# (Now Finished) PCM2902 USB-S/PDIF PCB Group Buy



## guzzler

Dear All, this is the OFFICIAL thread to sign up for the PCM2902 board. In difference to usual group buy setup I know the shipping cost, so there will be only *one* round of billing by PayPal. I can also take payment by cheques drawn in GBP. Shipping and fees will be *£1.50* internationally, and *£1* to the UK, regardless of the number ordered

*Please note, this design has NOT been prototyped, you are buying as is!*

*Final Price (150 units): €1.43 ($1.92)*

 The original thread: http://www6.head-fi.org/forums/showthread.php?t=105088

 The board: (note, the final board has space for an LED resistor and pads)







Orders will close on *Friday 18th March*
The more you order, the less they cost
PCBs will be ordered from my usual house (Eurocircuits)

 Please PM me with the title *PCM2902 Group Buy* with the number that you *DEFINATELY* want, and how many you *maybe* want, your *PayPal address*, *and location.*

_Participants_

 dsavitsk - 8 (12)

 Nisbeth - 7 + SMD

 agentpt5 - 5 (7)
 MattN - 5 + SMD
 pappucho -5 + SMD
 roibm - 5
 TV Man - 5 + SMD

 MikeD - 4 (7)
 aswils - 4 
 BradJudy - 4
 fbcn - 4
 tommak - 4 + SMD

 vpolineni - 3 (5) + SMD
 motherone - 3 (4)
 glemaire - 3
 icy006 - 3 + SMD
 individual6891 - 3 + SMD
 james902 - 3 + SMD
 mindgap - 3 + SMD
 needlz - 3 + SMD
 sft - 3
 shiggins - 3 + SMD
 Steel - 3

 fenwick - 2 (3) + SMD
 ~noober - 2 + SMD
 Botch - 2
 bzo - 2
 Construct - 2 + SMD
 cottonbuds - 2
 doobooloo - 2
 eastside504 - 2 + SMD
 Garbz - 2 + SMD
 Jamont - 2 + SMD
 Jhouser - 2
 judo - 2 + SMD
 Magsy - 2 + SMD
 mansfield - 2 + SMD
 phobus - 2 + SMD
 PYROTAK - 2
 randytsuch - 2 + SMD
 Suezo - 2 + SMD
 walangalam - 2

 andrzejpw - 1
 Bas Horneman - 1 
 guzzler - 1
 Voodoochile - 1 + SMD

*Total: 135 (148)*


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## Nisbeth

YGPM!


 /U.


 PS: It might be helpful to people if you could post an approximate cost for the boards (e.g. post the cost per board for 25 pcs. ordered)


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## phobus

ygpm


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## dsavitsk

ygpm


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## bg4533

Sorry if these have been asked in the other thread, but I haven't read through it in a while and I figured these questions are relevant to everyone.

 What will be the estimated cost to build this thing?

 This is USB powered, correct?

 What are the final dimensions of the board?


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## dsavitsk

Quote:


  Originally Posted by *bg4533* 
_Sorry if these have been asked in the other thread, but I haven't read through it in a while and I figured these questions are relevant to everyone.

 What will be the estimated cost to build this thing?_

 

There is a parts list (with prices) on page 4 (http://www6.head-fi.org/forums/showp...1&postcount=74) It is pretty inexpensive, in the range of $20 for parts i think.

  Quote:


  Originally Posted by *bg4533* 
_This is USB powered, correct?_

 

Yes

  Quote:


  Originally Posted by *bg4533* 
_What are the final dimensions of the board?_

 

It is very small. I would guess about 1.5" x 2"? Guzzler should know better, however.


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## DaKi][er

must... resist... 

 3 thanks


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## Garbz

I haven't the slightest need for this thing. I'll take 2

 YGPM


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## walangalam

2 as well. 

 pm on the way


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## james902

you got PM


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## individual6891

Sent the pm


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## Pappucho

I'll take five, thanks!


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## Icy006

YGPM. 3 to me. Mmm, S/PDIF.



 [size=xx-small](Shut up brain, or I'll stab you with a Q-Tip!)[/size]


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## guzzler

*^^Updated; sorry for the delay, I was away for the weekend.^^*

 the board dimensions are 45mm x 23mm (ie small!), which is 1.75" x 0.9" in imperial.

 Now past the 50 price break; quantities go up in 25 steps now; so there is no further discount until 75 pieces (or close enough that we can get some spare).

 thank you


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## eastside504

2 please, thanks


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## guzzler

Ok, we're nearly over the 50 limit now for definite orders, which means we need to order 75 boards. Only 15 to go if people fill their maybe orders too. I'm happy to hang on to up to 10 pieces personally... Slight confusion on price, I think it was a typo on my part carried through. The current price is €1.92 ($2.54), which is a little higher but still not going to break the bank 
	

	
	
		
		

		
			





 If people would like, to save on packing costs, ie 2 boards cost you $5, shipping, packing etc costs $6, I'd be happy to consider shipping in just plain envelopes, and that would take the costs for me way down. On the reverse side of the argument, they wouldn't be padded. If I could have your thoughts in the thread, it would be appreciated. I'm easy either way.

 g


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## Nisbeth

Quote:


  Originally Posted by *guzzler* 
_If people would like, to save on packing costs, ie 2 boards cost you $5, shipping, packing etc costs $6, I'd be happy to consider shipping in just plain envelopes, and that would take the costs for me way down. On the reverse side of the argument, they wouldn't be padded. If I could have your thoughts in the thread, it would be appreciated. I'm easy either way.

 g_

 

I don't think using plain envelopes are are problem because the boards are so small and light. If you put the boards in a small plastic bag to keep them from rattling too much around, they should be safe 
	

	
	
		
		

		
		
	


	




 /U.


