounding. 
 -tonally, everything sounds a bit white and dry colored, with a focus on the treble and a sense of airiness. the y-2 has a wider tonal palatte and a very black background. 
 -dynamics are subdued but can be acceptable with a higher SPL.
 -with volume matching, i had to crank the volume a bit more to get the front row perspective that the y-2 offers.
 -as far as resolving power goes, i guess they're about equal, but would give the nod to the y-2 as it offers a more front row presentation and more presence. if treble is your bag, then you might disagree. i personally find the DAC1's treble hyped. 
 -musically, the DAC1 can be hit or miss with the B22/DT990. however, the y-2 doesn't dick around and gets to the meat on the bone. where a note on the DAC1 kind of fades away into nothing, there's a definite sonic envelope with the y-2. the beat can ebb and flow like a fine analog source, and i can say i don't miss my Basis TT anymore. 

 long story short, i prefer the y-2. thanks for putting up with my prose, but i should get some credo for using the pro-audio term "hyped". 

 i think the DAC1 is a huge bargain and when paired properly, it's a lovely component. as much as it sounds like i'm slagging off the DAC1, i'm keeping it. it offers a different perspective that i want to have around. i love the Swiss Army knife appeal of it as well, offering balanced, pre vs. calibrated outputs, and an HP amp. 

 a HUGE thanks to Ti and Marshall
	

	
	
		
		

		
		
	


	




!!!


----------



## yeahyeah

Hi everyone

 I am considering to build the gamma 2. Before proceed, could you advice if the original parts (left hand side) can be replace by the parts on the right:
 1. SN74AHC1G08DBVR -> SN74AHC1G08DBVT
 2. WM8741GEDS/V -> WM8741GEDS/RV 
 3. OPA2365AID -> OPA2365AIDG4

 I want to do this because mouser has them out of stock and i don't want to wait. I have check datasheets but none give me the difference between them.

 Besides, I am going to drive my earphone and amp with it, so I should use AD8656ARZ and output cap of 470uF? Any drawback by driving amp with AD8656 instead of OPA2365?

 Thank you very much


----------



## MisterX

Quote:


 
 1. SN74AHC1G08DBVR -> SN74AHC1G08DBVT 
 

Yes. The difference is the packaging. 
 ("VR" code is for large tape reel packaging, "VT" code is for small tape and reel packaging)


  Quote:


 2. WM8741GEDS/V -> WM8741GEDS/RV 
 

 Yes, the difference is the packaging again. 
 ("RV" code is for reel packaging, "V" code is for tube packaging) 

  Quote:


 3. OPA2365AID -> OPA2365AIDG4 
 

Yes. 
 (the "G4" code allows you to purchase guaranteed Pb free parts when there are legacy parts in the supply chain (that may not be Pb free))

  Quote:


 Besides, I am going to drive my earphone and amp with it, so I should use AD8656ARZ and output cap of 470uF? 
 

You will only need the 470uF caps if you are planning on driving the phones without an amp. 

  Quote:


 Any drawback by driving amp with AD8656 instead of OPA2365?

 

No. 
 And there is no dis-advantage to using the 470uF caps either.


----------



## ShaneP

beat ;

 I did however find the first two parts you listed on the left hand side in stock at mouser.


----------



## Shahrose

Quote:


  Originally Posted by *fishski13* /img/forum/go_quote.gif 
_i decided to hook up my DAC1 for some comparisons. i've owned the DAC1 for 3 years now. i also know that a lot of people dislike it, saying it's cold, sterile, and lifeless. i've never felt the DAC1 was a limiting component with my M3 or Bijou - the combos sound great. listening via the B22 seeded an itch to scratch though...

 o.k. i don't DBT and ABXYZ or whatever they're called, but did roughly volume match with my Rat Shack analog SLM. i spent a few hours last night and today switching back and forth between the two DACs and my Pioneer and Oppo DVD players as transports, with the B22 and DT990/600ohm downstream.

 keeping in mind that we have different tastes and listening habits, i prefer my hifi to reproduce the performance with prescence and drama. "hi-fi" artifacts like soundstaging, imagining, air etc are all subservient to the music. is it too much to ask for tone and timbre as well? 

 with the B22/DT990, the DAC1 is in comparison to the y-2:
 -cooler, brighter, and analytical sounding. 
 -tonally, everything sounds a bit white and dry colored, with a focus on the treble and a sense of airiness. the y-2 has a wider tonal palatte and a very black background. 
 -dynamics are subdued but can be acceptable with a higher SPL.
 -with volume matching, i had to crank the volume a bit more to get the front row perspective that the y-2 offers.
 -as far as resolving power goes, i guess they're about equal, but would give the nod to the y-2 as it offers a more front row presentation and more presence. if treble is your bag, then you might disagree. i personally find the DAC1's treble hyped. 
 -musically, the DAC1 can be hit or miss with the B22/DT990. however, the y-2 doesn't dick around and gets to the meat on the bone. where a note on the DAC1 kind of fades away into nothing, there's a definite sonic envelope with the y-2. the beat can ebb and flow like a fine analog source, and i can say i don't miss my Basis TT anymore. 

 long story short, i prefer the y-2. thanks for putting up with my prose, but i should get some credo for using the pro-audio term "hyped". 

 i think the DAC1 is a huge bargain and when paired properly, it's a lovely component. as much as it sounds like i'm slagging off the DAC1, i'm keeping it. it offers a different perspective that i want to have around. i love the Swiss Army knife appeal of it as well, offering balanced, pre vs. calibrated outputs, and an HP amp. 

 a HUGE thanks to Ti and Marshall
	

	
	
		
		

		
			





!!!_

 

You should post this in the y2 dedicated impressions thread. Good read. Earlier in this thread pixeljedi said the y2 sounded very similar to the PS Audio DLIII+Stage IV Cullen Mod in terms of performance. Considering that DAC+upgrade costs $1300 USD, I think it speaks volumes of the y2.
 Source: http://www.head-fi.org/forums/6166747-post993.html

 That DAC has also been compared to the DAC1 and I've seen multiple accounts of owners of both who strongly preferred the PS Audio III+Cullen IV, so your impressions match what I've seen posted elsewhere.
 Source: http://forum.audiogon.com/cgi-bin/fr...gtl&1226448556


----------



## fishski13

Quote:


  Originally Posted by *Shahrose* /img/forum/go_quote.gif 
_You should post this in the y2 dedicated impressions thread_

 

excellent idea.


----------



## simwells

Quote:


  Originally Posted by *vixr* /img/forum/go_quote.gif 
_just finished mine...fabulous.



_

 

Is the red anodizing done by you? Or can you buy them anodized in different colours?


----------



## pixeljedi

Quote:


  Originally Posted by *simwells* /img/forum/go_quote.gif 
_Is the red anodizing done by you? Or can you buy them anodized in different colours?_

 

Comes in: Black, Silver, Red, Green, Blue and Gold

Box Enclosures


----------



## mattcalf

Wow vixr, I didn't think it'd look good mixing and matching the colours. That looks superb though. 
	

	
	
		
		

		
		
	


	




 Thanks for sharing.


----------



## yeahyeah

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Yes. The difference is the packaging. 
 ("VR" code is for large tape reel packaging, "VT" code is for small tape and reel packaging)



 Yes, the difference is the packaging again. 
 ("RV" code is for reel packaging, "V" code is for tube packaging) 


 Yes. 
 (the "G4" code allows you to purchase guaranteed Pb free parts when there are legacy parts in the supply chain (that may not be Pb free))



 You will only need the 470uF caps if you are planning on driving the phones without an amp. 



 No. 
 And there is no dis-advantage to using the 470uF caps either. 
	

	
	
		
		

		
		
	


	


_

 

I will use OPA2365 with 470uF for both my phones and amp then
 Thank you~


----------



## MASantos

A few questions:

 I am planning building a y1+y2, y1 configured for input only, so no dac or digital outputs on the y1 board.

 I read through amb's website and couldn't find what parts associated with the y1's dac can be ommited. 

 Also, since local LDO regulators are use, does it make sence to use the o11 to power these, as compared to an o25? Cost will increase quite a bit, so I'm not sure its worthiness.

 Thanks in advance!

 Manuel


----------



## grenert

Quote:


  Originally Posted by *MASantos* /img/forum/go_quote.gif 
_I read through amb's website and couldn't find what parts associated with the y1's dac can be ommited. 

 Also, since local LDO regulators are use, does it make sence to use the o11 to power these, as compared to an o25? Cost will increase quite a bit, so I'm not sure its worthiness.

 Thanks in advance!

 Manuel_

 

Look on the parts list for the Gamma1. There are different configurations A-F depending on what you want to leave out.

 Three-pin regulators do not do a very good job handling high frequency noise, so you could probably improve on that with the Sigma11. I won't get into the question of whether or not that will make an audible difference to you


----------



## Shahrose

Quote:


  Originally Posted by *MASantos* /img/forum/go_quote.gif 
_A few questions:
 ...Also, since local LDO regulators are use, does it make sence to use the o11 to power these, as compared to an o25? Cost will increase quite a bit, so I'm not sure its worthiness.

 Thanks in advance!

 Manuel_

 

You can build a Sigma-11 if you want an "overkill" PSU for your y2. The Sigma-25 measures almost identical to it though and costs a lot less.


----------



## fishski13

i'm still having intermittent problems. i had the y-2 shut down on me twice today. the switch turns from normal green to a very dim red. 

 i re-ohmed everything out on the y-2 board. there are no solder bridges on any legs of the SMDs and i reflowed all through holes. i also double checked every component for correct values and placement.

 i'm currently going through the same process on the y-1 board 
	

	
	
		
		

		
		
	


	




.

 btw, i found X1 SMD to be difficult to solder and reflowed this as well.


----------



## MisterX

Quote:


 the switch turns from normal green to a very dim red. 
 

As compared to bright red when there is no signal? 
 (I would monitor the supply voltage and see if it droops or if there is any other weirdness when the DAC does that)

  Quote:


 i found X1 SMD to be difficult to solder 
 

My method for soldering X1 (on the Y2 board) is to coat the pads on the part with solder first. 
 Then just flux the board, place the part, touch the iron to the pads, watch for the solder to flow and you're done. 
 It's a lot easier then trying to get the solder to wick between the board and pads or piling it up on the outer portion of pads on the crystal.


----------



## fishski13

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_As compared to bright red when there is no signal? 
 (I would monitor the supply voltage and see if it droops or if there is any other weirdness when the DAC does that)


 My method for soldering X1 (on the Y2 board) is to coat the pads on the part with solder first. 
 Then just flux the board, place the part, touch the iron to the pads, watch for the solder to flow and you're done. 
 It's a lot easier then trying to get the solder to wick between the board and pads or piling it up on the outer portion of pads on the crystal. 
	

	
	
		
		

		
		
	


	


_

 

thanks! i can only assume X1 is working properly.

 the red is much dimmer than normal bright red when no signal.

 btw, i'm using an o-11 for PS.


----------



## rds

In order to narrow down the possible sources I'd suggest running the DAC from usb power and see if the problem still occurs.

 EDIT I forgot to ask: When the problem occurs how do you get the DAC working again? Do you unplug the power cable from the y2 or do you turn the power supply on and off?


----------



## fishski13

Quote:


  Originally Posted by *rds* /img/forum/go_quote.gif 
_In order to narrow down the possible sources I'd suggest running the DAC from usb power and see if the problem still occurs._

 

good call - i didn't think about that. right now i'm taking a break and listening to the y-1 only to help isolate where the problem lies. so far no drop-outs or freezing.


----------



## fishski13

Quote:


  Originally Posted by *rds* /img/forum/go_quote.gif 
_
 EDIT I forgot to ask: When the problem occurs how do you get the DAC working again? Do you unplug the power cable from the y2 or do you turn the power supply on and off?_

 

i turn off the o-11. i don't power down the cd player either.


----------



## rds

Quote:


  Originally Posted by *fishski13* /img/forum/go_quote.gif 
_i turn off the o-11. i don't power down the cd player either._

 

OK, if you turn off the PS then that doesn't bring us any closer to knowing if it's the DAC or PS.
 I think running from usb is the next thing to do.


----------



## fishski13

Quote:


  Originally Posted by *rds* /img/forum/go_quote.gif 
_OK, if you turn off the PS then that doesn't bring us any closer to knowing if it's the DAC or PS.
 I think running from usb is the next thing to do._

 

copy that. i haven't tried powering it with USB yet. it's a steep learning curve for me as i've never tried USB for music playback before.

 so far, no issues with the y-1 in the last 2 hrs. i would have had a brief 0.5 sec. or so drop out by now with the y-2, but not necessarily a freeze up. freeze up = no music and very dim red switch. i'll leave it powered up without signal or load for the next 24hrs.

 EDIT: the y-1 will be connected to my B22 that is turned off.


----------



## fishski13

i will take some V-regulator measurements when/if it freezes up again.


----------



## rds

Quote:


  Originally Posted by *fishski13* /img/forum/go_quote.gif 
_copy that. i haven't tried powering it with USB yet. it's a steep learning curve for me as i've never tried USB for music playback before._

 

You don't need to playback with usb. You can use coax or optical. As long as you have usb plugged in it will get power.


----------



## fishski13

y-1 no issues over 24hrs with o-11. right now i have the y-2 board connected and USB powered via a dedicated hub.

 i have a couple dozen of discs burned with JRiver Media and listening to some tunes without issue. i'm running Vista 32-bit with 4G memory.

 i also took some new measurements.

 Vout USB = 4.89-4.95V, fluctuating V both when connected to B22 and when not.

 Vout o-11 = 4.88V, both loaded and unloaded.


----------



## Skubasteve

Does the Gamma 2 Full++ configuration use I2S or SPDIF? It looks to me like it uses SPDIF from the PCM2707 but I'm not sure.


----------



## ShinyFalcon

Yes, PCM2707 -> SPDIF -> CS8416 -> I2S -> WM8501/WM8741


----------



## fishski13

update:
 no freezing or drop-outs with the y-2 USB powered after 24hrs. i guess the next step would be to investigate the o-11 and switch out my digital IC for another. since my USB Vout is slightly higher than the o-11, could it be that i need to swap some zeners to shoot for a higher Vout?

 also, i'm getting quite a bit of crackling and drop-outs with WASAPI and ASIO with J River Media and Foobar when moving the mouse, otherwise quiet. when outputting DS, zero issues even when moving the mouse. i'm honestly having a hard time picking out differences between WASAPI/ASIO and DS - i hear bigger differences between cables 
	

	
	
		
		

		
			





. everything i've read indicates, or implies, that DS is inferior.

 i'm pretty pissed with the J River Media Center atm. i've had 4 blue screens on my PC today when i would move the mouse. over at their forum they said that it's a hardware or video driver issue.


----------



## amb

I don't have much luck with WASAPI either, on my HP Pavilion dv7 laptop running Windows 7 ultimate x64. ASIO4ALL works fine, though (as does DirectSound). On the same laptop running openSUSE Linux 11.2 x86_64 everything works great, so it's not a hardware problem. I think Windows Vista and Windows 7 still have some problems with its USB audio subsystem.


----------



## fishski13

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_I don't have much luck with WASAPI either, on my HP Pavilion dv7 laptop running Windows 7 ultimate x64. ASIO4ALL works fine, though (as does DirectSound). On the same laptop running openSUSE Linux 11.2 x86_64 everything works great, so it's not a hardware problem. I think Windows Vista and Windows 7 still have some problems with its USB audio subsystem._

 

i was just about to edit my post...i forgot that i hadn't tried ASIO4ALL in Foobar. it's loaded and working flawlessly via USB. i can hear a difference between ASIO and DS. one sounds more tube-like and the other SS 
	

	
	
		
		

		
		
	


	




.

 i'll try sorting out the o-11 tomorrow. i've spent a lot of time trying to figure out this whole 'puter for playback thing today and i just want to enjoy some tunes before bed.


----------



## Shahrose

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_I don't have much luck with WASAPI either, on my HP Pavilion dv7 laptop running Windows 7 ultimate x64. ASIO4ALL works fine, though (as does DirectSound). On the same laptop running openSUSE Linux 11.2 x86_64 everything works great, so it's not a hardware problem. I think Windows Vista and Windows 7 still have some problems with its USB audio subsystem._

 

WASAPI works for me in Windows 7 Ultimate x64 with foobar2000 (v1.0) through USB and Coaxial. I do rarely experience some sound cutting in and out with USB though (absent from Coaxial output). It happens maybe once every 2-3 hours of listening and is fixed by simply pausing and replaying.


----------



## MASantos

So I'm designing my own panels with FPE and using AMB's measurements, but the program rounds my hole coordinates to 1/10 of milimiter, and some holes need to be centered to 1/100 of milimiter.

 AMB, is 0,003mm of difference actualy a problem here?

 I'm almost sure not, as board mounted connectors are normally a bit loose on the holes, but wanted to check this out before I order the panels!

 Thanks in advance!


----------



## amb

MASantos, there is enough tolerance that rounding to the closest 0.01 mm should not be a problem.


----------



## mace1337

I'm sure this has been covered, but for the life of me I cannot find a conclusive answer.

 When starting from scratch and wanting to build a full-featured y2, do you need a full-featured y1 as well? 

 It would seem to me that the DACs provided by the y2 make the dac on the y1 superfluous, is this correct or not?

 I'm mainly interested in coax and optical inputs, USB would be a nice bonus, but apart from that I would like all the features (maybe sans the front-panel 3,5 mm jack, I don't really need that)

 Are there parts that can be omitted whilst still retaining all features.

 Again, sorry if it has been asked before but I read about 50 pages and searched the forum but I could not come up with a conclusive answer.


----------



## m1abrams

Quote:


  Originally Posted by *mace1337* /img/forum/go_quote.gif 
_I'm sure this has been covered, but for the life of me I cannot find a conclusive answer.

 When starting from scratch and wanting to build a full-featured y2, do you need a full-featured y1 as well? 

 It would seem to me that the DACs provided by the y2 make the dac on the y1 superfluous, is this correct or not?

 I'm mainly interested in coax and optical inputs, USB would be a nice bonus, but apart from that I would like all the features (maybe sans the front-panel 3,5 mm jack, I don't really need that)

 Are there parts that can be omitted whilst still retaining all features.

 Again, sorry if it has been asked before but I read about 50 pages and searched the forum but I could not come up with a conclusive answer._

 

The only reason to have the y1 DAC chip is if you want the front-panel 3.5mm jack. I am sure in this thread AMB lists what parts can be left off the y1 board if you do not need the DAC of the y1.


----------



## rjkdivin

mace1337,
 If you go to AMB's web site, you will find links to separate web pages for all of AMB's supported DIY projects:
AMB Laboratories DIY Audio Site
 From there you can link to the sites for the y1 and y2 that include full parts lists for each. The parts list for the y1 includes a matrix telling you which parts to include for each configuration.....it is very complete. The y2 page tells you which configurations of the y1 will work with the y2 and what features can be omitted. The 'Before You Start' sections are must reads for both the y1 and y2 to determine a final configuration.
 If you omit the y1 output jack and you decide to use AMB's case panels, you will have an empty hole in your panel....no big deal.
 I built the F++ version of the y1 to have maximum flexibility in my finished y2.


----------



## Beefy

Quote:


  Originally Posted by *mace1337* /img/forum/go_quote.gif 
_I'm mainly interested in coax and optical inputs, USB would be a nice bonus, but apart from that I would like all the features (maybe sans the front-panel 3,5 mm jack, I don't really need that)

 Are there parts that can be omitted whilst still retaining all features._

 

You will still need the SPDIF receiver/mux chip, selector switches, etc. to get coax and optical input, and these make up the bulk of the cost of the y1. Parts for the USB input only cost about $20, so it seems silly not to include these. Also, the y1 DAC chip and components are only a few bucks.

 So the only parts I would leave out are the SPDIF output components on the USB board.


----------



## MASantos

Quote:


  Originally Posted by *rjkdivin* /img/forum/go_quote.gif 
_mace1337,
 If you go to AMB's web site, you will find links to separate web pages for all of AMB's supported DIY projects:
AMB Laboratories DIY Audio Site
 From there you can link to the sites for the y1 and y2 that include full parts lists for each. The parts list for the y1 includes a matrix telling you which parts to include for each configuration.....it is very complete. The y2 page tells you which configurations of the y1 will work with the y2 and what features can be omitted. The 'Before You Start' sections are must reads for both the y1 and y2 to determine a final configuration.
 If you omit the y1 output jack and you decide to use AMB's case panels, you will have an empty hole in your panel....no big deal.
 I built the F++ version of the y1 to have maximum flexibility in my finished y2._

 

There is no indication on the y1 website regarding omiting the dac chip and associated parts for building a complete y2.

 From my understanding, one can remove the DAC IC and associated parts in the y1 schematic, and keep everything else for mutiple inputs and outputs.
 Can you confirm this Ti?


----------



## Beefy

Looking at the schematic of the y1 DAC board, I think you can leave off everything from R7D to the audio out. But not much more than that to keep all of the switching functions. But it is like $5 worth of parts...... seems silly to me to leave that out, when it gives you a second audio output.

 I've always thought that the best way to configure the y1/y2 is to use the y1 as a part-time headphone out only. Then configure the y2 output as a line-out to another amp.


----------



## mace1337

Thanks for the comments guys.

 @rjkdivin:
 Yeah, I noticed that. And granted, it's very clear what combinations will work and what parts are needed for those combinations, but there is no "you can omit this and that part if you want to build a y2".

 If it really boils down to a few bucks of difference I might as well go for a y1++ and be done with it, but I just don't see the need to put parts in the y1 that will just be bypassed by the y2.


----------



## MisterX

Quote:


 But it is like $10 worth of parts...... seems silly to me to leave that out, when it gives you a second audio output. 
 

FIFY


----------



## MASantos

Quote:


  Originally Posted by *mace1337* /img/forum/go_quote.gif 
_Thanks for the comments guys.

 @rjkdivin:
 Yeah, I noticed that. And granted, it's very clear what combinations will work and what parts are needed for those combinations, but there is no "you can omit this and that part if you want to build a y2".

 If it really boils down to a few bucks of difference I might as well go for a y1++ and be done with it, but I just don't see the need to put parts in the y1 that will just be bypassed by the y2. 
	

	
	
		
		

		
		
	


	


_

 

Exactly. And if one can save 10$ of parts that won't be needed then why spend that money? In my case, I want the amp to have the 3 digital inputs and the y2 analog output on the rear, so I see no point in spending extra money just because it can be done.

 Ti, if you could give some more information regarding what parts can be removed from the y1 board regarding this subject, we'd be most thankful!


----------



## ShinyFalcon

Code:


```
[left]DC Power in -> Power switching -> 3.3V, 4.5V regulators USB ┌───> LED indication via two transistors, one SMD chip, and via switch TOSLINK -> CS8416 -> I2S -> y2 ; I2S -> R7D -> WM8501 Coaxial └───> Input selection via switch[/left]
```

If you want to get rid of the y1 DAC section completely, then get rid of R7D, U3D, R8-10D, C21-C27D, J3D, U9D. If you don't want the switch and LED indication, get rid of U8D, R2-R3, R11-13D, Q1-Q2D, C28D, SW1. 

 I'd just install everything but leave J3D, C24-27D out. THen in the future if you want to expand it or play with a bigger enclosure then you can add those...


----------



## thoppa

Hi,

 I'm ordering parts to build a Gamma2 - I've got everything on order except the WM8741. The only place I can find it is Mouser and they want to charge me US$50 to get it to me in Hong Kong. Crazy for a US$15 chip.

 Can anyone give me some advice about how to get one of these chips for reasonable money ? 

 Many thanks !

 Tom


----------



## fordgtlover

^
WOLFSON MICROELECTRONICS|WM8741GEDS/RV|DAC, STEREO, 24BIT, 28SSOP | Farnell Hong Kong


----------



## thoppa

Oh my....I should be banned from the internet eh ? I searched for this on their site and couldn't find it....

 So, THANK YOU ! That was your good deed for today. Helping an idiot use a website...hehe


----------



## amb

thoppa, I can help, PM me for info.

 MASantos, yes, if you must omit the WM8501 (and the few surrounding parts to support it), you can. Read the schematic diagram (and circuit description) at the γ1 website to understand how it works, then it should be quite clear what to do.


----------



## fishski13

this DAC continues to impress. i want to give another big thanks to Ti and Marshall 
	

	
	
		
		

		
		
	


	




. if there's ever an "uber-DAC" from you guys, count me in.

 i reseated the BNC/RCA adapters on my Stereovox digital IC and changed out the power cord. no issues all day with drop-outs or freezing. if it's truly the IC, then this isn't the first time i've experienced odd behavior with a $150 cable 
	

	
	
		
		

		
		
	


	




.


----------



## fordgtlover

Quote:


  Originally Posted by *fishski13* /img/forum/go_quote.gif 
_this DAC continues to impress. i want to give another big thanks to Ti and Marshall 
	

	
	
		
		

		
		
	


	




. if there's ever an "uber-DAC" from you guys, count me in.
_

 

Agreed. A very deserved thanks indeed to Ti and Marshall for the excellent little Gamma2.

 As for the über-DAC, if it's a step up from the Gamma2, it will be an absolute cracker


----------



## mace1337

So if I understand correctly, I need to omit the parts I outlined in red on the schematic below, right?




 *clickable*

 Is it really that easy? 
	

	
	
		
		

		
		
	


	




 Only I have to make some custom panels.


----------



## MASantos

Quote:


  Originally Posted by *mace1337* /img/forum/go_quote.gif 
_So if I understand correctly, I need to omit the parts I outlined in red on the schematic below, right?




 *clickable*

 Is it really that easy? 
	

	
	
		
		

		
			





 Only I have to make some custom panels. 
	

	
	
		
		

		
		
	


	


_

 

PM sent about custom panels.


----------



## MisterX

Why would you want to keep U6D and the parts that support it if you remove U3D?


----------



## mace1337

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Why would you want to keep U6D and the parts that support it if you remove U3D? 
	

	
	
		
		

		
		
	


	


_

 

Right, missed that one, thanks.


----------



## MASantos

Here's a mockup of the panels I designed:

 If anyone want's the fpe files let me know.

 I'll be ordering these in a few days, if anyone want a pair, let me know and I could order together to save a few bucks, I am ordering 3 pairs, so if two more people want these everyone will have 10% discount


----------



## francisdemarte

Can you post up the Front Panel Express file for the front panel? with out the extra outputs?


----------



## pila405

Does the Gamma2 have balanced outputs?


----------



## Beefy

Quote:


  Originally Posted by *pila405* /img/forum/go_quote.gif 
_Does the Gamma2 have balanced outputs?_

 

No. Even the slightest glance over the website or this thread would tell you that.


----------



## linuxworks

the chip and the pc board have + and - outputs on the analog rails. but the op-amp filter section is all SE and that's what you get on the rca-outs.

 so, its half-half. if you tap into the holes and do your own thing, it *could* be balanced. but not as-stock.


----------



## WyldRage

I want to build a gamma 2 and full gamma 1, but I need some help ordering. I'm trying to buy all the parts, except the AMB ones, from Mouser (to keep the shipping price down), but some parts are out of stock.

 I think I've found some alternative parts, but I want to check out the following:

 - OPA2365AIDG4 instead of OPA2365AID.
 - 512-2N3904NLBU instead of 512-2N3904BU
 - An alternative to SN74HCU04D.

 Are these OK?


----------



## amb

Quote:


  Originally Posted by *WyldRage* /img/forum/go_quote.gif 
_- OPA2365AIDG4 instead of OPA2365AID._

 

Yes, it's fine. The G4 suffix merely means that it's guaranteed to be RoHS compliant when there are mixed versions in the supply chain.
  Quote:


 - 512-2N3904NLBU instead of 512-2N3904BU 
 

Any 2N3904 in TO-92 package (_except_ Fairchild with C suffix e.g., 2N3904CTA or 2N3904CBU) would work.
  Quote:


 - An alternative to SN74HCU04D. 
 

Lots of alternatives -- any 74HCU04 variant in SOIC-14 package would work.


----------



## mace1337

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Any 2N3904 in TO-92 package (except Fairchild with C suffix e.g., 2N3904CTA or 2N3904CBU) would work._

 

Just out of curiosity, why is this?


----------



## MisterX

Different pin out. 
 (the collector is in the middle with the "C" variant)


----------



## WyldRage

Thank you for the answers.

 Just checking if I'm understanding correctly: CD74HCU04M would be an acceptable alternative to SN74HCU04D?


----------



## linuxworks

C=cmos (check)
 U=unbuffered (check)

 sn just means texas instruments, no?


----------



## amb

WyldRage, if you're really want, you could compare the datasheets.


----------



## thoppa

Hi,

 Just thought I should share something with you guys about ordering parts from Mouser. 

 It may be different for you guys in the US but I had a real problem. I won't go into the details cos it's boring. Anyway, it seems they are overcharging for USPS postage and also place a "reserve charge" on credit cards. They wanted to charge me US$25 for USPS but AMB only charged me US14.20 for a larger and heavier order. 

 It may be that AMB is simply wonderful...true diy paradise....I'm sure we all agree to that eh ?...Thanks Ti ! Simple words but really, thank you.

 Unfortunately it does make Mouser something of a less-than-fair supplier in my experience. Incidentally, neither Farnell or RS do this and their customer service has been really good too.


----------



## rds

USPS has a lot of different services and options


----------



## thoppa

Yes, and in Mouser's defence, their parts prices on some things are the lowest. However, the USPS service AMB chose is quicker and cheaper than Mouser. 

 So I thought I'd share this because many ppl don't bother to read terms and conditions or find out about the 'correct' cost of shipping. 

 The only other places I know that do reserve charges are hotels, and for them I can understand why, but for Mouser, I can see no reason. Of course, everyone should check their credit card bills thoroughly, but again, many ppl I know don't. 

 So it was just a heads-up.


----------



## MASantos

Quote:


  Originally Posted by *thoppa* /img/forum/go_quote.gif 
_Yes, and in Mouser's defence, their parts prices on some things are the lowest. However, the USPS service AMB chose is quicker and cheaper than Mouser. 

 So I thought I'd share this because many ppl don't bother to read terms and conditions or find out about the 'correct' cost of shipping. 

 The only other places I know that do reserve charges are hotels, and for them I can understand why, but for Mouser, I can see no reason. Of course, everyone should check their credit card bills thoroughly, but again, many ppl I know don't. 

 So it was just a heads-up._

 

For most countries in europe, orders over 75€ qualify for fedex free shipping, so it pays off to order a few exra things and get the free shipping!


----------



## thoppa

Quote:


  Originally Posted by *MASantos* /img/forum/go_quote.gif 
_For most countries in europe, orders over 75€ qualify for fedex free shipping, so it pays off to order a few exra things and get the free shipping!_

 

....poor Europeans will pay import duty on orders over, IIRC, 50 euros, and that's around 15% depending on the country. In my home country, the delightful Royal Mail will, if they are not on strike, hold the package and charge the recipient a fee on top of the import duty.

 I dunno if FedEx UPS DHL etc also do this. I've never had to suffer such a thing.

 Do you know any way around this for Portugal ?


----------



## GWorlDofSPACE

Quote:


  Originally Posted by *thoppa* /img/forum/go_quote.gif 
_....poor Europeans will pay import duty on orders over, IIRC, 50 euros, and that's around 15% depending on the country. In my home country, the delightful Royal Mail will, if they are not on strike, hold the package and charge the recipient a fee on top of the import duty.

 I dunno if FedEx UPS DHL etc also do this. I've never had to suffer such a thing.

 Do you know any way around this for Portugal ?_

 

Orders from mouser are free of shipping cost and all other taxes (paid by mouser) except VAT. You just need to buy for an amount of money. So the best is to order for more projects to save money!! 

 Yes, we EUs have to pay all sorts of taxes!!! Every package that I got true USPS was inspected and hold by our major post office and I had to pay in most cases only VAT.


----------



## TzeYang

:\ be thankful you have mouser to rely on.

 i always cry when i have to pay an arm just to order special parts from the US.


----------



## nemmo

Does anyone have a link for a power cable for the gamma1/2 (preferably from mouser). Because I want to make a sigma25 for it with the same output jack as the gamma inputjack, but I can't find a cable with these plugs.


----------



## MisterX

Try 
 # 172-4206 (plug with wires)
 Or
 # 1710-1321 (plug)


----------



## nemmo

Many thanks!


----------



## ksnider1

Hi, I'm using Y2 for over two weeks now, I have small problem. When powered from power supply (sigma 11 5.02V) or usb with usb selected as input this happens.
 In the kitchen I will open my refrigerator to get some filtered water and water pump will kick in or when I open and close microwave door music will stop playing. Audio system is in leaving room, kitchen is behind. I'm using linux slackware on d610 here is dmesg:

  Code:


```
[left]usb 5-2: new full speed USB device using uhci_hcd and address 17 usb 5-2: New USB device found, idVendor=08bb, idProduct=2707 usb 5-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0 usb 5-2: Product: USB Audio DAC usb 5-2: Manufacturer: Burr-Brown from TI usb 5-2: configuration #1 chosen from 1 choice input: Burr-Brown from TI USB Audio DAC as /devices/pci0000:00/0000:00:1d.3/usb5/5-2/5-2:1.2/input/input24 generic-usb 0003:08BB:2707.0010: input,hidraw0: USB HID v1.00 Device [Burr-Brown from TI USB Audio DAC ] on usb-0000:00:1d.3-2/input2 hub 5-0:1.0: port 2 disabled by hub (EMI?), re-enabling... usb 5-2: USB disconnect, address 17 usb 5-2: new full speed USB device using uhci_hcd and address 18 usb 5-2: device not accepting address 18, error -71 usb 5-2: new full speed USB device using uhci_hcd and address 19 usb 5-2: New USB device found, idVendor=08bb, idProduct=2707 usb 5-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0 usb 5-2: Product: USB Audio DAC usb 5-2: Manufacturer: Burr-Brown from TI usb 5-2: configuration #1 chosen from 1 choice input: Burr-Brown from TI USB Audio DAC as /devices/pci0000:00/0000:00:1d.3/usb5/5-2/5-2:1.2/input/input25 generic-usb 0003:08BB:2707.0011: input,hidraw0: USB HID v1.00 Device [Burr-Brown from TI USB Audio DAC ] on usb-0000:00:1d.3-2/input2[/left]
```

I'm using mplayer to play *.flac or *.mp3 and when it happens mplayer returns this:

  Code:


```
[left][AO_ALSA] alsa-lib: pcm_hw.c:485:(snd_pcm_hw_status) SNDRV_PCM_IOCTL_STATUS failed: No such device [AO_ALSA] Cannot get pcm status: No such device[/left]
```

This doesn't happen when laptop is running on battery powering Y2.

 It looks like Y2 resets it self. Any ideas why this happens ?

 Thanks


----------



## MisterX

What happens to the output from the Sigma 11 when you get water out of the fridge or open the microwave?


----------



## ksnider1

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_What happens to the output from the Sigma 11 when you get water out of the fridge or open the microwave?_

 

nothing, it's steady 5.02V, I also tried sigma 25 with 4.98V. When using coaxial as input this doesn't happen, it's weird to me


----------



## Beefy

Your computer is probably dropping USB power then. Even when powered externally, the PCM2707 wants to see 5V at VBUS.


----------



## ksnider1

I'm looking on schematics and for U2U I used 771-AHC1G08GV125 instead 595-SN74AHC1G08DBVR but that shouldn't have affect, right ?


----------



## MisterX

Right. 
 I would be more inclined to follow where beefy is leading you... the log does indicate the PCM270X is "rebooting" (which is what would happen if the VBUS drops low enough that the host pin thinks the USB was disconnected from the computer). 
 Can you just restart the media player or do you have to unplug the USB cable and then plug it back in (to make it play music again)?


----------



## amb

Should be fine.


----------



## ksnider1

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Right. 
 I would be more inclined to follow where beefy is leading you... the log does indicate the PCM270X is "rebooting" (which is what would happen if the VBUS drops low enough that the host pin thinks the USB was disconnected from the computer). 
 Can you just restart the media player or do you have to unplug the USB cable and then plug it back in (to make it play music again)?_

 

Just restarting player works, I don't have to unplug USB cable. 
 I have Full++ with Y2, for testing purpose can I short 1-2 on JP2D now ?


----------



## Beefy

Sorry, I'm thinking of the wrong pin on the PCM2707...... HOST pin is the one that is probably dropping, located before U2U.


----------



## amb

Quote:


  Originally Posted by *ksnider1* /img/forum/go_quote.gif 
_I have Full++ with Y2, for testing purpose can I short 1-2 on JP2D now ?_

 

I wouldn't advise this, because you'd be shorting around circuitry within the TPS2115A power mutiplexer.


----------



## ksnider1

here is pic of my Y1++ if that helps, it's not best quality. Here is pic of my multimeter it's from my younger days.


----------



## fishski13

ksnider1,
 when the music stops, does the illuminated switch turn a very faint red?


----------



## ksnider1

Quote:


  Originally Posted by *fishski13* /img/forum/go_quote.gif 
_ksnider1,
 when the music stops, does the illuminated switch turn a very faint red?_

 

it's not fainted red, it's red like there is no signal. I can make pic tomorrow.


----------



## fishski13

Quote:


  Originally Posted by *ksnider1* /img/forum/go_quote.gif 
_it's not fainted red, it's red like there is no signal. I can make pic tomorrow._

 

i had a couple of glitches tonight with my o-11 powered y-2 off a dedicated hi-fi mains/AC circuit. no freeze ups, just very brief drop-outs and a concurrent brief flickering of green to red. my furnace and spaceheater have been working overtime. -10F tonight, and i'm not sure what the windchill is.


----------



## Volkum

Hi guys,

 I finished my y1 full++ config earlier in the night and it's working great (tested optical and USB) after I tracked down bad joint in U2, however my y2 board doesn't seem to output any sound. The y1 board works independently and when mated with the y2 board, however when the boards are mated, I get no sound out of the 3.5mm jack on the y2 board (3.5mm jack on the y1 still works--are these supposed to work simultaneously?). I reflowed most of the points on the bottom of the board. I also reflowed U4, U5, and U7 twice with no luck.

 Voltages with USB power (I don't have a separate PSU suitable for this at the moment):

 3.3v - 3.29
 5v - 5.01
 4.5v - 4.72 (TPS793475)

 Any ideas on how I can narrow down the issue?

 Pics:








 (sorry for the poor photography--not my specialty)


----------



## amb

Volkum, did you install the correct part in U3? Should be a MCP100, not MCP101.
 Other than that, use a loupe or other visual magnification to inspect for solder bridges between IC pins, particularly U4 and U5, and check the joints at X1.


----------



## Volkum

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Volkum, did you install the correct part in U3? Should be a MCP100, not MCP101.
 Other than that, use a loupe or other visual magnification to inspect for solder bridges between IC pins, particularly U4 and U5, and check the joints at X1._

 

U3 has MCP100 installed. I'll give those components another look over tomorrow or Saturday--I've looked them over so many times tonight that I'm possibly cross eyed now lol.


----------



## francisdemarte

I had a similar issue and it was X1. I had a hard time getting a good joint and not shorting it out.


----------



## Volkum

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Volkum, did you install the correct part in U3? Should be a MCP100, not MCP101.
 Other than that, use a loupe or other visual magnification to inspect for solder bridges between IC pins, particularly U4 and U5, and check the joints at X1._

 

 Quote:


  Originally Posted by *francisdemarte* /img/forum/go_quote.gif 
_I had a similar issue and it was X1. I had a hard time getting a good joint and not shorting it out._

 

It was X1! Woot!


----------



## madstudio

Hi guys, i searched and tried to read 92 pages to find out what do I need if I want to use Y2 with just SPDIF (preferable AES) input but I'm still not sure about. So, the Q is : do I need Y1 board for that? Is it possible to make it work with AES input standalone? Thanks


----------



## m1abrams

Quote:


  Originally Posted by *madstudio* /img/forum/go_quote.gif 
_Hi guys, i searched and tried to read 92 pages to find out what do I need if I want to use Y2 with just SPDIF (preferable AES) input but I'm still not sure about. So, the Q is : do I need Y1 board for that? Is it possible to make it work with AES input standalone? Thanks_

 

You need the Gamma1 board, you may be able to leave out some of the usb parts but those probably not amount to much in the way of cost. The Gamma2 board take only I2S input so you can leave out the Gamma1 if you provide I2S and the proper power (Gamma1 also provide the power).


----------



## madstudio

thanks, so Y1+Y2 or spdif to I2S + PSU+ Y2 is way to go? Am I right? Do you know some good source for spdif (Aes) to I2S?


----------



## Beefy

Quote:


  Originally Posted by *madstudio* /img/forum/go_quote.gif 
_Do you know some good source for spdif (Aes) to I2S?_

 

Well, the Gamma1 does a good job......


----------



## amb

Quote:


  Originally Posted by *madstudio* /img/forum/go_quote.gif 
_Hi guys, i searched and tried to read 92 pages to find out what do I need if I want to use Y2 with just SPDIF (preferable AES) input but I'm still not sure about. So, the Q is : do I need Y1 board for that? Is it possible to make it work with AES input standalone? Thanks_

 

How about reading the official websites?
The γ1 Modular Miniature DAC
The γ2 Compact High Performance DAC


----------



## leopoldiy

HI,
 y have recently build an AMD gamma2 Dac, and i purchase from AMB a M3.in a same boxe,I would directly plugg the dac to the M3,About C20 and C26 on gamma2, can I replace them by 3.3UF condensator.
 I have mundorf supreme silver/gold 3.3uF in stock and i want use it.
 thanks


----------



## MisterX

Did you check to see what the Y2 parts list page has to say about using 3.3uF coupling caps?


----------



## leopoldiy

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Did you check to see what the Y2 parts list page has to say about using 3.3uF coupling caps? 
	

