# [new project]  The BIY ("Buy It Yourself") High End DAC



## Atchoum

[size=medium]PART 1 : the research[/size]

 I'm building myself a (hopefully) high-end DAC and want to share back my findings because they mostly derivate from information gathered here. 

 My requisites after looking at several DIY DAC were :

 - upsampling
 - coax input with CS8416 (everybody seems to agree this is the best)
 - DAC in dual mono
 - price no object provided the value of component is "proven" (ie no voodoo black box inside)
 - single ended
 - I2S input for further tweaks
 - "must" be better than my modded (with lm49710 for output stage) yulong mini-DAC (pcm1798)
 - no need for an headphone amp (I own a Corda Opera 
	

	
	
		
		

		
			





 )
 - easy to build (no SMD soldering) because I'm very left-handed !

 So I went through reading all the DIY DAC layouts threads, commercial products, DAC reviews...here were my findings :

 - top commercial DAC are : Lavry DA10, Benchmark DAC1, Cambridge 840C
 - top "DIY" DACs are : Opus Kit, Oritek & Zapfiltered Zhaolu, a lot of PCM1792/4 kits

 So let's have a look at the insides of theses top DAC :

 DA conversion :
 - AD1955 for the DAC in the Lavry, the Cambridge (+ a special upsampling chip licensed from anagram tech). It looks like it is the most clean sounding DAC chip. That's what i'm looking for !
 - Wolfson 8740/8741 for the Opus
 - PCM 1792/94/98 in most other DAC


 Output stage :
 - Discrete analog stage seems to be a must and is present in almost all the top DAC (opus ballsie, oritek Zhaolu etc...)

 PSU :
 - Good psu (separated for the analog and digital part) seems a must and is found in most of the mentionned DAC

 [size=medium]PART 2 : conception[/size]

 The rave review (some are preferring it as a DAC over the Lavry !) the Cambridge 840 caught my attention so I went to look at it special upsampling chip and what I found is that its manufacturers do sell a evaluation board (http://anagramtech.com/getdoc.php?do...um=S2M-PL-100A) for this technology. The spec are dead on with my project with a CS8416 as a receiver, 384khz upsampler, quad AD1955 for the DAC, possible output to a custom analog stage. So I ordered one.

 I choosed the zapfilter 2 for the output because it comes with its own psu and it gets rave reviews.

 The only missing part is a PSU for the DAC board. I choosen a gold mini regulator (GOLD Reference Mini Regulator) for the +12V because of the great reviews this unit gets and because it is not too expensive.

 Right now everything has be ordered and I can't wait to received everything and to try !

 [size=medium]Part 3 : the building[/size]

 Final Design is :

 - Gold Mini Regulator +12V
 - Anagram Tech EVAL Board with : CS8416 > 384kHz upsampler > dual AD1955 DA conversion
 - Zapfilter 2 with its own PSU

 in a few weeks !


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## threEchelon

From what I've read, it seems like an R2R DAC like the PCM1704, a resistor I/V stage, and a tube or transformer output stage is the best.


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## ferds

How much is the Anagramtech Eval board?? tnx


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## Atchoum

Quote:


  Originally Posted by *ferds* /img/forum/go_quote.gif 
_How much is the Anagramtech Eval board?? tnx_

 

495€. See : http://anagramtech.com/shop


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## ezkcdude

Quote:


  Originally Posted by *Atchoum* /img/forum/go_quote.gif 
_[size=medium]PART 1 : the research[/size]


 - DAC in dual mono
 .
 .
 .
 - single ended_

 

Which is it? You want dual mono, but then convert to single ended? If you're going to the bother of dual mono (i.e. balanced), why make it single-ended on the output?


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## Atchoum

Quote:


  Originally Posted by *ezkcdude* /img/forum/go_quote.gif 
_why make it single-ended on the output?_

 

...because my current amp is SE ! 
	

	
	
		
		

		
		
	


	



 but I kept the dual mono layout because I "may" try full balanced once


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## utilisateur

Atchoum

 you'r planning to let the evaluation board do everything but the analog out?

 I cant really comment on it as i havent heard the board nor the cambridge player but the website intrigued me.
 I asume you have read trough their papers so,
 this "Q5"module is used in their upsampler as well as in their masterclock where they claim to supress jitter below 1ps ,
 Is the S2 board operating on the same masterclock? Are you planning to use clock injection to your source? And why not go I²S in the first place?