	
	
		
		

		
		
	


	


_

 

Actualy I use, a 470uF capacitor to drive directly my headphone with an impedance of 150 Ohm.
 But if i drive directly the m3 Amp, can I use a 3.3uF capacitor.

 The inpedance of the m3 is 47KOhm.

 fc=1/(2x Pi x R x C)
 fc=1/2xPix47000x0.0000033)
 fc=1.02614406 hz

 no ???


----------



## amb

I think you just answered your own question. 
	

	
	
		
		

		
		
	


	



 How would a Mundorf cap fit on the board (or in the Box B2-50 enclosure) is the other question.


----------



## GWorlDofSPACE

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_I think you just answered your own question. 
	

	
	
		
		

		
		
	


	



 How would a Mundorf cap fit on the board (or in the Box B2-50 enclosure) is the other question._

 

Whit a good shielded cable you could connect a good MKP to the board and mount the cap on the B2...eclosure?????


----------



## leopoldiy

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_I think you just answered your own question. 
	

	
	
		
		

		
		
	


	



 How would a Mundorf cap fit on the board (or in the Box B2-50 enclosure) is the other question._

 

lol, yes a mundorf cap don't fit on the gamma 2 board.

 I put in a same box, Sigma11--->gamma2 + sigma11--->M3 + mundorf + Audio Volume Relay Attenuator.

 thanks

 +


----------



## Beefy

Quote:


  Originally Posted by *GWorlDofSPACE* /img/forum/go_quote.gif 
_Whit a good shielded cable you could connect a good MKP to the board and mount the cap on the B2...eclosure?????_

 

Risky. Because you can't connect up your source to any other DC coupled amp, unless it has caps installed.


----------



## GWorlDofSPACE

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_Risky. Because you can't connect up your source to any other DC coupled amp, unless it has caps installed._

 

If you use big MKPs, maybe 10uf then it should go, not?


----------



## Beefy

I'm sorry, I don't understand what you mean.

 What I am saying is that regardless of the cap you use - size, type, doesn't matter - it is a bad idea to not have it in the DAC. Because while it will be fine with amps that do have a cap at their input, many do not.

 Connecting your DAC without a cap to an amp without a cap could cause serious damage to the amp or any headphones connected to it.


----------



## GWorlDofSPACE

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_I'm sorry, I don't understand what you mean.

 What I am saying is that regardless of the cap you use - size, type, doesn't matter - it is a bad idea to not have it in the DAC. Because while it will be fine with amps that do have a cap at their input, many do not.

 Connecting your DAC without a cap to an amp without a cap could cause serious damage to the amp or any headphones connected to it._

 

We have a misunderstanding here. I did not tell that I would use the DAC whitout caps! I wrote that I could use an extension wire for MKP caps and connect it to the pins of the previous CAP.


----------



## Beefy

Oh, I get you. You want to mount the caps outside the case. I saw the B2, and thought it was a typo for B22 amp.

 Yeah, that still seems like a bad solution to a problem that doesn't actually exist.


----------



## GWorlDofSPACE

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_Oh, I get you. You want to mount the caps outside the case. I saw the B2, and thought it was a typo for B22 amp.

 Yeah, that still seems like a bad solution to a problem that doesn't actually exist._

 

There is actual not a problem but I think whit MKP output caps the sound would improve. Its just experimenting not a problem - solution hunt.


----------



## madstudio

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_How about reading the official websites?
The γ1 Modular Miniature DAC
The γ2 Compact High Performance DAC_

 

Thanks, I asked about it because I have already build the IIS receiver board with DIR9001. Now, when I read the official site
  Quote:


 γ2 could also used standalone as an upgrade DAC for any device that already has an I²S bus (e.g., A CD player or digital media player). Simply connect the I²S bus to the γ2 board and hook up a 5V DC power supply. See the instructions section for details. 

 On the γ2 board, the digital audio stream is upsampled to 24-bit 96KHz by an asynchronous sample rate converter (ASRC) and then converted to analog with Wolfson's top-of-the-line ΔΣ oversampling DAC chip. An onboard ultra-low jitter oscillator provides the master clock for the ASRC and DAC chips. A high-performance analog output stage serves as a balanced-unbalanced converter, low-pass filter and line-drive buffer. 
 

I figured that onboard ultra-low jitter oscillator will improve the overall jitter performance. Mine reciever board with DIR9001 measures around 50ps. Can you tell me what amount of jitter should I expect with "gamma2" board?


----------



## GWorlDofSPACE

Quote:


  Originally Posted by *madstudio* /img/forum/go_quote.gif 
_Thanks, I asked about it because I have already build the IIS receiver board with DIR9001. Now, when I read the official site

 I figured that onboard ultra-low jitter oscillator will improve the overall jitter performance. Mine reciever board with DIR9001 measures around 50ps. Can you tell me what amount of jitter should I expect with "gamma2" board?_

 

Less then 1ps.


----------



## madstudio

Quote:


  Originally Posted by *GWorlDofSPACE* /img/forum/go_quote.gif 
_Less then 1ps._

 

thanks


----------



## BoogieWoogie

Hey guys I'm really undecided wether to get gamma y2 or the parasound-dac-1000.

 Since you are the makers I'm hoping you could give an honest opinion if the parasound should be better looking that the specs if you never listened to one.


----------



## MASantos

Quote:


  Originally Posted by *BoogieWoogie* /img/forum/go_quote.gif 
_Hey guys I'm really undecided wether to get gamma y2 or the parasound-dac-1000.

 Since you are the makers I'm hoping you could give an honest opinion if the parasound should be better looking that the specs if you never listened to one._

 

I was going to talk about this earlier when we were speaking. 

 From the "numbers" point of view, the gamma2 uses more recent and modern IC's, which have better specs and theoretical performance. 

 However, music is not about numbers and there are a number of cases of vintage gear sounding better than more recent equipment. 

 Many people still prefer the sound of non oversampling DACs as the TDA1543 and still it measures worse than most modern chips.

 So in the end it is always a matter of preferences and what sounds good to your ears. If you can, listening to both is the best way to decide, but it comes with a price. Since you liked the sound of the DACmagic, going with the gamma2 sounds like a good option as the DAC architecture is the same, with a different implementation, but still much more similar than the parasound (specifications).


----------



## rds

Quote:


  Originally Posted by *BoogieWoogie* /img/forum/go_quote.gif 
_Hey guys I'm really undecided wether to get gamma y2 or the parasound-dac-1000.

 Since you are the makers I'm hoping you could give an honest opinion if the parasound should be better looking that the specs if you never listened to one._

 

Going by specs the Gamma 2. Going by Headfier opinions... may god help you


----------



## jarpatus

Hi,

 Just quick question, would it be bad idea to use PANASONIC ECA0JAM471X 470UF 6.3V as C20 and C26, because I can't find those recommended Nichion KW or FW caps anywere and I may wan't to use gamma2 without amp occasionally. Dimensions seems to be the same (well, Panasonic is 0.2mm taller) as well as basic specs and those seems to be for audio applications as well. But don't know if there's something more complicated to consider.

 Ps. Actually, even 47Kohm miniature resistors are out of stock everywhere in Finland, uh oh... Ordered some Welwyn resistors, they are 0.1mm thicker than max specified dimensions, I hope they will still fit if carefully positioned... And also SRC4192IDB is out of stock, have to build firs version without upsampling :/


----------



## amb

jarpatus, you can use any audio-grade 470uF cap there, as long as it fits. Whether you like the "sound" is for you to decide.


----------



## mace1337

I checked it for you jarpatus, and it looks like that the only 470uF, min. 6.3v capacitor with a width of max. 6.3mm that Farnell has is the one you chose, and a Rubycon ZLH.

 Mouser has a pretty good selection though, they have the Nichicons ES, KW, FW and all that, and they deliver anywhere in the world for free if your order is over 75€


----------



## fordgtlover

^
 I really didn't like the Rubycon ZLH as output caps on the Gamma1 - way too harsh.


----------



## mace1337

About that, what's the difference between ZL and ZLH?


----------



## Beefy

Quote:


  Originally Posted by *mace1337* /img/forum/go_quote.gif 
_About that, what's the difference between ZL and ZLH?_

 

About 1 'H' I'd guess......


----------



## mace1337

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_About 1 'H' I'd guess......_


----------



## simwells

Just looking at ordering the necessary parts to build my Gamma-2 now, but was wondering if there was a paticular reason the recommended capacitors for the multilayer ceramic capacitor X7R 1µF 25V were these;

EPCOS|B37984M5105K|CAPACITOR, 1UF, 50V | Farnell United Kingdom

 These add up to a lot when I add the neccesary number, was wondering if there was a cheaper but equally good alternative available?

 Something like this maybe?

VISHAY BC COMPONENTS|K105M20X7RF53H5|Ceramic Multilayer Capacitor | Farnell United Kingdom


----------



## Beefy

I had that sound going through my head as I posted...... 
	

	
	
		
		

		
			





  Quote:


  Originally Posted by *mace1337* /img/forum/go_quote.gif 
_



_


----------



## amb

Quote:


  Originally Posted by *simwells* /img/forum/go_quote.gif 
_Just looking at ordering the necessary parts to build my Gamma-2 now, but was wondering if there was a paticular reason the recommended capacitors for the multilayer ceramic capacitor X7R 1µF 25V were these;

EPCOS|B37984M5105K|CAPACITOR, 1UF, 50V | Farnell United Kingdom_

 

The preferred part is actually TDK FK24 series for their low profile, but Farnell does not carry this line. The Epcos is still acceptable at 7.5mm high. Any higher and the cap will start to bump into parts on the other side when the two boards are plugged in to each other.

  Quote:


 These add up to a lot when I add the neccesary number, was wondering if there was a cheaper but equally good alternative available?

 Something like this maybe?

VISHAY BC COMPONENTS|K105M20X7RF53H5|Ceramic Multilayer Capacitor | Farnell United Kingdom 
 

This one is listed as "US Stock". Since you're in the UK, you'll have to pay an extra £15.95 fee...


----------



## simwells

Ah missed that, well I think I'll order everything but those caps and the other couple of bits not stocked through farnell via farnell anyway.


----------



## mace1337

Quote:


  Originally Posted by *simwells* /img/forum/go_quote.gif 
_Ah missed that, well I think I'll order everything but those caps and the other couple of bits not stocked through farnell via farnell anyway._

 

I mentioned this last page, but mouser carries a lot of the parts and all orders of 75€ or over are free shipping. Digikey has free shipping over 60ish.

 My parts for the M3 I built were here in three days from both mouser and Digi-key.

 Also, I'm not sure why you're going for 1uF when the parts list mentions 0.1uF, which should be significantly cheaper.


----------



## jarpatus

Quote:


  Originally Posted by *mace1337* /img/forum/go_quote.gif 
_Mouser has a pretty good selection though, they have the Nichicons ES, KW, FW and all that, and they deliver anywhere in the world for free if your order is over 75€_

 

Thanks mace1337, I totally missed free delivery and did not consider mouser because I tought I will have to pay extra (local in town suppliers can order from Farnell without extra fees but not from Mouser or other overseas-only company).

 It looks I am forced to build another y2 so I can order missing part(s) from Mouser within the same order 8) Is it against spirit of DIY if I'll make few extra DAC's and try to sell them and gain little profit?


----------



## fierce_freak

I got my y2 done yesterday but I'm getting no sound. When measuring voltages I get the proper 3.3v and 4.5v, but in the places indicated that should be 5v I'm only getting ~4.66v. Does that point to anything in particular? I'm going to go back over my soldering for the WM8741 and the SRC4192 when I get some spare time.


----------



## amb

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_I got my y2 done yesterday but I'm getting no sound. When measuring voltages I get the proper 3.3v and 4.5v, but in the places indicated that should be 5v I'm only getting ~4.66v._

 

If this is USB power, then it probably just means that your computer's USB "5V" is a little low, but not low enough to make things "not work".

 You have to be a bit more specific than "no sound". What other testing have you done? Does the companion γ1 work (i.e., you hear audio from the WM8501 output via the front jack)?
 Have you verified the polarity/orientation/value of all parts and their solder joints? All jumpers set properly for the configuration and options you're building? etc...


----------



## fierce_freak

Yep, the y1 portion works properly (I hear audio from the WM8501 output via the front jack). Polarity/orientation/value has all been checked. I'm almost willing to bet it's my soldering of the WM8741 and SRC4192. I just hope I can fix it without ruining another board and having to start over. I have a bad habit of lifting pads.


----------



## amb

There is little risk of lifting pads if all you're doing is reflowing the joints. Use plenty of liquid flux, only a tiny amount of solder, and avoid too much heat. If your X1 oscillator is the SMD version, then reflow its joints too.


----------



## rille2

I read here about alternatives for U7. But this was in a quite early state of the project. Could I use the LME49721? OPA2365 and AD8656ARZ are hard to get at the moment in Europe. The LME49721 is available. Are there any other alternatives?


----------



## amb

We never tested with LME49721, so I don't have any actual bench or sonic experience to share on this opamp. Based on the datasheet specs, it has enough supply voltage range and rail-to-rail swing capability to do the job. However some other specs are not as good as those of AD8656 and OPA2365, and its 9mA maximum output current also falls far short.

 A quick search of Farnell Germany shows both OPA2365AID and AD8565ARZ currently in stock...


----------



## GWorlDofSPACE

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_We never tested with LME49721, so I don't have any actual bench or sonic experience to share on this opamp. Based on the datasheet specs, it has enough supply voltage range and rail-to-rail swing capability to do the job. However some other specs are not as good as those of AD8656 and OPA2365, and its 9mA maximum output current also falls far short.

 A quick search of Farnell Germany shows both OPA2365AID and AD8565ARZ currently in stock..._

 

I have AD8565 installed and do not use Y2 direct whit my headphones, so
 does it make any difference to switch to OPA2365???


----------



## amb

Quote:


  Originally Posted by *GWorlDofSPACE* /img/forum/go_quote.gif 
_I have AD8565 installed and do not use Y2 direct whit my headphones, so
 does it make any difference to switch to OPA2365???_

 

They are both excellent, just slightly different in sonic character. Don't bother changing it unless you enjoy desoldering an SMD opamp (and risk board damage).


----------



## GWorlDofSPACE

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_They are both excellent, just slightly different in sonic character. Don't bother changing it unless you enjoy desoldering an SMD opamp (and risk board damage)._

 

I had some issues whit SMD X1, so I DO not enjoy SMD! 
 Thanks.


----------



## MisterX

Would be a major pain with all of those other parts in the way.


----------



## GWorlDofSPACE

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Would be a major pain with all of those other parts in the way._

 

You right, that would be a little tricky. If the sound would make a big difference I would do it but as Ti said, there are only little sonic differences,
 so I will not do it.


----------



## mace1337

AMB, I was just wondering if you were thinking of making a high-end no-compromise DAC.

 I mean, don't get me wrong, the gamma is fantastic work, but it seems like certain sacrifices were made for space. Think you'll start from scratch and design a killer dac?


----------



## GWorlDofSPACE

Quote:


  Originally Posted by *mace1337* /img/forum/go_quote.gif 
_AMB, I was just wondering if you were thinking of making a high-end no-compromise DAC.

 I mean, don't get me wrong, the gamma is fantastic work, but it seems like certain sacrifices were made for space. Think you'll start from scratch and design a killer dac?_

 

I am shore Ti will do it. Be patient as all of us. One day will be the great day...
 Besides GAMMA 2 is a very very good DAC.


----------



## mace1337

Quote:


  Originally Posted by *GWorlDofSPACE* /img/forum/go_quote.gif 
_I am shore Ti will do it. Be patient as all of us. One day will be the great day...
 Besides GAMMA 2 is a very very good DAC._

 

Again, I am not trying to say anything bad about the gamma 2, it was just a thought.


----------



## BoogieWoogie

Quote:


  Originally Posted by *GWorlDofSPACE* /img/forum/go_quote.gif 
_I am shore Ti will do it. Be patient as all of us. One day will be the great day...
 Besides GAMMA 2 is a very very good DAC._

 

I decided to go risk and already ordered my y2 , all I want its to sound as good as DacMagic or else its a fail and sold right after, lets see how this turns.


----------



## GWorlDofSPACE

Quote:


  Originally Posted by *BoogieWoogie* /img/forum/go_quote.gif 
_I decided to go risk and already ordered my y2 , all I want its to sound as good as DacMagic or else its a fail and sold right after, lets see how this turns._

 

I think you will be very surprised how good it sounds.


----------



## fishski13

Quote:


  Originally Posted by *BoogieWoogie* /img/forum/go_quote.gif 
_I decided to go risk and already ordered my y2 , all I want its to sound as good as DacMagic or else its a fail and sold right after, lets see how this turns._

 

congrats! i prefer it to my DAC1.


----------



## amb

Actually, there are very few compromises made for small size in the γ2. Yes, there are some features missing that you might find in spendy commercial DACs, such as volume control, balanced output, AES-EBU (XLR) input, fancy displays, etc., but those are not strictly necessary for high-performance. The fact that γ2 ended up being so small is nice, since it's meant to be an upgrade to γ1.

 I do have future plans to design a larger high-end DAC that adds these features and a few other enhancements too, but there is no timetable for it and I have other projects I want to do first.


----------



## Shahrose

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_I do have future plans to design a larger high-end DAC that adds these features and a few other enhancements too._

 

Now we're talkin'.

  Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_but there is no timetable for it and I have other projects I want to do first._

 

Bah


----------



## TzeYang

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Actually, there are very few compromises made for small size in the γ2. Yes, there are some features missing that you might find in spendy commercial DACs, such as volume control, balanced output, AES-EBU (XLR) input, fancy displays, etc., but those are not strictly necessary for high-performance. The fact that γ2 ended up being so small is nice, since it's meant to be an upgrade to γ1.

 I do have future plans to design a larger high-end DAC that adds these features and a few other enhancements too, but there is no timetable for it and I have other projects I want to do first._

 

Do you think there are other improvements to the signal quality that can be made for single ended WM8741 used in the Gamma2?

 I mean I don't really see those features such as volume control, fancy display, to be an "upgrade".


----------



## fishski13

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Actually, there are very few compromises made for small size in the γ2. Yes, there are some features missing that you might find in spendy commercial DACs, such as volume control, balanced output, AES-EBU (XLR) input, fancy displays, etc., but those are not strictly necessary for high-performance. The fact that γ2 ended up being so small is nice, since it's meant to be an upgrade to γ1.

 I do have future plans to design a larger high-end DAC that adds these features and a few other enhancements too, but there is no timetable for it and I have other projects I want to do first._

 

the y2 is already a Swiss Army knife in my book and not much larger 
	

	
	
		
		

		
		
	


	




. seriously, one shouldn't write it off just because it's small and doesn't cost $$$ to build. it's elevated the music no matter what i throw in downstream.


----------



## m1abrams

Quote:


  Originally Posted by *TzeYang* /img/forum/go_quote.gif 
_Do you think there are other improvements to the signal quality that can be made for single ended WM8741 used in the Gamma2?

 I mean I don't really see those features such as volume control, fancy display, to be an "upgrade"._

 

Well you could have 2 WM8741 run in mono, that would boost the on paper specs. Not sure if you would hear a difference though.


----------



## francisdemarte

So what's the deal with this Sabre DAC chip that everyone's talking about. Is it much better than the DAC chips used in the Gamma2?


----------



## m1abrams

Quote:


  Originally Posted by *francisdemarte* /img/forum/go_quote.gif 
_So what's the deal with this Sabre DAC chip that everyone's talking about. Is it much better than the DAC chips used in the Gamma2?_

 

Well hard to say because it is very closed device. They are not very DIY friendly with their chips.


----------



## mace1337

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Actually, there are very few compromises made for small size in the γ2. Yes, there are some features missing that you might find in spendy commercial DACs, such as volume control, balanced output, AES-EBU (XLR) input, fancy displays, etc., but those are not strictly necessary for high-performance. The fact that γ2 ended up being so small is nice, since it's meant to be an upgrade to γ1.
 I do have future plans to design a larger high-end DAC that adds these features and a few other enhancements too, but there is no timetable for it and I have other projects I want to do first._

 

Cool, can't wait!


----------



## LionPlushie

shall wait for that. hoping to get something of similar size to the b22.


----------



## K3cT

I finally finished assembling my γ2 and everything seems to be normal and working fine except I got only 4.1~4.3V when used with USB power. Is this normal?

 This thing sounds bloody amazing btw.


----------



## MisterX

it's pretty not normal for the USB voltage to be out of spec. 
	

	
	
		
		

		
			




 Is there a problem with your Y2 build that is pulling it that low or is it always that low?


----------



## K3cT

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_it's pretty not normal for the USB voltage to be out of spec. 
	

	
	
		
		

		
		
	


	



 Is there a problem with your Y2 build that is pulling it that low or is it always that low?_

 

Well, actually no. It only drops to that range when I use USB port from my computer to power both γ1 and γ2. Otherwise, the voltages are normal if I use σ25. It's a bit perplexing but otherwise everything is normal, all the I/Os are working and I can play music fine. I'm just a bit worried though...


----------



## pixeljedi

Quote:


  Originally Posted by *LionPlushie* /img/forum/go_quote.gif 
_shall wait for that. hoping to get something of similar size to the b22._

 

You could just put the γ2 in a bigger case with a σ11 and a 45lb plate if it would make you feel better


----------



## amb

K3CT, sometimes a computer's USB power voltage could be a little low, but not that low. I wonder if your computer is really out of spec? Try a different computer, and perhaps a different USB cable. Some USB cables may cause voltage drops (cable too thin or too long).


----------



## pixeljedi

Quote:


  Originally Posted by *K3cT* /img/forum/go_quote.gif 
_except I got only 4.1~4.3V when used with USB power. Is this normal?_

 

Are you plugging into a USB port directly from the PC or from a USB Hub connecting to the PC? I found the the Hub I use at work to be way below 5V.


----------



## Draguljce

Hi,

 I just started collecting all parts for my γ2 build (d-configuration γ1 +γ2) and after all the reading I'm still not sure what to use for output coupling capacitors. Especially since BG NX Hi-Q are unavailable (i use them for AlienDAC)
 Perhaps WIMA MKS2 3,3uF would be the most neutral solution. I tried nichicon muse bp and SILMIC on alien, but BG's are overall the best for me. What about SILMIC II ?

 Perhaps an ultimate solution would be CK2III +γ2 without output coupling capacitors 
	

	
	
		
		

		
		
	


	




 Thus avoiding sound coloring/degrading little bastards out of the way


----------



## m1abrams

Quote:


  Originally Posted by *Draguljce* /img/forum/go_quote.gif 
_Hi,


 Perhaps an ultimate solution would be CK2III +γ2 without output coupling capacitors 
	

	
	
		
		

		
		
	


	




 Thus avoiding sound coloring/degrading little bastards out of the way 
	

	
	
		
		

		
		
	


	


_

 

How do you plan on handling the DC offset then? The y2 will produce a dc offset without the coupling caps.


----------



## Draguljce

Quote:


  Originally Posted by *m1abrams* /img/forum/go_quote.gif 
_How do you plan on handling the DC offset then? The y2 will produce a dc offset without the coupling caps._

 

AFAIK CK2III has DC servo to handle DC offset, so in theory that should work...Maybe someone has some practical experience.


----------



## K3cT

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_K3CT, sometimes a computer's USB power voltage could be a little low, but not that low. I wonder if your computer is really out of spec? Try a different computer, and perhaps a different USB cable. Some USB cables may cause voltage drops (cable too thin or too long)._

 

What would normal voltage reading for y1+y2 look like when powered with USB? It's a pretty new laptop and I use a Newnex USB cable so they couldn't be the problem. Could U2U be possibly defective to cause this weird issue? 

  Quote:


  Originally Posted by *pixeljedi* /img/forum/go_quote.gif 
_Are you plugging into a USB port directly from the PC or from a USB Hub connecting to the PC? I found the the Hub I use at work to be way below 5V._

 

Directly.


----------



## MisterX

Quote:


 What would normal voltage reading for y1+y2 look like when powered with USB? 
 

How did you ever get past the third step in the "initial check" without knowing that? 

The &gamma;1 Modular Miniature DAC


  Quote:


 3.If your build involves the USB board (i.e., all except the S/PDIF DAC-only (E) and full++ (F) configurations), install a temporary jumper shunt across J2U pins 1 and 2 (labeled VBUS and VCC, respectively). Then, connect the USB cable between one of your computer's USB port and the γ1's USB port. If LEDU is populated, it should illuminate. Within a short moment your operating system should detect and identify the γ1 as a "USB Audio DAC". 

 Set your multimeter to DC V range and measure the voltage between the +5V test pad (next to J2U pin 1 "VBUS") and GND. This is your computer's USB port power voltage and should be very close to 5V. 

 Measure the voltage between the +3.3V test pad and GND. You should read a fairly accurate 3.3V. 

 Unplug the USB cable and remove the temporary jumper shunt. 
 



  Quote:


 Could U2U be possibly defective to cause this weird issue? 
 

Can you please follow the instructions? 

 (if U2U was a problem you would have never made it past the third step because the instructions also tell you "If, at any point you do not pass the check, do not proceed to the next step until the problem is first corrected")

 That way we have some idea if you have a problem with the Gamma 1 USB section, the Gamma 1 S/PDIF section or the Gamma 2 board. 
 Follow?


----------



## Wizik

Hello all, please, what could happen if I use in y2 WM8741 and U6 (MCP100-315DI/TO) together ? In schematic is when I use WM8741 then don´t install U6, but why ? Sorry for stupid questions, i´m new in DIY


----------



## amb

U6 is a chip reset manager. WM8741/8742 don't need one, because these chips have them built-in. Only WM8740 needs it.

 On the WM8741/8742 the pin that U6 is connected serves another purpose. If you connect an reset manager to it then it will have a side effect which you probably don't want.


----------



## jarpatus

Hi,

 Just quick question about C19 and C25... Parts list says 1µF metallized polyester capacitors "or metallized polypropylene (MKP) in a lower capacitance". Does it actually matter what I throw in or is it "up your personal preference"? I am currently building gamma2 and just remember that I have few leftovers from CK2III, 47nF Vishay MKP1837 (can you imagine I searched for years until I found local supplier with any MKP caps, got these few weeks ago, though I had to admit that I won't hear any difference between these and MKT's I user earlier...). They would physically fit in.

 Ps. If anyone does have extra SRC4192IDB or AD1896AYRS, please sell it to me, both are out of stock from Farnell and I do not want to order from Mouser since P&P would be too much.

 Thanks again!

 - Jari


----------



## Draguljce

jarpatus;6390499 said:
			
		

> Hi,
> 
> Ps. If anyone does have extra SRC4192IDB or AD1896AYRS, please sell it to me, both are out of stock from Farnell and I do not want to order from Mouser since P&P would be too much.
> 
> ...


----------



## Draguljce

jarpatus;6390499 said:
			
		

> Hi,
> 
> Just quick question about C19 and C25... Parts list says 1µF metallized polyester capacitors "or metallized polypropylene (MKP) in a lower capacitance". Does it actually matter what I throw in or is it "up your personal preference"?
> 
> ...


----------



## jarpatus

Draguljce;6390632 said:
			
		

> Quote:
> 
> 
> Originally Posted by *jarpatus* /img/forum/go_quote.gif
> ...


----------



## jarpatus

Quote:


  Originally Posted by *Draguljce* /img/forum/go_quote.gif 
_I presume that idea was to make a small trade-off because default part list uses panasonic for output coupling capacitors which are presumably less good sounding that some "fancy" capacitors and those bypass caps should compensate for this (especially for higher frequencies AFAIK). As you can read in many places some people prefer bypassing electrolytic and others don't._

 

I take that as "it's up to you decide" 
	

	
	
		
		

		
		
	


	




 I just don't trust my ears enough to tell the real difference without proper blind test so I try to rely on specifications which can be measuer or calculatred.

 But just as hobby, perhaps I actually do some kind of blind test. There is room for socket on the backside of gamma2 PCB, perhaps I'll try different caps with my friends and try if I can tell any difference when blindfolded.


----------



## K3cT

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_How did you ever get past the third step in the "initial check" without knowing that? 

The &gamma;1 Modular Miniature DAC








 Can you please follow the instructions? 

 (if U2U was a problem you would have never made it past the third step because the instructions also tell you "If, at any point you do not pass the check, do not proceed to the next step until the problem is first corrected")

 That way we have some idea if you have a problem with the Gamma 1 USB section, the Gamma 1 S/PDIF section or the Gamma 2 board. 
 Follow?_

 

Sorry if I didn't express myself properly. I did that test and the results were within specification. It seems that this drop only occurs when I mate the 2 boards together AND only when I use USB to power both boards. These are what I get:

 With Sigma25
 - 5V: 5.13V
 - DAC 4.75V: 4.754V
 - DAC 3.3V: 3.32V
 - USB 3.3V: 3.31V

 With USB
 - VBUS: 4.2V
 - 5V: 4.16V
 - DAC 4.75V: 4.01V
 - DAC 3.3V: 3.32V
 - USB 3.3V: 3.31V

 The y2 itself is working properly though with both power sources. It's detected normally and plays music fine. I tried switching computers and I got roughly the same reading, I'll see if I can borrow another mini-B USB cable to do further testing.


----------



## amb

K3cT, your γ1+γ2 is fine. The problem is your computer's USB voltage being out of spec at only 4.2V. While the DAC still "works" at this voltage, the 4.75V voltage regulator has dropped out of regulation because its input voltage is lower than what it's supposed to output, that's why you're only seeing only 4.01V at the test point. The result is that the analog output sections' supply rails aren't regulated (read - noise would get through), and you may experience clipping when the output peaks approach 0dBFS.

 As mentioned by others before, I hope you're not using a USB hub. They are notorious for low USB voltages. If your DAC is plugged in directly into the computer, and you still experience the low voltage, then I recommend using the σ25 at all times (even when using USB as your source), or use a different computer.


----------



## amb

K3cT, your γ1+γ2 is fine. The problem is your USB voltage being out of spec at only 4.2V. While the DAC still "works" at this voltage, the 4.75V voltage regulator has dropped out of regulation because its input voltage is lower than what it's supposed to output, that's why you're only seeing only 4.01V at the test point. The result is that the analog output sections' supply rails aren't regulated, and you may experience clipping when the output peaks approach 0dBFS.

 As mentioned by others before, I hope you're not using a USB hub. They are notorious for low USB voltages. If your DAC is plugged in directly into the computer, and you still experience the low voltage, then I recommend using the σ25 at all times (even when using USB as your source), or use a different computer.


----------



## Draguljce

jarpatus;6391834 said:
			
		

> I take that as "it's up to you decide"
> 
> 
> 
> ...


----------



## K3cT

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_K3cT, your γ1+γ2 is fine. The problem is your USB voltage being out of spec at only 4.2V. While the DAC still "works" at this voltage, the 4.75V voltage regulator has dropped out of regulation because its input voltage is lower than what it's supposed to output, that's why you're only seeing only 4.01V at the test point. The result is that the analog output sections' supply rails aren't regulated, and you may experience clipping when the output peaks approach 0dBFS.

 As mentioned by others before, I hope you're not using a USB hub. They are notorious for low USB voltages. If your DAC is plugged in directly into the computer, and you still experience the low voltage, then I recommend using the σ25 at all times (even when using USB as your source), or use a different computer._

 

Thanks for the re-assurance, Ti! At least I can rest easy knowing that the γ1+γ2 are fine. 

 I'm not using a hub though and I mentioned that I tried using different PCs to test this. Perhaps it's the cable.


----------



## Superfrag

I just wanted to ask.. what do you guys think, should using a musiland monitor 01 USD as a USB to SPDIF converter do a better job with the y2 DAC which in turn feeds the WA6? I have the above setup, I havent tried USB to y2 directly till now.. need to get the respective cable..


----------



## Beefy

It would depend entirely on whether you have any material at higher than 16/48. If you don't, I wouldn't bother with the Musiland.


----------



## knorthover

Finished mine last night, after a delay caused by soldering X1 in rotated 90 degrees counter clockwise from the correct orientation. I know I need glasses but I could have sworn I checked the dot orientation 
	

	
	
		
		

		
		
	


	




. I can vouch for Chip-Quik. 

 However everything survived both power on and desoldering. Worked straight away when I resoldered the X1 SMD in the right place. 

 It is a full y1++ configuration. Sounds sweet, will do some listening and comparisons over the weekend. 
 Thanks to amb, Mister X, and everyone on this forum for all the insights.
 Kevin


----------



## Superfrag

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_It would depend entirely on whether you have any material at higher than 16/48. If you don't, I wouldn't bother with the Musiland._

 

Ah thanks. I guess I'll stay with the Musiland.. got a lot of 24/96 files..


----------



## jarpatus

And another one lives, after having some problems with γ1 full++ and finally solving them all I had to solder missing op-amp and caps to γ2 and plug it in. And it works!

 This one is AD8656 with Panasonic ECA0JAM471X 470uF output caps, no bypass caps currently (plan to do some experimenting later this weekend) and no upsampling as U4 is currently traveling somewhere over Atlantic ocean. 

 First impressions? With CK2III: 
	

	
	
		
		

		
		
	


	




 Would have to do some blind listening to say more, but IMO this sounds at least, if not better, than my M-Audio Audiophile 2496 and to be honest, it's probably way above performance of my ears anyways!


----------



## punkerdood

Apparently I'm the only dummy who's done this: 

 On U4 - pin 26 "MODE0" I buggered it and the pad it sits on trying to get rid of some excess solder. The only thing it seems to connect to is pin 27. Am I correct? can I just drop a dollop of solder on those two pins and call it good?


----------



## amb

punkerdood, a look at the schematic should have answered your question...


----------



## MisterX

Yep, a solder blob should be enough to make it work as intended.


----------



## punkerdood

thanks yall,

 just wanted to make sure I was 
 1. not reading pcb schematic v.01
 2. not otherwise assed up...


----------



## unl3a5h3d

This is a noob question, but I have searched unsuccessfully. Can I get a kit for the Gamma 2? Thanks.


----------



## ShinyFalcon

I am unaware of anyone producing any kits at the moment. Right now is a good time to buy the main chips for the y1/y2 from Mouser as they are all in stock (WM8741, SRC4192, OPA2365, CS8416), so act fast... Only one of the transistors (2N3904), the 150mA 3.3V regulator for y1, and a couple of resistors are out of stock, but substitutes are available.


----------



## jarpatus

If anyone is interested, I created BOM calculator prefilled for y1+y2: http://keitin.net/jarpatus/BomCalculator.y1y2.xls

 It's pretty crude and simple and probably has some errors (didn't verify prices etc. and of course I have never programmed with VBA before and to be honest, it's most horrible programming language I have ever seen), but should give you some picture what building y1+y2 would cost and you can compare prices between different variations of y1 and different vendors. I found out that because I bought everything from Farnell, I paid almoset 100 euros more than I should have paid 8)

 Prefilled with prices taken from Finnish Digi-Key+Farnell+RS+Mouser EUR prices not including VAT so your prices may vary due to taxes, different currency etc. You can just update prices to Excel and you should see results real time (VBA code does calculate prices from quantities and prices).

 Sorry if something like this is already done, but if not, I hope this may give you some idea of prices.

 Edit: Oh and in case you wonder why I have added yellow background to some cells... if there are alternative componenets specified and they differ greatly in price or peraps in sound, you may wan't to check if you want to do the same choise as I. Usually I choosed the cheapest part if choice should not matter, but for some parts I choosed the most expensive (DAC) if choice could matter.


----------



## thoppa

Thanks Ti, another of your creations lives, breathes and SINGS ! and wow, it sounds really good paired with a Teralink X2 ! It's a 4192, ad8656, NX 220uF build....so I'm gonna build another with the opa2365 and nx 47uf to drive a Mini3.


----------



## Draguljce

As I'm waiting for all parts to come, some planing is still in progress. Since I choose to build D configuration without U1D on γ1 dac board, and instructions suggest that JP2D should be connected at 2-3 for USB power (or 1-2 for DC in) I presume that instead of jumper, switch can be used to power on/off γ2. Can anyone confirm this ?


----------



## amb

Draguljce, what you describe might subject the PCM2707 to be unpowered while plugged into the USB port (thus the VBUS and HOST are live with 5V). I don't know if this is a good idea or not.


----------



## kranius

what good DIY power supply would pair nicely with the gamma 2 ?

 any 5V linear regulated would do ?


----------



## amb

kranius, please read the γ1 website "parts list" section, under the "AC-DC adapter or power supply" heading.


----------



## kranius

I already did, and picked up the sigma 11, but one told me it was overkill 
	

	
	
		
		

		
		
	


	




 so any other DIY alternatives ? maybe I can give Tangent's PSUs a try...

 or should I just pick up a 5V wallwart ?


----------



## amb

Sometimes this hobby is all about overkill... 
	

	
	
		
		

		
		
	


	



 Anyway, the website also recommends the σ25.


----------



## kranius

the words were more "total waste" rather than "overkill" lol

 I'll take a look at σ25, thanks


----------



## rjkdivin

Kranious,
 Regulated 5v wallwarts with the small tip are hard to find. I used the Jameco 164101 retipped with the Jameco 71192 plug.....if you do this, pay close attention to the polarity. The 164101 is a 500mW unit.


----------



## jarpatus

Quote:


  Originally Posted by *rjkdivin* /img/forum/go_quote.gif 
_Kranious,
 Regulated 5v wallwarts with the small tip are hard to find. I used the Jameco 164101 retipped with the Jameco 71192 plug.....if you do this, pay close attention to the polarity. The 164101 is a 500mW unit._

 

Why not to power it thorugh USB? Even if you will not use this anyway near computers, you probably could buy some kind of USB charger with little money? Ok, those PSU's are probably switching rather than linear, but does it actually matter?

 At least in europe all major cellular phone manufacturers did agree on standard data+charger connector which they will be using for their new phones. Connector is Micro-USB. Is this true in US (and Asia and...) to? Because then one could use Micro-USB connector in gamma instead of original Mini-USB (are connectors pin & dimensions compatible?) and have no problem finding stand alone charger.

 Ps. Oh why they had to choose micro-USB instead of mini? I mean, I have dozens of mini-USB cables, but none micro...


----------



## m1abrams

Quote:


  Originally Posted by *jarpatus* /img/forum/go_quote.gif 
_Why not to power it thorugh USB? Even if you will not use this anyway near computers, you probably could buy some kind of USB charger with little money? Ok, those PSU's are probably switching rather than linear, but does it actually matter?

 At least in europe all major cellular phone manufacturers did agree on standard data+charger connector which they will be using for their new phones. Connector is Micro-USB. Is this true in US (and Asia and...) to? Because then one could use Micro-USB connector in gamma instead of original Mini-USB (are connectors pin & dimensions compatible?) and have no problem finding stand alone charger.

 Ps. Oh why they had to choose micro-USB instead of mini? I mean, I have dozens of mini-USB cables, but none micro..._

 

Because the mini was deprecated.


----------



## Horio

I'm wanting to build the σ25/σ24 to power the y2 (to perhaps enclose with a CKK3 or M^3), and I'm having a heck of a time finding the proper transformer for the (AMB recommends a 2.8VA with 9V secondary). Mouser and Digikey don't seem to stock these. Mouser stocks a 2.3VA but I'm not sure that will cut it. This is my first time doing a DIY power supply, so I'm a bit of a newb. Any advice or suggested alternatives is greatly appreciated.


----------



## m1abrams

Quote:


  Originally Posted by *Horio* /img/forum/go_quote.gif 
_I'm wanting to build the σ25/σ24 to power the y2 (to perhaps enclose with a CKK3 or M^3), and I'm having a heck of a time finding the proper transformer for the (AMB recommends a 2.8VA with 9V secondary). Mouser and Digikey don't seem to stock these. Mouser stocks a 2.3VA but I'm not sure that will cut it. This is my first time doing a DIY power supply, so I'm a bit of a newb. Any advice or suggested alternatives is greatly appreciated. 
	

	
	
		
		

		
		
	


	


_

 

Digi-Key - 567-1040-5-ND (Manufacturer - BV030-7597.0)


----------



## Horio

I saw that too, but I was hoping for something with a ship date earlier than April 13th. 
	

	
	
		
		

		
		
	


	




 Maybe I'll just have to bite the bullet.

  Quote:


  Originally Posted by *m1abrams* /img/forum/go_quote.gif 
_Digi-Key - 567-1040-5-ND (Manufacturer - BV030-7597.0)_


----------



## jarpatus

Quote:


  Originally Posted by *m1abrams* /img/forum/go_quote.gif 
_Because the mini was deprecated._

 

Checked the wikipedia and you are correct, it was deprecated in 2007. So why do I still have mini connectors in every single device I have bought after 2007... Oh well, industry is slow to change.

 Amb, did you know, you are using deprecated connector in gamma-1 
	

	
	
		
		

		
		
	


	




 Edit: Corrected micro -> mini


----------



## amb

Many Motorola, Blackberry (and others) cell phones use Mini-USB connectors for charging as well as for data. So a charger for such phones could be used, but they are usually switch-mode rather than linear, and could be rather noisy.


----------



## kranius

well I think I'm gonna stick to sigma 11 
	

	
	
		
		

		
		
	


	




 overkill sounds nice to me eh


----------



## K3cT

Quote:


  Originally Posted by *Horio* /img/forum/go_quote.gif 
_I'm wanting to build the σ25/σ24 to power the y2 (to perhaps enclose with a CKK3 or M^3), and I'm having a heck of a time finding the proper transformer for the (AMB recommends a 2.8VA with 9V secondary). Mouser and Digikey don't seem to stock these. Mouser stocks a 2.3VA but I'm not sure that will cut it. This is my first time doing a DIY power supply, so I'm a bit of a newb. Any advice or suggested alternatives is greatly appreciated. 
	

	
	
		
		

		
		
	


	


_

 

You can use a normal toroidal transformer and skip the σ24.


----------



## thoppa

Hi,

 I'm going to make a σ11 for the y2 to use as a desktop dac because it is the lowest noise psu I know of, and I'm sure the op amp will perform better with sweeter juice. The op amp only has the minimum decoupling so I don't agree that the σ11 is a 'waste'. I've also read that switching noise can increase jitter.

 I'm also using a y2 as a portable dac, running off usb power. I am thinking about how to clean up the usb power at the input using a pi filter or something similar, in addition to the onboard ferrites. I got a couple of chokes (100uH and 140uH) and I'm wondering what cap to put between them, or just use one and put a cap each side. Does anyone have any experience with doing this kind of power filter ?

 I think I want to have a pole frequency of around 30Khz, so with a 140uH coil, I'll need two .22uF....will this work ? 
 F = 1 / (6.3*((LC)^0.5))

 Thanks,

 Tom


----------



## linuxworks

tom, why do you assume you need to 'preclean' the y1/y2 ?

 the onboard regs are the limiting factor; so a 7805 or 317 is 'all you need'.

 s11 is fine. very very low noise. but its so low, its lower than the onboard regs. you are 'wasting' it, in a way. s11 puts out a lot of heat. I consider that wasteful since 90% (WAG) of it goes unused.

 if you really want to 'upgrade' the PSU, then swap out the onboards and find some lower noise solution for those. THAT would be an effective upgrade. but playing around 'before' the y2 seems mostly pointless to me.


----------



## ShinyFalcon

Since you're playing with "desktop size," how about bypassing the 4.5V analog regulator with the σ11 (and at the same time having the σ11 power the 3.3V regulators)? Will you have two y2's to play with? If it's just one this idea may be difficult to implement but possible.

 666th


----------



## thoppa

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_tom, why do you assume you need to 'preclean' the y1/y2 ?

 the onboard regs are the limiting factor; so a 7805 or 317 is 'all you need'.

 s11 is fine. very very low noise. but its so low, its lower than the onboard regs. you are 'wasting' it, in a way. s11 puts out a lot of heat. I consider that wasteful since 90% (WAG) of it goes unused.

 if you really want to 'upgrade' the PSU, then swap out the onboards and find some lower noise solution for those. THAT would be an effective upgrade. but playing around 'before' the y2 seems mostly pointless to me._

 

Hi,

 I've seen on a scope that regulators perform well at low frequencies but not so good at high frequency, so they don't do much to remove the original switching noise. Hence the 'need' for a filter for the usb-powered y2. The board uses quite a few ferrites already to filter noise, but I'd like to do 'more'.

 I didn't even think about the onboard regs for the desktop y2 - I'll definitely look into bypassing or replacing them. Thanks for that ! 

 I still don't see the waste - this dac uses puny amounts of current so the psu will only need small heatsinks - it'll only be burning off 1 watt or so. If you mean efficiency, well, yeah, it'll be less than 50% ..... 

 Tom


----------



## thoppa

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Since you're playing with "desktop size," how about bypassing the 4.5V analog regulator with the σ11 (and at the same time having the σ11 power the 3.3V regulators)? Will you have two y2's to play with? If it's just one this idea may be difficult to implement but possible.

 666th 
	

	
	
		
		

		
		
	


	


_

 

yes, very good point. I can set the psu to 4.75V (what is the maximum / minumum voltage ? )and replace the 3.3V regs with lower noise ones. 

 I intend to use a 5V 1ppm xo so I'll find out what the voltage requirements are for that too. Of course, I'll need to re-route power cos the xo uses 3.3V in the design.


----------



## amb

σ11's output voltage should not be set lower than 5V. Otherwise the devices will get too close to the edge of their linear region and the PSU would fall out of regulation. OTOH, the "4.5V" analog supply can be 5V so you could use σ11 to drive it directly.

 The LP2985AIM5-3.3 regulator's noise spec is ~30µV, 300Hz-50KHz. The TPS79333DBVR is ~35µV, 200Hz-100KHz. While these are not nearly as quiet as a σ11 at 5V, they are pretty good by any standard.

 The LP2985's ripple rejection is rated 40-something dB at 1KHz (no other frequencies listed) whereas TPS79333's ripple rejection is much better at ~70dB in the audio band, dropping to the 40-something dB range at 100KHz.

 Given this, there should be some benefit to using a σ11 upstream of the 3.3V regulators to form a two-stage regulator. The 3.3V regulators will add a very small amount of noise, but the σ11 should help filter out much of the USB power noise.

 My own testing of USB-power vs. σ25 external PSU on both γ1 and γ2 showed a measurable reduction in noise floor "hash". My computer's USB power is relatively clean, and I can't hear any of the noise even though I see it in the spectrum analyzer. FWIW, a few people have reported hearing noise with certain computers, and cured it by changing to either σ25 or σ11 external power.


----------



## thoppa

Excellent - thanks ! 

 So I think I'll keep the TPS79333 reg and use a 5.1V zener in the σ11 and not use a 4.75V reg - this will be fine right ? 

 I also plan to use a double-bobbin 0-9V trans and an iso trans too (if I can find a suitable one), so hopefully it will be super-clean power to the y1/y2. 

 I found some ultra-fast recovery diodes - just 25nS - so they seem slightly better than the legendary MUR820 at 35nS. 

 Thanks for your help.


----------



## amb

Quote:


  Originally Posted by *thoppa* /img/forum/go_quote.gif 
_So I think I'll keep the TPS79333 reg and use a 5.1V zener in the σ11 and not use a 4.75V reg - this will be fine right ?_

 

Even better would be to use a 5V voltage reference (i.e., LM336BZ-5.0 as described on the σ11 website).


----------



## linuxworks

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_My own testing of USB-power vs. σ25 external PSU on both γ1 and γ2 showed a measurable reduction in noise floor "hash". My computer's USB power is relatively clean, and I can't hear any of the noise even though I see it in the spectrum analyzer. FWIW, a few people have reported hearing noise with certain computers, and cured it by changing to either σ25 or σ11 external power._

 

have you seen any diff on the rmaa run between the s11 and s25? and a 317 based reg?


----------



## rille2

My gamma2 makes problems. It outputs music but it is distorted. Where should I start to look at? Voltages are ok. No shorts between the pins of the WM8741 or SRC4192. A sinus looks a bit like a square wave at the oscilloscope. It's likely not the opamp beause the signal looks the same before it.

 I made a screenshot:





 This should be a 1kHz sinus.

 Edit: I should also say that the gamma1 is ok. At his output there's no distortion.


----------



## amb

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_have you seen any diff on the rmaa run between the s11 and s25? and a 317 based reg?_

 

No, I don't have an available 5V σ11 to test with currently, or for that matter, a LM317-based one.


----------



## amb

Quote:


  Originally Posted by *rille2* /img/forum/go_quote.gif 
_My gamma2 makes problems. It outputs music but it is distorted. Where should I start to look at? Voltages are ok. No shorts between the pins of the WM8741 or SRC4192. A sinus looks a bit like a square wave at the oscilloscope. It's likely not the opamp beause the signal looks the same before it._

 

That's a strange one. I'd start by checking all the solder joints for good connectivity. As I said in the past, 90% of γ1/γ2 problems are solder-joint related.


----------



## ujamerstand

rille2, at least your gamma2 has sound! Mine doesn't even sing at this point. 
	

	
	
		
		

		
			





 The voltage readings looks fine, no visible solder joints anywhere; I'm quite puzzled by this...
 Gamma1 sections are working, so the problem must be on gamma2 section. But where should I start troubleshooting?


----------



## amb

ujamerstand, have you read through this thread to get ideas first?


----------



## linuxworks

one thing that sometimes happens to my y2 is that the bridge between the lower and upper boards can get loose. I get a whine and burst of static on mine. then I 'slap' the box and it works again. I must have not had the pins aligned well enough when I 'married' the 2 boards together.

 I am going to re-align both boards and resolder at least one of the rows of pins. I think others may also have to re-check their pin alignment. its really easy to get those off center just a wee bit.

 check that. especially if you had the 'worked once but not now' syndrome.


----------



## ujamerstand

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_ujamerstand, have you read through this thread to get ideas first?_

 

I have, but that was quite a while ago... I'm just depressed that it didn't work for the first time, that's all. I'll report back when I'm really stuck.


----------



## pixeljedi

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_one thing that sometimes happens to my y2 is that the bridge between the lower and upper boards can get loose. I get a whine and burst of static on mine. then I 'slap' the box and it works again._

 

Like this?


----------



## linuxworks

Quote:


  Originally Posted by *pixeljedi* /img/forum/go_quote.gif 
_Like this? 
	

	
	
		
		

		
		
	


	


_

 

man oh man, what a blast from the past


----------



## thoppa

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Even better would be to use a 5V voltage reference (i.e., LM336BZ-5.0 as described on the σ11 website)._

 

Excellent - much lower noise and accurate enough - thanks again !

 BTW the rectifier diodes I chose are Fairchild FFPF10H60STU 

FAIRCHILD SEMICONDUCTOR|FFPF10H60STU|DIODE, FAST, 10A, 600V, TO-220F | Farnell Hong Kong


----------



## rille2

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_That's a strange one. I'd start by checking all the solder joints for good connectivity. As I said in the past, 90% of γ1/γ2 problems are solder-joint related._

 

They look ok. I will order connectors to make cables for the connection between the boards so I could test them better.

 I also had a bad 3,5mm jack in one gamma1 so one output was shorted.

 P.S. I built 3 gamma2, the other 2 are working.


----------



## linuxworks

I just fixed 2 y2 baseboards (the y2 board part). both mine and another one (friend's) had misaligned pins (like I was referring to). I did not have to unsolder them, they are not hard to bend and straighten by hand. so folks, do check that: solder the pins to the board, bend them so they're perfect, then use THAT as a guide to place and solder the mating female socket on the y1 board part. that will ensure they both mate and align well.

 just regular finger pressure bends them back into alignment.


----------



## m1abrams

Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_I just fixed 2 y2 baseboards (the y2 board part). both mine and another one (friend's) had misaligned pins (like I was referring to). I did not have to unsolder them, they are not hard to bend and straighten by hand. so folks, do check that: solder the pins to the board, bend them so they're perfect, then use THAT as a guide to place and solder the mating female socket on the y1 board part. that will ensure they both mate and align well.

 just regular finger pressure bends them back into alignment._

 

TIP: If you use your finger to hold the pins in place while doing a tack solder make sure you put you finger on a pin you are NOT soldering! Those pins conduct heat really quickly!


----------



## mattcalf

My fixed up y2 arrived today, currently listening to it playing Beethoven's Piano Conerto No.5. Marvelous.


----------



## linuxworks

Quote:


  Originally Posted by *m1abrams* /img/forum/go_quote.gif 
_TIP: If you use your finger to hold the pins in place while doing a tack solder make sure you put you finger on a pin you are NOT soldering! Those pins conduct heat really quickly!_

 

also has the interesting side-effect that you can now use your index finger to grate cheese!

 lol


----------



## mrtndoog

Quote:


  Originally Posted by *mattcalf* /img/forum/go_quote.gif 
_My fixed up y2 arrived today, currently listening to it playing Beethoven's Piano Conerto No.5. Marvelous. 
	

	
	
		
		

		
		
	


	


_

 

just wondering how did you get it fixed? I might need some help if i try one


----------



## K3cT

I have this beautiful combo running for a while so now it's time to enjoy the fruit of my labor. Please don't mind the rubber bands as I have yet to purchase the custom faceplates. 
	

	
	
		
		

		
		
	


	
























 Sonics-wise, I think it's marvelous and punches far above its cost. I happen to have a popular high-end DAC on loan with me now and the γ2/σ25 combo can stand proudly side-by-side with the Goliath. I can foresee myself using this combo for a long time until the need arises for a balanced setup. 

 I want to thank several people that make this project possible: Ti Kan for his patience and countless support in various forms, psychoaudio (a local DIY-er and designer) for his kind help when building got rough, MisterX for introducing me to the world of γ project, Budi for helping me to source the majority of the parts (it's insanely difficult to acquire them here!), fordgtlover for parts consultation and last but not least the people in this thread. A big thank you for all of you!


----------



## fishski13

K3cT,
 congrats! i like the o-25 too.


----------



## mace1337

Not to knock the o25, but that's just a 78XX based power supply done well, I don't see whats so special about it. I have been making them like that for years.


----------



## linuxworks

Quote:


  Originally Posted by *mace1337* /img/forum/go_quote.gif 
_Not to knock the o25, but that's just a 78XX based power supply done well, I don't see whats so special about it. I have been making them like that for years._

 

correct, its 'just a 78xx' (any 7800 series, of course; even 7900) in a small footprint (very close to what the TREAD uses for space). it has molex offboard connector provision (tread does not, sadly) and it has some heatsink on the groundplane to help (tread also has no internal HSing).


----------



## amb

Actually, you can't use the 79xx series regulator on σ25. The pin-out is different. But, as the σ25 website shows, you can still implement a negative supply using the 78xx IC.


----------



## linuxworks

ooops, yes, of course amb's right. I was thinking of running 2 7800's to create bipolar supplies but yes, you have to use 2 positive chips, not a plus and minus chip.

 doh!


----------



## vekkt0r

Ok, this is kind of my first post(buying feedback doesnt really count does it? 
	

	
	
		
		

		
		
	


	




) Have been idling for some years just reading but felt it was time to do some posts now 
	

	
	
		
		

		
		
	


	




 First of all I didnt really expect an improvement in sound from this build, mostly built for the fun of it. But when testing I found out it sounds much better than my previous DAC(aliendac) just after some hours of listening, so thanks AMB for a great build!

 Of course I forgot to order some parts but I was to eager to test it out that I didnt want to wait until monday for all parts to arrive to I frankensteined it a bit to get it to work 
	

	
	
		
		

		
		
	


	




. First of all I ordered the wrong voltage converter and got 3 4.75v regulators instead of 2 4.75 and 3 3.3 regs. Luckilly enough i had a 3.3 regulator laying around that i replaced the usb regulator with(this regulator felt least important noisewise) Also managed to mount Q1D and Q2D reversed using 2n2222 transistor as replacement and not checking pinout correctly..

 The two last errors can be spotted in the following pictures(one on DAC board and one(two) on usb board) 
	

	
	
		
		

		
		
	


	

















 Is it worth it to use other supply than usb? Thinking of building some own supply but doesnt really feel like its worth it.


----------



## mace1337

I finally ordered some parts from Ti Kan! (Basically all the parts he offers for y1 and y2)

 I'm just gonna go with the full++ config + y2 and everything, with sprinkles on top. 
	

	
	
		
		

		
		
	


	




 Now I have to order from Mouser on monday and I should be set in about a week or two.


----------



## bellahsu

I have the opportunity in the last 3 months to extensively listen to CDs played by a CD/SACD player that uses WM8742 (i.e. Onkyo C-SVL5). To my ears Wolfson DAC indeed sounds good. However, in my opinion what truly sets WM8742 apart from the rest is its ability to use one of the build-in advanced digital filters - Minimum Phase Apodizing filter. The super high-end Meridians 808.2 also uses Minimum Phase Apodizing (although Meridians has to use a 150 MIPS processor and other circuitry to implement it). This filter swept away much of the problem associated with "digital" sound (i.e. fatiguing hardness, edginess, and glare... etc.). The resulting sound signature is almost "analogue". Unfortunately Minimum Phase Apodizing filter in WM8742 is sw controlled (a bad mistake) thus it could not be selected and be easily taken advantage by gamma2.


----------



## fordgtlover

Quote:


  Originally Posted by *vekkt0r* /img/forum/go_quote.gif 
_snip...

 Is it worth it to use other supply than usb? Thinking of building some own supply but doesnt really feel like its worth it._

 


 Well done. Yes, it is a noticeable improvement over the Alien DAC.

 I tried an external PS with my Gamma 1 and could hear any difference over the USB power, as a result I didn't bother testing the Gamma 2 with external power. No noise that I can hear to worry about.

 YMMV and it may depend on how noisy your USB power is.


----------



## particleman14

I too am curious how a o25 or o11 will affect the gamma 2. i am saving up right now to build this, and if I don't have to buy an o11 i may be able to start sooner!


----------



## francisdemarte

Searching the thread a lot of people see little or no difference with an external power source over USB. I didn't notice any differences between using external power and usb power from my desktop.

 People who do have issues tend to be on laptops with noisy power supplies.


----------



## thoppa

Quote:


  Originally Posted by *francisdemarte* /img/forum/go_quote.gif 
_Searching the thread a lot of people see little or no difference with an external power source over USB. I didn't notice any differences between using external power and usb power from my desktop.

 People who do have issues tend to be on laptops with noisy power supplies._

 

Yeah, I can only hear _very_ slight changes, so slight in fact that I think USB power wins if you need convenience. But if not, then using a battery or a very good linear regulated supply is the way to go. Maybe the 'best' thing is to use a good reg chip like an LT1084 ?

 I've been trying various filters to see if I can improve the USB but so far I've not had any great success. I want a physically small filter that will fit in the case, but most small chokes with reasonably high Henries have too much dc resistance and so reduce the input voltage. 

 The other option is to use large value capacitors with low esr, like Sanyo oscon, together with the existing ferrite beads, so I'm going to look into this next. But to be honest, I'm just having fun, I'm not really gaining much, if any, real performance increase.


----------



## MisterX

Quote:


 The other option is to use large value capacitors with low esr, like Sanyo oscon, together with the existing ferrite beads, so I'm going to look into this next. But to be honest, I'm just having fun, I'm not really gaining much, if any, real performance increase. 
 

Been there tried that and found there was very little to be gained there but don't let me discourage you from having some fun.


----------



## thoppa

Yeah, I think the chips and circuit design are so good the performance is confined to a very narrow envelope, with very little room for tweaking. In a word, excellent. 

 But then part of the fun of diy is discovering circuit behaviour and playing with it.....right ? 

 So far, my 'best' tweak is filtering the usb power with a pi filter of 1uF x7r - 100uH 5amp toroid - 1uF X7R. This has a corner frequency of around 15Khz so it seems to work where the onboard regs are less effective and provide a bit of a cleaner supply way up into the Mhz region. 

 One thing I'm wondering about on the y1 usb board, would be the effect, if any of swapping the position of c10u and r4u. If I did this then it would be easier to implement the pi filter. R4u would become a 1uF ceramic and vbus could be connected to VCC via the toroid and the second 1uF ceramic could go across VCC to gnd.

 What do you reckon ?

 BTW, I'm pairing the Y1 usb as the i2s source for a y2.

 EDIT : the change would make L2u and r4u into an lr low pass filter - 3.2x10^-11 H and 47k R = no effect, but would it affect U2U or the host pin ? I assume not....


----------



## MisterX

Quote:


 But then part of the fun of diy is discovering circuit behaviour and playing with it.....right ? 
 

Absolutely. 
	

	
	
		
		

		
		
	


	




 If you are using the the USB board as an I2S source what are you doing with the DAC portion of the Y1 board? 
 I am thinking with all of the unused holes in that section and with the way the power is routed you could mount the filter parts over there (where the theoretical EMI is less likely to effect the analog output?) and it would give you a real easy way to jumper it in and out of the circuit for comparative testing?


----------



## thoppa

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Absolutely. 
	

	
	
		
		

		
		
	


	




 If you are using the the USB board as an I2S source what are you doing with the DAC portion of the Y1 board? 
 I am thinking with all of the unused holes in that section and with the way the power is routed you could mount the filter parts over there (where the theoretical EMI is less likely to effect the analog output?) and it would give you a real easy way to jumper it in and out of the circuit for comparative testing?_

 

Yep, that's exactly what I'm planning - on y2, the toroid will connect vbus to vcc through J5 and locate near the jp2 jumpers. The second 1uF X7R will go across vcc and gnd on J5. on the y1 usb board, I might replace C10U with an oscon and move c10u so it shunts vbus and gnd near J2U, or put it near J5 on y2.

 I will probably completely remove the y1 dac board for another project.

 EDIT : I tried two Oscons 47uF as the caps for the pi filter with a 100uH and it blew the regulators on the y2. oops. I changed the 3.3v no problem but pin 3's solder pad for the 4.75V reg came off the board. umm. So I soldered on a bridge wire between pins 1 and 3...... and she's fine.... enough fun for one day I think.... 

 Here's the final filter : 100uH coil connecting Vbus and VCC and Sanyo 100uF across VCC and Gnd. It has a significant effect on noise, and doesn't introduce any emi. However, the USB earth is still very polluted and this is now the limiting factor for everything. Anyone know how to filter an earth line effectively ?






 Here are scope photos showing the noise on the usb power line before the filter and the noise after the filter, which is the same as the noise on the earth.


----------



## amb

For those sourcing parts for γ2, AD8656ARZ and OPA2365AID are both out of stock at Mouser, Digikey and Newark, Digikey shows that they are restocking AD8656ARZ in just a few days (3/3/2010). Mouser has some OPA2365AID coming in in early April, and you can buy from Newark's Farnell-UK direct-ship and receive them in 7 business days (a flat service fee of $20 applies, look at their part number 61M8029).

 FYI.


----------



## mace1337

Aww damn, just when I wanted to order parts. 
	

	
	
		
		

		
		
	


	




 I see that Mouser is also out of the TI SRC and Crystek OSC for the y2


----------



## amb

mace1337, since you're in Holland, maybe your best bet is to source as much parts as possible from Farnell.


----------



## MisterX

The OPA2365AID is available from Avnet or Arrow, either of which are cheaper for US buyers then the Farnell export service.


----------



## mace1337

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_mace1337, since you're in Holland, maybe your best bet is to source as much parts as possible from Farnell._

 

Yeah, but Mouser or Digi-key aren't bad either, since they have free shipping over an X amount, and Mouser takes care of import taxes as well. With Digi-key you have to pay the UPS man at the door. 
	

	
	
		
		

		
		
	


	




 Both Mouser and Digi-key ship fast, Mouser uses Fedex and Digi-key UPS, potayto potahto.


----------



## slowpogo

I'm looking at building the σ25 + σ24 to power the y2. I did the calculations on the σ25 page, and it seems for the y2 you would need a 9VAC secondary transformer, at least 3.3VA, to meet the 5VDC/300ma requirement of the y2.

 Of course, after going through the data sheets on amb's site for part numbers, it appears that neither Mouser, Digikey, Farnell, or Allied stock any EI30 transformers that meet these requirements. In the event that I might be able to sneak by on 3.2VA, I checked for those, but none of those are in stock either. 
	

	
	
		
		

		
		
	


	




 Am I missing something or is it not possible to build a σ25 + σ24 to power the y2 at this time?


----------



## MisterX

Where are you located? 
 If it was me I would snag one of those $12 Multicomp toroids from Newark (# MCFM70/09) but they are much more expensive for people in other countries. 



http://www.head-fi.org/forums/f6/gam...ml#post6169217


----------



## Volkum

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_Am I missing something or is it not possible to build a σ25 + σ24 to power the y2 at this time?_

 

I ran into the same thing. I have 567-1040-5-ND on intergalactic backorder with Digikey (estimate is 6/9). I figure I'll just use USB power until I get it later this year or get a toroid if I feel the need.


----------



## ShinyFalcon

1k or so units will arrive on June... for the time being, use a wallwart or another transformer... Many to choose from.


----------



## slowpogo

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Where are you located? 
 If it was me I would snag one of those $12 Multicomp toroids from Newark (# MCFM70/09) but they are much more expensive for people in other countries. 



http://www.head-fi.org/forums/f6/gam...ml#post6169217_

 

I suppose that's nearly as convenient, since I didn't really care about stacking the boards.

 Maybe a question for an o25 thread..but what enclosure line works well for a little power supply like that? I'm thinking something as small as possible, about the size of a typical laptop/printer PSU, plastic...


----------



## MisterX

A wall mount enclosure? 
http://www.head-fi.org/forums/f6/sou...-cases-463121/
 or something like was shown on page 76 of this thread?


----------



## slowpogo

Thanks, the Teko website has something very suitable, and apparently they send free samples.

 Another snag with the o25 - the 7805 regulator part numbers listed are NA anywhere. Would this be one of the mentioned "acceptable substitutes"? The specs seem to match:

KA7805AETU Fairchild Semiconductor Linear Regulators - Standard


----------



## thoppa

Hi,

 I was wondering what is the most effective way to create a clean earth from usb power ? It's for a laptop-usb powered y2.

 I was thinking about a series choke, or perhaps a paralled cap and resistor ? I don't know what will work best so I need some direction please ....

 I've cleaned up the power line with a simple filter but the earth line is still horribly noisy - 5mV or so, and a wide bandwidth. 

 Thanks !


----------



## mace1337

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_Thanks, the Teko website has something very suitable, and apparently they send free samples.

 Another snag with the o25 - the 7805 regulator part numbers listed are NA anywhere. Would this be one of the mentioned "acceptable substitutes"? The specs seem to match:

KA7805AETU Fairchild Semiconductor Linear Regulators - Standard_

 

Any 7805 will do, they are all the same.


----------



## fishski13

i posted some impressions of "differences" between PSs for the y-2 (see post #85). ymmv. 
	

	
	
		
		

		
		
	


	




.

http://www.head-fi.org/forums/f7/amb...45/index6.html


----------



## thoppa

Hi,

 Tbh, I haven't heard any improvement from the power filter but I can see a substantial improvement on the scope so I'm hoping that this will be one of a series of accumulative changes. 

 I am thinking about upgrading the xo but I have a Euroquartz in there at the mo and the datasheet says it has less than 1ps of noise. Hard to believe that, but the y2 does sound superb... cap changes might happen too.... 

 Nonetheless, I'd love to kill that usb common noise somehow. I see in your post that you can actually hear it ? Have you tried anything to do reduce it yet ?

 cheers


----------



## fishski13

Quote:


  Originally Posted by *thoppa* /img/forum/go_quote.gif 
_Hi,

 Tbh, I haven't heard any improvement from the power filter but I can see a substantial improvement on the scope so I'm hoping that this will be one of a series of accumulative changes. 

 I am thinking about upgrading the xo but I have a Euroquartz in there at the mo and the datasheet says it has less than 1ps of noise. Hard to believe that, but the y2 does sound superb... cap changes might happen too.... 

 Nonetheless, I'd love to kill that usb common noise somehow. I see in your post that you can actually hear it ? Have you tried anything to do reduce it yet ?

 cheers_

 

it's only audible with the Bijou. i have components for a ground loop breaker. btw, i'm using a desktop computer.


----------



## K3cT

Having completed the γ2, I wonder whether there is a difference, if any, between the ASRCs SRC4192 and AD1896? Anecdotal evidences here and various sources in the Internet are inconclusive at best but the datasheet for SRC4192 seems to suggest that it has better specs than the AD1896. What do you guys think?


----------



## amb

The fact that they are pin-compatible to each other is nice, so if one is not available there is a second-source. If you have both available to you, then I would recommend using SRC4192 over AD1896. Both are good, but the TI part indeed has better specs.


----------



## Shahrose

Quote:


  Originally Posted by *K3cT* /img/forum/go_quote.gif 
_Having completed the γ2, I wonder whether there is a difference, if any, between the ASRCs SRC4192 and AD1896? Anecdotal evidences here and various sources in the Internet are inconclusive at best but the datasheet for SRC4192 seems to suggest that it has better specs than the AD1896. What do you guys think?_

 

Not going to comment on the differences, but these might help:

http://www.head-fi.org/forums/f6/asr...rc4192-101566/
Any feedback on new CS8421 high-res ASRC? - Page 2 - diyAudio
Mr White's "Opus", designing a simple balanced DAC - Page 69 - diyAudio


----------



## jarpatus

Yes! Finally I got those SRC4192 I ordered from eBay! Funny how it took 20 days them to arrive via USPS while shipments from amb took only 5 days (seller did post them on time, can see it from USPS sticker)... perhaps this one got stuck in customs and amb's shipment did not.

 But back to business, soldered the chip into the PCB and... nothing. No sound at all. Bugger. This time I was sure of my solder joints so figured out that it must be due to flux - I mean I had extremely odd problems with gamma-1 until I cleaned the PCB throughoutly, quick cleaning with isopropyl alcohol did not wok... So once again I found myself playing with one litre bottle of spiritus fortis 
	

	
	
		
		

		
		
	


	




 Look at it shine after good bath:






 Afterwards, instant music. Impressions? Does kick ass 
	

	
	
		
		

		
		
	


	




 No way I use this at work with laptop like I planned beforehand, this goes to my desktop system.

 Thank you again everyone for making this class of DIY possible!

 - J


----------



## Beefy

I finally got my y2 panels today......






 More pics and details in the main DIY build thread here


----------



## MisterX

Nice, the text filled in the empty space and the contrasting colors work pretty well together.


----------



## m11a1

Hi guys, quick questions:

 What's filter selection for? And what's anti-clipping mean? 

 Also, case-mountable optical jacks I can get in case I want to use my own case? 

 Thanks!


----------



## m1abrams

Quote:


  Originally Posted by *m11a1* /img/forum/go_quote.gif 
_Hi guys, quick questions:

 What's filter selection for? And what's anti-clipping mean? 

 Also, case-mountable optical jacks I can get in case I want to use my own case? 

 Thanks!_

 

Filter selection: To select the different filter options available on the 8741 and 8742 chips. Best to check AMB site and the white paper of the chip to learn what the differences are between the filters.

 Anti-clipping: is a feature of the 8741 and 8742 chips that from what people state pretty much just does a 2db attenuation.


----------



## vixr

AMB put an excellent section in the tech highlights area of the y2 on his webstore. You might go check it out...it will answer all your questions.

 hahaha...too slow


----------



## mace1337

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_mace1337, since you're in Holland, maybe your best bet is to source as much parts as possible from Farnell._

 

Acutally, I just checked, and if I were to order the parts from Farnell instead of Mouser, I'd have to pay about twice as much. 
	

	
	
		
		

		
			





 So I'm ordering some parts that are out of stock at Mouser from Farnell, and the rest I'll order from Mouser.


----------



## jarpatus

Quote:


  Originally Posted by *mace1337* /img/forum/go_quote.gif 
_Acutally, I just checked, and if I were to order the parts from Farnell instead of Mouser, I'd have to pay about twice as much. 
	

	
	
		
		

		
		
	


	


_

 

I calculated recently prices from Finnish Farnell vs. Mouser, results for y1 full++ and y2 were EUR 225,64 vs. EUR 152,57 not including VAT and including panels from Amb. Quess where I did buy from? Of course from Farnell since I didn't bother to check if Mouser will ship to Finland with reasonable P&P 
	

	
	
		
		

		
		
	


	




 Lowest possible price for minimum possible y1+y2 configuration was EUR 94 not including VAT (without panels but with enclosure).

 -J


----------



## mace1337

Quote:


  Originally Posted by *jarpatus* /img/forum/go_quote.gif 
_I calculated recently prices from Finnish Farnell vs. Mouser, results for y1 full++ and y2 were EUR 225,64 vs. EUR 152,57 not including VAT and including panels from Amb. Quess where I did buy from? Of course from Farnell since I didn't bother to check if Mouser will ship to Finland with reasonable P&P 
	

	
	
		
		

		
		
	


	




 Lowest possible price for minimum possible y1+y2 configuration was EUR 94 not including VAT (without panels but with enclosure).

 -J_

 

So farnell was the expensive one right?

 In that case, I think you made the wrong choice my friend, since Mouser ships for free with FedEx on orders over 75€, and their prices also include the tax and import duties already, so no nasty surprises having to pay the mailman at the door.


----------



## jarpatus

Quote:


  Originally Posted by *mace1337* /img/forum/go_quote.gif 
_So farnell was the expensive one right?

 In that case, I think you made the wrong choice my friend, since Mouser ships for free with FedEx on orders over 75€, and their prices also include the tax and import duties already._

 

Right, Farnell was most expensive, Mouser was cheapest one. Combining Farnell+Mouser would decrease price few EUR since some parts are cheaper at Farnell 
	

	
	
		
		

		
		
	


	




 Yes, I am now painfully aware that Mouser would have shipped parts for free...


----------



## mace1337

Quote:


  Originally Posted by *jarpatus* /img/forum/go_quote.gif 
_Right, Farnell was most expensive, Mouser was cheapest one. Combining Farnell+Mouser would decrease price few EUR since some parts are cheaper at Farnell 
	

	
	
		
		

		
		
	


	




 Yes, I am now painfully aware that Mouser would have shipped parts for free..._

 

Ah well live and learn.

 In the meantime there are a bunch of parts that are not in stock like AMB mentioned, some of them have lead times of 28 weeks or more.


----------



## jarpatus

Quote:


  Originally Posted by *mace1337* /img/forum/go_quote.gif 
_In the meantime there are a bunch of parts that are not in stock like AMB mentioned, some of them have lead times of 28 weeks or more. 
	

	
	
		
		

		
		
	


	


_

 

What parts you are missing? Isn't there any local electronics shop which could order you stuff from Farnell without P&P, even if you order most of the stuff from Mouser?

 I have one extra SRC4192 and could sell & post it should you need it (Farnell did not stock it when I ordered my parts so I bough two from eBay), but others chips I don't have.


----------



## mace1337

Quote:


  Originally Posted by *jarpatus* /img/forum/go_quote.gif 
_What parts you are missing? Isn't there any local electronics shop which could order you stuff from Farnell without P&P, even if you order most of the stuff from Mouser?

 I have one extra SRC4192 and could sell & post it should you need it (Farnell did not stock it when I ordered my parts so I bough two from eBay), but others chips I don't have._

 

That's exactly what I need, I can order Farnell thru my work (they don't like to do it but they will if I ask nicely) and between farnell, AMB's shop and mouser the SRC is the only chip that's unavailable. Please PM me with your details so we can hook it up, thanks!


----------



## xnor

Are there any RMAA measurements (with dummy loads) available of the AD8656 configuration which can be used to drive headphones directly?
 And where can I find specs like the maximum output voltage prior to clipping / power output (like seen on amp spec pages)?


----------



## thoppa

Hi,

 On the AMB site it says the output voltage for the 4.5V and 4.75V regs. IIRC it is something like 1.6 and 1.7 volts. The op amp is configured for a 0.7 gain. From this you can work out the power output into the cans impedance P = V^2 / R. 

 I'm using HD650 directly from the ad8656 with BG NX 220uF caps. It is loud enough for me but I'd like more headroom for a more dynamic sound. However, it really is quite a surprise to me how well the the ad8656 does.

 I'd be very interested to hear what tonal and spatial differences there are between the two op amp choices. 

 If you want specs for the AD8656 you can look at the datasheet. Of course, this is not as nice as seeing how it performs in the circuit....but it's a start.

AD8656 | Low Noise, Precision CMOS Dual Amplifier | Operational Amplifiers (Op Amps) | Amplifiers and Comparators | Analog Devices


----------



## amb

γ2's output voltage @ 0dBFS is 1.4Vrms. With AD8656's low output impedance it essentially doesn't change down to 32 ohms load or less.


----------



## xnor

Thanks! I'm still interested in an rmaa test with 32 ohms load, though.


----------



## thoppa

hehe...sure me too....but I'm more interested in a diy dac with src4392, selectable xo's for input and output, wm8742, and fully balanced and discrete output stage, remote volume control....all in a sesame seed bun.. hint hint Ti ...


----------



## francisdemarte

A balanced y2 would be awesome


----------



## dumbears

Today, my y2 started to make a lot of noise after playing music thru USB for sometime. However, there isn't any problem when plugging in y1 phoneout.

 What is the possible cause of it? I'm thinking if it's my doing of adding a 5V transformer to y2 2 days ago. My fault was I didn't check its voltage until recently. The reading I got is 5.2V.

 Pls advise. Thanks in advance.

 -----------------------

 I opened up the case and check all the soldering points again. Once again, I found a few ground soldering points weren't soldered properly. I wonder how I can secure all the ground soldering points. I did solder them and checked on them, but they just didn't hold well. 
	

	
	
		
		

		
			





 Any good suggestions in ground soldering? Sorry, I knew I asked this before, and I tried the suggested methods. I'm still lack of the skill to get the solder hold on the ground.


----------



## xnor

Btw, does the ASRC buffer audio and thus reduce usb audio glitches?
 (spec says something about 64 samples, isn't that less than 1ms with 96kHz?)

  Quote:


  Originally Posted by *thoppa* /img/forum/go_quote.gif 
_but I'm more interested in ..._

 

an asynchronous diy usb dac that supports at least 24/96 
	

	
	
		
		

		
		
	


	



 (I'd prefer doing the upsampling on the computer.)


----------



## thoppa

I'll leave it to someone else to explain async upsampling....not to mention software vs hardware upsampling... not getting drawn into that....

 ....but I will say my y2 does support 96/24...because I'm not (yet) using the y1 as the iis source...I'm using a usb Teralink x2 which is asio and 96/24 and has iis output.... and it's a lovely combination.


----------



## xnor

Quote:


 I'm using a usb Teralink x2 which is asio and 96/24 and has iis output.... and it's a lovely combination. 
 

How would that work with USB if the product page says "no driver needed"?


----------



## thoppa

There is a driver in development, and Michael at Teradak very kindly sent it to me, so a few people here at head-fi have been testing it.

 It works well with XP sp3 and Foobar, and others tell me it works with Vista and Win 7. I haven't found anyone with Win 7 64 bit and an X2 to test it yet.

 I don't know the details of how the data is sent but it seems to me that iis gives better definition than spdif, but I've only tried this with the X2 and y2 so I don't know if this is a 'generally true' thing.


----------



## xnor

I see. 

 I've got more questions. 
	

	
	
		
		

		
		
	


	




 So with the AD8656 the y2 can also drive headphones, but is there a catch? (compared to the OPA2365)

 And secondly, how well does it cope with usb latency? My laptop shows ~1ms latency spikes (measured with DPC latency checker) every now and then, that's a problem right? (Disabling wi-fi seems to help.) The rest is in the 250 - 500us range.


----------



## thoppa

I guess it's true to say there is no free lunch.......I believe from what I remember reading on the datasheets that the op will outperform the ad for things like distortion and rejecting noise and ripple on the power supply. 

 However, they have 'character'. From the op amp rolling I've done, AD chips often sound neutral, dynamic with a strong centre focus. BB chips seem to be more varied but are often a bit warmer and have less of a centre focus. LM chips tend to be a bit brighter and more detailed with a wider soundstage. But that's a very broad generalisation.

 I think latency problems will depend on how good your PC is. But I generally first find out what size buffer will cause audible errors and then add at least 50% to that. The driver for the x2 has an auto buffer. However, if you are not doing editing and mixing, and just playing files, then I don't see why anyone would want low latency, unless they can hear a difference between buffer sizes. I can't but I haven't 'really tried'. No doubt there is a thread somewhere discussing this....with some people saying you can't, and others saying you can, and others stoking the debate...and someone saying some esoteric and ultra-expensive widget solves it....

 For the y2, I just tried a Ploytech usb asio driver to work with the y1 usb module I just finished (y1 provides iis to the y2). It is a weird install, asking me to remove and re-attach the y1 several times, and delete a newer file for an older one, but it works and improves the sound quality. Unfortunately, it is far from free and costs over half the price of the x2. And I think I prefer the x2 anyway !


----------



## xnor

thoppa, I appreciate your answers but I'm more of a facts guy. And that generalization (whoever it originates from) really is stupid, imo. :/

 You're mixing up things when talking about latency. I was not talking about playback latency (which doesn't matter (to me)).

 Afaik, the y1 USB DAC is a PCM2707 with a sampling rate of up to 48 kHz max. Event the most exotic driver couldn't change that, right?


----------



## thoppa

Latency is a loop-back delay no ? Feel free to educate me 

 But maybe you should PM me....this thread is supposed to be about the y2...and we're adding noise...


----------



## WyldRage

I need some help with my gamma2 build. It didn't work at first, the voltage measures were exact, but my computers didnt recognize it when I plugged it in. The switch does turn red, with either the walwart or USB plug. After resoldering the SMDs for the third time, it actually worked ONCE, even managed to get sound out. So I put it in its enclosure, and try again an hour later: it doesn't work anymore. 

 I still get correct readings on voltage, but the switch is red and the computers don't recognize it. I'm uploading pictures of my build, I'm thankful for any help I can get.

 Cheers,


----------



## ShinyFalcon

First thing I would do is to clean the flux off. There may be an unintended connection somewhere on the USB portion. Do you have an external optical/coaxial out device that you can test the y1's optical/coaxial in with?


----------



## WyldRage

Tried the optical, there is a slight reduction in noise, but that's all. The light still stays red. 

 Also gave it (another) good scrub, no dice.


----------



## amb

- Does the computer recognize it as "USB Audio DAC" when plugged into the USB port?
 - Did you install the correct parts in U4D and U9D (MCP100 and MCP101, respectively)? Check the voltage at U2D pin 9 after power-up, it should be at 3.3V.


----------



## mace1337

Quote:


  Originally Posted by *WyldRage* /img/forum/go_quote.gif 
_I need some help with my gamma2 build. It didn't work at first, the voltage measures were exact, but my computers didnt recognize it when I plugged it in. The switch does turn red, with either the walwart or USB plug. After resoldering the SMDs for the third time, it actually worked ONCE, even managed to get sound out. So I put it in its enclosure, and try again an hour later: it doesn't work anymore. 

 I still get correct readings on voltage, but the switch is red and the computers don't recognize it. I'm uploading pictures of my build, I'm thankful for any help I can get.

 Cheers,

 -Removed pictures-_

 

Looking at these pictures I can see a few things:

 -Clean off all flux
 -Clean of all blobs of solder that don't belong, you have a few sticking to parts and to the board.
 -Check the length of the leads of the through-hole parts, some of them look too long, or have a tuft of solder on them. 
 -Check for bridged pins with a multimeter, U1D on the Y1 for example looks like it might have some bridged pins on the picture. Check all IC's


----------



## WyldRage

My thanks for the help, I got it working (again). I just reflowed... re-soldered the SMD components, for the 3rd or 4th time.