_If the board Does offer the masterclock qualities aclaimed by their clock module and a wc out it seems interesting_


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## regal

Quote:


  Originally Posted by *threEchelon* /img/forum/go_quote.gif 
_From what I've read, it seems like an R2R DAC like the PCM1704, a resistor I/V stage, and a tube or transformer output stage is the best._

 



 I agree 100%.


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## Atchoum

Quote:


  Originally Posted by *utilisateur* /img/forum/go_quote.gif 
_you'r planning to let the evaluation board do everything but the analog out?
 this "Q5"module is used in their upsampler as well as in their masterclock where they claim to supress jitter below 1ps]_

 

The eval board does not embody their proprietary "timelock" clock which claims to provide extremly low jitter below 1ps. But the onboard Q5+Sonic modules do reclock (from a local "high quality clock") the I²S signal and this is claimed to help reduce jitter from source. See : http://www.anagramtech.com/wordpress...upsampling.gif

 I'll therefore start with the whole board (except the analog out) including the "local" clock. Then i may bypass the digital input to use my own I²S input (using TwistedPear's I²S sources and selector to come).

 I do not feel the need to inject clock to my source since their Q5 module is here to remove source's clock effects.


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## Cauhtemoc

There is much more to no compromise performance than you might think, it is not as easy as simply putting together a bunch of parts. While this will probably sound quite good, is not the way to go for a no compromise, cost no object solution.

  Quote:


  Originally Posted by *Atchoum* 
_- coax input with CS8416 (everybody seems to agree this is the best)_

 

The best by todays standard is the WM8804. The jitter rejection of most other recievers look like a joke compare to this.

  Quote:


  Originally Posted by *Atchoum* 
_- easy to build (no SMD soldering) because I'm very left-handed !_

 

The DAC, SPDIF and whatever upsampler you choose will be in SMD package. You will also need SMD capacitors for decoupling for the DAC, SPDIF and upsampler. This is not an option.

  Quote:


  Originally Posted by *Atchoum* 
_So I went through reading all the DIY DAC layouts threads, commercial products, DAC reviews...here were my findings :

 - top commercial DAC are : Lavry DA10, Benchmark DAC1, Cambridge 840C
 - top "DIY" DACs are : Opus Kit, Oritek & Zapfiltered Zhaolu, a lot of PCM1792/4 kits

 So let's have a look at the insides of theses top DAC :

 DA conversion :
 - AD1955 for the DAC in the Lavry, the Cambridge (+ a special upsampling chip licensed from anagram tech). It looks like it is the most clean sounding DAC chip. That's what i'm looking for !
 - Wolfson 8740/8741 for the Opus
 - PCM 1792/94/98 in most other DAC_

 

The big advantage with the WM8740/1 is that it is voltage output, this is much easier to handle for (I assume) a first timer like you. The WM8741 is very good, a definite step up from the WM8740.

  Quote:


  Originally Posted by *Atchoum* 
_Output stage :
 - Discrete analog stage seems to be a must and is present in almost all the top DAC (opus ballsie, oritek Zhaolu etc...)_

 

The Ballsie is not discrete, it uses an opamp.

  Quote:


  Originally Posted by *Atchoum* 
_PSU :
 - Good psu (separated for the analog and digital part) seems a must and is found in most of the mentionned DAC_

 

A good power supply is critical for no compromise performance. A LM317 or LT1085 is not enough here. You need a Jung Super Regulator, like this for example. You should use four of them at least, one +5V for analog section of the DAC, one +3.3V for the digital section, SPDIF reciever etc., and two +/- 15V for the output stage.

 One thing you have also missed is a low jitter clock. This is of utmost importance for sigma delta DACs. A very good (and cheap) alternative is the TentLabs XO clock module. This also needs a good power supply, you might even want to use a dedicated +3.3V super regulator.


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## Atchoum

Hi Cauhtemoc and thank you for all your advices !

 About SMD soldering : I've choosen Anagram's eval board because all (receiver, upsampler, clock, DACs) is already soldered ! 
	