 I just hope it will work more than once this time.


----------



## linuxworks

straighten j4 and j5. common problem (for me, anyway). if the contacts from the headers are not exactly perfect and aligned AND your sockets aren't also perfect, you will get intermitant 'works and then it doesnt'.


----------



## ujamerstand

YES. I have finally gotten my gamma-2 DAC to output sound! There is no words to describe my joy right now. Finally a SMD soldering project that works on me! After hours of painful debugging, I've found some really tiny soldering bridges between pins on the DAC chip. My attempt to "sweep out" the remaining solder resulted some very frail looking pins; I was almost afraid that I might have fried the chip. Well, after ohming out everything, I gathered enough courage to try it out. AND IT SINGS. Did I say it was one of the happiest moment of my life?


----------



## francisdemarte

I had a similar problem, near invisible solder bridges that I needed to sweep out with a larger iron tip!


----------



## thoppa

Quote:


  Originally Posted by *ujamerstand* /img/forum/go_quote.gif 
_AND IT SINGS. Did I say it was one of the happiest moment of my life?_

 

I know that feeling very well - I'm happy for you too !


----------



## fishski13

Quote:


  Originally Posted by *ujamerstand* /img/forum/go_quote.gif 
_YES. I have finally gotten my gamma-2 DAC to output sound! There is no words to describe my joy right now. Finally a SMD soldering project that works on me! After hours of painful debugging, I've found some really tiny soldering bridges between pins on the DAC chip. My attempt to "sweep out" the remaining solder resulted some very frail looking pins; I was almost afraid that I might have fried the chip. Well, after ohming out everything, I gathered enough courage to try it out. AND IT SINGS. Did I say it was one of the happiest moment of my life?_

 

kudos!


----------



## mace1337

The TPS79333 was not in stock at Mouser, so I ordered the EP version.

 I guess those are better?


----------



## slowpogo

I ordered the OPA2365AID from Arrow, as they are the only ones in America who have it in stock apparently. Unfortunately it cost me like $12 in shipping.

 The funny, or not-so-funny thing, is the packaging. This single chip, about 20 square millimeters in size, arrived in a two-foot-long triangular box which was stuffed with paper...the chip was inside a two-foot antistatic tube, which was stuffed with nearly two feet of a foam strip.

 Good lord. I'm sure the majority of their customers order things in bulk, but could they seriously not have _any_ smaller, more eco-friendly method of packaging a single SOIC chip? It's ridiculous and I'm gonna write them a little note about it, even though I doubt I'll even get an answer.


----------



## ShinyFalcon

Haha... I know, it really makes me mad when there isn't an economical shipping option. If it comes fast though, I don't mind at all.

 $12 for two feet of stuff! At least you can reuse it... you should buy some more OPA2365 in bulk and set up a group buy... What else can the OPA2365 be used for? Are there that many y2 builders out there?


----------



## steven2992

Another one lives! yeay 
	

	
	
		
		

		
			




 I'll post some pics later this week


----------



## slowpogo

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Haha... I know, it really makes me mad when there isn't an economical shipping option. If it comes fast though, I don't mind at all._

 

I wish they all offered First Class USPS like Digikey does. You can order a crapload of stuff, and it will cost like $3 to ship and be there in 2-3 days (including Saturdays). Awesome.

 From what I saw, no other vendors will have the OPA2365 in stock for quite a while...maybe a good candidate for AMB to add to his store?


----------



## CodeToad

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_I wish they all offered First Class USPS like Digikey does. You can order a crapload of stuff, and it will cost like $3 to ship and be there in 2-3 days (including Saturdays). Awesome._

 

No doubt. Mouser sucks because they jack up the shipping and they usually take at least 1 day before they actually ship. It takes a week no matter which way I ship it from them but 2 days USPS first class from Digikey for 1/3 the price. 

 I cringe every time I order from Mouser much the same way I do every time I buy a game from EA.


----------



## Beefy

I find Mouser *FAR* superior for my orders from countries outside the US, moreso those outside continental North America.

 And once you hit the $200 order limit, free Fedex priority from Mouser with all duties and customs fees included is a fantastic option.


----------



## linuxworks

I just placed a mouser order on monday. they did nothing monday then said they'd ship tuesday 'next day' to get my 2 day shipment on time.

 agreed that mouser is 2nd to digikey on shipping. mouser is cheaper on prices but they aren't nearly as good for shipping time.


----------



## ksnider1

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Haha... I know, it really makes me mad when there isn't an economical shipping option. If it comes fast though, I don't mind at all.

 $12 for two feet of stuff! At least you can reuse it... you should buy some more OPA2365 in bulk and set up a group buy... What else can the OPA2365 be used for? Are there that many y2 builders out there?_

 

I got my OPA2365AID free samples from TI few days ago.


----------



## slowpogo

Quote:


  Originally Posted by *ksnider1* /img/forum/go_quote.gif 
_I got my OPA2365AID free samples from TI few days ago._

 

Since a few weeks ago, they have been back ordered until April 15 (samples) according to TI's website. So what you say does not make much sense. When did you order the samples?

 I will soon have all necessary parts to build the y2, so I decided to pay $15 rather than wait 6 weeks for a sample to arrive...


----------



## ksnider1

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_Since a few weeks ago, they have been back ordered until April 15 (samples) according to TI's website. So what you say does not make much sense. When did you order the samples?

 I will soon have all necessary parts to build the y2, so I decided to pay $15 rather than wait 6 weeks for a sample to arrive..._

 


 I ordered them at the end of February, and got them few days ago.


----------



## slowpogo

Quote:


  Originally Posted by *ksnider1* /img/forum/go_quote.gif 
_I ordered them at the end of February, and got them few days ago._

 

Huh...you must have gotten your request in right before they ran out, because that is about the time I checked the website. Darn.

 P.S. Did you really need to take FIVE samples? Leave some for the next guy! Just kidding...sort of


----------



## rds

I can guess what op-amp TI will soon be removing from their sample program


----------



## mace1337

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_I find Mouser *FAR* superior for my orders from countries outside the US, moreso those outside continental North America.

 And once you hit the $200 order limit, free Fedex priority from Mouser with all duties and customs fees included is a fantastic option._

 

$200? I get that at 75€


----------



## Beefy

Quote:


  Originally Posted by *mace1337* /img/forum/go_quote.gif 
_$200? I get that at 75€ 
	

	
	
		
		

		
		
	


	


_

 

It varies by country.

  Quote:


  Originally Posted by *rds* /img/forum/go_quote.gif 
_I can guess what op-amp TI will soon be removing from their sample program 
	

	
	
		
		

		
		
	


	


_

 

Indeed. "Oh noes, I have to wait a few weeks for an OPAMP! I'll lie to get it instead."


----------



## thoppa

I think we can also expect the pcm2706/7 to disappear from the samples too. It is back-ordered until 24th March. The OPA2365 is back-ordered until 14th April. Gah.

 I am lucky - I have my own business here so I can get samples and keep my integrity. What little I have left that is.


----------



## slowpogo

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_Indeed. "Oh noes, I have to wait a few weeks for an OPAMP! I'll lie to get it instead."_

 

Have you read the sample terms?

Standard Terms and Conditions of Sale for Semiconductor Products

 None of us is "lying" unless we sell the samples, or use them in a product for sale, or export them illegally, etc. They say they provide samples for "experimental and testing purposes only." That's a pretty big umbrella.

 One might assume, "Well, the people they really WANT to get their samples are people who might manufacture a product using TI parts and order them in the 1000's." That's a fair assumption. But if that were the case, then TI could easily adopt additional measures to ensure they are only providing samples to actual businesses or manufacturers - a lot of companies definitely do this. If not that they could at least put a qualifier to that effect in the legal terms. But they don't. They let any Joe Schmoe sign up and take samples. 

 And this policy certainly could be to their advantage. If I, simply an enthusiast, were able to order the OPA2365 as a sample and save $15 and a bunch of eco-unfriendly shipping material, that would make me feel good. I would like TI a little more. And who knows what this might do in terms of word of mouth about their company, or future prospects. Just because I'm not a large company now doesn't mean I won't be someday. For example, didn't Apple (or was it Microsoft?) famously end up boycotting a major chip manufacturer for decades, because they treated them badly when they were just some geeks putzing around in their garage? And doesn't that last part basically describe most of us (so to speak)?

 It's certainly possible to abuse the privilege by ordering dozens of samples every month. But if you or I order an occasional sample (me, a couple times a year max) and the sample terms remain so open-ended, then there's no shame, dishonesty, splitting hairs or lack of integrity involved. So shut yer yappers.


----------



## thoppa

any joe ....... with a business email address.....? Is your business genuine ?


----------



## Beefy

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_None of us is "lying" unless we sell the samples, or use them in a product for sale, or export them illegally, etc. They say they provide samples for "experimental and testing purposes only." That's a pretty big umbrella._

 

Yeah, you just keep telling yourself that.

  Quote:


 So shut yer yappers. 
 

Yeah, whatever


----------



## slowpogo

Quote:


  Originally Posted by *thoppa* /img/forum/go_quote.gif 
_any joe ....... with a business email address.....? Is your business genuine ?_

 

I signed up with a Charter email address. Maybe they used to, but they never mentioned anything about requiring a business email address. Again, read the terms and conditions.

 Do you think that TI, by omitting any mention of businesses or manufacturers in their legal terms, are putting their _trust_ in all of us to _infer_ that we shouldn't order samples unless we meet some imaginary unstated conditions? Come on, don't be naive.


----------



## slowpogo

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_Yeah, you just keep telling yourself that._

 

You're projecting a paradigm on the company that they themselves do not bother to enforce, or even mention casually. So your point of view does not have much validity. But I guess you can "keep telling yourself that." What is this, The Breakfast Club? If in another 2 years or so when I do a project after this one, I'm having a hard time tracking down a part like I was this time and I remember that TI gives samples, and I go there and the legal terms are changed to explicitly state that I can only order if I'm actively developing a product for the market, I will refrain. Otherwise, they and their 1000 lawyers have left the terms exactly as they want them, most likely for the reasons I stated above, and I won't feel bad when I order a sample from my Charter Communications email address and don't violate those terms...


----------



## Beefy

Lack of enforcement does NOT condone abuse of the program.


----------



## mace1337

Guys, this discussion has been made countless of times before on countless of different fora, and I hate to be blunt, but do you really think this is in any way a postive addition to this topic? 

 I used to sample a lot too, but that was when I was a "starving student", I have a decent job now and I just buy my stuff. No need to mooch off of uncle TI when I can pay for it myself easily.


----------



## slowpogo

Edit: This silly spat has been sitting here all day? Enough, gone...


----------



## thoppa

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_I signed up with a Charter email address. Maybe they used to, but they never mentioned anything about requiring a business email address._

 

Actually you are right. I just realised my business email address just gets me free shipping.


----------



## slowpogo

Quote:


  Originally Posted by *thoppa* /img/forum/go_quote.gif 
_Actually you are right. I just realised my business email address just gets me free shipping._

 

Yes, thanks for saying so...I wasn't just talking out of my butt in an effort to rationalize bad behavior. They literally do not seem to care if you are a business, and for all appearances an enthusiast like me is welcome to order samples.


----------



## Beefy

You didn't sample. You used the program because you didn't want to wait to buy.

 Pretty damn big difference.


----------



## slowpogo

Beefy, I remind you that I did not actually use the program, I bought the part. I haven't sampled in over two years.

 Reread my post #1612 - this issue, and marketing in general, are far more complex than you allow. Besides, this is quite a small, dumb thing to get so puritanically, morally indignant about (assuming it is "wrong" as you think it is). But if you want to think I'm The Great Satan for considering sampling a $3 part that's hard to find, go ahead.

 Either way, I'm pretty excited because my package arrived today from Mr. Ti Kan, and the building of the y2 will commence in earnest this evening. !!!


----------



## mace1337

Guys, please, just stop.

 Continue the argument in PM's or something but keep this topic clean please, nobody cares about your disagreements.


----------



## thoppa

Quote:


  Originally Posted by *mace1337* /img/forum/go_quote.gif 
_Guys, please, just stop.

 Continue the argument in PM's or something but keep this topic clean please, nobody cares about your disagreements._

 

I disagree.....I like reading poor-man's rhetoric online  It certainly is a nice break from reading datasheets to find a sot-23 ldo with less than 30uV noise and better than 60dB PSRRrrrrrrraahhhhhzzzzzzzz 
	

	
	
		
		

		
		
	


	



 [size=medium]
 If anyone does know who makes a 3.3v ultra-low-noise (10uV ?) and good line/load reg and psrr ldo for the y2, please let me know. [/size]

 I found a 7812A that does this (not ldo though of course ; Farnell 1087090) for the Mini3 so I'm sure such a thing must exist. BTW I also found that (some?) ldo's don't seem to work in the Mini3 - both lm2940 and lm2937 seem to give 13.2V in the Mini3 circuit.


----------



## rds

The recommended TPS79333 is pretty much as good as it gets. You want a sot23-5 ldo right?


----------



## thoppa

Actually, although I'd prefer the same package, I'm starting to think this isn't possible. So maybe a to92 and I'll bend the legs or something and use the appropriate pads on the board to connect it. Just as long as it isn't smaller....do you know any awesome 3.3V regs ? I hope so....thank you !

 EDIT: I think I found one - LT1761 - but it is 100mA and I'm not sure it'll be stable with the Oscon cap on the output. Noise is 20uV. Any thoughts anyone ?

http://hk.farnell.com/linear-technol...3-5/dp/1663779

 Ti also do the REG113 which seems to have slightly lower noise - is this a suitable substitute ?


----------



## thoppa

TEXAS INSTRUMENTS - REG113NA-3.3/250G4 

 The datasheet says that with an a 10uF output cap, a 10nF noise reduction cap on pin 4 to earth and a 100nF cap on the input will give less than 7uV noise. With just the nr cap it is about 27uV. It says it is stable with no or almost any output cap up to 10uF or more. The dropout is fine (max 400mV) for a 4.5v to 3.3v drop. It'll handle 400mA. Ripple rejection at 120Hz is 65dB but that has dropped to 30dB for 100kHz to 1Mhz. Line and load regulation seem to be 1%. 

 So it seems this is an upgrade for the TPS 3.3v reg. Any thoughts anyone ?


----------



## amb

thoppa, looks like the LT1761 might have a compatibility problem. Pin 4 (BYPASS) according to its datasheet should have a capacitor going to OUTPUT, rather than to ground like the TPS793xx or LP2985-xx. I don't know if it would still perform the same if you simply dropped one in as a replacement. Even though the noise spec is lower than TPS793xx, I don't think it's significant enough to matter in the end (keep in mind that the noise spec may also not be directly comparable between parts from different manufacturers due to differing measurement methodology).

 The REG113 seems like it would work, but here the noise difference against TPS793xx is even smaller.

 I have tested neither of these so if you want to try them, you're on your own.


----------



## mace1337

AMB, I ordered the EP version of the TPS7333 reg, (TPS79333DBVREP)

 Do you think it's an improvement over the original? I just got it because it's in stock and the normal one isn't.


----------



## thoppa

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_The REG113 seems like it would work, but here the noise difference against TPS793xx is even smaller.

 I have tested neither of these so if you want to try them, you're on your own._

 

Hi,

 Thanks for the reply !

 It seems the Reg113na is a slight improvement over the TPS and pin and cap compatible so I'll give it a try. I'll try it in the y1 dac board first - the CS8416 reciever datasheet says noise on the power line affects jitter so I hope slightly lower noise will improve the definition slightly. I realise it might not be audible but it's worth a try.

 I noticed that you changed the PLL filter on the CS8416 - I assume this was because the y1 is limited to 96Khz so the filter can be adjusted ? If I was only going to run 44.1Khz into the y1 dac board, could I adjust the filter to further improve performance ? I doubt I will; I'm just curious !

 Thanks very much for you help.


----------



## francisdemarte

Probably more for my edification then anything practical but i'm curious about balanced output. Doing some research into "hacking" balanced outs into the y2.

 Can I wire L+/L- and R+/R- test points into a TP IVY III + PS and get balanced outputs?

 Is there an easier way of getting balanced outputs with all the benefits of the y2's analog output stage?

 I know MisterX mentioned something about replacing the RCA's with mini's then getting mini to XLR converters. Can someone please go into a little more detail on this?


----------



## MisterX

Quote:


 Do you think it's an improvement over the original? 
 

Not for this application. 

Enhanced Products from Texas Instruments


----------



## amb

Quote:


  Originally Posted by *thoppa* /img/forum/go_quote.gif 
_I noticed that you changed the PLL filter on the CS8416_

 

Changed from what?


----------



## mace1337

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_Not for this application. 

Enhanced Products from Texas Instruments_

 

Thanks.

 Oh well, at least they're not worse.


----------



## amb

Quote:


  Originally Posted by *francisdemarte* /img/forum/go_quote.gif 
_Can I wire L+/L- and R+/R- test points into a TP IVY III + PS and get balanced outputs?_

 

In theory, yes. I have not tested that though.


----------



## slowpogo

I finished my build last night (y1 + y2, Full++)...it all seemed to go well. The SMD chips went pretty well. But alas, no music.

 Is there a reliable way to test for solder bridges on the SMD chips? I've used the multimeter to test continuity of adjacent legs - but obviously, some of them might actually be connected internally. 

 For example, on the SRC4192IDB, if I measure continuity of adjacent legs, the first several all show continuity (1&2, 2&3, 3&4 etc). But I've reflowed, flooded and solder wicked, done all the tricks several times now. I cannot see any bridges even under a magnifying glass. I've checked for continuity this same way on all the other SMD chips, and none of them show continuity between adjacent legs - only those first several of the async sample converter.

 I've both boards under the magnifying glass, reflowed many joints, but still nothing...


----------



## amb

slowpogo, use the schematic diagram to help you determine whether any adjacent pins should be connected to each other.


----------



## ShinyFalcon

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_I finished my build last night (y1 + y2, Full++)...it all seemed to go well. The SMD chips went pretty well. But alas, no music._

 

First off, what works and what doesn't? Is your computer able to find the USB device? Does the light light up green? Have you tried using coaxial/optical? How are your voltage test points? Does your y1 work by itself? Does the contact pins/receptacles show continuity? Did you install the pin on JP1D?


----------



## slowpogo

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_First off, what works and what doesn't? Is your computer able to find the USB device? Does the light light up green? Have you tried using coaxial/optical? How are your voltage test points? Does your y1 work by itself? Does the contact pins/receptacles show continuity? Did you install the pin on JP1D?_

 

Alright ShinyFalcon...I sense frustration that you feel I was asking for help without providing any info. I was really just going after the solder bridge stuff and was aware I left out a lot, but I wasn't quite ready for full-blown debugging crisis mode. Since you asked, however, we might as well go there:

 1. Computer finds USB device OK
 2. My switch lights up red
 3. I've tried both USB and coaxial
 4. Voltage test points read fine
 5. I installed the pin.

 All jumper settings are as they should be (basically, all open except JP1U shorted with resistor lead). I have cleaned the board with alcohol (including around the SMD pins with a toothbrush/alcohol).

 As far as the y1 working on its own -- this means I have to temporarily install the 5 connecting wires, correct, to test if it works on its own?


----------



## amb

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_1. Computer finds USB device OK_

 

OK, this means at least U1U and U2U are ok.

  Quote:


 2. My switch lights up red
 3. I've tried both USB and coaxial 
 

Try reflowing the joints of the CS8416.

  Quote:


 As far as the y1 working on its own -- this means I have to temporarily install the 5 connecting wires, correct, to test if it works on its own? 
 

You can use the y2 board as the "bridge", no need to connect actual wires.


----------



## MisterX

Or you can just install the jumper across J2U pins 1 and 2, connect either or both of the S/PDIF outputs on the USB board to the DAC board, plug in an external power supply and away you go.


----------



## ShinyFalcon

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_Alright ShinyFalcon...I sense frustration that you feel I was asking for help without providing any info._

 

Oh no, it wasn't that. 
	

	
	
		
		

		
			





 Sorry if it seemed like that. I was rushing a bit and after reading it, my message does have a negative tone to it. Just think of it as a canned response.


----------



## thoppa

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Changed from what?_

 

Hi, sorry, lazy post....

 The CS8416 has a PLL filter on pins filt and agnd ( 7 and 8 ). There's a diagram on page 21 of the datasheet. It says at the bottom **** For best jitter performance connect the filter ground directly to the AGND pin. See Table6 on page 54 for PLL filter values.
 For 32-192Khz
 RFLT CFLT CRIP Settling Time
 23kΩ 22nF 1nF 4 ms

 On the y1 the components are C18D, C19D and R4; 
 3kΩ 33nF 1nF

 This would appear to double ( ? certainly quite a change....) the settling time, so it seems to agree with the idea of using sample rates from 32-96Khz instead of 32-192Khz ? I don't know how this chip or PLL filters work so I'm just guessing.

 So I'm curious about the filter change from the one given in the datasheet....and what would be the effect on jitter of changing rflt and cflt.


----------



## slowpogo

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Try reflowing the joints of the CS8416.

 You can use the y2 board as the "bridge", no need to connect actual wires._

 

I reflowed those; they all look shiny and proper, but no change. I tried the y1 output using the y2 as the bridge, but same outcome.

 I'm not sure if this is significant - I plugged in the y1 DAC board to my 5V power supply, nothing else connected to anything...when I check the 3.3v test pad against ground, I get 1.9v. 
	

	
	
		
		

		
		
	


	




 But 4.5 to ground measures as it should (in my case 4.75v).

 On a side note - it's frustrating because I'm not entirely sure I've got my Emu 1212m configured correctly to use its coax out; I've never used its digital outputs before and the Patchmix software is notoriously confusing, so that's another unknown I ironically can't be sure about until the y1/2 are working. Also, I'm using Foobar to test USB input; but that has its own quirks and I'm not entirely sure I'm doing that right either. When the y1 is plugged in, I have the option to choose DirectSound: USB Audio Device, and I choose that. I play a tune, and the visualizer jumps around like it's all hunky-dory...but no sound.


----------



## thoppa

Hi,

 I've had similar problems. I reflowed CS8416 several times to get the y1 working. If you're getting anything other than 3.3V then the reg isn't working - it might need reflowing or replacing. Check the voltages on pins 1 and 5 - in and out - and pin 3 - start - which is shorted to pin 1. Check the circuit diagram to make sure I've got this right 

 If you get a green light on y1 it means either the cs8416 has a bridged connector or you are getting a correct signal from the EMU. If you can get a red light also from another source selection, and green from the emu, then it means the emu signal is being received and the cs8416 has successfully locked.


----------



## slowpogo

Quote:


  Originally Posted by *thoppa* /img/forum/go_quote.gif 
_Hi,

 I've had similar problems. I reflowed CS8416 several times to get the y1 working. If you're getting anything other than 3.3V then the reg isn't working - it might need reflowing or replacing. Check the voltages on pins 1 and 5 - in and out - and pin 3 - start - which is shorted to pin 1. Check the circuit diagram to make sure I've got this right _

 

That was all it needed - I reflowed the regulator, and all is good, MUSIC!!!

 EDIT: OK, it was working like a dream for about 20 minutes. But now I'm getting intermittent bursts of static followed by a high whine. I'm guessing this is some kind of connectivity issue between the y1/y2 boards? I've tried kind of pressing on the boards, or rocking them, in case they are not quite connecting somehow, but it doesn't help.

 Hope to get this resolved quickly - it was sounding fantastic


----------



## jarpatus

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_That was all it needed - I reflowed the regulator, and all is good, MUSIC!!!

 EDIT: OK, it was working like a dream for about 20 minutes. But now I'm getting intermittent bursts of static followed by a high whine. I'm guessing this is some kind of connectivity issue between the y1/y2 boards? I've tried kind of pressing on the boards, or rocking them, in case they are not quite connecting somehow, but it doesn't help.

 Hope to get this resolved quickly - it was sounding fantastic 
	

	
	
		
		

		
		
	


	


_

 

I had similar problems, first it worked like a charm but then most weirdes pitching whine, cracks pops etc. and finally led went red first for seconds then for minutes etc. Turned out it was flux. I had cleaned the boards using isopropyl alcohol but it was not enough, somehow there were still enough left to short circuit stuff.

 So try to clean you boards again very carefully? I actually submerged whole boards to pure ethanol to get everything off but that's not probably recommended as connectors and switches probably will suffer no matter how well you dry them. Next time I do throughout cleaning BEFORE soldering connectors and switches


----------



## thoppa

I've had crackle then silence from the y1/y2 join - it was the iis connections. I desoldered them and reworked the connections and all was fine.

 I don't use flux.


----------



## slowpogo

I did a thorough cleaning of the boards, with an alcohol/acetone mixture...fingers crossed, but the static/whine is gone, and has been playing beautifully for a while now. 
	

	
	
		
		

		
		
	


	




 EDIT: OK, now it's back again. thoppa, what are the "iis" connections?


----------



## Beefy

Acetone? Yikes! Considering that acetone dissolves many plastics, using it is an extraordinarily bad idea......


----------



## slowpogo

acetone also comes in a plastic bottle 
	

	
	
		
		

		
			





 Apparently, this is a common mixture people use to clean PCBs, just google "homemade flux remover." The main ingredients in commercial flux remover are alcohol and acetone, so it's tried and true, and safe. There's absolutely no visual difference (other than clean of flux) to my board or plastic parts after using it. And, it works better than isopropyl alone.


----------



## nattonrice

Yup and they tend to make the flux tacky and annoying imo.
 I find that isopropyl and a toothbrush works much better than any off shelf flux remover.


----------



## Beefy

Quote:


  Originally Posted by *nattonrice* /img/forum/go_quote.gif 
_I find that isopropyl and a toothbrush works much better than any off shelf flux remover._

 

I agree. In the medical device half of my lab they only ever use isopropanol because of the damage that acetone can do.

 Never mind the OH&S considerations of acetone.


----------



## mace1337

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_EDIT: OK, now it's back again. thoppa, what are the "iis" connections?_

 

He probably means I2S


----------



## amb

Acetone could wash the markings off some parts, such as certain electrolytic caps.


----------



## slowpogo

I think my TREAD might be my problem. I was worried that it might be overheating - I have it housed in a Radio Shack project box with toroidal, IEC input, etc. Even with ventilation holes the box was getting quite warm, and always after 10-20 minutes was when the static/whine problems would start; whenever it hissed with static, the green switch would dim slightly, so I theorized that was when the LM317 began to overheat.

 I've run the y2 on USB power for over an hour with no problems, so that seems to confirm the TREAD was the issue.

 I ended up drilling a bunch more holes in my PSU box, right above the TREAD, for ventilation. Now there are 30 holes in a tight pattern (using the big Dremel bit, I think it's around 1/8"). Seems like there should be plenty of ventilation now, but when I switch over to the TREAD, after 10-20 minutes the problems are back...only the area immediately around the holes is warm now (as expected) rather than a big portion of the box.

 What might cause the TREAD to malfunction after a short time period, apart from overheating?

 Also, what are people's experience with burn-in? I'm using SilmicII and Nichicon ES caps - from my experience these require burn-in, as do the Wimas. Has anyone experienced the sound opening up after a certain time period? (It sounds great as it is, I'm just curious if I can look forward to even better things)


----------



## slowpogo

UPDATE: I had both USB and the TREAD psu plugged into the y1+y2. I turned the TREAD on and off a few times (not rapidly, like 1-2 seconds between) to see if I heard a difference when the USB took over. After I did it maybe the third time, there was a whine and static; now there is NO music, no sound at all.

 The USB board voltages still measure fine. But the y1 DAC board voltages are screwed up now... the 3.3v test point has an unstable read of 2.95-2.99, the 4.5v point reads a steady 2.99.

 Uh-oh. I imagine I fried a part somehow...?


----------



## nattonrice

Sounds like you may have damaged the power multiplexer.
 Similar things happened when I left my wallwart near my feet...


----------



## ShinyFalcon

How are the voltages on the y2? Is the 5V line stable on the y2 and the y1 (use y2's J1's VCC/VBUS, and y1's JP2D's pin 2 (center))? The 2.99V reading on both regulators looks like the 5V line is sagging when it gets to the y1.


----------



## K3cT

I'm not sure this is an issue or not but I thought I'd ask anyway.

 The automatic power switching between USB and DC power behaves quite strangely in a certain condition. Usually, I plug the USB cable first before plugging the DC cable from Sigma 25 and all is well here, the Gamma 2 is still recognized, there is no interruption to the music and I can unplug and plug the DC cable no problem. 

 However, if I start up the Gamma 2 in reverse ie. plugging in the DC cable first before the USB, I found out that I will get an error if I unplug the DC cable afterwards. The device is still recognized but the LED goes red. Replugging the USB cable will make it work again. 

 Is this normal?


----------



## ShinyFalcon

Here's an example of what's happening. The USB line is at 4.92V. At this moment, the PCM2707 and the CS8416 is happy. Plug in the PSU, and the voltages jump to 5.01V, and they are both still happy. If you do it in reverse, the voltage is at 5.01V, and the mux give the PSU priority. If you removed the PSU, the PSU shuts off but the capacitor still has charge. This will bring the voltage down to 3V volts, at which point both chips' digital section stop working because the voltage is too low.The mux kicks in the USB power, and both chips restart, but the lock with the computer will be lost.  If you used coaxial or optical, you probably would notice a short discontinuity in the music but the music should still go on.

 Edit: Sorry, I'm confusing myself. I don't know why it happens when you simply unplug. The grey portion above only applies if your PSU has a switch, and mines does.


----------



## MisterX

K3cT: 
 What are the numbers on the resistor you have installed in the R4U position? 
 (the low USB voltage you described earlier combined with the switching behavior you just described have me thinking you might could have the wrong value there)


----------



## K3cT

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_K3cT: 
 What are the numbers on the resistor you have installed in the R4U position? 
 (the low USB voltage you described earlier combined with the switching behavior you just described have me thinking you might could have the wrong value there)_

 

Thanks, Marshall. I hope I got the right numbers for you: J50C 4752 F752. This is the Mouser # if it helps: 71-RN50C-F-47.5K.


----------



## slowpogo

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_How are the voltages on the y2? Is the 5V line stable on the y2 and the y1 (use y2's J1's VCC/VBUS, and y1's JP2D's pin 2 (center))? The 2.99V reading on both regulators looks like the 5V line is sagging when it gets to the y1._

 

J1 VCC/VBUS to Gnd measures 2.90v. JP2D pin 2 to Gnd is 2.69v. Pin 7 of the power muxer (OUT) measures same as 3.3v test point, fluctuating between 2.95-2.99.

 If the power muxer is indeed shot (seems that way) I will order another one ASAP. But in the meantime, the project notes say this part can be eliminated if you plan to use only USB power. Is there a way I can temporarily achieve this (USB power only) for now, so I can enjoy the y2 while I wait for new parts?

 Dagnabbit...also, the original problem I was trying to address is that USB power worked fine for long periods, but when using external power (in my case a TREAD with toroidal) after about 15 minutes I would get intermittent static/digital whine. I was thinking the TREAD might be causing this, but could it be that the power muxer or some other part on the y1 was damaged all along, and the static was a precursor to its failure (meaning the TREAD is actually fine)?


----------



## amb

If your VBUS is not showing ~5V then something is not right. I don't know what you did, but try rebooting your computer.


----------



## ShinyFalcon

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_J1 VCC/VBUS to Gnd measures 2.90v. JP2D pin 2 to Gnd is 2.69v. Pin 7 of the power muxer (OUT) measures same as 3.3v test point, fluctuating between 2.95-2.99._

 

Let's measure JP2D's pin 1 and pin 3 with everything plugged in. Also measure your USB board's VBUS. Pin 1 of JP2D (square) measures your TREAD's voltage, and pin 3 measures VBUS, your USB's power. I'm looking for two VBUS measurements because I'm thinking the contacts aren't making proper connection with your boards. If one of the inputs is 2.9V, then it would mean the power section of either your TREAD or your computer is bad.

 If you want to use USB power, you can just jumper JP2D accordingly. You won't have to remove the mux, just don't plug in the TREAD. Don't do anything yet until we get new measurements.


----------



## slowpogo

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Let's measure JP2D's pin 1 and pin 3 with everything plugged in. Also measure your USB board's VBUS. Pin 1 of JP2D (square) measures your TREAD's voltage, and pin 3 measures VBUS, your USB's power. I'm looking for two VBUS measurements because I'm thinking the contacts aren't making proper connection with your boards. If one of the inputs is 2.9V, then it would mean the power section of either your TREAD or your computer is bad.

 If you want to use USB power, you can just jumper JP2D accordingly. You won't have to remove the mux, just don't plug in the TREAD. Don't do anything yet until we get new measurements._

 

Pin 1 of JP2D: ...is weird. It first measured 4.95v, but then as I was watching, the voltage started slowly going down until about 4.7v - a few seconds later I measured again, and it was dropping rapidly, ending up around 3.7v. I measured again after waiting 5 minutes, and it was back up 4.95v, then started dropping, the same behavior. 

 But then I waited several minutes, a second time, to see if the behavior repeated, and that time it was still down at 3.7v - it did not jump back to 4.95 like it had previously.

 I will mention, however, that when measured directly from the DC plug, the TREAD voltage remained exactly 5.00v, all the time, even as Pin 1 was getting lower.

 Pin 3 of JP2D: 5.05v

 The 5.0v test pad next to VBUS on the USB board measures the same as Pin 3 above, 5.05v. But the other 5.0v test pad (next to VCC on USB board) - AND the 3.3v test pad above it - BOTH measure 2.4v.


----------



## ShinyFalcon

Some more things to measure:
 - Measure the voltage before and after the ferrite L4D
 - Check resistances of R14-16D
 - Make sure all pins of JP2D are not shorted to ground (resistance should be high)

 Does your y2 work fine if you use either USB or TREAD only? If not, you can jumper JP2D for USB power only and see if it works. For now, your TREAD is probably not the problem.


----------



## slowpogo

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Some more things to measure:
 - Measure the voltage before and after the ferrite L4D
 - Check resistances of R14-16D
 - Make sure all pins of JP2D are not shorted to ground (resistance should be high)

 Does your y2 work fine if you use either USB or TREAD only? If not, you can jumper JP2D for USB power only and see if it works. For now, your TREAD is probably not the problem._

 

1. voltage on either side of ferrite is 4.95v
 2. R14-16D are color-coded correctly, though when measured in the board they read 23.2k, 23.2k, and 1.2k, respectively.
 3. JP2D pad 3 measures high resistance, 1 and 2 measure around 30 ohms

 USB plugged in alone: when first connected to USB the source switch turned on green (coax source plugged in), and there was hissing and whining. Then, the switch went to red and there was a constant droning sound.

 TREAD plugged in alone: switch turns on red, absolutely no sound at all

 When JP2D is jumpered for USB power only, it works perfectly.


----------



## ShinyFalcon

Do you have the SPDIF out on the y1 populated? Keep the y1 and y2 separated and powered separately, and connect their opticals or coaxials together. I think you may need to connect USB's VCC And VBUS temporary, but I won't force you to do it. 

 Did you measure the JP2D measurements while it was on? I wanted unpower measurements, but was the TREAD plugged in at this time?\]

 Edit: One thing that bothers me. Since both your TREAD and USB's voltage are so similar, I think it may also be a source of your problem. The mux might be oscillating between DC and USB input. Bring the TREAD's voltage to 5.1V , but no more than 5.5V, remove the jumper at JP2D, and see what happens when you plug them both together at the same time.


----------



## slowpogo

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_Do you have the SPDIF out on the y1 populated? Keep the y1 and y2 separated and powered separately, and connect their opticals or coaxials together. I think you may need to connect USB's VCC And VBUS temporary_




Did you mean keep the y1 USB and DAC boards separated and powered separately? I did this, and connected coax out on the USB board to coax in on the DAC, used the y1 3.5mm output - and it works fine. (the y2 was sitting on the other side of the desk for this) The TREAD apparently works great in this scenario.

  Quote:


 Did you measure the JP2D measurements while it was on? I wanted unpower measurements, but was the TREAD plugged in at this time? 
 

The measurements I gave were unpowered, nothing plugged in.

  Quote:


 Edit: One thing that bothers me. Since both your TREAD and USB's voltage are so similar, I think it may also be a source of your problem. The mux might be oscillating between DC and USB input. Bring the TREAD's voltage to 5.1V , but no more than 5.5V, remove the jumper at JP2D, and see what happens when you plug them both together at the same time. 
 

I bumped the TREAD power up to 5.25v, then connected everything (y1 + y2, USB and TREAD, coax input). When I first plugged in USB, it gave a warbly analog-synth-sounding drone, switch was red. Then when I turned on the TREAD in addition to this, the switch turned green for about half a second, then went red, and there was a static hiss with some faint whining.

 EDIT: Just for giggles I tried jumpering JP2D for external power only, and attached the y2 and used its output. At first it worked perfectly, but after 20 seconds or so it reverted to red switch hissy-fit mode.


----------



## amb

The power mux won't oscillate between the two power sources. Preference is given to external power if both are present. The switching threshold has hysteresis to prevent oscillatory behavior.


----------



## slowpogo

It looks like maybe ShinyFalcon is only a weekend headfi-er...in the meantime if anyone else has some insight on my build, here is what I can gather:

 -although voltages do not measure correctly on either the y1 USB or DAC boards, when they are powered separately and left unbridged, but connected from the USB board coax output to the DAC coax input - y2 not connected - it seems to work fine
 -when jumpered for USB power only, the y1+y2 combo works fine

 Basically, any time external power is thrown in the mix, things go awry - unless the y1 DAC is kept totally isolated (the first scenario above). The y1 DAC plays with itself just fine, but does not like to play with others. I might guess it is an issue with the bridge pins, but they all show continuity when the boards are connected.

 All parts are correct and in the right place - so it seems the only explanation is a damaged part at this point. Especially considering that everything worked fine at first, then problems gradually started appearing, and then failure. I will try to reflow joints another time but they all look good and show continuity..

 I would like to be able to use my TREAD, as I did notice a (slight) sound improvement over USB power...


----------



## thoppa

The first thing I'd try is an external power source other than the Tread. Have you got a usb cable you can cut in half/the end off ? Use the black and red wires from that to hook up to a suitable power connector so you are providing a regulated 5V (that you know works) through the external power connector ? This'll test whether it is the Tread or the input circuit that is to blame. 

 BTW, my mux has never worked. I dunno why - all connections test fine - so I have to use a jumper to get the y1 board to work. It doesn't matter for me so I haven't bothered to debug this. I suspect the chip. Maybe it got some electrostatic charge and is dead.... 

 Check the jumpers - I can't remember which but they set things like i2s or spdif output from the usb y1. So check all of them. It could be a simple 'wrong jumper'. For the i2s and spdif connections, I'd double check it is connected up right first of all because if the coax-coax works, then so should the i2s/spdif. If that is all okay, then check and perhaps reflow all the i2s/spdif connections in the circuits on both boards. A real pita but that's what I'd do. I'd pay special attention to the ground plane connections cos for me, I had to use quite a lot of heat and 'high-flow' solder to ensure a good connection. (I've got 3 types of solder - cheap bulk stuff, some finer stuff that flows much better, and a little bit of silver stuff for quality-critical things like headphone plugs).

 You have my sympathy - I hate debugging - but when it does finally work, oh man, the joy.....and in the meantime it's proof of your immeasurable patience and persistence right ?


----------



## amb

slowpogo, is the LM317 in your TREAD getting very hot? What transformer are you using to power the TREAD? The current consumption of the γ1+γ2 combo is not insignificant, if you're asking the LM317 to drop too much voltage, it may be dissipating enough heat to get into thermal shutdown.


----------



## slowpogo

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_slowpogo, is the LM317 in your TREAD getting very hot? What transformer are you using to power the TREAD? The current consumption of the γ1+γ2 combo is not insignificant, if you're asking the LM317 to drop too much voltage, it may be dissipating enough heat to get into thermal shutdown._

 

amb, I am using this transformer, recommended by someone in this thread a ways back:

MULTICOMP|MCFM70/09|Miniature Toroidal Transformer | Newark.com

 Its specs check out, as far as I am aware. Also, the little holes in the case that you can see, are NOT the only ventilation holes...there are like 30 larger holes on the top.


----------



## slowpogo

Quote:


  Originally Posted by *thoppa* /img/forum/go_quote.gif 
_The first thing I'd try is an external power source other than the Tread. Have you got a usb cable you can cut in half/the end off ? Use the black and red wires from that to hook up to a suitable power connector so you are providing a regulated 5V (that you know works) through the external power connector ? This'll test whether it is the Tread or the input circuit that is to blame. 

 BTW, my mux has never worked. I dunno why - all connections test fine - so I have to use a jumper to get the y1 board to work. It doesn't matter for me so I haven't bothered to debug this. I suspect the chip. Maybe it got some electrostatic charge and is dead.... 

 Check the jumpers - I can't remember which but they set things like i2s or spdif output from the usb y1. So check all of them. It could be a simple 'wrong jumper'. For the i2s and spdif connections, I'd double check it is connected up right first of all because if the coax-coax works, then so should the i2s/spdif. If that is all okay, then check and perhaps reflow all the i2s/spdif connections in the circuits on both boards. A real pita but that's what I'd do. I'd pay special attention to the ground plane connections cos for me, I had to use quite a lot of heat and 'high-flow' solder to ensure a good connection. (I've got 3 types of solder - cheap bulk stuff, some finer stuff that flows much better, and a little bit of silver stuff for quality-critical things like headphone plugs).

 You have my sympathy - I hate debugging - but when it does finally work, oh man, the joy.....and in the meantime it's proof of your immeasurable patience and persistence right ? _

 

Thanks for the advice - I think I have an old USB around somewhere. And I'll check the jumpers and other connections.