	
	
		
		

		
		
	


	




 Lazy me...The other thing that made me look at this board is that it is quite easy to bypass a part and to add another. I may quite easily bypass the onboard CS8416 receiver and feed the upsampler with one WM8804 as you suggested.

 I had considered the Opus kit (with the WM8740 and now WM8741) and while I'm sure it is easier to do something with the WM8740 / 41, i wanted to try an AD1955 based because the cambridge 840c and the Lavry that I do like very much use this chip.

 For power supply units : I do understand it is important, a review on a french forum did an extensive comparison between JungsSuper Regulator and many others and found the Gold Mini Regulator to sound the best in a DAC thus my choice. I'll start with 2 psu (one for the digital + receiver) and one for the output stage. I may add more later following your advices.

 I did not missed the clock : one "high quality, low jitter local clock" is availaible on the board and its easy to add an higher quality clock later (bnc connector + jumper already connected on the board).


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## Cauhtemoc

Quote:


  Originally Posted by *Atchoum* 
_About SMD soldering : I've choosen Anagram's eval board because all (receiver, upsampler, clock, DACs) is already soldered ! 
	

	
	
		
		

		
		
	


	




 Lazy me..._

 

You're right, that is lazy. 
	

	
	
		
		

		
		
	


	




  Quote:


  Originally Posted by *Atchoum* 
_I may quite easily bypass the onboard CS8416 receiver and feed the upsampler with one WM8804 as you suggested._

 

Does Anagram's eval board have their TimeLock technology built in? If so there is little to gain by changing the CS8416 for a WM8804. The advantage of the WM8804 compared to other SPDIF recievers is that it works very good straight out of the box, it's jitter rejection is far, far better than anything else commonly availible. TimeLock works somewhat better still, regardless of the actual SPDIF reciever used.

  Quote:


  Originally Posted by *Atchoum* 
_I had considered the Opus kit (with the WM8740 and now WM8741) and while I'm sure it is easier to do something with the WM8740 / 41, i wanted to try an AD1955 based because the cambridge 840c and the Lavry that I do like very much use this chip._

 

The thing with AD1955 is that for ultimate performance you need a proper discrete I/V converter. The way Zapfilter does it is okay, but it's not the best.

  Quote:


  Originally Posted by *Atchoum* 
_For power supply units : I do understand it is important, a review on a french forum did an extensive comparison between JungsSuper Regulator and many others and found the Gold Mini Regulator to sound the best in a DAC thus my choice. I'll start with 2 psu (one for the digital + receiver) and one for the output stage. I may add more later following your advices._

 

Do you have a website to this forum, and perhaps to where these regulators are sold?


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## 00940

Quote:


  Originally Posted by *Cauhtemoc* /img/forum/go_quote.gif 
_ The advantage of the WM8804 compared to other SPDIF recievers is that it works very good straight out of the box, it's jitter rejection is far, far better than anything else commonly availible. TimeLock works somewhat better still, regardless of the actual SPDIF reciever used._

 

As far as I can read in the datasheets, the Texas Instruments DIR9001 is at least as good as the wolfson part. The graphs about jitter are also more detailled, with wolfson throwing in only one measurement. And the DIR9001 is cheap at digikey.


 Edit: Wrt regulators for DAC, it's worth spending some time on pinkfishmedia 's diy forums.


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## Atchoum

Quote:


  Originally Posted by *Cauhtemoc* /img/forum/go_quote.gif 
_Does Anagram's eval board have their TimeLock technology built in?_

 

Not the Timelock module itself which is nothing but a very good clock 'as far as I understand) but the "reclocking" solution is built in their Q5 upsampling technology using the local clock (which "should" be not as good as their Timelock but still on par with a XO clock I think)

  Quote:


  Originally Posted by *Cauhtemoc* /img/forum/go_quote.gif 
_The thing with AD1955 is that for ultimate performance you need a proper discrete I/V converter. The way Zapfilter does it is okay, but it's not the best._

 

This is interesting ! what do you think of exactly ?


  Quote:


  Originally Posted by *Cauhtemoc* /img/forum/go_quote.gif 
_Do you have a website to this forum, and perhaps to where these regulators are sold?_

 

The thread is here : homecinema-fr.com : Voir le sujet - Alimentations ( DAC ) Faisons le point
 The Mini Reg can be found here : GOLD Reference Mini Regulator


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## pabbi1

This is an option for discrete output. And, one is availble in the Source FS section now.