 I actually had my "eureka" moment once already, where it worked like a dream for 20 minutes with external power...at least, I am actually being quite patient with this process, more so than in the past. I guess it gets a little easier with each project.


----------



## MisterX

How are the secondaries connected to the tread?


----------



## amb

slowpogo, I am not sure from the angle of your photo but looks like you wired your transformer secondaries in series (red and orange wires go to the TREAD, and the yellow and black wires are connected to each other). This means you have 18V+ AC before rectification, which ends up at least ~26V DC before the LM317. Since the LM317 is set up to output 5V, then it has to drop 20V+. If the y1+y2 boards are drawing 200mA+ of current, then the power dissipation will be at least (20V * 0.2A) = 4W. That's a lot of heat for the little heatsink you have on there, particularly in an enclosed box (even with those little holes you added).

 You should re-wire the transformer secondaries in parallel. I.e., red+yellow wires go to one input of the TREAD, and the black+orange wires goes to the other input.


----------



## slowpogo

yes, it is wired in series. But, I just did thoppa's test, using a USB into the external power section, and it was the same story. By one viewpoint would that not suggest the Tread is not the problem?

 Or could both be the problem...at first, it worked several minutes before getting strange, now it doesn't work at all. Maybe the Tread was having difficulty, at the same time a part like the mux was failing?


----------



## ShinyFalcon

You did mention that the first couple of pins or so on the SRC4192 all showed continuity with each other, and that is especially concerning. If these did show continuity, it might explain why you're not getting any music. Did you hear the hiss/warbling/bloop on both outputs?

 - Check y2's JP2 and see if any of them are shorted to each other
 - Check y2's R1 and y1's R7D. You should get four separate 68 ohm readings (pins 1 & 2, 3 & 4, etc should read 68 ohms)


----------



## amb

Pick up your DMM and start measuring voltages before and after the power mux chip. Use the schematic diagram, it should be fairly evident where to measure.


----------



## MisterX

Quote:


 Maybe the Tread was having difficulty, at the same time a part like the mux was failing? 
 

More likely the transients fried the mux when you did the thing with the switch. 
	

	
	
		
		

		
			





  Quote:


 I turned the TREAD on and off a few times (not rapidly, like 1-2 seconds between) to see if I heard a difference when the USB took over. After I did it maybe the third time, there was a whine and static; now there is NO music, no sound at all.


----------



## ShinyFalcon

slowpogo, did you ever put up pics of your y1/y2?


----------



## fierce_freak

Given more room to work with than the default case, what would be the best place to cut traces and wire a pot in for volume control (and is it a bad idea)? After the low pass filters?


----------



## amb

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_Given more room to work with than the default case, what would be the best place to cut traces and wire a pot in for volume control (and is it a bad idea)? After the low pass filters?_

 

A pot at the output would raise impedance and cause the signal to be subjected to interference and stereo crosstalk down the interconnect cable. If you want a volume control, then you should add another buffer stage after it (before the signal goes out to a cable). But why do that when you could just connect the DAC to an amp (with a volume control)?


----------



## fierce_freak

I'll probably end up going that way, but I was considering just using the built-in output stage as amp for my IEMs.


----------



## zxc

Hi. I just finished a Gamma-1 last weekend. I was getting the parts for Gamma-2 from Mouser, and they are out of OPA2365AID... Any idea where I can get one, with reasonable shipping costs?


----------



## MisterX

eBay? 
OPA2365 Dual OpAmp 50MHz Low Noise 2.2V Amp (x2) - eBay (item 170436649364 end time Mar-25-10 00:10:57 PDT)


----------



## zxc

Awesome. Thanks.


----------



## slowpogo

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_You did mention that the first couple of pins or so on the SRC4192 all showed continuity with each other, and that is especially concerning. If these did show continuity, it might explain why you're not getting any music. Did you hear the hiss/warbling/bloop on both outputs?

 - Check y2's JP2 and see if any of them are shorted to each other
 - Check y2's R1 and y1's R7D. You should get four separate 68 ohm readings (pins 1 & 2, 3 & 4, etc should read 68 ohms)_

 

Those were solder bridges (invisible, basically) on the SRC4192, which I was able to remedy. No adjacent pins of my SMD chips show continuity anymore, except a few cases where they are supposed to.

 -none of y2's JP2 are shorted to each other
 -both those resistor networks measure properly (all within 0.2 ohms of 68)


----------



## slowpogo

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Pick up your DMM and start measuring voltages before and after the power mux chip. Use the schematic diagram, it should be fairly evident where to measure._

 

First off, I did wire my transformer to the Tread in parallel. It didn't change any behavior, but sounds like it will be better for when things are working. Also, there are now a bunch of ventilation holes on top of the PSU enclosure, like 30 big ones - plenty of airflow now, probably overkill.

 I did measure the power mux chip with the Tread plugged in, and the y1 halves unbridged (the only way I can actually get at the chip to test it while powered). 

 - Pin 8 (IN1) shows 5.18v - Tread is set at 5.2v right now
 - Pin 6 (IN2) shows 0.3v (shouldn't it be 0 without any USB power?)
 - Pin 7 (OUT) shows 3.5v (shouldn't it be the same as the "dominant" power source, in this case 5.18v?)

 The y1 DAC 3.3v test pad reads exactly 3.3v. The 4.5v test pad reads exactly 3.5v


----------



## slowpogo

Quote:


  Originally Posted by *ShinyFalcon* /img/forum/go_quote.gif 
_slowpogo, did you ever put up pics of your y1/y2?_

 

Sorry for the shadows, outdoors is the only place I can get enough light for my aging camera:


----------



## amb

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_- Pin 8 (IN1) shows 5.18v - Tread is set at 5.2v right now_

 

OK.

  Quote:


 - Pin 6 (IN2) shows 0.3v (shouldn't it be 0 without any USB power?) 
 

0.3V is close enough to 0 -- there may be some residual.

  Quote:


 - Pin 7 (OUT) shows 3.5v (shouldn't it be the same as the "dominant" power source, in this case 5.18v?) 
 

Yes, or very close to it -- the in-chip MOSFET will drop a small amount of voltage but it should not be significant.

 Seems like your power mux had gone bad.


----------



## m1abrams

slowpogo - It is hard to tell from the photo but it looks like you have some long leads on that board. You should clip those short because you may short them with the case.

 On the y2 chip U4 double check the pins 10,11,12 it appears you may have a bridge there.

 Not that this has anything to do with you problem but how did you solder mask get so cut up?


----------



## slowpogo

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Seems like your power mux had gone bad._

 

OK. I will order a replacement. Does it seem plausible that replacing the mux could basically fix all issues?


----------



## MisterX

Quote:


 Does it seem plausible that replacing the mux could basically fix all issues? 
 

It's easy enough to test. 
	

	
	
		
		

		
			




 Remove the existing U1D, install a temporary jumper between JP2D holes 1 and 2 (this "hardwires" the DC jack as the only power input). 
 If everything is good you found the problem.


----------



## slowpogo

Quote:


  Originally Posted by *m1abrams* /img/forum/go_quote.gif 
_slowpogo - It is hard to tell from the photo but it looks like you have some long leads on that board. You should clip those short because you may short them with the case.

 On the y2 chip U4 double check the pins 10,11,12 it appears you may have a bridge there.

 Not that this has anything to do with you problem but how did you solder mask get so cut up?_

 

Thank you...I clipped all leads to the board. I also checked and there is a bridge between 11-12, and a real tricky person at that.

 At times I used a very small solder tip (0.5mm) which didn't actually work very well to solder the SMD chips, but was able to get between the pins and sweep out bridges. It was also sharp enough to cut the board - I think that is where a lot of that came from.


----------



## slowpogo

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_It's easy enough to test. 
	

	
	
		
		

		
		
	


	



 Remove the existing U1D, install a temporary jumper between JP2D holes 1 and 2 (this "hardwires" the DC jack as the only power input). 
 If everything is good you found the problem._

 

I did just that, and - YES - it works! Fingers crossed, that it doesn't start acting up later...

 Only one thing bothers me...I went to work on pins 11-12 of the src4192, as they showed continuity with each other. I worked on them enough that I really cannot see any possible solder bridge, even under a mag. glass (they look exactly like other non-continuous pairs), but they still show continuity.

 YET - the thing seems to work fine.

 On the data sheet these are identified as IFMT1 and IFMT2 - Input Port Data Format Control Inputs. Is there any way these are supposed to be connected? If not then why does it work when they show continuity? I am not seeing an overall schematic like other data sheets have, and do not know enough to be able to tell this...


----------



## MisterX

http://www.amb.org/audio/gamma2/gamma2_v100_sch.png
http://www.amb.org/audio/gamma2/gamma2_v100_pcb.png

 Check either the schematic or the PCB layout and you may note that pins 11 and 12 of U4 should be connected to each other (through the ground plane).


----------



## slowpogo

Thanks MisterX.

 Well, it's been going strong all night - I think it's all good now. I ordered a new power mux, as well as replacements for the parts I melted while reflowing the ICs...I know they still function and it doesn't matter, but I don't like the thought of the y2 looking that way, even inside the case. 
	

	
	
		
		

		
		
	


	




 Thanks everyone for coming through and helping me debug quickly - I also learned some things in the process. Headfi-ers are a solid bunch. 
	

	
	
		
		

		
		
	


	




 Been listening to Ravel/Debussy String Quartets - John Coltrane - Crowded House - Radiohead - all sounds amazing!!! And a definite step up from the Emu 1212m, which I already thought sounded pretty great. Happy.


----------



## ujamerstand

I've been listening to the gamma-2 for several days now. I've also been making periodic readings of the various voltage points, and everything seems to be operating within the specified parameters. The voltage output from my computer is not in spec though; it is outputing 4.67V as oppose to 5V. I will need to get that sigma25 hooked up soon... Other then that, initial listening impression is good. I usually doubt it when my tin ears seems to be hearing any difference, but holy crap, is that recording noise in one of my favourite songs?!


----------



## linuxworks

do you have good usb cables going directly to the computer's usb port?

 sometimes thru a hub, you get less than 5. sometimes powered hubs work well.

 I've noticed a few tenth's of a volt diff from a long cheap usb cord to a shorter nicer one. but nicer, I still mean below $10 for the cord; but just nicely made and not ultra thin.


----------



## ujamerstand

Its a nice short cord, going directly to the mobo. I'd think Corsair power supplies shouldn't have this kind of problems, apparently not. Oh well, I've got that sigma25 running, just need to find that damn molex pin; I completely forgot where I put it. -_-

 Edit: I've completely forgotten about fuse! How could I have forgotten about fuse? Will need to drop by the local electronic shop tomorrow for some 500mA slow-blows.


----------



## tucsonmike

so i bent a pin using desoldering braid, argg!
	

	
	
		
		

		
		
	


	




 fixed it and have continuity between a couple pins and wanted to make sure it should be like this.

 i have continuity between pins 16/17, and 17/18.

 is this supposed to be like this?
	

	
	
		
		

		
		
	


	




 thanks for the help!


----------



## amb

tucsonmike, a look at the schematic would have given you the answer.


----------



## tucsonmike

Yeah, sorry about that. I did look, but wasn't sure. You're proly tired of the dumb noob questions by now.

 So, i'm going to assume its all good since the arrows in the schematic are touching. As you can tell i'm not well versed in the realm of schematic reading.

 thanks for a great product.


----------



## amb

It's not the fact that they "touch" that matters. The little triangle symbol means "ground" so all those pins you mentioned (and some others too) connect to the board's ground plane.


----------



## tucsonmike

It makes sense now.


----------



## tucsonmike

Hey Ti, i accidentally put in R2 backwards, and broke it pulling it out.

 I was wondering if you have a part number for r2?(resistor network SIP-8 isolated 68Ωx4)

 cant seem to find it using the search box.

 looking to order from digikey.
 thanks, -mike

 edit: will this work?
 4308R-2-680LF-ND
 from digikey


----------



## m1abrams

Quote:


  Originally Posted by *tucsonmike* /img/forum/go_quote.gif 
_Hey Ti, i accidentally put in R2 backwards, and broke it pulling it out.

 I was wondering if we could set something up so i could order another from you.

 I tried going through the site, but it would be almost $9 for this .25 piece cause of shipping.

 Thanks for the help, -Mike_

 

How do you install a resistor backwards?


----------



## tucsonmike

Quote:


  Originally Posted by *m1abrams* /img/forum/go_quote.gif 
_How do you install a resistor backwards?_

 

The pin marker, which is a circle, goes to the square pad.
 I put it in opposite because r1 is opposite direction from r2, and didn't catch it until it was too late.
 i'm assuming it matters since it was described in the instructions.


 anyway, will this work for R2? 4308R-2-680LF-ND -from digikey


----------



## amb

R2 is a resistor network, which, depending on its type (bussed or isolated), may require a specific mounting orientation (or not). You're in luck, in this case, because R2 is isolated, so you're ok. Be careful about the 47K resistor networks on the γ1 board, though. Those are bussed and _must_ be oriented correctly.


----------



## tucsonmike

Thanks, AMB.

 I already broke it.

 Will this replacement work, it's from digikey.

 4308R-2-680LF-ND


----------



## amb

Yes, that would work fine.


----------



## tucsonmike

Thanks


----------



## ujamerstand

Man, I must be cursed. After coming home from work today I sat down to have a nice listening session with my y-2. To my surprice there was static noise coming out from y-2's output. The noise is not unlike the symptoms of a cold joint. The noise is present in both channels, and it is present from the l and r test points. So I'm guessing its either the DAC or the upsampling chip. Sigh, time to reflow those joints.

 Edit: what seemed to be a simple problem has escalated into a bigger one. Now I am experiencing static AND dropouts. So far, I've determined that a) the I2S pin is well connected. b) the static noise occurs independent of the security of I2S pin between y-1 and y-2. c) the voltage readings of y-2 during the dropout are within the range of operation. @ 3.28V and 4.60V respectively. d) all the ground connections have no cold joints. e) there are no solder bridge between pins of the DAC and upsampling chip, unless they are connected on the schematics. I am suspecting the SMD clock right now, because its rather hard to solder, and I was afraid that I might have connected the pins together through the top plate. Turns out there are no solder bridges; but I'm afraid I might've screw it up anyways. -_- The static and dropoffs comes on and off every now and then, the pattern seems to be completely random. As I said, its independent of how hard I try to ensure the I2S pins are connected. Just when I thought I am done with this project once and for all... 
	

	
	
		
		

		
			





 cold joint cold joint where are you >:[


----------



## K3cT

I notice that sometimes I will experience random dropouts and/or static noise when I connect my amplifier to the y2. I noted several things regarding this issue:
The dropout/static occurs with both y1 and y2 outputs and with both USB and external power.
It's not an amplifier issue because I tested with another source and it's working perfectly. It's not an interconnect issue either.
The dropout occurs when I make the RCA/mini connector touches the inner metallic part of the respective jacks.
Wiggling the jacks seem to cure the static issue while replugging the USB cable will cure the dropout.
When the dropout occurs, the device is still detected with the computer.
This "issue" happens quite rarely but still, I'm not satisfied until I have a completely working result. What could be the case here?


----------



## Beefy

Quote:


  Originally Posted by *K3cT* /img/forum/go_quote.gif 
_This "issue" happens quite rarely but still, I'm not satisfied until I have a completely working result. What could be the case here? 
	

	
	
		
		

		
		
	


	


_

 

Are you using USB as the source? I find that when using USB I get similar dropouts, caused by the computer. No matter how much I buffer in my playback software or ASIO, I still get the occasional pop. It was the same with my old Corda 2Move.

 It is worse at home than at work, which I think is because I use wireless at home that requires more CPU cycles.


----------



## linuxworks

again, I keep suggesting this because it worked for me.

 the pin headers NEED to be perfectly straight. actually, so do the female sockets but you can't change those once they are in. the male headers can be bent with your fingers to make them perfectly straight. often, this can be a cause of intermittant problems. the fix worked twice for me.

 open the 2 pc board halves and look down with your eye to see if all the pins are exactly (very exactly) straight inline. bend some left and right to get them all in a perfect row. try that.


----------



## Horio

So I finished building my gamma1 Full++ and gamma2. I cleaned up the flux, checked for shorts per the instructions, and then plugged the two together and connected/powered via the USB. The computer recognizes and powers the DAC correctly. I measured the voltages at the test locations, and they all check out except for the 4.5V on the gamma2. I am getting around 1.95V there for some reason. I double checked U1 and it looks like I have the correct voltage regulator in there (the Texas Inst TPS unit). Has anyone run across this issue, or have an idea what the issue may be?

 The unit plays music but there is a significant amount of interference/static.

 Thanks for the help.

Gamma1 Picture

Gamma1&2 Wiring


----------



## amb

Did you try reflowing U1's solder joints? Also, what are the markings on U1?


----------



## Horio

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Did you try reflowing U1's solder joints? Also, what are the markings on U1?_

 

The markings on U1 are PHJI which matched the website (first thing I checked after the odd voltage measurement). I'll try reflowing the joints for grins as soon as I get home.

 You think this could be the culprit for all the noise in the outputs? I was thinking the air-wiring may be part of the noise issue as well.


----------



## MisterX

What kind of noise? 
 Operating the op-amp and output stage in the DAC at 1.95V would explain clipping and major distortion but I'm not sure I would label that as noise. 
 I would suggest reflowing U5 while you are at it.


----------



## Horio

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_What kind of noise? 
 Operating the op-amp and output stage in the DAC at 1.95V would explain clipping and major distortion but I'm not sure I would label that as noise. 
 I would suggest reflowing U5 while you are at it. 
	

	
	
		
		

		
			



_

 

The noise is not a buzzing or screeching sound, but more like distortion. If I pick it up and move it at all it gets a little worse or changes a little. Not sure how to explain it exactly.

 I'll see if reflowing U1 does the trick first, before I mess with U5 (that thing was a pain first time around).


----------



## Horio

Reflowing the U1 joints seems to have done the trick. I'm now getting 4.75V as expected. Some nice sound coming out of this DAC into my Audio-GD Phoenix.

 I think the noise I am getting is related to the bee's nest of temporary wiring and the fact I have everything sitting on the ground right now. If I move the RCA connectors around just right, the noise goes way down.

 Good work AMB! I look forward to comparing this DAC to my PS Audio DLIII. Like what I am hearing so far.


----------



## K3cT

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_Are you using USB as the source? I find that when using USB I get similar dropouts, caused by the computer. No matter how much I buffer in my playback software or ASIO, I still get the occasional pop. It was the same with my old Corda 2Move.

 It is worse at home than at work, which I think is because I use wireless at home that requires more CPU cycles._

 

Yeah, I'm using USB. I see... if it's the computer then I guess I'll have less to worry about. BTW, is that a laptop or desktop, Beefy? 

 Thanks anyway, Beefy. 

  Quote:


  Originally Posted by *linuxworks* /img/forum/go_quote.gif 
_again, I keep suggesting this because it worked for me.

 the pin headers NEED to be perfectly straight. actually, so do the female sockets but you can't change those once they are in. the male headers can be bent with your fingers to make them perfectly straight. often, this can be a cause of intermittant problems. the fix worked twice for me.

 open the 2 pc board halves and look down with your eye to see if all the pins are exactly (very exactly) straight inline. bend some left and right to get them all in a perfect row. try that._

 

Actually, I just opened it up and I see that the VBUS male pin is ever so slightly bent. It's a very small indentation though but I'll try to straighten it up. Thanks for the heads-up, linuxworks.


----------



## tucsonmike

I'm kind of having the same issues here,

 I just finished the y1 full/y2, and it sounds great, but...

 i have a low level hum when using the 24/25 as a power source. Power levels at test points are way low. I verified 5.01v coming from ps.

 The hum and low voltage levels resolve themselves when i use usb as a power source. All test points are accurate at this point.

 Could you guys point me in the right direction? I'd like to use my 24/25 power supply.

 Thanks!


----------



## Beefy

Quote:


  Originally Posted by *K3cT* /img/forum/go_quote.gif 
_Yeah, I'm using USB. I see... if it's the computer then I guess I'll have less to worry about. BTW, is that a laptop or desktop, Beefy?_

 

Laptop. I generally listen while working, so often have many programs open at the same time.


----------



## kunalraiker

Would someone build one for head-fiers


----------



## steven2992

You should ask MisterX


----------



## amb

Quote:


  Originally Posted by *tucsonmike* /img/forum/go_quote.gif 
_i have a low level hum when using the 24/25 as a power source. Power levels at test points are way low. I verified 5.01v coming from ps.

 The hum and low voltage levels resolve themselves when i use usb as a power source. All test points are accurate at this point._

 

By "power levels" I think you meant "voltages". What specifically are you getting in your measurements? Have you tried reflowing the solder joints for U1D?


----------



## tucsonmike

Yes, sorry about that. Power levels=voltages. I'm a noob.

 So, i think those low readings were a result of powering the y1, then plugging in y2. Voltages are accurate(with one exception) when plugging in y1 into y2 before plugging in ps.

 exception:

 So all voltages are within spec except the 5v test points that are closest to the ground strip. Readings are .01v for y1 and y2. The other 5v test points, furthest from ground strip, are 4.96v.

 Both 5v test points for y1 and y2 are at 4.8v with usb power. 

 yes i reflowed u1d. 


 hum is very low level, i have to pause music and turn up my amp to hear it. sounds like plugging in a guitar into a tube amp.



 gamma is dead quiet with usb power.

 thanks for your help, -mike


----------



## amb

Quote:


  Originally Posted by *tucsonmike* /img/forum/go_quote.gif 
_So, i think those low readings were a result of powering the y1, then plugging in y2. Voltages are accurate(with one exception) when plugging in y1 into y2 before plugging in ps._

 

If I understand you correctly, you applied power to the y1 board before mating the y2 board to it? That's not a valid mode of operation.

  Quote:


 So all voltages are within spec except the 5v test points that are closest to the ground strip. Readings are .01v for y1 and y2. The other 5v test points, furthest from ground strip, are 4.96v.

 Both 5v test points for y1 and y2 are at 4.8v with usb power. 
 

This is normal. If the unit is not connected to the computer through the USB cable, then there is no VBUS.

  Quote:


 hum is very low level, i have to pause music and turn up my amp to hear it. sounds like plugging in a guitar into a tube amp.

 gamma is dead quiet with usb power. 
 

Do you have your σ24 transformer located very close to the DAC boards or signal wiring? You might be getting some interference.


----------



## tucsonmike

Yes, initially i messed up by plugging y2 into a powered y1.

 Maybe this is what "broke" the 1.3mm power circuit. 

 Same issue came back, low voltages on 4.5 and 5v test points.
 around 2.8v. 

 i took out u1d and put in a jumper for 1.3mm jack power. no change.

 ohh well. Still works with usb.

*which brings me to my next question.*

 can i use the 24/25 with a mini b connector to power gamma?


----------



## slowpogo

I've been wondering, how flexible is the value of the output capacitors?

 I recall that if using the unit to drive headphones directly, you should use 470uf caps rather than 22uf. So that suggests some possible further flexibility to me.

 I ask because I have some Black Gate NX 47uf caps I'd love to try. Would those work OK for y2 C20/26?


----------



## JamesL

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_I've been wondering, how flexible is the value of the output capacitors?

 I recall that if using the unit to drive headphones directly, you should use 470uf caps rather than 22uf. So that suggests some possible further flexibility to me.

 I ask because I have some Black Gate NX 47uf caps I'd love to try. Would those work OK for y2 C20/26?_

 

Sure, why not. 
 The value of the capacitor will define the -3db roll off on the hpf.
 I personally think the 1uF polyester is good enough for use with >50k impedance pots, while the electrolytes offer more flexibility. The 47uF will probably be satisfactory with some higher impedance headphones as well(~300ohm)


----------



## amb

Quote:


  Originally Posted by *tucsonmike* /img/forum/go_quote.gif 
_can i use the 24/25 with a mini b connector to power gamma?_

 

Yes. But doing so precludes you from using a USB source (the connector will be "occupied").


----------



## tucsonmike

thanks


----------



## slowpogo

Quote:


  Originally Posted by *JamesL* /img/forum/go_quote.gif 
_Sure, why not. 
 The value of the capacitor will define the -3db roll off on the hpf.
 I personally think the 1uF polyester is good enough for use with >50k impedance pots, while the electrolytes offer more flexibility. The 47uF will probably be satisfactory with some higher impedance headphones as well(~300ohm)_

 

I threw those 47uf Black Gates in, and they sound fantastic. I hear no discernible difference in the bass, at least not for the worse.


----------



## tucsonmike

So, previously i thought i had something wrong with my y1/y2.
 Voltages were low while using 24/25 for power.

 USB power works great.

 I put a USB-mini connector on my 24/25 and low and behold, i'm only getting 3v into the gamma. This corresponds to my measurements and symptoms while using the 1.3mm jack.

 I show 5.02v coming out of the 24/25, but when its connected, it drops to 3v.

 Any ideas? 

 Thanks


----------



## MisterX

Quote:


 Any ideas? 
 

Do you have pictures of the Q24 and Q25?


----------



## MisterX

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_I threw those 47uf Black Gates in, and they sound fantastic. I hear no discernible difference in the bass, at least not for the worse._

 

Where did you get the idea you would? 
	

	
	
		
		

		
			





 Did you try it without the film "bypass" caps yet?


----------



## slowpogo

Because the size of the caps affects the corner frequency...sometimes changing it can be detrimental, I thought.

 Haven't tried it without the bypass caps - have you? Is it worthwhile?


----------



## K3cT

Quote:


  Originally Posted by *JamesL* /img/forum/go_quote.gif 
_Sure, why not. 
 The value of the capacitor will define the -3db roll off on the hpf.
 I personally think the 1uF polyester is good enough for use with >50k impedance pots, while the electrolytes offer more flexibility. The 47uF will probably be satisfactory with some higher impedance headphones as well(~300ohm)_

 

Hmm... this is interesting. Are you saying that the 47uF choice is more suitable for higher impedance cans compared to the default 22uF?


----------



## JamesL

Quote:


  Originally Posted by *K3cT* /img/forum/go_quote.gif 
_Hmm... this is interesting. Are you saying that the 47uF choice is more suitable for higher impedance cans compared to the default 22uF?_

 

I said they'd be satisfactory with higher impedance cans when they are being driven directly out of the DAC.
 I think amb's default recommendation of 470uF KW's are generally better suited for driving headphones directly out of the DAC though.


----------



## thoppa

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_Because the size of the caps affects the corner frequency...sometimes changing it can be detrimental, I thought._

 

You could go down to about 4.7uF and not notice any change. 47uF would be okay for 300ohm cans and 470uF for 32 ohm cans.

  Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_I haven't tried it without the bypass caps - have you? Is it worthwhile?_

 

If you mean coupling caps, it's a very bad idea. The dc offset will cause a large voltage and current to short through the drivers and pop them. Bye bye headphones. I'm sure you knew this.

 If you mean to keep the coupling caps and not use the additional bypass, then this would result in the loss of some detail and a slightly rougher top end. How much worse would depend on the quality of the electrolytics - BG NX Hi-Q are great so it'd only be a small difference.

 I think MrX is having an evil day....


----------



## MisterX

Are you done editing yet?


----------



## thoppa

haha...yeah...I posted w/o reading the posts above....it was only six or seven edits....


----------



## kunalraiker

I PMed, he didn't get back after I asked what was the difference between gamma 1 and gamma 2.


----------



## amb

Quote:


  Originally Posted by *kunalraiker* /img/forum/go_quote.gif 
_I PMed, he didn't get back after I asked what was the difference between gamma 1 and gamma 2._

 

You could read the websites yourself:
The γ1 modular miniature DAC
The γ2 compact high performance DAC


----------



## thoppa

Hi Ti,

 Can I ask you about the y1 ? The CS8416 datasheet suggests this
 RFLT CFLT CRIP 
 23kΩ 22nF 1nF 

 On the y1 the components are C18D, C19D and R4; 
 3kΩ 33nF 1nF

 So I'm curious about the filter change from the one given in the datasheet....and what would be the effect on jitter of changing rflt and cflt ?

 Thanks.


----------



## kunalraiker

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_You could read the websites yourself:
The γ1 modular miniature DAC
The γ2 compact high performance DAC_

 

I was asking for a build, with major differences and price variations.


----------



## Nebby

Quote:


  Originally Posted by *kunalraiker* /img/forum/go_quote.gif 
_I was asking for a build, with major differences and price variations._

 

I might be reading what you wrote wrongly, but AMB doesn't sell builds. As for the differences and price variations, you can deduce that from the BOM's and interestingly enough, the price variations really depend on what you want so it really depends on you


----------



## amb

Quote:


  Originally Posted by *thoppa* /img/forum/go_quote.gif 
_Can I ask you about the y1 ? The CS8416 datasheet suggests this
 RFLT CFLT CRIP 
 23kΩ 22nF 1nF_

 

I don't know which datasheet you're looking at, but The CS8416 datasheet at Cirrus Logic Home Page, on page 54, Table 6, recommends Rfilt=3KΩ, Cfilt=22nF, Crip=1nF for any sampling rate between 32KHz and 192KHz.

  Quote:


 On the y1 the components are C18D, C19D and R4; 
 3kΩ 33nF 1nF 
 

Yes, so the only difference is Cfilt. I don't really remember why we chose 33nF instead of 22nF, but I didn't observe anything bad from this. If you want, you could use 22nF.


----------



## thoppa

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_ I don't really remember why we chose 33nF instead of 22nF, but I didn't observe anything bad from this. If you want, you could use 22nF._

 

My bad on the component value - must be the drugs...wearing off....
	

	
	
		
		

		
			





 I assumed you had chosen a different value because the y1 is limited to 96Khz ? I'm guessing that increasing the value of cfilt will increase the settling time, which would make it harder to lock onto a 192khz signal but perhaps would reduce jitter for 96Khz and below ? What do you think ?

 Thanks !


----------



## amb

I have no trouble getting the CS8416 to lock on a 192KHz stream via either the coax or optical inputs, even though γ1's WM8501 DAC as configured (256*fs) could only support up to 96KHz. But on the γ2 the ASRC will happily accept the 192KHz stream (and downconvert to 96KHz) before sending it to the WM874x DAC.

 EDIT: I should add that SRC4192 in the γ2 will support 192KHz but AD1896 won't. This is due to the 256*fs master clock configuration.


----------



## morks

Just wanted to chime in and say that my Gamma2 is alive and kicking. Thanks amb! Now I only have to find good music. 
	

	
	
		
		

		
		
	


	




 Although, could you please say somewhere on the Gamma2 site that for the G2 to work with the G1 D config (and others?), you need more parts than what its' parts list suggests (see MisterX' post somwhere in this thread)? Beginners like me would appreciate it. I wondered why it didn't work at first until someone pointed out to me that the G2 board wasn't getting any power because there was no connection from the USB power line to the G2. Good thing I randomly ordered more parts from you than I thought I needed


----------



## thoppa

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_I have no trouble getting the CS8416 to lock on a 192KHz stream via either the coax or optical inputs, even though γ1's WM8501 DAC as configured (256*fs) could only support up to 96KHz. But on the γ2 the ASRC will happily accept the 192KHz stream (and downconvert to 96KHz) before sending it to the WM874x DAC.

 EDIT: I should add that SRC4192 in the γ2 will support 192KHz but AD1896 won't. This is due to the 256*fs master clock configuration._

 

So if it doesn't affect lock-on, then I could increase cfilt to reduce jitter further ? Did you try any other values ?


----------



## Draguljce

Although, could you please say somewhere on the Gamma2 site that for the G2 to work with the G1 D config (and others?), you need more parts than what its' parts list suggests (see MisterX' post somwhere in this thread)? Beginners like me would appreciate it. I wondered why it didn't work at first until someone pointed out to me that the G2 board wasn't getting any power because there was no connection from the USB power line to the G2. 

 Can you be more precise ? I build gamma 1 D-config but still waiting for SRC4192 for gamma 2


----------



## amb

Quote:


  Originally Posted by *morks* /img/forum/go_quote.gif 
_Although, could you please say somewhere on the Gamma2 site that for the G2 to work with the G1 D config (and others?), you need more parts than what its' parts list suggests (see MisterX' post somwhere in this thread)? Beginners like me would appreciate it. I wondered why it didn't work at first until someone pointed out to me that the G2 board wasn't getting any power because there was no connection from the USB power line to the G2. Good thing I randomly ordered more parts from you than I thought I needed 
	

	
	
		
		

		
		
	


	


_

 

What more parts did you need? The parts lists on the websites should be correct.
 As for the connection from USB power line to the γ2 (with γ1 "D" config), you don't need more parts. All you need to do is to solder a wire to bridge the VBUS and VCC lines on the γ1 board.


----------



## ShinyFalcon

I think I'm experiencing some deja vu here... I saw your post yesterday, or am I imagining things?

 Anyways, the y1 pages does list a table of jumper settings, and for configuration D (USB-> I2S) it does states in notes, "also short J2U pins 1 and 2," which connects USB's 5V (VBUS) to VCC.

 Are you stuck on something? If you are not using the SRC4192 then you will have to jumper (use straight resistor clippings) four pins on y2's JP2. This connects the I2S line from y1's USB board directly to the WM8741 DAC. When you install the SRC4192, you have to remove those jumpers.


----------



## Nebby

I think he was quoting morks' post in the previous page, but didn't use the quote function.


----------



## Draguljce

Quote:


  Originally Posted by *Nebby* /img/forum/go_quote.gif 
_I think he was quoting morks' post in the previous page, but didn't use the quote function._

 

True. I'm quite sure that i pressed (quote - reply with quote) 
	

	
	
		
		

		
		
	


	




 BTW. I just went trough all instructions and inspected boards and can't find any problems, VBUS and VCC are bridged by JP2D pins 2 and 3 (or U1D) and connected via gamma2 board back to J2U thus providing power for both boards.

 I didn't begin building gamma2 as I'm still waiting for SRC, so for now I'm only watching this thread 
	

	
	
		
		

		
		
	


	




 Gamma1 D-config is live and kicking.


----------



## CodeToad

I made a BOM/Worksheet to build a Y1-D config USB Only Gamma2. It is hard wired to run on wall power...NO USB POWER in the BOM so adjust accordingly if you want to run regular unleaded in your Formula1 car 
	

	
	
		
		

		
		
	


	




 Use the Combined BOM to buy the parts and use the "Print Worksheet" to build each board.

 Start with the Y1 "Print Worksheet" (print it out and mark off each step as you go) and follow it top to bottom...all the parts are in the order they need to be installed and the jumpers are already figured out. Notes give you tips so you don't have to learn the hard way. 

 Repeat for Y2.

 If you find mistakes please let me know so I can fix it.

 This will net you a Gamma2 with a nice green LED on the front panel and usb input only and powered by wall power only.


----------



## MisterX

Quote:


 Because the size of the caps affects the corner frequency...sometimes changing it can be detrimental, I thought. 
 

Bass ackwards, assuming the load is unchanged increasing the capacitance lowers the corner frequency of the filter. 


  Quote:


 Haven't tried it without the bypass caps - have you? 
 

Of couse I have tried it. 


  Quote:


 Is it worthwhile? 
 

Yes but I am not a fan of using the Wima MKS2 series as coupling caps so...


----------



## MisterX

Quote:


 If you mean to keep the coupling caps and not use the additional bypass, then this would result in the loss of some detail and a slightly rougher top end. How much worse would depend on the quality of the electrolytics - BG NX Hi-Q are great so it'd only be a small difference.

 I think MrX is having an evil day.... 
 

Not even close..... but if I was I would tell you an implication that all film capacitors have the same sonic effect in that position is ridiculous.


----------



## K3cT

Quote:


  Originally Posted by *JamesL* /img/forum/go_quote.gif 
_I said they'd be satisfactory with higher impedance cans when they are being driven directly out of the DAC.
 I think amb's default recommendation of 470uF KW's are generally better suited for driving headphones directly out of the DAC though._

 

I see. So you're talking about in the context of driving it straight from the DAC. Thanks, man. 

 The latest talk of the choice of bypass film caps is interesting. Do you guys think there is a merit of changing these Wima caps from MKS2 to MKP2? It seems that there is a common belief that polypropylene > polyester. 

 The only drawback I can see is size though Ti's γ2 site mentions that you can go lower with these bypass caps. Is there a limit on how low in capacitance you can go before things become detrimental?


----------



## amb

Quote:


  Originally Posted by *K3cT* /img/forum/go_quote.gif 
_The only drawback I can see is size though Ti's γ2 site mentions that you can go lower with these bypass caps. Is there a limit on how low in capacitance you can go before things become detrimental?_

 

You can do the math yourself. The corner frequency is:

 fc = 1 / (2 * pi * R * C)

 where,
 R = the load impedance in ohms
 C = The coupling capacitance in Farads (you need to apply 10^-6 for uF)
 pi = 3.1416

 I would like fc < 10Hz, maybe 5Hz if feasible.

 For example, if you are planning to drive a 10K ohm load (i.e., the input of Mini³ amp), and you use a 1uF MKS cap only, plugging the numbers into the formula gets you fc = ~16Hz. I would be happier with a 2.2uF or 3.3uF instead which will drop fc down to ~7Hz or ~5Hz, respectively.

 On the other hand, if you plan to drive 32 ohm headphones directly out of the DAC, you'll need hundreds of uF to attain the goal. 470uF will get you fc = ~11Hz.


----------



## slowpogo

Interesting, amb, thanks. I realize this is just showing my ignorance, but I can't fathom how a geometrical value like pi factors into electrical equations...fascinating.

 I may try those MKP 1837 caps that people seem to really like, as bypass to my Black Gate NX's. The largest capacitance that would fit is only 0.022uf. Is that too small to have sufficient effect against the 47uf Black Gates?


----------



## JamesL

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_You can do the math yourself. The corner frequency is:
_

 

hmm.. I've been wondering.

 If the amplifier has a input capacitor, would that act as a second capacitor in series with the first, or does r9/r16 (y2 schematic) change the behavior?


----------



## K3cT

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_You can do the math yourself. The corner frequency is:

 fc = 1 / (2 * pi * R * C)

 where,
 R = the load impedance in ohms
 C = The coupling capacitance in Farads (you need to apply 10^-6 for uF)
 pi = 3.1416

 I would like fc < 10Hz, maybe 5Hz if feasible.

 For example, if you are planning to drive a 10K ohm load (i.e., the input of Mini³ amp), and you use a 1uF MKS cap only, plugging the numbers into the formula gets you fc = ~16Hz. I would be happier with a 2.2uF or 3.3uF instead which will drop fc down to ~7Hz or ~5Hz, respectively.

 On the other hand, if you plan to drive 32 ohm headphones directly out of the DAC, you'll need hundreds of uF to attain the goal. 470uF will get you fc = ~11Hz._

 

Thanks, Ti! That's very interesting. Learning never stops indeed. 

 Just one thing, I'm mirroring JamesL's question. How does one determine the load impedance of an amplifier? Via its volume pot?


----------



## K3cT

OK, I just did a rough calculation assuming that load impedance is 50K (is that even right?), the value of C needs to be at least 0.33uF to make fc < 10Hz. That makes it insanely difficult to find a matching MKP cap that will fit size-wise.


----------



## slowpogo

Quote:


  Originally Posted by *K3cT* /img/forum/go_quote.gif 
_OK, I just did a rough calculation assuming that load impedance is 50K (is that even right?), the value of C needs to be at least 0.33uF to make fc < 10Hz. That makes it insanely difficult to find a matching MKP cap that will fit size-wise._

 

I believe 'C' is the capacitance of any and all output caps on that channel...meaning C19+C20, or C25+C26.

 So assuming your math is correct, it means C19+C20 needs to be 0.33uf or greater. So you could do it like:

 C19: small MKP, 0.022uf or whatever
 C20: 10uf electrolytic, for example

 The total is 10.022uf, which is obviously greater than 0.33uf, so it's all good


----------



## K3cT

That makes more sense, slowpogo. Thanks, man.

 EDIT1: Still, the load input resistance is such a huge value that it's more significant than the others. I'm still unclear what's the "correct" value for this one.

 EDIT2: It's tricky to get the fc close to 5Hz using commonly available capacitance values.


----------



## amb

Quote:


  Originally Posted by *K3cT* /img/forum/go_quote.gif 
_Just one thing, I'm mirroring JamesL's question. How does one determine the load impedance of an amplifier? Via its volume pot?_

 

Most of the time, yes. The volume pot's resistance usually dominates the input impedance of a non-inverting amplifier, especially those with FET inputs (or tube). BJT-input amps may have slightly lower input impedance than the pot when the pot is turned up to maximum.


----------



## amb

Quote:


  Originally Posted by *JamesL* /img/forum/go_quote.gif 
_If the amplifier has a input capacitor, would that act as a second capacitor in series with the first, or does r9/r16 (y2 schematic) change the behavior?_

 

When two caps are in series, then their equivalent capacitance is reduced. The formula is:

 Ctotal = 1 / ((1 / C1) + (1 / C2))

 R9 and R16 does add complication to the total response because instead of one single high-pass filter, now it's two of them in series, and they influence each other's response.


----------



## m1abrams

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_Interesting, amb, thanks. I realize this is just showing my ignorance, but I can't fathom how a geometrical value like pi factors into electrical equations...fascinating.
_

 

Because we are dealing with wave forms not constant values. Everything non-DC electrical is based in the trig world. Heck wait til you try to understand power factors and dealing with imaginary numbers which makes imaginary power that funny enough the power company will not accept imaginary money for!