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## Cauhtemoc

Quote:


  Originally Posted by *00940* 
_As far as I can read in the datasheets, the Texas Instruments DIR9001 is at least as good as the wolfson part. The graphs about jitter are also more detailled, with wolfson throwing in only one measurement. And the DIR9001 is cheap at digikey._

 

The datasheets say very little. The WM8804 is by far the best availible today, trust me on this.

  Quote:


  Originally Posted by *Atchoum* 
_This is interesting ! what do you think of exactly ?_

 

Here is an example.

  Quote:


  Originally Posted by *Atchoum* 
_The thread is here : homecinema-fr.com : Voir le sujet - Alimentations ( DAC ) Faisons le point
 The Mini Reg can be found here : GOLD Reference Mini Regulator_

 

That regulator is a text book copy of a super regulator, originally built by Walt Jung. You can find his original articles here:

http://waltjung.org/PDFs/Regs_for_High_Perf_Audio_1.pdf
http://waltjung.org/PDFs/Regs_for_Hi..._Audio_2_A.pdf
http://waltjung.org/PDFs/Regs_for_Hi..._Audio_2_B.pdf
http://waltjung.org/PDFs/Regs_for_Hi..._Audio_2_C.pdf
http://waltjung.org/PDFs/Regs_for_High_Perf_Audio_3.pdf


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## 00940

On what basis should I trust you ? Have you any jitter measurements lying around to back up your point ? "By far" is quite a statement...


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## luvdunhill

There have been some measurements by spencer at diyaudio on the DIR9001 and he shows it to have "by far" the lowest jitter 
	

	
	
		
		

		
			





. I think his measurements were 50ps for the DIR9001.


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## Cauhtemoc

Quote:


  Originally Posted by *00940* 
_On what basis should I trust you ? Have you any jitter measurements lying around to back up your point ? "By far" is quite a statement..._

 

On the basis that I probably know more than you? 
	

	
	
		
		

		
		
	


	




 Joking aside, I have aquired jitter measurements on the WM8804 from the good people at Wolfson. I do not believe they would appreciate if I share these however, you will have to email them and ask for yourself.

 I will try to explain what makes the WM8804 different from almost every other SPDIF reciever out there.

 The DIR9001 uses PLL to lock on to the incoming signal, a fairly standard PLL at that. This is the same methods as used by most other SPDIF recievers, including the CS8416. I will not go into how a PLL works, you have to read up on this yourself. The DIR9001 have an intrinsic jitter of 50 ps. That is, when it is fed a perfectly clean and jitter free signal, the output will have some 50 ps of jitter added by the PLL.

 In reality however the input signal is never clean and jitter free. Quite the opposite in fact, several nanoseconds of jitter are quite common. The PLL will try to keep lock on the signal, constantly making small adjustments to the VCO. Regardless of how good the PLL is, a certain amount of jitter from the input signal will make it's way to the output. The lower the amount, the better the jitter rejection of the reciever. For example, under normal circumstances the DIR9001 might have some 200 ps of jitter.

 The WM8804 is different. Rather than using an normal PLL, it uses a fractional-N PLL locked on to an external crystal. The speed of this PLL is adjusted by a second, digital control loop which then recovers the data. This offers far superior jitter rejection. So good in fact that unless the PLL looses lock, the output jitter will be almost indistinguishable from the intrinsic jitter of the PLL.


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## 00940

Now I've got a basis to trust you 
	

	
	
		
		

		
		
	


	




 I confess I'm as defiant on the web as I'm trusting in real life.

 I'll fire an email to wolfson. It's a bit strange that they didn't publish those graphs if they're so good. The lonely "50ps intrinsic jitter" lost in their datasheet doesn't tell much.

 Is there a way to easily get wm8804 ? None of the big distributors carry it.


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## Cauhtemoc

I see that you live in Belgium. Email Wolfson in the UK and ask for samples, they are very helpful.


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## Atchoum

Here is a page with more info on the design/part list for my project : the "BIY" (Buy It Yourself) DAC

 I'll keep posting updates here.


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## Atchoum

update :

 Design is finished !