----------



## K3cT

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_When two caps are in series, then their equivalent capacitance is reduced. The formula is:

 Ctotal = 1 / ((1 / C1) + (1 / C2))

 R9 and R16 does add complication to the total response because instead of one single high-pass filter, now it's two of them in series, and they influence each other's response._

 

Well, this is turning out to be a tricky affair. Ignoring R9 and R16, it's still difficult to find a matching C1 and C2 values using commonly available capacitors that can fit inside the y2 to get a corner frequency below 10Hz. Assuming input resistance is 50K Ohm, the recommended values of C1 = 22uF and C2 = 1uF seems to work well in most cases.


----------



## JamesL

Quote:


  Originally Posted by *K3cT* /img/forum/go_quote.gif 
_Well, this is turning out to be a tricky affair. Ignoring R9 and R16, it's still difficult to find a matching C1 and C2 values using commonly available capacitors that can fit inside the y2 to get a corner frequency below 10Hz. Assuming input resistance is 50K Ohm, the recommended values of C1 = 22uF and C2 = 1uF seems to work well in most cases._

 

He was referring to my question, where c1 and c2 are the output coupling capacitor of the source, and the protection cap on the amplifier.

 In the case of g2's output capacitors, they are in parallel and therefore additive. ct=c1+c2


----------



## K3cT

Quote:


  Originally Posted by *JamesL* /img/forum/go_quote.gif 
_He was referring to my question, where c1 and c2 are the output coupling capacitor of the source, and the protection cap on the amplifier.

 In the case of g2's output capacitors, they are in parallel and therefore additive. ct=c1+c2_

 

You're right, a quick look at the schematic proves that. *facepalm* Thanks for the heads-up, man.


----------



## slowpogo

I got my panel today...I wanted the front to be silver to match my other stuff, so I made my own template. I basically copied amb's design, except I stylized the logo a little and made it green, and counter-sunk the screw holes. The back is the exact same as amb's but the bottom "Designed by..." part is green. It turned out perfectly, though I wish I had made the panel a little wider. It's just barely as wide as the case, but it looks fine.

 The picture doesn't quite do it justice...the green is more vivid, and overall it's quite handsome if I do say so myself.


----------



## K3cT

That's very nice looking, slowpogo. Where do you customize your faceplate?


----------



## slowpogo

Thanks. I should have mentioned, it's from Front Panel Express.

 I just used the technical drawing and measurements on the y2 website to create the template. It was quite a bit more expensive than those that amb offers...but sometimes you can't put a price on customization.


----------



## m1abrams

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_Thanks. I should have mentioned, it's from Front Panel Express.

 I just used the technical drawing and measurements on the y2 website to create the template. It was quite a bit more expensive than those that amb offers...but sometimes you can't put a price on customization._

 

Looks great and added in-fill color really adds to the cost. Also AMB most likely orders enough to get a bulk discount.


----------



## landau

Hi all!

 I've just enlivened my gamma2, so far without the USB chip, sadly. It worked immediately without any problems. Although I was quite afraid to solder all those expensive SMT chips, since I hadn't soldered any SMT before, it went fine. I was even able to desolder the 4.75V regulator and solder it to another place without destroying it, using no special equipment (I had only one and wanted to use it for the gamma2 board only; alas I soldered it to the DAC section of gamma1 instead). 

 If interested, you can find some photos here: Picasa Web Albums - gamma2 
 Now I only hope to get hold of the PCM2707 to be able to finish it completely. 
 Thank you, Ti, for this superb project!

 EDIT: I got PCM2707 and soldered it. Everything works! It is marvelous!


----------



## MisterX

Quote:


 Now I only hope to get hold of the PCM2707 to be able to finish it completely. 
 

It appears they are available at the AMB audio shop again. 
	

	
	
		
		

		
			




 And.. I assume you meant to use the orange RCA jack as the coaxial S/PDIF input jack?


----------



## landau

MisterX, no, the reason for the orange RCA is that they didn't have red in Mouser at the time I ordered and I just didn't want to delay the shipment because of this triviality. So I meant it as a replacement of the proper red one. Then, naturally, I swapped the white one and orange one by mistake.

 The other question is, why I didn't buy it from AMB. It is so because I didn't want to go over $60 per package, when they start to charge you customs, VAT and a significant manipulation fee here in Switzerland.


----------



## mace1337

Hi all. 
	

	
	
		
		

		
		
	


	




 I finally got my order in from Mouser today and I have been assembling my y1++ and y2 boards. I finished the y1 first and wanted to test it. I just tested the DAC board not the USB board because I didn't bother to connect them yet.
 Also, I forgot to order the USB connector. 
	

	
	
		
		

		
		
	


	




 The DAC board worked flawlessly, that is, until I shorted something and killed it. 
	

	
	
		
		

		
		
	


	




 I think I killed my TPS2115APW because the 3.3 and 4.5 volt test points give weird voltages. When I apply power directly to the middle pin of JP2D then it works flawlessly again, at least on coax because I haven't tried optical yet.

 Long story short, does anyone have a spare TPS2115 they can send me? And maybe a USB connector that fits the y1? I have a bunch of them but they all are SMD so they're no good. I will pay of course.


----------



## Draguljce

My freshly finished gamma 2 is behaving very strange, there is audio but it doesn't sound right. At first i thought it was fine, but vocals seemed hollow, after trying other tracks and playing with winamp, vlc and foobar i can't figure what's going on. For example in winamp (without asio plugin) if i move balance slider to the left it sounds fine and plays only on left side but if i move it to the right it plays fine but on both sides ?!? Leaving it centered sound is somehow hollow and like clipping/cracking especially on vocals. Vlc behaves different, left channel sounds totally wrong (like heavy clipping) Foobar (with asio) behaves just like winamp.

 Both boards are passing initial checks, all voltages are fine, can't find any short bridges or dry joints. All measurements in signal path from 8741 to OP amp and signal out are fine, everything is perfectly clean...

 Any suggestions welcome


----------



## amb

Sounds like an output wiring problem, either at the output jacks or interconnect cable.


----------



## Draguljce

It was wrong wiring of output jack (soldered of board), exactly as MisterX pointed out


----------



## slowpogo

Has anyone been crazy enough to try the $15 Vishay "naked" resistors in their y2? They have the appropriate lead pitch, and could just be slanted to the side if they interfere with connecting the y1 and y2 boards.

 I know people have said that even just a pair of these resistors (in other projects) can make a big difference...


----------



## mace1337

AMB, do you carry the USB connector used on the y1?

 I would like to order 2 TPS2115's from you, and if at all possible also buy the USB connector so I don't have to save up to the minimum order for places like Mouser or Farnell.


----------



## amb

mace, you should contact me directly about such matters.


----------



## jc9394

I have not read thru all posts, but from memory, gamma2 does not support balanced out. Is there any changes?


----------



## amb

Quote:


  Originally Posted by *jc9394* /img/forum/go_quote.gif 
_I have not read thru all posts, but from memory, gamma2 does not support balanced out. Is there any changes?_

 

No changes.


----------



## jc9394

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_No changes._

 

Any plans on the balanced out in the future?


----------



## m11a1

Probably Gamma 3






 just kidding


----------



## morks

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_What more parts did you need? The parts lists on the websites should be correct.
 As for the connection from USB power line to the γ2 (with γ1 "D" config), you don't need more parts. All you need to do is to solder a wire to bridge the VBUS and VCC lines on the γ1 board._

 

I installed J1D, L4D, R(13|14|15)D, C(1|2|3)D and U1D as suggested by MisterX. If the thing with the jumpers really is mentioned somewhere on the site, I should have triple-checked it. Someone pointed it out to me, but it didn't work (bad joint somewhere else), so I thought that I needed to install those additional parts. Oh well, I now have the option to power the G2 externally.


----------



## K3cT

Quote:


  Originally Posted by *jc9394* /img/forum/go_quote.gif 
_Any plans on the balanced out in the future?_

 

You can probably hack a balanced connection out from the test points but it's going to be ugly and you will lose the final op-amp filtering.


----------



## m1abrams

Quote:


  Originally Posted by *K3cT* /img/forum/go_quote.gif 
_You can probably hack a balanced connection out from the test points but it's going to be ugly and you will lose the final op-amp filtering._

 

Couldn't you use the IVY board from Twisted Pair to get balanced out from the test points?


----------



## Olli1324

Mouser, RS, Farnell and Digikey are all out of SRC4192IDB. 
 I cannot seem to find AD1896AYRS for less than about 24 quid, which seems *extremely* expensive.

 Any ideas?


----------



## MisterX

Quote:


 If the thing with the jumpers really is mentioned somewhere on the site 
 

Check the "Jumper settings" section of the Gamma 1 instructions page.


----------



## Beefy

Quote:


  Originally Posted by *Olli1324* /img/forum/go_quote.gif 
_Mouser, RS, Farnell and Digikey are all out of SRC4192IDB. 
 I cannot seem to find AD1896AYRS for less than about 24 quid, which seems *extremely* expensive.

 Any ideas?_

 

Leave it out for now, and install it later


----------



## MisterX

Quote:


  Originally Posted by *Olli1324* /img/forum/go_quote.gif 
_Mouser, RS, Farnell and Digikey are all out of SRC4192IDB. 
 I cannot seem to find AD1896AYRS for less than about 24 quid, which seems *extremely* expensive.

 Any ideas?_

 

SRC4192IDB - Texas Instruments - datasheet

 or

SRC4192 192 kHz Stereo ASR Sample Rate Converter on eBay (end time 03-May-10 19:41:19 BST)


----------



## Olli1324

LOL new record for most expensive postage - one of those companies (avnet) want $47.99 for FedEx economy! for a chip hardly bigger than my finger nail...

 Arrow also wanted 20 bucks postage.

 That eBay one looks the most likely contender; although it is still about 8 squids more expensive than mouser/avnets prices...

 Is the ASRC paramount to sound quality? Will I be kicking myself if I don't install it (yet)?


----------



## m1abrams

Quote:


  Originally Posted by *Olli1324* /img/forum/go_quote.gif 
_LOL new record for most expensive postage - one of those companies (avnet) want $47.99 for FedEx economy! for a chip hardly bigger than my finger nail...

 Arrow also wanted 20 bucks postage.

 That eBay one looks the most likely contender; although it is still about 8 squids more expensive than mouser/avnets prices...

 Is the ASRC paramount to sound quality? Will I be kicking myself if I don't install it (yet)?_

 

Well if you want to use any of the filters beyond the brickwall filter you really want to have ASRC since the other filters without the higher sampling rate will cutoff the high freq. Now of course the question is do the other filters make a difference, I personally hear no difference between them however a difference is clearly visible in Ti tests online just not sure if that will make an audible difference for you.


----------



## m11a1

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_SRC4192IDB - Texas Instruments - datasheet

 or

SRC4192 192 kHz Stereo ASR Sample Rate Converter on eBay (end time 03-May-10 19:41:19 BST)_

 

What a great search engine, thanks for that!


----------



## K3cT

Quote:


  Originally Posted by *m1abrams* /img/forum/go_quote.gif 
_Couldn't you use the IVY board from Twisted Pair to get balanced out from the test points?_

 

I think that's possible. Anyone crazy enough to try it out?


----------



## mace1337

It's not a far fetched idea at all, I'd say go for it.


----------



## lampee

Or somebody could build a balanced output stage from the datasheet of the WM8741 DAC chip. It would be probably cheaper than TPA's because you don't need the Balanced - SE converter. Good luck if anybody tries it!


----------



## yeahyeah

After a long search of parts, i find all parts i need and receive my board today. 

 Before building it, I want to confirm if DA chip on gamma 1 is not used, I can also omit these?
 1. From R7D to J3D
 2. U6D (looks like it provide 4.5V to U3D only?)

  Quote:


  Originally Posted by *Olli1324* /img/forum/go_quote.gif 
_Mouser, RS, Farnell and Digikey are all out of SRC4192IDB. 
 I cannot seem to find AD1896AYRS for less than about 24 quid, which seems *extremely* expensive.

 Any ideas?_

 

I find it on RS for HKD177, around 14.75 quid
 and yes, it's double of SRC4192.........but i don't want to wait either


 Now waiting for the oscillator C3391 from mouser, don't know when they're going to ship it.....


----------



## slowpogo

Quote:


  Originally Posted by *yeahyeah* /img/forum/go_quote.gif 
_Now waiting for the oscillator C3391 from mouser, don't know when they're going to ship it....._

 

You could just order the Abracon equivalent, which is in stock -

ACHL-24.576MHZ-EK ABRACON Oscillators


----------



## Olli1324

I ordered the Abracon oscillator.

 I have now ordered everything, inc. ASRC and the opamp, except the case and the NPN transistors. I could have sworn RS offer free shipping, but they want a fiver for shipping a bag of transistors. But oddly enough it was free to ship 5 metres of M4 studding, 250 M4 nuts and 250 M4 washers... Hmmm... Anyway, the old man is looking into it; see if he can't figure it out.

 Until then, I am trying to find the cheapest place to get the box. Newark, kindly refrain from telling you postage costs (after 20 damn minutes filling in the registration form (and giving my mobile number 4 times for some reason)). I am now gonna look at Farnell. It appears to be a very similar website. Farnell better tell me how much it costs to post these damn things...


----------



## Olli1324

ARGH 20 quid minimum bloody order! What spackos. Anyone got any advice on the case? I'll hold off on ordering it tonight..


----------



## K3cT

RS-Components carry it but I'm not sure what's the shipping going to be like for you.


----------



## Olli1324

Yeah, to get it from RS is 21.98 quid. I'll likely pay it; there doesn't seem to be a cheaper source that I can find.


----------



## Olli1324

Is this a suitable wall-wart?


----------



## ShinyFalcon

The 2.1mm plug is too big for the y2. If you are willing to cut the plug and replace it with a 1.3mm then it will work. Also, it's likely a switching type, which can introduce some static and noise in the power line. As long as the output voltage is under 5.5V (measure it, don't guess) then it will work, but is not an ideal source.


----------



## Olli1324

Hmm. Anyone know a good source of linear regulators in the UK then?


----------



## TestSpecimen

I have a fairly basic question:

 In the schematic for the gamma 1 the SMD U1U (Square chip) has some pins that have a line going out of the chip and then just stop. Does this mean that it is essentially not connected to anything i.e. its not used?


----------



## MisterX

Yep, that is what it means.


----------



## TestSpecimen

OK thanks for the quick reply. Trying to soldier my way through the gamma 2 build at the moment. I still can't get over how small some of the chips on here are. Just makes me more appreciative of some of the excellent soldering that i've seen displayed here before


----------



## particleman14

flood and suck.. flood and suck lol


----------



## Olli1324

Mmkay.. I think I'm onto something here...

This wall-wart (there is a 300mA version; but I thought it might be good to have some headroom?)

 To counter the 2.1mm plug size, I could then use model number: FK08J from Maplin to make it fit the gamma.

 Sound like a plan?


----------



## MisterX

An AC adapter rated @ 300mA output current has adequate headroom.


----------



## Olli1324

Oh ok, it's just that the site said '300mA+', so I took 300 to be something of a minimum. But if 300mA is indeed more than suitable, I will go for that and save myself 2 quid. Cheers.


----------



## MisterX

I reckon you need one with a UK style plug? 
 Looks like Farnel has one that would fit the bill but it does not explicitly say it has a UK plug, which means it problably has a euro style plug?


----------



## Olli1324

I just ordered this one.. Now that you mention it, it doesn't say it has a UK plug, but it is a .co.uk website and based in England, so I assume it is a UK 3 pin...


----------



## Olli1324

Oddly enough, that one from Farnell is the same as the one I ordered from the other website.

 I think I will cancel my order, and order both the case and the power supply from farnell... cheaper overall. Edit: ooo farnell also have the transistors I need...

 Editedit: The Fairchild NPNs AMB recommends aren't in stock.... Are these a suitable replacement?


----------



## MisterX

This is the one I was referring to----> 
MULTICOMP|LG050030RBS|ADAPTOR, REG, 5V, 300MA | Farnell United Kingdom


 Funny though I just "logged on" to check the part number in your link to see if this one ---> 
STONTRONICS|AD-0530RBS2.1|ADAPTOR, 5VDC, 300MA, UK | Farnell United Kingdom

 was the same one


----------



## Olli1324

I saw the Multicomp one you suggest, but it is twice the price. Would the cheaper Stontronics one + adapter plug (6.39 all in) be considerable less desirable?


----------



## MisterX

Dunno, the Multicomp one is listed as a regulated but the other one isn't and the datasheet Farnell provided doesn't help much. 
 Did you check at RS?


----------



## Olli1324

Haven't looked at RS; I'm focusing on Farnell because RS is 22 quid for the case alone (10 quid handling and postage fee because it is in the 'extended range') For that 20 quid at Farnell, I can get power supply, transistors and the case.


----------



## Olli1324

Ordered everything now.. Cost approx £135.18 +/- a couple of quid because some of the y1 bits were bought last year from AMB shop at a different exchange rate. This is for y1 SPDIF only and a y2.

 Can't wait for it all to arrive


----------



## rhester

Anybody know where to get the oscillators and opamps right now? All out of stock for a while at ouser and DigiKey?


----------



## amb

Oscillator:
Mouser 815-ACHL-24.576-EK (through-hole, 50ppm)
Mouser 549-C3391-24.576 (SMD, 25ppm, est. restock May 4)
Mouser 549-C3392-24.576 (SMD, 50ppm)
Mouser 774-CB3LV-3I-24M576 (SMD, 50ppm)

 Opamp:
Mouser 595-OPA2365AID (est. restock May 10)
Arrow North Amercia (search for OPA2365AID, they claim to have stock but I don't know if it's real or not)
Digikey AD8656ARZ-ND (est. restock May 13)


----------



## slowpogo

Quote:


  Originally Posted by *amb* /img/forum/go_quote.gif 
_Oscillator:
Mouser 815-ACHL-24.576-EK (through-hole, 50ppm)
Mouser 549-C3391-24.576 (SMD, 25ppm, est. restock May 4)
_











How much of a difference do you think 25ppm vs 50ppm makes?


----------



## amb

Not a whole lot, but some people are pedantic.


----------



## MisterX

That is why "those people" choose the 20ppm one from Mouser instead.


----------



## yeahyeah

Hi i didn't start solder yet but get stuck on the self-tapping screws of the B2-080....
 do you guys use a screw driver or a drill to do it?


----------



## Iniamyen

Quote:


  Originally Posted by *yeahyeah* /img/forum/go_quote.gif 
_Hi i didn't start solder yet but get stuck on the self-tapping screws of the B2-080....
 do you guys use a screw driver or a drill to do it?_

 

If they are like most self-tapping screws that I've used, they are pretty difficult to screw up 
	

	
	
		
		

		
		
	


	




 You can just use a regular screwdriver, and apply firm pressure and torque. The first time you screw them in make sure you screw them in all the way and you should be good to go.


----------



## Nebby

Complete! Thanks for the quick shipping on the parts I managed to somehow forget to order or managed to lose. Amazingly the thing powered up and worked on first try! I inspected everything in triplet but I was afraid I still missed something. Glad it turned out to be ok 
	

	
	
		
		

		
		
	


	




 Thanks again for the design and support AMB!

 Btw, in case anyone needs M3x10mm socket head screws, shoot me a PM. I bought a 100 pack from McMaster-Carr because nobody local had them in stock, hah.


----------



## bridge8989

is there a link to a cart with all the parts included in it? I looked through the list of y1 parts and its really annoying counting how many of what i need for a full y1.


----------



## Beefy

Quote:


  Originally Posted by *bridge8989* /img/forum/go_quote.gif 
_is there a link to a cart with all the parts included in it? I looked through the list of y1 parts and its really annoying counting how many of what i need for a full y1._

 

Its a DIY project. What do you expect?


----------



## slowpogo

Quote:


  Originally Posted by *bridge8989* /img/forum/go_quote.gif 
_is there a link to a cart with all the parts included in it? I looked through the list of y1 parts and its really annoying counting how many of what i need for a full y1._

 

Just open up Notepad (or whatever you use), and do it, make the list. In fact, by creating that post and waiting just a few minutes for a response, you could have done it in that time.

 I assume you were referring to amb's store...anyway, you will want an actual list of the parts you got from amb, that you can edit - it will make it easier to know what parts you need to order from other places.


----------



## fordgtlover

Quote:


  Originally Posted by *bridge8989* /img/forum/go_quote.gif 
_is there a link to a cart with all the parts included in it? I looked through the list of y1 parts and its really annoying counting how many of what i need for a full y1._

 

You do know that the Y in DIY stands for 'Yourself'? Maybe you want DIFY.


----------



## MisterX

2 33pF ceramic caps. 
 4 100pF film caps. 
 4 220pF film caps. 
 1 1nF ceramic cap. 
 10 .01uF ceramic caps.
 1 .022uF ceramic cap. 
 23 .1uF ceramic caps. 
 6 1uF films caps. 
 4 1uF ceramic caps. 
 7 or 3 22uF electrolytic caps. 
 4 or 0 470uF electrolytic caps. 
 5 47uF electrolytic film caps.


----------



## bridge8989

Quote:


  Originally Posted by *MisterX* /img/forum/go_quote.gif 
_2 33pF ceramic caps. 
 4 100pF film caps. 
 4 220pF film caps. 
 1 1nF ceramic cap. 
 10 .01uF ceramic caps.
 1 .022uF ceramic cap. 
 23 .1uF ceramic caps. 
 6 1uF films caps. 
 4 1uF ceramic caps. 
 7 or 3 22uF electrolytic caps. 
 4 or 0 470uF electrolytic caps. 
 5 47uF electrolytic film caps._

 

Thanks!


----------



## Beefy

Quote:


  Originally Posted by *bridge8989* /img/forum/go_quote.gif 
_Thanks!_

 

It would actually be easier to copy down part numbers directly from the website......


----------



## particleman14

ya that was one dif I noticed between y-1 and y-2 parts list.. the y-2 parts are consolidated while the gamma-1 goes down the line for each part listing individually even if they repeat later. just gotta peel your eyes and focus so you dont skip or misread a line or something(like I did
	

	
	
		
		

		
		
	


	




)


----------



## TestSpecimen

I was wondering if someone can point me in the right direction. Essentially, i've built the gamma 1 and 2 at the same time.

 However, when I connect them I only get distortion from both the gamma 1 section and gamma 2 section. So I hardwired the connection between the usb section of the gamma 1 and the dac section of the gamma 1, and everything worked perfectly (which is nice).

 All voltages seem to check out ok on the gamma 2. I don't have U4 installed (because it won't arrive till next month), so I therefore don't have U3, R1, C7 and C8 installed either, and i've jumpered all four pairs of JP2 pins.

 Questions:

 1) I have X1 installed, is this likely to have an effect as i understand its not needed with the exclusion of U4 (as mentioned above).

 2) Does this sound like anything other than bad pin connectivity between the boards or cold/bad soldering, as I have read this is the main problem. I'm just wondering what on the gamma 2 board would mess up the signal on the gamma 1 at the same time.

 Thanks in advance

 Mike


----------



## amb

Quote:


  Originally Posted by *particleman14* /img/forum/go_quote.gif 
_the y-2 parts are consolidated while the gamma-1 goes down the line for each part listing individually even if they repeat later._

 

There is a reason for this. It's because γ1 has six different main configurations in the parts list table (A through F). If the parts are consolidated then it becomes difficult to differentiate between those configurations.

  Quote:


  Originally Posted by *TestSpecimen* /img/forum/go_quote.gif 
_I don't have U4 installed (because it won't arrive till next month), so I therefore don't have U3, R1, C7 and C8 installed either, and i've jumpered all four pairs of JP2 pins.
 ...
 1) I have X1 installed, is this likely to have an effect as i understand its not needed with the exclusion of U4 (as mentioned above)._

 

That is the problem. If U4 is not installed, then X1 must also not be installed. Otherwise you'll have two master clocks "fighting" each other -- one from the original I2S bus and the other one that's generated by the local oscillator.


----------



## TestSpecimen

Ah ok i see. I will attempt to remove it then and see if I get better results.

 Thanks for the reply


----------



## TestSpecimen

I have just made the modification mentioned above and all is working! It sounds beyond amazing.

 I would like to thank everybody that has helped me with certain issues along the way and a huge thanks to the AMB team for providing such an excellent project for DIY enthusiasts.


----------



## spiftacu1ar

I jsut ordered all the parts to make a gamma1 Full++, gamma2, and sigma11. In the process, I made an excel with links for all the parts, as well as the quantity you need in each link. It has links for all options, so you can change the quantity for a given part, and the price estimate at the bottom will change accordingly. Mouser is the primary supplier, but not in stock for everything.

 I have attached it if anyone wants it. (xlsx format)

 EDIT: btw, the gamma1, gamma2, and sigma11 are in different sheets.


----------



## slowpogo

I'm curious, is this an acceptable part for the oscillator:

Digi-Key - 535-9318-1-ND (Manufacturer - ASV-24.576MHZ-E-J-T)


----------



## MisterX

Yes.
 It's the same as Mouser # 815-ASV-24.576-EJ-T


----------



## Nebby

I have found out by accident that the y1/y2 combo does not like to be fed 12v. :facepalm: At first I hoped that the regulators sacrificed themselves to save the rest but after replacing them it's obvious they didn't. SMD (de)soldering is twice as fun with parts all around!


----------



## MisterX

It's not to bad once you get the big caps out of the way. 

 The example below is from a death by starving student repair job:


----------



## Nebby

Yea, I guess I'll suck it up and desolder the caps. Been doing the soldering with them in place so far 
	

	
	
		
		

		
		
	


	




 I must say though, it was definitely an anti-climactic moment when the voltages checked out and all I got for my work replacing the regs was static filled music 


 I see the bits of metal in your pic there; do you cut off the leads then desolder? It worked well with me for the regs but I haven't done any of the larger chips with that method. Was contemplating buying a chip-quick pack just in case it didn't work well for those.


----------



## slowpogo

OK...I was always bothered that in amb's parts list, he says the Abracon through-hole oscillator listed has slightly inferior specs. That was the only part from the list in stock when I built my y2, so I used it, but was always on the look out for one of the better oscillators to be available. I'm one of the 'pedantic' people amb mentioned. 
	

	
	
		
		

		
		
	


	




 Anyway, I replaced the inferior part with the one mentioned above (20ppm, better temp tolerances, etc)...I didn't get sound at first, which is why I checked that it was compatible, but it turns out I had it rotated 90 degrees from where it should be. I fixed that, and now it works.

 I'm sure many would not believe it - but I'm getting better sound with this 'better' oscillator. Before, with the cheaper through-hole, there was a definite glassy harshness on the upper end, especially noticeable with high orchestral strings. That is greatly reduced now. I didn't expect to hear much difference, if any at all - I made the change mostly to satisfy my neurotic obsession with milking that last 1% of sound quality, which I acknowledge is mostly just trying to squeeze blood from a stone. BUT, to my surprise, it was a definitely noticeable, if not earth-shaking, improvement.


----------



## ShinyFalcon

Would chip quick make through-hole desoldering a snap as well? I would guess that it would be more difficult to handle the parts because of the heat that lingers around, assuming the chip quick that's on the component continues to heat the component up.

 Interesting, slowpogo. I feel like playing with another y2 now


----------



## slowpogo

I tried briefly to desolder the through-hole oscillator, but I realized that without something like chip-quik it just wasn't gonna happen. I ended up just twisting it off the board with some pliers 
	

	
	
		
		

		
		
	


	




 which was pretty easy. I removed the leads still sticking out and that was it. Of course that part is ruined, but I was banking that the new one would at the very least work as well.

 I had to rotate the SMD oscillator...I ended up using a resistor lead to bridge two of the SMD pads, then piled on a crapload of solder, in the style of chip-quik. The resistor lead allowed the big solder blob to bridge the pads, so I could then lift that side.


----------



## Beefy

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_I'm sure many would not believe it - but I'm getting better sound with this 'better' oscillator._

 

*puts up hand* I don't believe it.


----------



## MisterX

Quote:


 I see the bits of metal in your pic there; do you cut off the leads then desolder? It worked well with me for the regs but I haven't done any of the larger chips with that method. Was contemplating buying a chip-quick pack just in case it didn't work well for those. 
 


 Both...
 I just cut the leads off the PCM2707 but used chip quik to remove U2U (I turned it every which way and couldn't get my knife in there real good so figured plan B was the better option for that one). 
 But I also had the chip quik right there in the drawer so it was an easy choice. 
	

	
	
		
		

		
		
	


	




  Quote:


 Would chip quick make through-hole desoldering a snap as well? 
 

Yes. 
 In fact it makes a lot of those "tough task" de-soldering jobs doable with a single soldering iron (like replacing a pot for example).


----------



## slowpogo

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_*puts up hand* I don't believe it._

 

Yeah, I know your type is out there. Doesn't matter to me though, I hear what I hear.

 You're better off really - less neurotic, more rich.


----------



## Nebby

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_Yeah, I know your type is out there. Doesn't matter to me though, I hear what I hear.

 You're better off really - less neurotic, more rich. 
	

	
	
		
		

		
		
	


	


_

 

I like my bronze ears very much thank you


----------



## K3cT

I know what you mean, slowpogo. 
	

	
	
		
		

		
		
	


	




 I plan to replace the bypass film caps with MKP2 since this would be a quick and dirty job. I'll let you know how it sounds later.


----------



## Beefy

Quote:


  Originally Posted by *K3cT* /img/forum/go_quote.gif 
_I know what you mean, slowpogo. 
	

	
	
		
		

		
		
	


	




 I plan to replace the bypass film caps with MKP2 since this would be a quick and dirty job. I'll let you know how it sounds later._

 

Well sure, coupling caps directly in the signal path...... no question that they could affect the sound quality.

 But an oscillator with slightly lower specs? After admitting that he was unhappy with the old oscillator because of a neuroses? Not even A-B'ed, but compared from audio memory after a difficult part removal, having to rotate the new oscillator, then being relieved the whole thing actually still works?

 Colour me unsurprised that somebody _wants_ it to sound better.


----------



## Nebby

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_Well sure, coupling caps directly in the signal path...... no question that they could affect the sound quality.

 But an oscillator with slightly lower specs? After admitting that he was unhappy with the old oscillator because of a neuroses? Not even A-B'ed, but compared from audio memory after a difficult part removal, having to rotate the new oscillator, then being relieved the whole thing actually still works?

 Colour me unsurprised that somebody wants it to sound better._

 

Confirmation bias - Wikipedia, the free encyclopedia perhaps?


----------



## fishski13

since we're on the topic of confirmation bias, i've been reassessing the o11 powering the y2 before i dedicate the PS to my nearly completed B1 buffer. well...there's a definate improvement with the o11. i stated in the past that i couldn't hear a difference between USB, wallwart, or o11. my excuse, my K702 only had a handful of hours on them 
	

	
	
		
		

		
		
	


	




. i have a few LM7805 lying around that i will try as well.


----------



## slowpogo

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_Well sure, coupling caps directly in the signal path...... no question that they could affect the sound quality.

 But an oscillator with slightly lower specs? After admitting that he was unhappy with the old oscillator because of a neuroses? Not even A-B'ed, but compared from audio memory after a difficult part removal, having to rotate the new oscillator, then being relieved the whole thing actually still works?

 Colour me unsurprised that somebody wants it to sound better._

 

I'm capable of examining my own thoughts, biases and psychology - I do it all the time. I'm not one of Pavlov's dogs. And I'm well aware of the completely unscientific 'testing' employed here. I've done all this, and I still think it sounds better. For the record, I do have quite excellent audio memory - perfect pitch and tempo memory, for example. I exercise these abilities a lot, as I am a trained musician. For me, audio memory is pretty much like taste memory. I may not have tasted restaurant x's chicken curry for many months - doesn't mean I can't decide I think restaurant y's curry is a lot better tonight.

 As far as this debate...Beefy, you're igniting an old, pointless debate that's been had many times and goes nowhere. As I recall, you have a tendency to do this (remember, you persistently picked at the sampling thing a few months ago). If you want to talk psychology, we could do that about your habits, too. We should probably just drop this one.


----------



## Beefy

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_As far as this debate...Beefy, you're igniting an old, pointless debate that's been had many times and goes nowhere. As I recall, you have a tendency to do this (remember, you persistently picked at the sampling thing). If you want to talk psychology, we could do that about your habits, too. You should probably just move on.._

 

Rowr, kitties got claws.

 If you weren't interested in a debate, you wouldn't have posted "I'm sure many would not believe it......"


----------



## MisterX

Quote:


 You should probably just move on. 
 

Or you could probably just leave it alone and not try to defend a ridiculous position.


----------



## slowpogo

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_If you weren't interested in a debate, you wouldn't have posted "I'm sure many would not believe it......"_

 

Just because I acknowledge that a well-established debate exists, doesn't mean I'm inviting it or interested in having it. Still, when you shoot those snarky little arrows my way, I'll probably respond. I suppose it is my fault for encouraging your behavior.

 "Changing parts in DAC affects sound" = "ridiculous position"...OK.

 Gahh...I'm getting sucked in again, aren't I? OK, I'm not going to look at this thread for a few days now.


----------



## Beefy

Quote:


  Originally Posted by *slowpogo* /img/forum/go_quote.gif 
_I suppose it is my fault for encouraging your behavior._

 

Similarly, if somebody like myself doesn't say something, then nobody is placing any burden of proof on you. The Emperor keeps strutting around naked.

  Quote:


 OK, I'm not going to look at this thread for a few days now. 
 

Sounds good to me!


----------



## Nebby

How about we just all agree that very generally speaking, DIY'ers will usually go for higher spec'd parts regardless of whether they are audible or not. Overkill for the sake of overkill, perhaps?


----------



## MisterX

Quote:


 
 "Changing parts in DAC affects sound" = "ridiculous position"...OK.

 


 Position not conclusion. 
	

	
	
		
		

		
		
	


	




*Here is the position you offered:* 

  Quote:


 OK...I was always bothered that in amb's parts list, he says the Abracon through-hole oscillator listed has slightly inferior specs. That was the only part from the list in stock when I built my y2, so I used it, but was always on the look out for one of the better oscillators to be available. I'm one of the 'pedantic' people amb mentioned. 

 Anyway, I replaced the inferior part with the one mentioned above (20ppm, better temp tolerances, etc)...I didn't get sound at first, which is why I checked that it was compatible, but it turns out I had it rotated 90 degrees from where it should be. I fixed that, and now it works. 
 

The ridiculous parts are underlined.


----------



## Nebby

Quote:


 4. Crystek, EuroQuartz and Aker are SMD, with slightly better specs. Abracon is through hole. 
 

Not defending or opposing anyone, but this is what is in note 4 of the gamma2 part list.


----------



## lampee

Hi Everybody!

 I have just finished my gamma2, and it doesn't seem to work properly. The instructions on amb.org wrote that, if U1D is populated, then it should detect which power supply to use, but the device only gets power from USB if I short the right jumper. It's no big deal, but it would be good, if it worked.
 My other problem is, that the DAC is really noisy. I plug it into USB, and the music plays, but it is too loud and a lot of digital noise are in it. If I switch it to Coaxial or Optical, then strange noise comes out from it, even if there is no signal on the inputs.
 Please tell me if you have experienced problems like that, and if you had, please tell me how to solve them. Thanks!


----------



## particleman14

could be from your usb power? my usb ports on my comp give kind of dirty power, and I sometimes get a hiss. maybe try dif usb ports (on dif computers too) to see if it changes?


----------



## lampee

It's not some kind of hiss, not just a little amount of noise, a lot of. It's like half signal half noise. And I think the opa is configured unity gain, or something like that, and if I plug a simple earphone into it, it almost kills it with the high volume.


----------



## amb

lampee, did you go through all the initial checks? Do all the test points show the correct voltage? Are all the jumpers set correctly? Does the γ1 portion work properly (front panel output)?


----------



## lampee

All the voltage point are good, 3.3V is 3.29V, 5V is 4.97V and 4.5V is 4.49. I didn't populate the gamma1 DAC part and the usb-spdif converter part, because I don't really need them. Now I tried the DAC with a PC speaker with built in amp, and there is only hiss no sound. I think I will reflow everything I can (although I did it onve) and I will see what happens.
 I also thought that I try the dac with only USB input with the proper jumper setting, and I will know where the problem comes from. I will let you know with the further information, as soon as I figured out what could be the problem.


----------



## lampee

I screwed up everything I could. Probably not, but the three 3.3V regulators are messed up, so I have to order more of them. Until then I will not post I think. If you have som idea though, about the noise, share with me.

 After some experimenting I tried USB, Optical, and Coaxial too and the result was the same. Noise noise noise and a little music.


----------



## lampee

OK.
  Let me continue my experience with the soldering and testing.
  I resoldered the voltage regulators and populated the gamma1 DAC part. The gamma1 DAC sounds really good, no hiss, no noise, just music. Everything works, so the usb, the optical and the coaxial, too.
  But when I try the gamma2 output the music becomes noisy. There is a lot of cracking and clipping in the sound and I don't really knoww where it comes from. If somebody could find out and tell me what could cause the problem, I would be really thankful.
  On monday I will get a scope, but until then I'm looking for advices.


----------



## amb

lampee, how about posting clear pics of your γ2 board?


----------



## francisdemarte

Reflow the solder on the X1 oscillator. That part was a pain to soldier for me and causes similar problems, make sure you don't have too much solder.


----------



## lampee

I have figured out what caused the problem. The X1 oscillator was the problem indeed, but the problem was not with the soldering, but that it was soldered. As I found out when the ASRC isn't populated, the X1 cause a lot of problem when soldered. So again I was a fool .
  The DAC sounds really great now. Thanks for the advice.


----------



## slowpogo

Back when I used the Emu 1212m, and before it the Juli@, I read about a common mod people do for sound cards...bypass caps on the voltage legs of the opamp (legs 4 and 8).  People recommended organic caps like os-con or similar.
   
  I'm not even sure if there's room to do this with the y2, but would there be any benefit?  Is it even worth trying?


----------



## amb

γ1/γ2 already has "organic" (conductor polymer) caps on all its power rails, and then it's further decoupled with MLCCs at each chip.  There is no benefit to adding even more caps.


----------



## MisterX

Quote:


smeggy said:


> Never!!!
> 
> 
> 
> ...


 

 Is it soon yet?


----------



## unl3a5h3d

I really want to make one of these but I want to buy all of the parts as a kit. Does anyone sell them?


----------



## Nebby

I did a cursory look around when I started planning my build and to my knowledge there is no kit available from anyone thus far. To be fair it's not too difficult to put together a BOM from AMB's parts lists.
  
  Quote: 





unl3a5h3d said:


> I really want to make one of these but I want to buy all of the parts as a kit. Does anyone sell them?


----------



## K3cT

Quote: 





unl3a5h3d said:


> I really want to make one of these but I want to buy all of the parts as a kit. Does anyone sell them?


 

 No kit but AMB's site is comprehensive enough that you can order your own "kit" easily.


----------



## Shahrose

Quick question guys: does anyone know if the 2dB anticlipping switch degrades SQ? I mean does it reduce the bits in the digital domain. If not, how exactly does it attenuate the signal?


----------



## MisterX

http://www.wolfsonmicro.com/uploads/documents/en/WM8741.pdf
   
  Page 41


----------



## Shahrose

Quote: 





misterx said:


> http://www.wolfsonmicro.com/uploads/documents/en/WM8741.pdf
> 
> Page 41


 

 Thanks Marshall. Subjectively, I hear no difference in SQ by toggling the anticlip switch, but I was curious anyways.


----------



## Townyj

Anyone builders within Australia who would knock me on of these up..?? PM me please.


----------



## viking87

Hey everyone, 
   
  quick question: I'm sick of waiting for opa2365aid, and I think I can get a opa2365aidr, so can I use this instead? I do not know what the r suffix means Thanks!


----------



## amb

Quote: 





viking87 said:


> Hey everyone,
> 
> quick question: I'm sick of waiting for opa2365aid, and I think I can get a opa2365aidr, so can I use this instead? I do not know what the r suffix means Thanks!


 

 The R-suffix means nothing here.  It's the bulk packaging option (for "taped Reel").  If your vendor offers them as "cut tape" in single quantities then it's fine.


----------



## viking87

Awesome, thanks!


----------



## ccbass

I'm interested in have one of my friends build this for me.  From what I can tell, I need to build the y1 minus the enclosure, and then build the y2 and then stuff both into the enclosure of the y2?


----------



## Nebby

If you're going for the full++/y2 build then yes, you need both parts of the y1, the y2, and the y2 box enclosure. There are MANY options for building the dac though, so make sure to read AMB's documentation on his website


----------



## ccbass

I am a little bit lost over all of the options available. Any suggestions on either stable builds/features, or the best quality sound?


----------



## amb

Quote: 





ccbass said:


> I am a little bit lost over all of the options available. Any suggestions on either stable builds/features, or the best quality sound?


 

 All the configurations are "stable" and offer quality sound.  Which option to choose depends on what features and functions you want and need.  Read the y1/y2 websites for complete details.


----------



## K3cT

I have replaced the default MKS output bypass caps with Wima MKP2s and I'm detecting an improvement to the bass and treble.


----------



## lampee

I really don't know how, but somehow my y2 got messed up. The right channel now sound like crap, when bass sounds on left the right is cracking like hell. I checked everything I could, I reflowd the complete right channel. After that I checked the sound at every point, and it seems like the right channel of the opa messed up somehow, because the music is good right after the dac both +- testpoints and it is also good before R15 but the opa side solder point of R15 gives cracking sound. Could somebody help me what could cause this, or tell me if not the opa, then what is the problem?


----------



## lampee

Ok, now i know that the opa is bad. I airwired the opa's left channel to the right and the sound was clear, so I ordered the opa again. I will upload pictures of the flying opa later


----------



## phishhead92

how much does this all cost with the Full++/y2? i was looking at the jambo DAC, then realized it only supports 44.1kHz, i need more than that


----------



## Ntropic

The y1 full++ cost me about $100 before shipping, and the y2 costs around $90 before shipping. This is without an enclosure.
  