 I've received all parts except the enclosure and the Jung Super voltage regulators that should arrive this week. 

 - I've choosen this enclosure : modu (black, 400mm depth version with 4mm front panel see) 






 - LC-Audio's zapfilter arrived but looks like it has alreadry been used ! One input is severly burned and missed a solder pad ! 
	

	
	
		
		

		
		
	


	




 LC Audio kindly offered to send a new one. Bad QC check here but great customer care !


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## MrMajestic2

Any update on this project? Kind of interested myself, but not until I finished my Opus build. Twisted Pear has a new TXD I/V stage that would be nice for this build I think.


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## J.D.N

Quote:


  Originally Posted by *Atchoum* /img/forum/go_quote.gif 
_update :

 Design is finished !

 I've received all parts except the enclosure and the Jung Super voltage regulators that should arrive this week. 

 - I've choosen this enclosure : modu (black, 400mm depth version with 4mm front panel see)

http://www.modu.it/pesante_nero.jpg
_

 

Did the website work in english when you used it? I really like the case, but the site is terrible!


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## MrMajestic2

Quote:


  Originally Posted by *J.D.N* /img/forum/go_quote.gif 
_Did the website work in english when you used it? I really like the case, but the site is terrible!_

 

Try this link instead:
modu

 Hifi2000 cases are nice, I've bought 11 of them so far


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## Atchoum

Ok a little update after a busiest week...
 I have psu problem. When plugged my JSR psu (+12/-12V) give only +2V on the + side although it works perfectly unloaded....

 I also have difference in current draw between my left an right side. I will debug this this WE and post pics of the current build.

 Anyway I still can also try my zapfilter instead of using the onboard output stage (which requires the +-12 non working psu)...


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## Cauhtemoc

Quote:


  Originally Posted by *Atchoum* 
_I have psu problem. When plugged my JSR psu (+12/-12V) give only +2V on the + side although it works perfectly unloaded...._

 

You're drawing too much power.


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## Atchoum

I solved my issu with the psu (missing contact on gnd... ). I'll test everything tomorow.


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## Atchoum

...again...

 ok i've got the psus right, every part has the correct voltage.... but when i plug the board on my transport (sb3) i can't get it to output any kind of noise...

 the receiver lights seems to be unable to lock on the stream... blinking and shutting down from times to times...


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## sp502

Quote:


  Originally Posted by *Atchoum* /img/forum/go_quote.gif 
_...again...

 ok i've got the psus right, every part has the correct voltage.... but when i plug the board on my transport (sb3) i can't get it to output any kind of noise...

 the receiver lights seems to be unable to lock on the stream... blinking and shutting down from times to times..._

 

The DIY path isn't as easy as it seams most times...
 Why don't you give it a try with other sources that you might have, like a dvd player for example.
 Maybe on the other hand the cable is the problem, is it a real 75 Ohm cable?
 I hope to everything work out right at the end.


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## Atchoum

Yes the cable is a true 75ohm one (Blue Jean Cable). I do not have any other spdif source at home...Still investigating...


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## sp502

Quote:


  Originally Posted by *Atchoum* /img/forum/go_quote.gif 
_Yes the cable is a true 75ohm one (Blue Jean Cable). I do not have any other spdif source at home...Still investigating...
	

	
	
		
		

		
		
	


	


_

 

Any news? 
 Did you manage to find any other spdif source?


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## Atchoum

no other source yet. I've got to reach my old optical to spdif converter to try my cdp as a digital source.


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## randytsuch

Hi
 I was looking at the Sonic2 user manual.

 So, the "audio stream lock" LED is blinking?

 Did you check and make sure all the configuration jumpers are in the right places? Pages 33 and 34 showed how it is supposed to be. I know it is supposed to be the default, but it does not hurt to check.

 If your SB3 is working with you other DAC, it should work with this one too, so I would be surprised if another source acted differently.

 Good luck,
 Randy


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## Jocko Homo

Quote:


  Originally Posted by *Cauhtemoc* /img/forum/go_quote.gif 
_The DIR9001 uses PLL to lock on to the incoming signal, a fairly standard PLL at that. This is the same methods as used by most other SPDIF recievers, including the CS8416. I will not go into how a PLL works, you have to read up on this yourself. The DIR9001 have an intrinsic jitter of 50 ps. That is, when it is fed a perfectly clean and jitter free signal, the output will have some 50 ps of jitter added by the PLL.

 snip.......