  Quote: 





phishhead92 said:


> how much does this all cost with the Full++/y2? i was looking at the jambo DAC, then realized it only supports 44.1kHz, i need more than that


----------



## phishhead92

okay thats not bad, thank you for the quick reply.


----------



## viking87

hey all, 
   
  I've finally got all of the parts together for my y2 and found the time to put it together, but of course, I screwed something up... I put the two boards together and connected it to usb and everything seems to work except there is no sound from the rca's. the led does switch to green when I press play on my computer, so that is working. I think my voltages are fine, but here they are:
  Top VCC test point = 4.87
  4.5v test = 4.73
  3.3v test = 3.28
  Bottom VCC test = 4.87
   
   and the two 5v test points by the bottom VCC are 4.87 and 4.9 volts.
   
  Any ideas?? thanks in advance!


----------



## viking87

NVM all, I was troubleshooting for awhile, and turns out reflowing the X1 did the trick... I didnt really know how to do that on right any ways so that figures that was it... Thanks all, and I apologize for the unnecessary posts... and finally...
   
  A BIG thanks to AMB and MisterX for their time and effort, as well as this awesome forum. 3 months of waiting... and now its alive! Thanks!


----------



## godog

I'm wondering if there will be a non-compact high performance dac


----------



## Nebby

Not yet, but I believe it's on AMB's to-do list


----------



## mattcalf

Howdy amazing troubleshooting resourse that is this thread.
   
  My (ex-)DAC has malfunctioned after 5 minutes of use in it's new home. It was packed very well in the hammond enclosure (no faceplates). It then became unrecognized and ceased outputting music. 
   
  Current pictures available here.
   
   
  Here's the problem:
  Quote: 





> When I first plug in the usb cable, the selector switch led is bright red and the unit is recognized by my mac (but won't play music). But after a minute or so, the red led begins to flicker, goes dim and then the computer no longer sees the dac. Even when I select it as the audio source from my computer, the led never turns green.


 
   
  Any ideas?


----------



## Kibble Fat

Sorry to interject, but does anyone have a (6) spare polypropylene film capacitors (100pF, 100V)?  Name your price!
   
This would help me finish my gamma-2 a month sooner


----------



## amb

Kibble Fat, try Mouser 505-FKP2100/1000/5.


----------



## MisterX

You could also try Mouser part numbers:
  80-PFR5101J400J11L4 & 80-PFR5221J400J11L4


----------



## Kibble Fat

Well then, assuming nothing is back-ordered at AMB, here are all 4 items holding up my Mouser order.  Since I couldn’t find a suitable replacement for the 22K resistors, I guess I’ll have to make a separate order from Digi-Key.

 (6) 505-FKP2100/100/2.5
 OR 505-FKP2100/1000/5, 80-PFR5101J400J11L4 & 80-PFR5221J400J11L4

 (1) 595-TPS79333DBVR

 (1) 595-OPA2365AID

 (10) 270-22K-RC
 I couldn’t find a suitable replacement.  ¼ watt wouldn’t fit, would it?

 Thanks for the help.  I can’t say this is the last you will hear from me in this thread


----------



## amb

Quote: 





kibble fat said:


> (1) 595-TPS79333DBVR


 
   
Any of these would do.
   
  Quote: 





> (1) 595-OPA2365AID


 
   
  Mouser shows that they will be in stock in about one week, so you could order now and have them hold the entire order until all back-ordered parts arrive.
   
  Quote: 





> (10) 270-22K-RC
> I couldn’t find a suitable replacement.  ¼ watt wouldn’t fit, would it?


 
   
  Most ¼ watt wouldn’t fit. Try this one: 71-RN50C2212F


----------



## midoo1990

sorry if this has been answered before,but are all the parts available at amb shop?i looked at the part lists and wrote down what i will need,but apparently not all available at the shop.
  i was looking forward to build the mini3 first and then the y2 because its more complex but i am a bit confused by all the parts and i cant get them from many online retailers because customs will kill me.
   
  is there anyone that offer it as a whole kit?
   
  sorry if i missed the answer of this question somewhere.


----------



## amb

Quote: 





midoo1990 said:


> is there anyone that offer it as a whole kit?


 

 No.


----------



## Kibble Fat

Thanks for the help Ti!  I bought (10) 1%tol 22K resistors on ebay for a dollar.  Shipping was only a couple dollars + change.  Now I just have to wait for paypal money to arrive...


----------



## i_djoel2000

anyone can help me? i just bought gamma1 full config, and it is said to be easily upgradable to gamma2?
   
  what other parts do i have to buy to build gamma2? as for the casing, i think i will just drill the old gamma1 full config case as it already fits the gamma2 enclosure


----------



## xnor

@i_djoel2000: http://amb.org


----------



## i_djoel2000

Quote: 





xnor said:


> @i_djoel2000: http://amb.org


 

 found it. i was not searching it thoroughly. thanx!


----------



## K3cT

I haven't posted here in a while but has anyone here tried to run the C20 and C26 positions without the film bypass? If the 'lytic is of high enough quality, don't you guys think it will be better?
   
  Gah, I'm bordering on OCD already I know.


----------



## QRomo

I had some extra Blackgate NX's I ordered for whenever I get around to doing a diyMod that I used in C20 and C26. I've omitted the bypass caps for now as I've read some people suggest that the BGs don't need them (some even said their BGs sounded worse when bypassed).  I can't really offer any impressions, though, as I haven't had a chance to do any critical listening.  I'm just finishing off an amp to pair with the γ2 and still have to get my hands a nice set of full size cans.


----------



## TBomb06

I have a couple of questions regarding the technical capability and sound signature of the various chips used in the y2 compared to my current DAC, a Musiland MD-10. I am not asking for a "which is better" comparison or anything like that, as I know that AMB's projects are all top notch and easily compete with off-the-shelf products that cost several times as much. I am more interested in what is to be gained or lost if I were to sell the MD-10 and build a y2. For what it's worth, I primarily use optical out from my computer to the Musiland, and then use RCAs to connect to a Millett Hybrid MOSFET Max feeding Grado SR225s. According to another thread I found here, the chips used in the MD-10 are:
   
  DAC: Cirrus CS4398
  Op-amp: Analog Devices OP275
   
  From what I have gathered, the Wolfson DAC and Burr-Brown upsampling chips used in the y2 are pretty much the best thing going as far as DACs are concerned. I haven't seen much about the Cirrus. So, does anyone have any thoughts?


----------



## Beefy

Quote:  





> So, does anyone have any thoughts?


 


 Only that I really enjoy my y2 into a MiniMax as my work setup.


----------



## K3cT

Quote: 





qromo said:


> I had some extra Blackgate NX's I ordered for whenever I get around to doing a diyMod that I used in C20 and C26. I've omitted the bypass caps for now as I've read some people suggest that the BGs don't need them (some even said their BGs sounded worse when bypassed).  I can't really offer any impressions, though, as I haven't had a chance to do any critical listening.  I'm just finishing off an amp to pair with the γ2 and still have to get my hands a nice set of full size cans.


 

 Yeah, that's what I've heard too about the Blackgates. I'm rather curious about them as they are expensive and hard to acquire. Right now I'm using Elna Silmic II in C20, C26 bypassed with MKP2. I'm happy with the sound but I guess it doesn't hurt to try new experiments.
   
  Let me ask you something though. How do you find the y2 sound with the NX? Is it more to the slightly warmish side or more to the bright side?

  
  Quote: 





tbomb06 said:


> I have a couple of questions regarding the technical capability and sound signature of the various chips used in the y2 compared to my current DAC, a Musiland MD-10. I am not asking for a "which is better" comparison or anything like that, as I know that AMB's projects are all top notch and easily compete with off-the-shelf products that cost several times as much. I am more interested in what is to be gained or lost if I were to sell the MD-10 and build a y2. For what it's worth, I primarily use optical out from my computer to the Musiland, and then use RCAs to connect to a Millett Hybrid MOSFET Max feeding Grado SR225s. According to another thread I found here, the chips used in the MD-10 are:
> 
> DAC: Cirrus CS4398
> Op-amp: Analog Devices OP275
> ...


 

 I haven't heard the MD-10 so I only can offer anecdotes on the y2 part. I guess the clear tell-tale signs of a better DAC is instruments become clearly differentiated from one another instead of coming to you as mushed together. On top of that, you should be able to hear more details. If I compare vocals between the y1 and y2, it is clear the the vocal is more nuanced and detailed in the y2. It's the same case with guitar picks.
   
  I'm not sure about the MD-10 but isn't it able to do asynchrnous via USB? The y2 certainly doesn't have this capability so this will be your loss. How much this translates to a loss in SQ is of course, another question.


----------



## TBomb06

Quote: 





beefy said:


> Only that I really enjoy my y2 into a MiniMax as my work setup.


 

 I'm thinking I'll be using a Mini3/grubDAC (Carrie USB style) for my work setup, since I need something a little more discrete.
   
  Quote: 





			
				K3cT said:
			
		

> I haven't heard the MD-10 so I only can offer anecdotes on the y2 part. I guess the clear tell-tale signs of a better DAC is instruments become clearly differentiated from one another instead of coming to you as mushed together. On top of that, you should be able to hear more details. If I compare vocals between the y1 and y2, it is clear the the vocal is more nuanced and detailed in the y2. It's the same case with guitar picks.
> 
> I'm not sure about the MD-10 but isn't it able to do asynchrnous via USB? The y2 certainly doesn't have this capability so this will be your loss. How much this translates to a loss in SQ is of course, another question.


 
   
  Oh man, I am not really sure about asynchronous USB. I know that via USB it can only handle 16bit/48khz input.


----------



## QRomo

Quote: 





k3ct said:


> Yeah, that's what I've heard too about the Blackgates. I'm rather curious about them as they are expensive and hard to acquire. Right now I'm using Elna Silmic II in C20, C26 bypassed with MKP2. I'm happy with the sound but I guess it doesn't hurt to try new experiments.
> 
> Let me ask you something though. How do you find the y2 sound with the NX? Is it more to the slightly warmish side or more to the bright side?


 
   
  Well, I'm not blessed with golden ears, but since you asked I grabbed the Mini3 I built for my brother and had a listen with a pair of Shure 530s. So far, they sound pretty neutral to me. I may not have been listening to the most revealing source material, though, nor do I really have good basis for comparison (like another γ2 with stock Muse caps). So my probably not so helpful opinion is that they sound pretty good to me. 
   
  That said, I doubt I'd bother ordering them special to go in the γ2. My main reason for ordering them was for their size when using them in a diyMod LOD. I figured if I was going to be ordering them anyway, I might as well pick up some extras for other projects. The only place I could find them was at Sonic Craft for about $5 a pop. I see now they're up to $8 each. That's, what, 50 times the price of an Elna Silmic II? Unfortunately I can't compare the two head to head, but by all accounts the Silmic's are pretty darn good. I doubt whatever difference I might detect (if any) would be worth the huge price gap. So if I didn't already have the BGs, I'd probably have done the same thing you did.
   
  If you're really keen on trying them out, I picked up enough extras that I can spare a couple. Shoot me a PM and I can send you a pair for the price I paid for them.


----------



## MASantos

I had a pair of Nx's in a malfunctioning alien dac and removed them to use in my gamma2. I really like the sound but since I haven't heard a gamma2 with another choice of output caps I can't offer any comparison!
   
  Here are some photos of the wood case I'm building for it:
   
  The two outer boards are just there for distributing the pressure while the glue cures. 

   
  And one of these 3 veneers (the top one is actually more yellowish) will be used on the case, what would you guys choose? I'm think the black one would look the best.

   
  More picstures soon!


----------



## K3cT

That's a very interesting case project that you got there. I do plan to case my Beta22 in a wooden case as well but I'm not sure with the amount of heat it generates!
   
  Anyway, do you use your NX-es bypassed or on their own?
   
  @QRomo
  Check your PM bro.


----------



## i_djoel2000

can i replace WM8501 in gamma1 full config(A) with WM8741 without any adjustment or modification?
   
  will it actually improve the sound quality in my gamma1?


----------



## amb

Quote: 





i_djoel2000 said:


> can i replace WM8501 in gamma1 full config(A) with WM8741 without any adjustment or modification?


 

 No, they are not pin-compatible.  To use WM8741 you need to build a γ2 to complement the γ1.


----------



## viction

Just finished building a y2 and connected it to my preamp and laptop. The laptop reads the USB DAC and the y2 switch lights up green when I played music but I have no sound. After a couple of late nights of stuffing the boards I find myself totally stuck. I'm not electronically savy and do not even own a DMM. I have gotten away with building quite a few amps found on this site's DIY section including my newest Bijou tube amp by following directions very carefully and by being very meticulous. So how do I start diagnosing my y2? And I'll be picking up a Fluke 87 tomorrow!


----------



## MisterX

Quote: 





> So how do I start diagnosing my y2?


 
   Does the Gamma 1 output work?
   
  When you have your DMM in hand run through the steps outlined in the respective "Initial check" pages and we'll have a better idea which direction to point you.


----------



## midoo1990

one question.how do i solder the X1 part?thanks
  also will the orientation differ?


----------



## MisterX

Tin the pads on the crystal, apply flux to the PCB, place the component, apply heat and watch for the solder to flow. 
  Or:
  Apply flux to the PCB, place the part, put a little solder on the tip of your iron and then touch it to the pad.


----------



## MisterX

Quote: 





midoo1990 said:


> also will the orientation differ?


 


 The crystal should be marked.


----------



## midoo1990

what crystal?
  edit,got it.
  EDIT2: should the solder touch the openings on the pcb?


----------



## midoo1990

ok i did it.thank you Mr.x


----------



## Kibble Fat

Quick question.  On the gamma-1, are there supposed to be any continuities between adjacent pins on U1U and U2D?  I have 1 continuity on each with no visible solder bridges.
   
  I checked their datasheets and didn't find any
   
  EDIT:
  for U2D, TSEL0 and TSEL1
  for U1U, pins 25 and 26
   
  I answered my own question... :embarrassed:


----------



## pterodactilo

How many of these parts do I need to build a full gamma1 , full++   (i've not decided which one yet) and gamma2 ?
   
  Gamma1:
   
  JP1D, JP2U-1, JP2U-2, JP2U-3
   

   [size=smaller]2P short pin header[/size] [size=smaller]517-647-01-36 (break apart)[/size]
   
  JP1U, JP2D
   

 [size=smaller]3P short pin header[/size] [size=smaller]517-647-01-36 (break apart)[/size]
   
  -
   

   [size=smaller]2P jumper shunts[/size] [size=smaller]649-68786-202LF (single)[/size]
   
   
  Gamma2:
   
   
  J3
   

 [size=smaller]2P pin receptacle[/size] [size=smaller]517-850-01-08 (break apart)[/size]
   
  JP2
   

 [size=smaller]2-row 4P short pin header[/size] [size=smaller]649-67997-108HLF[/size]
   
   
  If I go with the full ++ route and later upgrade to gamma2, then I have to desolder the ribbon cable which provides connectivity between the USB and DAC modules?


----------



## amb

Quote: 





pterodactilo said:


> How many of these parts do I need to build a full gamma1 , full++   (i've not decided which one yet) and gamma2 ?


 
   
  Have you looked at the parts lists and notes at both the γ1 and γ2 websites?  Your answers are all there.
   
  Quote: 





> If I go with the full ++ route and later upgrade to gamma2, then I have to desolder the ribbon cable which provides connectivity between the USB and DAC modules?


 
   
  Yes.


----------



## MASantos

Update on Gamma2 case, I did the front and rear panels today. Front Panel is glued to the case and the rear panel is removable. It holds in place like a few portable amps, a threaded rod fixed to the case with thumb nuts holding it together. Case was sanded with a belt sander and I noticed that the top panel was slightly convex in the middle, hence the white bitumen in the middle. A few other recessions where also taken care of. Overall I'm quite pleased with the result taking into account that I'm using old spares of wood. Next week I'll be veneering the case.
   
  Front Panel with holes for the Gamma2 Switches.

   
   
  Top and back panel, I opted to make a large rectangular opening on the back instead of drilling the individual holes for each connector as this proved much easier and faster, andwill make veneering much easier too. Still some sanding to do on the inside corners .




 Detail of the inside of the side panel. The top rail is slightly deeper because of the wider gamma1 pcb.
   


 Back panel removed, you can see the treaded rod assembly, will be glued with epoxy after the veneer is done.



 Back with the Gamma2 inside, there is good clearance around each connector and I'm satisfied with the result.



 Front with Gamma2, the left top hole isn't perfectly centered around the switch, but I'll grind it better, the veneer will also correct this.


----------



## midoo1990

guy,i bought some parts from the only electronic store in my country but i feel that the materials are of bad quality and not like the parts i ordered from Digikey.i am really not sure if it would make any difference.
  here are pics


----------



## midoo1990

^^any help please?


----------



## amb

midoo, those ceramic disc capacitors are awful.  You should use multilayer ceramics as specified in the parts list.  As for the electrolytics, they are probably of questionable quality as well.


----------



## midoo1990

ya i knew they were terrible.i tried telling the electrician who brought them to me that these should go to the bin and that they are not multilayer but he argued it wont matter.i will order many parts from digikey tonight and also parts from amb shop.
  what a money waste.i will put them in the bin.


----------



## jdkJake

Finally finished my y2 build this week (quiet house, warn iron). This is the option D version y1 with corresponding y2:
   

   
  I had two issues, a soldier bridge on U4 pin 8 and 9, which manifest itself as pin 14 (mute) asserting not ready to pin 15 (as it should!). Thanks to AMB and MisterX for the well placed test points to determine that relatively quickly. The second issue was the ground pin on X1. Even though I hit it a couple of times with the old iron, Still no clock. I pulled the chip and low and behold, the ground pin was clean. Too clean. A wise tech I know always said to tin a gold contact prior to soldering. I did this on my GrubDac, but not on this one. Turns out he was right (as usual) and it works great now. He is still laughing at me.
   
  I am going to power it with this beauty:
   

   
  Now to case it up.
   
  I am starting to get the hang of this SMD stuff. Still not a big fan, but, capable nonetheless.


----------



## phishhead92

I got a fresh new PCB and all of the reccomended components, i put it all together it did not pass the initial check, then i just reflowed EVERY SINGLE JOINT (there were no visible bridges or cold joints) and it still does not pass the initial check, this is the second board i have gone though i have no idea what i am doing wrong
   
  I omitted U4 and all the components the note tells you to omit, i also used a WM8741 so i omitted U6 as it says, i jumpered all the JP2 slots.
   
  then i just rechecked it and the same problem, it does not pass the initial check. Here are my testing results (multimeter set at 2000k ohms)
   
  4.5V: 072
  3.3V: 000
  5V(top): starts around 750 and slowly climbs till it evens out at about 930
  5V(bottom): infinite (so it checks out)
   
  it is clear that the 3.3 has a break in the circuit somewhere (if i am not mistaken)
   
  but i have no idea what is wrong with the others, also its weird because if i switch up the leads then i get a negative number on 4.5 (-025)
   
  also i just rechecked 4.5 and now it is giving me 024, and still a negative number when i switch it (-006)
   
  can someone please help me


----------



## jdkJake

Can you post some pictures of both boards, top and bottom?



 Lots of light and focus please. 

 BTW, you should be measuring voltage and not resistance.


----------



## MisterX

Continuity checks when the meter is set on a high (2000k ohms) scale are not very useful.
  Do you have some pictures?


----------



## phishhead92

Quote: 





jdkjake said:


> Can you post some pictures of both boards, top and bottom?
> 
> 
> 
> ...


 

 i am checking for continuity first, because if it has shorts or bridges there is no point in checking voltage until i fix them.

  
  Quote: 





misterx said:


> Continuity checks when the meter is set on a high (2000k ohms) scale are not very useful.
> Do you have some pictures?


 

 Oh, my bad, i put it down to 200 (lowest my meter goes)
   
  all are infinite except 3.3V
  thats around 50  +/-5
   
  and i dont have any pictures atm, i will take some tonight


----------



## MisterX

Without an X1, L5, C8, U4, L4, C7 and U3 installed the 3.3 volt problem is either with U2 or U5.
  Are you sure you have the right part installed in the U2 position and that U5 is installed the right way around?


----------



## phishhead92




----------



## MisterX

Several of the U5 pins need more attention, R1 is unnecessary and it looks like you need to get busy with some flux remover.


----------



## jdkJake

Can you provide a picture of your gamma 1 as well?
   
  As MisterX has pointed out, 91% alcohol will do wonders to remove the excess flux. Scrub and rinse with a nylon toothbrush works really well. Firm, yet gentle.
   
  A number of your joints look "cold". Are you using an adjustable temp soldering iron? You might want to hold just a bit longer on the joint under solder to insure the flow adheres to the part (or the lead in this case). 
   
  Do you have solder braid available? Putting some flux on U5 and sliding the braid against those pins to remove the excess solder will go along way. Again, be sure to clean it when finished.


----------



## phishhead92

Quote: 





misterx said:


> Several of the U5 pins need more attention, R1 is unnecessary and it looks like you need to get busy with some flux remover.


 

 o is flux conductive? cause thats probably it, i have 91 proof iso but it doesnt do it, i need to find some legit flux remover
   
  and yeah ill try getting in there and resoldering those.
   
  and im almost 100% on the U2 i made sure on the ICs especially (like triple checked) before they went on, and i already checked the U5 vs the board picture on amb
   
  does anything else look suspicious?


----------



## Kibble Fat

I had 91% for a while but found 99% at a meijer
   
  I read this in another thread.  Not sure how Tangent feels about being quoted, but this is the internets.
  Quote: 





			
				tangent said:
			
		

> Quote:
> 
> 
> I just got in a pound of 63/37 kester .025" solder
> ...


----------



## Kuze

Is it better to go with this over the σ24, also what type transformer is this and where can it be had, thank you.
  
  Quote: 





jdkjake said:


> I am going to power it with this beauty:


----------



## jdkJake

kuze said:


> Is it better to go with this over the σ24, also what type transformer is this and where can it be had, thank you.







 http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=TE62011-ND

 Thank MisterX, he found it first. I am just following his lead.


----------



## MrDavis

I think I made things worse trying to remove a bridge.  Yes, I think that is exposed metal where it should be green.  Is my board still usable?


----------



## amb

Quote: 





mrdavis said:


> I think I made things worse trying to remove a bridge.  Yes, I think that is exposed metal where it should be green.  Is my board still usable?


 
  Yes, you merely scraped off some soldermask, that's all.


----------



## K3cT

If you're that paranoid, you can use nail polisher to cover the exposed board.


----------



## steven2992

Aren't those pins supposed to be connected anyway? The traces both seem to lead to ground.


----------



## MisterX

Yep, both of those pins connect to the ground plane so it's not much more then an eyesore.


----------



## MrDavis

Quote: 





misterx said:


> Yep, both of those pins connect to the ground plane so it's not much more then an eyesore.


 

 Great news!  I'll leave that solder bridge right where it is.  Don't want to make things even worse.


----------



## phishhead92

I finally finished! turns out a nice cleaning and redoing some pins on U4 was all it took
   
  only 1 pin was not connected (but i redid some suspect ones)
   
  Yes! i'm super excited i finally finished this, and i leave for college on thursday, perfect timing


----------



## midoo1990

i finished my gamma2 full configuration++ and i tested the y1 board first and its not working.my computer is not recognising it.i tried it on two computers,one running windows7 and the other vista.
  i rechecked everything again and orientations....and its ok.
  any help?


----------



## amb

Quote: 





midoo1990 said:


> i finished my gamma2 full configuration++ and i tested the y1 board first and its not working.my computer is not recognising it.i tried it on two computers,one running windows7 and the other vista.
> i rechecked everything again and orientations....and its ok.
> any help?


 

 Did you go through the initial check steps at the γ1 website?  If so did any step not pass?  What are your measured voltages?


----------



## midoo1990

i just rechecked again.the JP2D pin 2 and the 4.5+ pin are reading zero with GND.the others are reading few ohms.
  something that i dont understand,i shouldnt hard wire the y1 board right?


----------



## amb

Quote: 





midoo1990 said:


> i just rechecked again.the JP2D pin 2 and the 4.5+ pin are reading zero with GND.the others are reading few ohms.
> something that i dont understand,i shouldnt hard wire the y1 board right?


 

 Are you measuring resistance? (I assume so if you're saying "ohms")
  If that's the case then you have solder bridges causing shorts to ground.
  I also asked you to report your _voltage_ measurements according to the initial check procedures.
   
  Quote: 





> something that i dont understand,i shouldnt hard wire the y1 board right?


 
   
  The "initial check" section tells you exactly what you need to do.


----------



## pterodactilo

I don't have  a 20nF cap to populate C19D on the gamma1 module. Can I use 10nF caps instead?


----------



## MisterX

That is arguably the most important cap value on the whole board and should not be changed.


----------



## midoo1990

sorry for the late response Mr.Ti .i was very busy.i will do the tests first thing in the morning and report back.


----------



## pterodactilo

Thanks MisterX. So I'll have to order this cap. Damn, and I triple-checked my mouser order!


----------



## nightanole

If i have a tube amp that can take 3-4 volts of dc offset, would it be better for me to bypass the output capacitors and run dc strait to the amp?  The tube amps driver stage is cap coupled to the output stage.  The driver tube is biased at -7 volts, so the +-2.5v signal with a 2.5v dc off set still leaves 2 volts of head room.


----------



## amb

Quote: 





nightanole said:


> If i have a tube amp that can take 3-4 volts of dc offset, would it be better for me to bypass the output capacitors and run dc strait to the amp?  The tube amps driver stage is cap coupled to the output stage.  The driver tube is biased at -7 volts, so the +-2.5v signal with a 2.5v dc off set still leaves 2 volts of head room.


 

 Maybe.  However, a DC offset may shift the operating point of your tube amp input stage enough away from the "center" (0V) to affect its linearity (assuming that the sweet spot is at the center, which may or may not be the case).


----------



## jdkJake

Finally had a break in the weather and the humidity dropped by a considerable amount. Still hot, but much more bearable.
   
  So, that means I was finally able to access my drill press and assorted power tools and complete my Gamma2/Sigma25 casework:
   

   
  First time cutting in a snap-in IEC socket. It is mostly straight.    Next one will be perfect now that I know what I am doing.
   

   
  I debated long and hard about bring the filter and clipping switches out the front, but, I figured I would go crazy not being able to manipulate them. At least for an initial listen. So, I might remake the front panel after I determine the setting I like best. I have really been getting into minimalistic panels lately.
   

   
  In any case, it is finished and sounds great. No hum or buzz that I can hear. The case is sized not only to match up with my other gear, but, also leave room for the inevitable update to the Gamma3 (or whatever follows). I learned that lesson once with the Gamma1.
   
  In any case, initial listening is quite positive. Who knows, I might just be able to finally retire the Keces.


----------



## nightanole

Uh am i really looking at a $15 panel mount switch craft usb port?  I was eyeballing them but couldnt bring myself to spend half a grubdac budget on a pannel connector...


----------



## MisterX

Looks more like a $6 Neutrik to me


----------



## Nebby

$15? That seems a bit high even for the switchcraft one. I'm pretty sure that one is a Neutrik NAUSB, about $4.30 from Markertek. I can't complain about prices myself, as I've spent more than $15 on a power button before 
	

	
	
		
		

		
			




   
  edit: darn you MisterX....too quick.


----------



## jdkJake

It is the Neutrik (available at mouser).



 While there is a $6 silver one available, I splurged and bought the $10 all-black one. Call me crazy, I'm like that sometimes.



 The goal was an attempt, however impetuous, to future proof the chassis through another DAC upgrade. It also made swapping out of my main two DAC's painless as they both now support B style female jacks. A win for me, YMMV.


----------



## MisterX

What $10 one?
   
http://www.mouser.com/Search/Refine.aspx?Keyword=NAUSB
   
  The one that was discontinued because it was not USB 2.0 compliant?


----------



## jdkJake

Well, what do you know, you are indeed right!
   
  I looked up my shipment confirmation:
   
   

 [size=small]568-NAUSB-W-B
Neutrik USB & Firewire Connectors
USBA-USB B A
US HTS: 8536.69.4020 ECCN:EAR99

 [size=small]1[/size] [size=small]1[/size] [size=small]5.630[/size] [size=small]5.63[/size]
[/size]   
  Score!! I am hitting the town big-time tonight!!


----------



## FishHead

Hi Gang,
   
  Just finished the y2 to go with the y1 full++.  I am experiencing voltage issues.
  I re-flowed U1 and U2.  It did help but it appears I am not getting enough voltage from the Y1.  Y1 was tested and it worked quite nicely with voltages correct at all places.  In looking at u2 the .021 looks like I need to hit it again with solder. 
   
  Readings:
   
  Bottom 5v = .039
  Top 5v = 2.4
   
  3.3 v = .019
   
  4.5 = 2.38
   
   
   
  U1:
   
  2.39v  |       |  ?
           |        | 0
  2.39v  |       | 2.39v
   
  U2:
   
  1.19v  |       |  2.39v
            |      |   0v
  .021v  |       |  2.39v
   
   VCC= 2.39v
   
  If you can point me to the next area to re-flow I would appreciate  it.


----------



## MisterX

With your meter in ohms mode measure between the 3.3 volt test pad on the Y2 board and ground. 
  If the meter reads very low ohms check the X1 soldering
  If the meter is reading high ohms repeat the test for the 4.5 volt test pad.
  (sounds like you have a short circuit on the Y2 and it's pulling the PSU/USB-VBUS (5 volt pads) low)


----------



## FishHead

You got it.  Last night I started probing around and found the 3.3 v test was shorted to ground.  I futzed with X1 because my soldering was sloppy.  That did not do it.   Nothing was obvious on main soldering so I pulled the schematic and traced out the 3.3 v pins that were next to a ground.  There it was U5 pin 23 to 24.  A little flux and a brief touch with the iron and we have green lights with sound!
   
  I am hearing a little noise floor with my UE Pro 5s during some quiet passages and would like some suggestions.
   
  I should get the box this week and will post a picture when finished.
   
  As of now yet another y2 lives!


----------



## K3cT

Use external power.


----------



## jdkJake

Quote: 





k3ct said:


> Use external power.


 


  That is probably a good suggestion. 
   
  What are you using as the input source? USB, optical or coax?
   
  Mine is USB-only and I never actually tried it with straight USB power as I built it for external power only. That being said, mine is dead quiet. And I mean DEAD quiet. I was quite impressed. The circuit and implementation is top notch all the way.


----------



## FishHead

Input was a(n) USB cable.  Foobar2000 ,FLAC rip using DBpoweramp,  DVD quality output.  I was just testing the guts to see if it would work.  Newark messed up my enclosure order so I am waiting for it before I start to hyperventilate about anything.  
   
  I just hooked up again using a Stancore (5v .6A) switching regulated wall wort .  Output 1 definitely has a white noise floor esp when compared to Output 2.   Upon further listening to output 2 it may be my imagination as there is a certain amount of white noise rolling around in my head anyway.  As for Output 1 the noise floor is about as loud as my breathing.  
   
  I then tested USB.  Same on both except for the dang windows dong which rattled my noggin.  Ouch!


----------



## Horio

So I'm running into some problems with my gamma-2.  I am building a single box gamma-2 (sigma25 powered) + CKK3 with a selector switch.  I had the gamma-2 working just fine several months ago when I tested it.  When I ran it off the USB power, it worked just fine.  Now that I have gotten to casing up the build, the gamma2 doesn't seem to be ouputting any sound. 
   
  I carefully checked the wiring through the selector switch and into the amp board, and everything seems fine.  The sigma is creating 5V as it should, the 5V test pads show 5V, the 3.3V pad shows 3.3V, and the 4.5V pad shows 4.7V.  When I plug it in via USB, the computer detects it and tries to output it sounds to the gamma-2.  I even tried the coax input via my CD player and still nothing.
   
  Could I be having some sort of grounding issue?  Maybe something to do with the NKK switches I used for the DAC input and dac filter selection?
   
  I'm really at a loss here.  Any ideas?
   
  Here are a few pictures:


----------



## Horio

Seems that a good isoproyl alcohol bath seemed to do the trick!


----------



## flexium

I have a question.
   
  What if I plug my 75 watt, 8Ohm speakers into gamma 2? What will happen? no sound because not enough power from gamma 2?
   
  The reason I am asking because I bought a pair of bookshelf speakers and I want to test them asap but have no way of testing them yet


----------



## amb

Quote: 





flexium said:


> I have a question.
> 
> What if I plug my 75 watt, 8Ohm speakers into gamma 2? What will happen? no sound because not enough power from gamma 2?
> 
> The reason I am asking because I bought a pair of bookshelf speakers and I want to test them asap but have no way of testing them yet


 

 It will make some sound, but not a heck of a lot before clipping. If your γ2 has the AD8656 in its output buffer rather than the OPA2365 it would be a little better into such a low Z load, but there is only so much it could do.


----------



## flexium

Ooo...you mean I can actually try it without damaging anything?
   
  I am not sure what opamp I have. I didn't really read into schematics when I asked Marshall to build it for me. Which one is the standard one?


----------



## amb

Quote: 





flexium said:


> Ooo...you mean I can actually try it without damaging anything?


 

 Both opamps have output current limiting protection so nothing should be damaged.
   
   
  Quote: 





> I am not sure what opamp I have. I didn't really read into schematics when I asked Marshall to build it for me. Which one is the standard one?


 
   
  There is no "standard" one, both are recommended.  You could open it up to have a look.


----------



## flexium

I think I am supposed to look at U7? 2365A... So it's the better one. Would the anticlipping setting do anything?
   
   
  I am having a hard time outputing "bit-perfect" to the dac(through SPDIF) using winamp and ASIO plug-in. Feels like my computer is not detecting the dac at all. 
   
  I tried the following setting but winamp won't play. it just keeps on skipping to the next song.


----------



## nightanole

your computer cant detect anything via optical/coax out.  It just sends it out, regardless if anything is connected.  Id work backwards.  Set winamp to wave out, see if you can get anything on spdif out.  To double check asio (guess your running xp) try foobar2000 with it.  I take it you did not make a usb version of the y1?  If you did then its not detected.


----------



## flexium

Quote: 





nightanole said:


> your computer cant detect anything via optical/coax out.  It just sends it out, regardless if anything is connected.  Id work backwards.  Set winamp to wave out, see if you can get anything on spdif out.  To double check asio (guess your running xp) try foobar2000 with it.  I take it you did not make a usb version of the y1?  If you did then its not detected.


 


  Got it but not sure exactly what i did. many thanks 
	

	
	
		
		

		
		
	


	



   
   
  I thought of a new question regarding dac to speaker problem.
   
  What if I go from the 3.5mm jack to speaker? Are all the output connected to U7 or are they separated? From the schematic page, I think the phone jack between RCA connection are coming from U7 and I don't see the front 3.5mm jack.


----------



## amb

Quote: 





> Originally Posted by *flexium*
> 
> I think I am supposed to look at U7? 2365A... So it's the better one. Would the anticlipping setting do anything?


 
   
  OPA2365 and AD8565 are both excellent opamps in this application, I wouldn't necessarily say that the OPA2365 is "better", they're just slightly different and subject to preferences.  The AD8565 has lower output impedance and much more output current capability, so it could drive low-Z loads much more effectively.
   
  As far as the anti-clipping switch goes, no, it does not prevent clipping caused by excessive loading at the analog output.  The anti-clipping switch's function is to lower the DAC's volume by 2dB to avoid digital clipping with some recordings.  See the WM8741 datasheet for info.


----------



## flexium

Quote: 





amb said:


> OPA2365 and AD8565 are both excellent opamps in this application, I wouldn't necessarily say that the OPA2365 is "better", they're just slightly different and subject to preferences.  The AD8565 has lower output impedance and much more output current capability, so it could drive low-Z loads much more effectively.
> 
> As far as the anti-clipping switch goes, no, it does not prevent clipping caused by excessive loading at the analog output.  The anti-clipping switch's function is to lower the DAC's volume by 2dB to avoid digital clipping with some recordings.  See the WM8741 datasheet for info.


 

 Oops yeah i read your previous comment about 2365 incorrectly. Thanks for correcting me. 
   
  skimmed it..seems like the anticlipping switch doesn't apply to my situation at all. 
   
  I saw that the U7 is driving 3.5mm jack in the back but didn't see the front jack. Is the front 3.5mm jack driven by a different(weaker) opamp from the original gamma 1 design???


----------



## amb

Quote: 





flexium said:


> I saw that the U7 is driving 3.5mm jack in the back but didn't see the front jack. Is the front 3.5mm jack driven by a different(weaker) opamp from the original gamma 1 design???


 

 U7 drives the 3.5mm and RCA analog output jacks on the rear panel.  The front analog jack is driven by γ1's WM8501 DAC directly.  It's not really "weaker" than the AD8656.  WM8501 has a stout internal output stage and needs no external opamp, and is capable of driving fairly low-Z loads directly (Wolfson datasheet says that it could swing 1Vrms into 16 ohms).  Into an 8 ohm speaker that might be a surprisingly amount of volume, but I don't think the performance would be too good when being so severely loaded.  Since neither γ1 nor γ2 was intended to drive speakers, and I don't expect them to work well as such, I never tested them that way.


----------



## herro

Is anyone selling full kits for a complete γ1/γ2 build?
   
  Also, what is needed to omit from the BoM if I only require USB inputs?


----------



## francisdemarte

You'd want the "B" configuration. http://www.amb.org/audio/gamma1/


----------



## herro

What is the price difference for the components between a full config and a lighter one? If the difference is only twenty or thirty dollars I think I will just do a full γ1.


----------



## Ntropic

$20, maybe? But you make up for that by requiring an external power supply. It's just simpler to go full++.


----------



## herro

Anyone have a completed/used one they are looking to sell (or full++ y1)? Under $300 or less shipped to N. America as that is a current offer I am trying to beat. I can't post in the classifieds section for some reason..


----------



## herro

Do I need a 4 wire or 5 wire cable for this? I've never heard of a 5-wire cable until now...


----------



## Kibble Fat

You need at least 100 posts to be able to use the classifieds.  It keeps the scammers at bay most of the time


----------



## amb

Quote: 





herro said:


> Do I need a 4 wire or 5 wire cable for this? I've never heard of a 5-wire cable until now...


 

 ???


----------



## herro

I guess I am not up to date with my USB. It was my understanding that all usb wiring was standard +/-/D+/D-, but when I was looking for cables there are 5 pin ones apparently?
  
  Quote: 





amb said:


> Quote:
> 
> 
> 
> ...


----------



## amb

http://pinouts.ru/Devices/mini-USB_pinout.shtml
   
  USB is a 4-wire system, but the Mini-USB connector has an extra 5th pin (which is unused on the γ1 DAC).  Despite this, you should use a 5-wire cable to ensure that the plug willl mate properly (γ1 has Mini-B connector).  Also, don't confuse Micro-USB connectors with Mini-USB.  They are diffferent.


----------



## MisterX

Here is an example image of a 4 pin mini B type USB connector: 
   

   
  Here is an example image of a 5 pin mini B type connector:
   

   
  (images borrowed from http://www.l-com.com/content/USB-Connector-Chart.html )
   
   
   
   
   
  Big thanks the person that fixed my account.


----------



## slowpogo

I am considering building a sigma11 to power my Gamma2. Right now, I'm using a TREAD with a toroidal. I know a TREAD isn't terrible but I suspect I might hear a difference by using the sigma11, which is much higher quality.
   
  Has anyone done a similar upgrade with their Gamma2 - from a TREAD or wallwart up to something more serious, and how much better does it sound?


----------



## amb

Quote:  





> Has anyone done a similar upgrade with their Gamma2


 

 Lots of people are using the σ11 to power their γ2s, a good number of them are upgrades from other supplies; USB power, linear regulated wallwart, or 3-terminal-regulator based supplies.
   
  Quote: 





> how much better does it sound?


 
   
  42.
   
   
   
   
  That's going to be difficult to quantify, don't you think?


----------



## slowpogo

Quote: 





> 42.
> 
> 
> 
> That's going to be difficult to quantify, don't you think?


 

 You cheeky monkey, you. I was thinking along the lines of either, "If there is a difference it's pretty small, the sigma is probably overkill." Or, "It sounds much better, a totally worthy upgrade!"
   
  I'm not a very hard sell so I'll just go for it. Maybe I can use the current TREAD setup to power the Hiface I am probably getting....I can never escape DIY for too long. Damn you, head-fi!


----------



## Dan55

Hi all, 
   
  I'm attempting to upgrade my y1 full and can't even pass the initial test! I'm getting considerably less than 3.3V at that test point. It was at first 1.81V, and after I reflowed U2 I am now measuring just over 2V. I have an extra regulator and will try to replace U2 unless there might be another culprit. Does anyone have any ideas? Sorry for the lack of pictures and the newbie question.
   
  Many thanks,
  Dan 
   
  edit: After doing some more reading, I think the problem is likely attributable to solder bridges on X1, U4, or U5. I think I need some more desoldering braid!
   
  edit 2: After attempting to clean up X1, U4, U5 and measuring the same voltage at the 3.3V test point (~2V), I've concluded that I have absolutely no idea where the problem is...


----------



## Dan55

I probably shouldn't have posted the above just before the holidays. Is replacing U2 a decent approach or way off base? The continuity at each pins seems fine, so I'm not sure what the problem might be, but I'm also not sure where else to look. Thanks!


----------



## jdkJake

Pictures? Lot's of light, as much focus as possible.

Really, really helps.


----------



## Dan55

Sorry about that. The only camera I have at the moment is on my camera, and I'm still trying to figure out how to upload to my computer. Someone forgot to mention that in the 200 page manual.


----------



## PScal

Check the marking on the voltage regulator in question.  I had Mouser send me the wrong part on the 3.3v regulator.


----------



## Dan55

I believe it says PHUI, though I imagine that's not of much help. The packaging indicates 3.3V.