 The WM8804 is different. Rather than using an normal PLL, it uses a fractional-N PLL locked on to an external crystal. The speed of this PLL is adjusted by a second, digital control loop which then recovers the data. This offers far superior jitter rejection. So good in fact that unless the PLL looses lock, the output jitter will be almost indistinguishable from the intrinsic jitter of the PLL._

 

TI tried that approach in the ill-fated DIR170x series. Maybe Wolfson will have better luck.

 Anything has to be easier to use than a '8416. To say nothing of their idiotic front-end design. At least TI has enough sense to tell you in the data sheet that you need an external amplifier before the chip.

 (How many times, over how many years have I been saying that? No one seems to listen.)

 Jocko


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## error401

Quote:


  Originally Posted by *Jocko Homo* /img/forum/go_quote.gif 
_TI tried that approach in the ill-fated DIR170x series. Maybe Wolfson will have better luck.

 Anything has to be easier to use than a '8416. To say nothing of their idiotic front-end design. At least TI has enough sense to tell you in the data sheet that you need an external amplifier before the chip.

 (How many times, over how many years have I been saying that? No one seems to listen.)

 Jocko_

 

It seems to be the approach used in DIX4392 as well. Do you have any more detail on this part's performance? I've got a couple laying around I might try implementing...


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## Atchoum

ok the project is on hold for a moment...

 - i sent back the anagram eval board since i found no way to make it output any sound...


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## MrMajestic2

Quote:


  Originally Posted by *Atchoum* /img/forum/go_quote.gif 
_ok the project is on hold for a moment...

 - i sent back the anagram eval board since i found no way to make it output any sound..._

 

Man that sucks. Do you suspect that there is something wrong with it or its just very hard to get it working?


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## sp502

Quote:


  Originally Posted by *Atchoum* /img/forum/go_quote.gif 
_ok the project is on hold for a moment...

 - i sent back the anagram eval board since i found no way to make it output any sound..._

 

That is really bad.
 Anagram recently suspended the online store and redirects to
 abc-pcb.com that I assume it was the manufacturer of the evaluation
 boards. The problem is that they (abc-pcb) don't reply to emails...
 DIY is the hard way after all...

 Good luck Atchoum


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## ecodoppler

Dear Atchoum
 I wish to accomplish a dac with Anagram S2 and I've seen your thread on this website. How does your DAC sound? Did you finish it and find problems during the realization?
 thank you
 Ecodoppler


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## tenzip

Quote:


  Originally Posted by *ecodoppler* /img/forum/go_quote.gif 
_Dear Atchoum
 I wish to accomplish a dac with Anagram S2 and I've seen your thread on this website. How does your DAC sound? Did you finish it and find problems during the realization?
 thank you
 Ecodoppler_

 

If you had read the thread, you would have seen this:

  Quote:


  Originally Posted by *Atchoum* /img/forum/go_quote.gif 
_ok the project is on hold for a moment...

 - i sent back the anagram eval board since i found no way to make it output any sound..._


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## ecodoppler

Hi
 Yes, but the project is on hold since March 2008; it's impossible. I've sent an email to Mr Lavanchy of ABC PCB to request their price list:the Edel Fs kit costs 275 euro and Edel S2 kit 545 euro.
 regards
 Ecodoppler


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## regal

Quote:


  Originally Posted by *threEchelon* /img/forum/go_quote.gif 
_From what I've read, it seems like an R2R DAC like the PCM1704, a resistor I/V stage, and a tube or transformer output stage is the best._

 



 Bingo, add a PDM100 filter and use a SE tube stage (no SRRP) and you have it. I have a design (posted here somewhere) that you can add to the D1 clone that is fantastic. avoid the new DAC chips and opamp outouts like the plague


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## ecodoppler

Bingo, add a PDM100 filter and use a SE tube stage (no SRRP) and you have it. I have a design (posted here somewhere) that you can add to the D1 clone that is fantastic. avoid the new DAC chips and opamp outouts like the plague


 Could you post schematics of your project and/or photos?

 thank you

 Ecodoppler


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