----------



## amb

Quote: 





dan55 said:


> I believe it says PHUI, though I imagine that's not of much help. The packaging indicates 3.3V.


 
   
  See the γ2 website "Instructions" section, there is a table of markings on these SOT-23-5 devices.  PHUI is a Texas Instruments TPS79333DBVR.
[size=smaller]TPS7933T3DBVR[/size]


----------



## pterodactilo

From the gamma 1 thread
  Quote: 





amb said:


> This should really be in the γ2 thread now that you're debugging that board, but anyways...
> Thes second 5V test point (VBUS) will read low if the USB cable isn't connected to the computer.  So that's probably normal (if you're only using wallwart power).
> The fact that the first 5V test point (VCC) has 4.86V means that the voltage regulators U1 and U2 are getting the correct input voltage, but your 3.3V and 4.5V test points show that they are not producing any output.  Make sure that you have the correct chips installed in U1 and U2 locations (what do the markings say?).
> 
> EDIT: I assume your two 5V test points are as I described (VCC and VBUS).  If they're the opposite, then it would be a different problem.


 


  My bad,  I forgot to specify which 5V test points I am refering to. It's the opposite: 5V (VCC) reads 1.38Volts and 5V (VBUS) 4.87V. I used the USB cable only to power the boards. If I connect the wallwart too I get the following voltages:
  5V (VBUS) : 5.09V 
  5V (VCC) :1.34 V 
  3.3V :  0.03 V
  4.5 V: 0.00V
   
  With external power only:
   
  5V (VBUS): 0.03V
  5V (VCC): 1.34V
  3.3V: 0.02V
  4.5V: 0.00V
   
  The markings on the regulators: U1 is PHJI and U2 is LPKL.  I double checked that the pin headers and receptacles that correspond to VCC make contact . The DMM reads around 2 ohms in J1 and J5 .


----------



## amb

pterodactilo, what you observe seems to point back to a problem on the γ1 side.  If you measure only 1.34V at γ2's 5V (VCC), then U1D on γ1 board isn't putting out enough voltage.  You could verify this by measuring the voltage at the γ1 5V (VCC) test point, as well as U1D pin 7.  They are probably all measuring 1.34V, when it should be 4.8xV according to your VBUS reading.  I know we've been down this path before and you've replaced U1D (and verified R13D, R15D and R16D values), but it's got to be something around there.  As I said, there is not much there that could cause this.  Look at the schematic diagram (and the TPS2115A datasheet) and think about why this is.


----------



## pterodactilo

Quote: 





amb said:


> pterodactilo, what you observe seems to point back to a problem on the γ1 side.  If you measure only 1.34V at γ2's 5V (VCC), then U1D on γ1 board isn't putting out enough voltage.  You could verify this by measuring the voltage at the γ1 5V (VCC) test point, as well as U1D pin 7.  They are probably all measuring 1.34V, when it should be 4.8xV according to your VBUS reading.  I know we've been down this path before and you've replaced U1D (and verified R13D, R15D and R16D values), but it's got to be something around there.  As I said, there is not much there that could cause this.  Look at the schematic diagram (and the TPS2115A datasheet) and think about why this is.


 


  What puzzles me is the fact that this only happens when y1 is mated to the y2 board. I've tested y1 alone and when dac and usb sections are connected with wires all test points give the correct values and U1D's pin 7 sends the correct voltage: 4.80 volts or so when USB cable is connected and 5.10 with external power.


----------



## amb

The only possibility for that to happen is U1D went into current-limiting protection mode, dropping its output voltage.  Something on your y2 board is drawing too much current, and the most likely cause is a short somewhere.  Could you post clear, high-res photos of your y2 board, top and bottom?


----------



## IPodPJ

Quote: 





dan55 said:


> The only camera I have at the moment is on my camera,


 

 Huh??


----------



## Dan55

Haha. That should say my phone. I wrote that in a hurry this morning and knew something was wrong, but I just couldn't put my finger on it. 
	

	
	
		
		

		
		
	


	



   
  Thanks, amb. I guess I can't blame the problem on Mouser.


----------



## pterodactilo

Quote: 





amb said:


> The only possibility for that to happen is U1D went into current-limiting protection mode, dropping its output voltage.  Something on your y2 board is drawing too much current, and the most likely cause is a short somewhere.  Could you post clear, high-res photos of your y2 board, top and bottom?


 

  
  Thanks for your help, I know that without pictures it's hard to say where the problem  may be but right now I  only have my nokia 5800 which makes horrid photos .   I've shorted JP2D(3-2) and in this case gamma1 works with gamma2 mated to it. This apparently points to U1D once again, but then the  gamma 2  board should function while it does not. Test points give : 3.3V -> 0.02V, 5V (VBUS) -> 4.84 V, 5V (VCC) -> 4.84V, 4.5 V -> 4.75V. I've already replaced the 3.3 voltage regulator , the one with  a "LPKL" marking on it. Given that now both inputs are correct it should output 3.3Volts and not 0.0V. Ok. I'm leaving  it here until I get a proper camera.


----------



## Mullet

If I had 3 extra 647-UKW1H220MDD laying around from my previous y1 build could I use them as as C11 and C13 on an upcoming y2 board and as C22D on the y1 board and use Elna Simic IIs for my output caps? What I'm getting at is would the mix of caps effect the overall sound of both DACs? Otherwise I'll just buy 7 Silmics from Digi-Key.


----------



## K3cT

I have experimented with the analog capacitors of my γ2 extensively and I could say that you want to put your best caps there. That being said, the KW should do well.


----------



## Mullet

So your suggestion is to go KW on the y1 and Silmic II on the y2 oooooooorrrrrrrr I could just go with 4 Blackgate NXs on the y2 at $15 a pop on eBay. Should I pull the trigger? What will that extra $60 get me? Eternal DAC bliss?


----------



## slowpogo

The only caps you need to concern yourself with are on the y2.  You're not going to use the analog output of the y1, right? 
	

	
	
		
		

		
			





 If that was your plan, there would be no point in building the y2.
   
  C20/C26 will be most important to how the y2 sounds - they are the analog output coupling capacitors.  I am using Black Gate NX in that position, bypassed by Vishay MKP1837 (in C19/C25).  This sounds really, really nice.  I don't know your situation and can't decide for you if it's worth $15 each - but I can say that if I had to pay $30 for those caps in C20/26, knowing what I know now, I would do it.


----------



## pterodactilo

Quote: 





amb said:


> The only possibility for that to happen is U1D went into current-limiting protection mode, dropping its output voltage.  Something on your y2 board is drawing too much current, and the most likely cause is a short somewhere.  Could you post clear, high-res photos of your y2 board, top and bottom?


 


  amb, I don't have a camera to take high res pics, but I've made some progress. I've reflowed  U5's pin 22. Since it is connected to U2's out I think it was shorted or something and that provoked U2 to output 0 Volts. Now when gamma 1 and gamma2 are mated together the two boards  pass all test points and gamma1 works but gamma 2 doesn't.  There is no sound at all out of the 3.5mm jack , aside from white noise. That looks like the Wolfson chip was damaged I guess. 
	

	
	
		
		

		
		
	


	



   
  Edit: now I've reflowed U4 pins and... IT SINGS!. What satisfaction!.


----------



## K3cT

Quote: 





mullet said:


> So your suggestion is to go KW on the y1 and Silmic II on the y2 oooooooorrrrrrrr I could just go with 4 Blackgate NXs on the y2 at $15 a pop on eBay. Should I pull the trigger? What will that extra $60 get me? Eternal DAC bliss?


 

 I'm honestly not sure whether the NX is worth $60. The good thing about the NX is it's almost transparent although a bit to the bright side while the Silmic II in comparison is definitely warmer but I suppose more forgiving than the NX. I would suggest Silmic II in C20, C26 and Cerafine (ROA) in C10, C13 if budget is a constraint. 
   
  I have to say that I end up using a similar configuration like slowpogo (nice coincidence, bro) and I'm throughly satisfied although admittedly with the JISBOS line driver making a comeback perhaps I should experiment again.


----------



## pterodactilo

Will these screws fit in the gamma 2 case? :
   
  http://cgi.ebay.com/DUB2272-Socket-Head-Cap-Screw-3-5mmx15-4-/270592411870?pt=Radio_Control_Parts_Accessories&hash=item3f009088dehttp://cgi.ebay.com/DUB2272-Socket-Head-Cap-Screw-3-5mmx15-4-/270592411870?pt=Radio_Control_Parts_Accessories&hash=item3f009088de


----------



## rds

If you don't intend to drive headphones directly from the y2 I suggest NXs for decoupling and film caps for the analog out ...that's what I did anyways, but I bought the NXs when they were $2.50 each from parts connexion.  
  Also just in case I want to drive headphones directly I put electrolytic caps on the y1 output.


----------



## amb

Quote: 





pterodactilo said:


> Will these screws fit in the gamma 2 case? :
> 
> http://cgi.ebay.com/DUB2272-Socket-Head-Cap-Screw-3-5mmx15-4-/270592411870?pt=Radio_Control_Parts_Accessories&hash=item3f009088dehttp://cgi.ebay.com/DUB2272-Socket-Head-Cap-Screw-3-5mmx15-4-/270592411870?pt=Radio_Control_Parts_Accessories&hash=item3f009088de


 

 Yes, but you will also need to buy a 3.5mm tap to make the threads in the holes.


----------



## Mullet

Hrrrmmm... so many options... I think for simplicity's sake I'll just use the KWs for the y1 since the sound doesn't really matter. I already bought the Wimas via AMB so I guess I'm good there. Then I'll buy 4 more Elna Silmic IIs from Digi-Key for the y2 and I'll be set. I just can't justify 60 extra bucks for something that might not sound better to my ears. The Silmic IIs seem to have a really good rep around here, so why not. Unless someone has two spare NXs that they want to let go at a reasonable price.


----------



## Dan55

I believe my voltage problem was due to a bad soldering joint on pin 2 or 3 of u2.
   
  I just wanted to say thanks to amb and MisterX for another great project.
   
  edit: I think this dac should come with a disclaimer, as I have not been able to stop listening to music since getting it to work.


----------



## Mullet

Bought a gamma-2 from a fellow head-fier about a year ago. This was right when I was getting into DIY and just was about to build a CMOY, so I hadn't built my own gamma-2 yet. Anyways, on to my issues. Came home last night and at first the Y2 wouldn't work. Optical input only stayed on red. I unplugged everything and replugged everything in including power. At this point at least I get a green light for optical, but my left channel is very weak and crackly. I tried using USB as my input with the same results. Then I decided to see if the Y1 part of the Y2 was acting up. Everything seems to be fine with the exception of one time getting distortion. I'm going to do some more conclusive tests on Monday, such as the normal Y2 voltage checks. Anything else I should be looking at?


----------



## steven2992

If the y2 output is crackly and the y1 output is fine combined with both the usb and optical being the same, it might be a bad solder joint on the y2 dac's left output pins. A few weeks after i built mine it started crackling in one channel and it turned out that there wasn't enough solder on one pin to make a solid connection.


----------



## Mullet

Ok, I'll have to check that out. I've had the Y2 for over a year without an issue and I've moved it around quite a bit as well. You never know if something is going to go bad though I guess.


----------



## Mullet

So things didn't quite work out as planned. I had tried to give U5 a good reflowing and ended up creating a big mess. I had to use chipquik to remove the whole chip. In the end I lifted a solder pad - pad 21 to be exact. From the looks of the schematic it doesn't look like pin 21 is in use. However, it seems like another pad near 21 is damaged as well. What would you guys do? Just buy a new y2 board and reuse some parts like caps, etc? or just try and replace U5 and hope for the best?
   
  On a side note, I just realized that I accidentally installed U6 on a separate Gamma-2 that has the WM8741. Will having U6 installed do harm to U5?


----------



## amb

Quote: 





mullet said:


> So things didn't quite work out as planned. I had tried to give U5 a good reflowing and ended up creating a big mess. I had to use chipquik to remove the whole chip. In the end I lifted a solder pad - pad 21 to be exact. From the looks of the schematic it doesn't look like pin 21 is in use. However, it seems like another pad near 21 is damaged as well. What would you guys do? Just buy a new y2 board and reuse some parts like caps, etc? or just try and replace U5 and hope for the best?


 

 It's up to you -- you be the judge of the extent of board damage and whether it is salvageable.
   
  Quote: 





> On a side note, I just realized that I accidentally installed U6 on a separate Gamma-2 that has the WM8741. Will having U6 installed do harm to U5?


 
   
  U5 won't be damaged, but it won't perform as designed in such a situation.


----------



## user02

Does Gamma 2 use analog volume attenuator or is it digital attenuation?  If it is digital then dynamic range is lost, no?


----------



## tacitapproval

There is no attenuator in the standard build. It can be used to drive headphones with a preferred opamp substituted for this purpose, but you need to supply attenuation elsewhere in the chain. In general though, it's just a DAC.


----------



## JamesMcProgger

Ive only made a cmoy. and that is my only experience with PCB's work.
   
  Is the Y2 something a newbie could pull off or is it too complicated?


----------



## bcg27

It's nothing too bad. The only challenge is there is a decent amount of smd work with fairly small pitch, which can take some practice. I recommend watching some youtube vids on smd soldering and make sure you have plenty of solder wick and flux on hand. There is no casework though if you buy the faceplates from AMB and use the recommended enclosure.


----------



## JamesMcProgger

you mean you have to solder like this
   





   
  instead of going trough the PCB and solder in the back? never done that and it looks quite delicated.
   
  I'm considering pay someone in cse is too risky for me to blow it


----------



## particleman14

I'll just leave this here..http://store.curiousinventor.com/guides/Surface_Mount_Soldering/101/


----------



## bcg27

^^ yes that's a great video.


----------



## JamesMcProgger

thnaks guys, will watch it now.


----------



## MisterX

Solder paste and a hot air station is a much easier method.
   Also a lot faster but not exactly cheap, especially if you're only going to use it for one project.
   
  Here's an example youtube video:


----------



## JamesMcProgger

^ lol, we just exchanged a couple of mails regarding Y1 and Y2...
   
  thanks for the video, Im considering if worth trying, personal satisfaction wise.


----------



## particleman14

yes go for it.  y-1 was my 1st experience with smd components.  it's challenging, but worth it for the long run.  if you mess up ur pcm2706/7   pm me I got a buncha spares


----------



## Blast

Does anyone here build these and sell them?


----------



## JamesMcProgger

^ a lot of people actually, MisterX is kind of like "the official" builder for the AMB designs


----------



## shrimants

I read the website about the volume control issue. I am planning to buy Denon D2000 soon but right now even my audioengine A5 seems to get way too loud a volume. i cant control volume via windows because windows doesnt touch the audio going into the gamma 2. I CAN control volume through fubar, but for example, if I'm using stumbleupon on firefox and getting a bunch of random videos from random flash video websites, I would have to constantly switch the volume to lower in the flash video itself.

The A5's are amplified but need to be set to a certain low volume otherwise speaker imbalance occurs. Essentially, I need to control the volume AFTER the gamma2 and BEFORE the speakers or headphones.

After reading, I'm seeing that simply using a volume pot or inline stereo volume control completely screws up the frequency response because of the varied impedence. It seems that a heapdhone amp is the only way to go to control volume.

Knowing this prior info, is the Fiio E5 a worthwhile purchase for the denon d2000 along with being a volume control for the A5's? Or should I save up more and use something like Fiio E7?

I am eventually going to build the Mini3 as my main portable amp and probably the X1 upgrade for it also, but thats only once I save up enough money. Until then, will Fiio E5 do or is it of such low quality that I might as well not bother? or worse, will the amped output screw with the input of my A5's?


----------



## Billyk

I have happily used these with my Gamma 2:
  Passive = Lightspeed Attenuator
  Active/buffer = B1
  And my favorite, the Bottlehead Crack OTL (it is for high impedance cans tho)
   
  All of them are DIY the lightspeed and B1 are very doable and under $100.00


----------



## shrimants

But is the E5 going to do a bad job? Is is better to wait until i can afford a proper amp rather than spend even 20 bucks on the E5?


----------



## MrMojo1

Hi all,
 Got a new audio student here 
	

	
	
		
		

		
			





  I'm looking into building a full++ y1 and a y2; right now I'm in the part picking phase.  Is 7 the correct number of 22µF 6.3V+ electrolytics needed for both? (not driving headphones directly)

 As far as cap choice, I'm looking at Silmic IIs.  How do they compare to the Nichicon Muse sonic-ly?

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=604-1112-ND
 Is this the correct 22µF cap to use?  It meets the capacity and size dimensions, but it is 16V.  My guess is it is fine, but I wanted to be sure 
	

	
	
		
		

		
		
	


	



   
  Thanks a lot


----------



## MisterX

7 is right and the RFS series from Digi-Key are fine.


----------



## MrMojo1

Awesome 
	

	
	
		
		

		
		
	


	




  Thanks for the quick reply and for your work on this project


----------



## Kibble Fat

Quick question.  What is the max. current draw of a Gamma2 Full++ with a 5V supply?


----------



## amb

Approximately 200mA.


----------



## Kibble Fat

Thank you! I'm looking into making a low budget, hi-fi, semi-portable listening rig with the gamma2 and "the amp that shall not be named".  I'm thinking I will stuff a b2-080 with lithiums and base the regulating circuit off that of the Chi 1.  I already have the gamma2


----------



## ericj

Wow, no posts since november? 
   
  I got tired of trying to decide whether i was going to buy a dac kit out of china and went ahead and bought a gamma 1 kit from glass jar audio, and gamma 2 bits from amb and mouser. 
   
  This will join the nano-atx touchscreen system i recently bought off ebay for office jukebox duty.


----------



## peterotto

I'm going to build a gamma2, but there are other places to post for help instead of a 139 page behemoth.   How do you plan to use the touchscreen with gamma?


----------



## amb

Quote: 





peterotto said:


> I'm going to build a gamma2, but there are other places to post for help instead of a 139 page behemoth.   How do you plan to use the touchscreen with gamma?


 

  
AMB DIY audio forum


----------



## ericj

Quote: 





peterotto said:


> I'm going to build a gamma2, but there are other places to post for help instead of a 139 page behemoth.   How do you plan to use the touchscreen with gamma?


 


  I should have been more clear - i bought a very small all-in-one computer with a touchscreen on it. It'll probably end up running linux and xbmc if there are linux drivers for the touchscreen. The gamma2 will be attached via toslink, probably.


----------



## shrimants

Theres a weird thing i've noticed. With both of my laptops (dell vostro 1500, asus eeepc 1215n) I have perfect performance out of my gamma 2 F++. When I plug my girlfriend's laptop via USB though I get horrible rumbling from my subwoofer. I think its the USB noise floor but I have no idea what could be causing that. This is the case with ALL the usb ports on her laptop. Any ideas?


----------



## MisterX

Sounds like a ground loop.
   Was the laptop running on batteries or was the power adapter plugged in?


----------



## shrimants

Happens in both cases, regardless of if the laptop is plugged in or batteried. I was thinking it could be an internal ground loop. Thats what the problem used to be on my dell. They had everything grounded to the chassis, and that caused it to have a high pitched whining sound. I covered the sound card in electrical tape and made it so the sound card ground was insulated from the chassis ground and all the whining went away.


----------



## Kibble Fat

amb, MisterX,

I am having trouble getting my Full++'s optical input to read a signal. The LED switch stays red, the toslink fiber is glowing red, and I can see the sound level changing in my laptops control panel. Obviously the first thing to try would be swapping out the DAC and swapping out the source, but since I have nothing else that would work, I'm wondering if you have any troubleshooting pointers?

The laptop is an ASUS running Windows 7 x64. It has a 3.5mm headphone/optical output combo controlled by a Realtek driver. I switch to the digital output using the Sound control panel.

Thanks for any advice!


----------



## shrimants

Hey man, try uninstalling the realtek driver and using microsoft's one off of windows update. You should also remember to set your output driver to SPDIF or whatever windows labels your optical output as. Also, make sure that your player itself is using the correct output.


----------



## Kibble Fat

After a few hours of changing settings, uninstalling/installing various sound drivers, restarting/reconnecting, disabling/enabling, and trying to use AC3Filter, I got it to crackle for a few minutes playing the control panel test sound. The LED switch was switching between red and green very rapidly. Do I have a bad solder joint or IC?


----------



## shrimants

it could still be the computer itself, but if nothing else its a bad solder joint. I dont think bad IC though, or im pretty sure the whole thing wouldnt work.


----------



## MisterX

Does it behave the same way when the USB to optical output is patched into the optical input?


----------



## Kibble Fat

So USB > DAC then run the toslink from output to input? Fiber doesn't light up on any switch settings, so there's no sound. USB sound works perfectly


----------



## Kibble Fat

Here are my boards (again) in case you can spot something that's obviously wrong.


----------



## MisterX

From the Y1 instructions page:
   
   
  Quote: 





> Take care not to mix up the fiber optic receiver and transmitter modules. They look identical except for the shutter color: The TORX147PL is black and the TOTX147PL is grey. The opposite is true for the Sharp modules: The GP1FMV31RK0F has a grey shutter while the GP1FMV31TK0F is black.


 
   
  It appears you did not use the Sharp modules so......


----------



## Kibble Fat

misterx said:


> The soldering looks pretty good so let's assume reflowing is not going to help.
> What are the numbers on the component you have installed in the U2U position?
> What's the color code supposed to be for a 22 ohm resistor?
> And... check that you don't have the TORX and TOTX modules crossed up.






kibble fat said:


> U2U reads: A08L
> My 22 ohm resistor must be mislabeled
> 
> 
> ...




from here: http://www.head-fi.org/t/355293/y1-gamma-1-dac/1395#post_6864744

So I've already switched the TOTX and TORX once. I'll have to double check the part numbers when I get home.


----------



## Kibble Fat

Just got back from a meet at Jude's secret hideout and was able to test my Gamma2 input and laptop output (individually). 

My Gamma2 performed flawlessly when fed by the optical out of Jude's iPod > Fostex HP-P1. False alarm guys!!! 

My laptop graphically showed that the test signal was playing, but there was no sound from thread's MicroDAC > SR71B. I'm actually kind of relieved that my laptop was the problem. While this may be harder to fix or find a fix for, I at least have all of my electronics problems consolidated on one P.O.S. ASUS gaming laptop. Hooray.


----------



## shrimants

Lol you know you're an audiophile/electronics geek when you would rather have your 2000 dollar laptop break than your 200 dollar project.


----------



## ericj

gamma 1 kit finally arrived from glass jar audio the other day and i completed my build yesterday. 
   
  Except for two capacitors and a reset manager that i forgot to order from mouser for the gamma 2. 
   
  (doh).


----------



## Mullet

Need some trouble shooting help here.
   
  Here's the back story of what happened:
   
  I've built a few Gamma-2s and 1 Gamma-1. About a year or so ago I had one channel go on one of my Gamma-2s and took the kitchen sink approach and rebuilt a complete Gamma-2 board. This evening I was playing two amps from the Gamma-2 portion of the DAC (one via RCA jacks and the other via the 1/8" jack) and I was fiddling with the amp (turning up the volume) that was connected to the 1/8" jack and I saw a few sparks because a metal 1/8" connector was touching the pot, which is also metal. This tripped the E12 on my CTH -- the other amp. I proceeded to unplug the first amp (A47) and then after firing up the CTH again noticed a buzz coming out of the left channel and proper audio coming out of the right channel. I tested the Gamma-1 portion and it plays music normally. So I know its the Gamma-2 with the issue. This time I want to avoid rebuilding the whole y2 board. Any ideas on what to check what died or is dying? U7, U5? What voltage readings and what pins should I check?


----------



## Mullet

Upon using a DMM I'm getting these readings... I've decided to do the typical tests when done with a Gamma-2. Everything checks out with these voltages. Then I decided to take a look at the outputs of U7. On a known working Y2 I got these readings going into C20 (R) and C26 (L) -- 2.27v and 2.28v. With the bad Y2 I got 2.202v on C20 and 4.33v on C26. I'm assuming now that there is something wrong with U7 and I'll try and use some chipquik to get the chip out. I tested the points coming out of the U5 and I got similar readings of 2.2 to 2.3 volts for L and R of both sides of the DAC. So I'm thinking the DAC isn't the problem and it's most likely U7 that got severely damaged. Keep in mind -- no magic smoke and the right channel still works. Does this make sense?


----------



## jdkJake

Pics would help,

I would also reflow the main parts and use your DMM to check for shorts between the pins. No reason to remove any chips quite yet. The y2 is very easy to soldier bridge on the SMD parts if you are not careful.


----------



## jdkJake

BTW, you might get better response to these questions by posting on AMB's forum.


----------



## shrimants

I would just like to say that I am watching/subsrcibed to this thread and only havent said anythign because I have no idea what to say in this situation. I'm not quite at that level yet heheh.


----------



## Mullet

@jdkJake... I don't think reflowing will solve the issue. Nor will posting pics. This was a working Y2 for the past year or so. Just to reiterate - I shorted out a metal knob and metal 1/8" connector, which in turn was connected to and subsequently zapped my Gamma 2 with probably way more voltage than what U7 or U5 can handle. This is just a guess. The one anomaly is more voltage being fed to C26, which should be getting around 2.2v.
   
  I'm going to post to ambs forum, but usually come here first. This is my DIY home.


----------



## MisterX

Might be a good idea to check the voltage on U5's VMIDR and VMIDL pins but replacing U7 sounds like a pretty reasonable place to start to me.


----------



## Mullet

I'm assuming it's easiest to check this by using the vias on the the bottom of the board for those respective positions. What voltage reading should be normal? ~2.2v?


----------



## MisterX

Closer to 2.3 then 2.2 volts but both sides being roughly the same is more important then the actual reading.


----------



## Mullet

So to complete the proverbial circuit here's an update with my fried Gamma 2:
   
  Measured VMIDL and VMIDR and got close the 2.3v readings. Then measured Pins 1/3 and 5/7 and got the 3.5v readings on 1 and 3. 5 and 7 measured just fine. I still got 4.5v readings at C26.
   
  I proceeded to order a new U7 and U5 (just in case) and pulled out some of the box caps around U7. Then using some chip quik I pulled U7 and put the new one in. Then I put back the box caps I pulled. Fired the puppy up and took some measurements via USB from both a Mac Pro and MacBook Pro...
   
  Mac Pro

 VMIDL 2.326
 VMIDR 2.315

 pin1 2.327
 pin3 2.312
 pin5 2.298
 pin7 2.273

 MacBook Pro

 VMIDL 2.264
 VMIDR 2.254

 pin1 2.270
 pin3 2.253
 pin5 2.241
 pin7 2.216
   
  Finally, I plugged in my CTH and some phones and Voila! Everything works again!
   
  I've got an extra U5 (WM8471) now if anyone needs it.


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## jdkJake

Good news mullet.

What did you think of using chip-quik? I had to temporarily remove the crystal oscillator from mine (long story) and used a precision tip heat gun with the part surrounded by a cooper tape cone. It worked well, but that was only four pins. Not sure how it would work for the multi pin chips.

I see where Fry's carries chip-quik, so, I might pick some up to have on hand.


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## Mullet

Chip Quik really works for SMDs, but helps with through hole devices as well. It's definitely worth having on hand. I'd imagine it would be helpful with the receptacles and pin headers if they needed to be pulled. Otherwise, I'd think they'd be near impossible to pull.


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## DanBa

The Android-powered smartphone Samsung Galaxy S III interworks with the Gamma 2:
  http://forum.xda-developers.com/showpost.php?p=27247705&postcount=279


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## peterroumian

sorry about the stupidest question in the world, but
   
  is the gamma 2 still the best in it's price range
   
  what about for $100 more - is there something better?


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## Mullet

I'd say it's still pretty damn good. Another alternative that gives way less features in terms of I/O, but is still really good none-the-less is the PupDAC. I'm also going to be building the Subbu v3 DAC, which is based off the ESS Sabre 9023.


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## DutchGFX

I think I want to add balanced output to my Gamma2, few questions:
   
  1) I should just tap the Balanced outputs of the chip, add some caps, and then it should be good?
  2) The normal outputs would function fine if I didn't use the XLR's, correct?


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## MisterX

1)  Capacitors and resistors. And you will also need to figure out where and how to add the XLRs.
  2) Yes.


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## DutchGFX

Quote: 





misterx said:


> 1)  Capacitors and resistors. And you will also need to figure out where and how to add the XLRs.
> 2) Yes.


 
   
  I am adding them through holes in the case where i'll string the wires through. So I can just tap VOUTLP/N and VOUTRP/N, add a capacitor or 2, and then ill be good to go? Got any recomendations as to what series of caps and resitors I should use?


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## MisterX

Quote: 





> Could you maybe assist in which places on the board I should tap?


 
   
   
   
http://www.amb.org/audio/gamma2/gamma2_v100_pcb_top.jpg
   
   
  See the labeled holes by C10?


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## DutchGFX

Quote: 





misterx said:


> http://www.amb.org/audio/gamma2/gamma2_v100_pcb_top.jpg
> 
> 
> See the labeled holes by C10?




 OH Awesome! I totally missed that! And what do think i should add in line before the XLR?


I was thinking of following the Opus DAC schematic. 22uf caps, and 100k resitors to ground for each, will that work?


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## MisterX

Quote: 





> 22uf caps, and 100k resitors to ground for each, will that work?


 
   
  Yep, that will work.


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## DutchGFX

misterx said:


> Yep, that will work.




Sweet, ordered some resistors and the OPuS caps, will drill holes in back prolly. Thanks for your help! Ur the man!


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## shrimants

Ugh my gamma2 randomly started getting a "not recognized by windows" error. Research showed that its probably a blown chip.


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## francisdemarte

Unsoldering that chip is a pain, I had to use a small blow torch. Have you double checked/reflowed your solder around the chip and usb adapter?
   
  Quote: 





shrimants said:


> Ugh my gamma2 randomly started getting a "not recognized by windows" error. Research showed that its probably a blown chip.


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## Billyk

If you need to remove the chip, look into some chip quick.


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## linglingjr

Hey I'm sorry to be asking questions like this but how much does the PCB and all the components cost to buy for both the y1 and y2?  My neighbor is an electrical engineer and could probably put this thing together with his eyes closed.  Also, how much of a difference does a dedicated PSU make compared to a normal walwart or powering it by USB? Would you guys say it's worth the extra work/money?  I plan on using this with a Lake People G109 and HD600s and then eventually LCD 2s hopefully


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## MisterX

Quote: 





> how much does the PCB and all the components cost to buy for both the y1 and y2?


 
   
   
  Roughly $230.


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## 3l3tric

Sorry if this has already been asked, but is it possible to build a gamma 2 without assembling the USB board on the gamma 1?
  I'm not going to use the USB input at all, so it would be relatively pointless for me to build it if it isn't necessary.


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## MisterX

Sure, you could build a Y2 without a USB section.
  There are no ready made panels available for that configuration though.


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## Tautologi

I have a gamma2 which is making humming noises when using USB connection with my desktop computer but not when connected to my laptop. SPDIF/coax and external power works fine.
  
 Possible ground loop? What steps can i do to fix it of find the problem?


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## shrimants

Start by testing your test points with a multimeter. Specifically the ones around the USB chip and the voltage regulator there. Also they other USB port non a different computer. Mine makes a humming when I use my gf laptop because of the USB port itself. Its fine otherwise.


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## Tautologi

I will do that, but what should i look for?


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## shrimants

tautologi said:


> I will do that, but what should i look for?




Have you read the documentation on the AMB website? There are test points all over the device, you are testing those test points with a multimeter. The test points are labeled with a voltage, and that is also visible on the website. So logically, you are looking to see if the test points are all reading the correct voltages.

But first try on a different computer.

Did you build yourself or what?


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## Tautologi

Built by MrX/MisterX.
  
 Found the documentation. I will check on another computer tomorrow.
  
 Thanks for your help!


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## rbc3

I am interested in adding balanced out to the Gamma2 I'm building because I want to drive a fully balanced amp.  I'm considering a Violectric HPA V181 to go with my Hifiman HE-500.  I have a couple of questions.  It's my understanding that one of the main benefits to running balanced is that by not having a common ground between the two channels, channel crosstalk is eliminated or at least significantly reduced.  But it looks like the ground is shared for the balanced outs.
  
 I'm just looking for a sanity check that I should wire the ground near the Right and Left positive and negative balanced leads to the ground pin in a 3-pin XLR.
  
 My plan is to drill some holes in one of the plates and mount a pair of these mini XLR 3-pin sockets for Left and Right balanced outs, along with the serial 22uf caps and 100k resistors from the Right and Left positive and negative to ground as shown in the Twisted Pear Opus schematic.  Here are the sockets I want to use.  I'm looking for confirmation that these will fit.  The back mounting nuts are 14.2mm diameter and the hole diameter for the socket needs to be 11.2mm.  Will the nuts fit between the Gamma 1 and Gamma 2 boards?  Since I'm not done with the build I don't know the distance between the two boards.
  
 http://www.rean-connectors.com/en/products/tiny-xlr-chassis-connectors/rt3mp
  
 If this doesn't work, I'll run cables out of the case to some XLR 3 pin plugs.
  
 Thanks for any help,
 Robert


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## rbc3

Another thought I have is to sacrifice the mini stereo output socket on the front and mount a Mini 4pin XLR socket there in its place. I can then build a custom Mini 4pin XLR to 2x 3pin XLR splitter interconnect cable and solder the shield to the grounded coupler on the Mini 4pin XLR plug since the ground for each channel doesn't appear to be seperate. 

I should be able to finish up my build today and take some measurements to figure out if the Mini XLR socket will fit or not. 

It would be a great help to get some feedback about the ground from someone who has a better grasp of balanced signals than I do. This will help me make a decision about two separate Mini 3pin XLR sockets vs. one Mini 4pin XLR socket.

-Robert


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## shadowkiller

So I recently decided I wanted to build a gamma2. I was wondering if 5.24V from the 5V ac adapter would be acceptable or should i return it and get another adapter. It is rated at 5V 3A.


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## amb

From the "Parts list" section of the γ1 website:

"A 5V DC regulated AC adapter ("wallwart") or external 5V DC regulated power supply may be used to provide power to any γ1 configuration equipped with U1D and the 1.3mm DC power jack.

The AC adapter or power supply's output plug should be a barrel-type with 1.3mm ID female, the polarity is center-positive. A compatible plug for the 1.3mm DC power jack is the CUI PP3-002D (Digi-Key CP3-1003-ND).

The appropriate input AC mains voltage, frequency and plug style depends on your country. The output voltage should be between 4.85V and 5.4V DC, with a minimum current capacity of 300mA.

..."


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## dhp

So sadly I am having issues with my y2 build... the y1 side works perfectly and i can hear music just fine.  When I mate with the y2 board, all the voltage checks are fine (5V pin reads out at around 4.85ish, which I think would be ok?)  Initially when I set it all up, I was getting music out of the stereo output of the y2, but then when I unplugged the usb and replugged it, the sound started dying and then just stopped altogether.
  
 I would like to bypass the ASRC and see if I can test U5.  Would jumpering JP2-n as well as lifting the input pins on U4 (pins 2, 4, 5, 6) be sufficient to achieve that?


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## amb

No, to bypass the ASRC you would also have to remove the X1 oscillator. I don't recommend that as a way to debug it. Try inspecting and reflowing the solder joints on the ASRC and DAC chips, as well as on X1.


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## dhp

amb said:


> No, to bypass the ASRC you would also have to remove the X1 oscillator. I don't recommend that as a way to debug it. Try inspecting and reflowing the solder joints on the ASRC and DAC chips, as well as on X1.


 
  
 I did try reflowing all the solder joints, although those ground pins have been making life difficult even with the iron turned up to 850F.  Are there any other checks I might do?  The fact that the y2 board is mated to the y1 seems to make some debug checks difficult.


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## amb

Inspect the solder joints with a loupe and see if there might be solder bridges or cold joints. Most problems with these builds are solder-joint related and yours is most probably no exception.


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## Tautologi

Probing around with a DMM and seeing where you have potential is also a good method. Or measure resistance trying to find faults.


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## JustinBieber

Is there anyway to use USB input with the power supplied by the external 5v wall supply? My computer has tons of USB noise.


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## OJNeg

justinbieber said:


> Is there anyway to use USB input with the power supplied by the external 5v wall supply? My computer has tons of USB noise.


 
  
 Assuming you have the y2 fed by the y1 board, it should simply be a matter of setting the jumper on JP2D correctly. Look under the "Instructions" tab on the gamma1 page.


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## amb

If it's a γ1 + γ2 combo, and U1D is installed, then you can just plug in an external 5V DC regulated power supply. The DAC auto-selects the external supply when both USB power and external power are connected simultaneously. There is no need to set jumpers.


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## JustinBieber

It's a combo and U1D is installed and JP2D is open. So, I guess it has to be something else causing the noise. It isn't hum, but static and hissing. The noise goes away when my CPU is at full power when benchmarking with Prime 95. If you close P95 the noise is there again... odd.
  
 Also, when I'm using a different input, like optical, when I plug in the USB cable the noise instantly comes back. 
  
 Just noticed this too, should I replace that cap?
  
 Thanks for the advice everyone.


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## amb

Is your computer a desktop or laptop? If the latter, does this noise occur when running on battery? Also what are you using as an amp? Is it AC powered too?

I suspect a ground loop via your USB cable:
computer > USB cable > gamma2 > interconnect cable > amp > AC power cord > wall outlet > AC power cord > computer

That melted cap is likely due to a soldering iron mishap. If it looks ugly to you then replace it, but it's probably still working fine.


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## JustinBieber

I'm using a desktop. My amp is a Schiit Valhalla 2, which I'm pretty sure is AC.
  
 Do you recommend using an RCA ground loop isolator? 
  
http://www.amazon.com/PAC-SNI-1-Noise-Isolator/dp/B000K50HJE/ref=sr_1_2?ie=UTF8&qid=1435522793&sr=8-2&keywords=pac+ground+loop+isolator


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## amb

Such ground loop isolators typically contain a cheap transformer that will affect sound quality.

It would appear that the Schiit amp does not have a ground loop breaker inside (i.e., its signal ground is connected directly to its AC ground). If it was a DIY amp then I would recommend a modification, but such mods would surely void Schiit's warranty.

One solution is to always use S/PDIF (coax or optical), as these are both galvanically isolated on the γ2.
Another possible solution is a USB isolator.


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## jimjimmyjimjim

Hi, I'm new to this forum and I'm interested in building the Gamma-2. I'm wondering two things: I am planning to use this on my home stereo using my ipad2 playing flac files as a source. I expect to use the usb connection to the dac (using an Apple Camera Connection Kit) and rca connects to the pre-amp.  I searched the forum but I can't find any info on this particular configuration. Do you see any problem with the ipad recognizing the dac or in some other way messing things up?  And second, has anyone written a parts script for digikey or mouser?
  
 Thanks for any help you have to offer.  Jim H.


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## jimjimmyjimjim

Oh, and one more thing: If I connect to the ipad2 via usb am I limited to 16bit/44khz?  Some of the flac files are up to 24bit/192khz. Putting aside the debate about whether the 24/192 sampling rate is worth it, does connecting the gamma-2 via usb mean that those flac files will be limited to 16/44?  Or am I missing something fundamental?  Thanks again, Jim H


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## DingoSmuggler

jimjimmyjimjim said:


> Oh, and one more thing: If I connect to the ipad2 via usb am I limited to 16bit/44khz?  Some of the flac files are up to 24bit/192khz. Putting aside the debate about whether the 24/192 sampling rate is worth it, does connecting the gamma-2 via usb mean that those flac files will be limited to 16/44?  Or am I missing something fundamental?  Thanks again, Jim H


 
 Pretty sure all of ipads are usb audio class 2 compliant, and will support 24/192, the lightning based ones certainly do.
 You might need to use a USB hub after the camera CC, otherwise get the "this device uses too much power" error.


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## amb

The γ2 is capable of 24/192 via its coax or optical inputs, but only 16/48 maximum via USB. If you are interested in 24/192 USB audio in a small form factor, you should look at the new γ1.5. Both will work with iPhone/iPad via the USB Camera connection kit, but through a powered USB hub because the iPhone/iPad cannot supply enough current to power the devices.


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## jimjimmyjimjim

amb said:


> The γ2 is capable of 24/192 via its coax or optical inputs, but only 16/48 maximum via USB. If you are interested in 24/192 USB audio in a small form factor, you should look at the new γ1.5. Both will work with iPhone/iPad via the USB Camera connection kit, but through a powered USB hub because the iPhone/iPad cannot supply enough current to power the devices.


 
 Excellent!  I will try that.  It's not so much that I'm convinced that I need 24/192 but I'd like to see if I can hear anything different with the different sampling rates etc.


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## jimjimmyjimjim

amb said:


> The γ2 is capable of 24/192 via its coax or optical inputs, but only 16/48 maximum via USB. If you are interested in 24/192 USB audio in a small form factor, you should look at the new γ1.5. Both will work with iPhone/iPad via the USB Camera connection kit, but through a powered USB hub because the iPhone/iPad cannot supply enough current to power the devices.




I took a look at the 1.5 and it looks very interesting. Am I correct in assuming that even though it's a DAC and HP amp I can plug it directly into my stereo pre-amp without a problem? Thanks, JH


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## amb

jimjimmyjimjim said:


> I took a look at the 1.5 and it looks very interesting. Am I correct in assuming that even though it's a DAC and HP amp I can plug it directly into my stereo pre-amp without a problem? Thanks, JH



Yes, you can do that.

The fact that it could serve as a headphone amp simply means that it has a bit of gain (3x default) and has very low output impedance (a good thing in any event). If you use it as just a DAC, then you can set the γ1.5's volume knob to somewhere around the 1-2 o'clock position and leave it. Then use your preamp as the master volume control.


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