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## walangalam

yeah I had someone from Hongkong send me cs8412 and tda1541. He just stuck them in a square of styrofoam, put it in a small plastic zip lock and mailed it to me using ordinary airmail envelop.

 No probs.


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## guzzler

^bump^ need a few more orders to fulfil 75 
	

	
	
		
		

		
		
	


	




 g


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## dsavitsk

Quote:


  Originally Posted by *guzzler* 
_^bump^ need a few more orders to fulfil 75 
	

	
	
		
		

		
		
	


	


_

 

Is it worth a post at diyaudio to see if we can get a few more people?

 -d


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## individual6891

I can handle the middle-man type stuff between head-fi and diyaudio.com if needed? Can't handle any shipping - just communication


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## Nisbeth

I think it's a good idea, so I've just posted it link 

 Hope it's OK, guzzler? 
	

	
	
		
		

		
		
	


	




 /U.

 EDIT: Andy, perhaps you can post the in the thread at diyaudio?


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## individual6891

They might move it cos it's at the wrong thread:

http://www.diyaudio.com/forums/forum...?s=&forumid=46

 ...maybe


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## sft

3 please, thanks.


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## guzzler

Of course


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## guzzler

Hello All, just a quick note to read the things in the first thread. I've been looking at the design, and didn't like the layout of the oscillator. Considering it's a 12MHz part, there were too many twists in it's traces, and a little too long. I've reorganised all that area of the board, at the expense of .5mm extra length, which I don't think will be noticed. If it's too much, please let me know.

 Also, stupidly, I've measured the board wrong. It's about 3cm in width, not 2.5cm. Price has changed slightly accordingly, up about 15c or so. Again, please get in touch if you don't like that. 

 Finally, it's worth noting that this design *hasn't been prototyped*, so you're buying *as is*. The layout is simple, and traces have been kept as short and as logical as possible, it's been checked and rechecked and there is no physical reason it shouldn't work. It was the same with the original USB DAC, that was a straight run of boards with no prototype. Again, if you aren't happy with that, please get in touch

 Lastly, changed shipping/fees cost 
	

	
	
		
		

		
		
	


	




 regards

 g


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## Eric1285

Out of curiosity, what does this thing do?


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## Nisbeth

Quote:


  Originally Posted by *Eric1285* 
_Out of curiosity, what does this thing do?_

 

It converts a USB audio signal to SPDIF (the standard transmission format for digital audio), which you can then feed into a D/A-converter, either a stand-alone one or something like a surround receiver. 
	

	
	
		
		

		
		
	


	





 /U.


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## guzzler

Final design is up (first post), and here is the updated BOM. I've opted for through hole conversion resistors as 0805 precision resistors in those values proved a little tricky to find. Also, the LED resistor is a higher dissipation than 0805 can take safely... The led itself is a standard 3mm, but can, of course, be mounted off the board:

 1 x PCM2902 (SSOP28)
 1 x 74HC04 (SO14)
 1 x TPS793 4.75V (SOT23-5) (possibly optional)

 1 x 560µF 6.3V Panasonic FC
 2 x 22µF 10V OS-CON SC (or equivalent similar, FCs are fine)
 4 x 1µF Wima MKS-02 (or similar, tantalum should be ok, 2.54mm pitch)
 1 x 100nF 5mm (0.2") pitch capacitor (Wima MKS-2 or similar)
 5 x 100nF 0805 ceramic capacitors
 1 x 10nF 0805 ceramic capacitor
 2 x 33pF 0805 ceramic capacitors

 1 x 1M 0805 resistor
 1 x 1K5 0805 resistor
 2 x 22R 0805 resistor
 1 x 91R 7.5mm resistor (Vishay Dale appropriate, or generic 1% metal film)
 1 x 360R 7.5mm resistor (Vishay Dale Appropriate, or generic 1% metal film)
 1 x generic resistor for LED, V ~ 4.5V

 1 x 12MHz HC49 crystal oscillator
 1 x 10µH 1210 package inductor
 1 x USB B-type connector
 1 x 3mm low voltage LED
 1 x RCA socket
 1 x case
 1 x USB cable 

 As the design is altered, you are naturally free to withdraw


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## dsavitsk

This is a parts list for DigiKey only -- some of these are probably lower quality than recommended by guzzler, but if you are into one stop shopping, I think they should work, maybe?

 * indicates a change from the earlier parts list.

 please PM me with errors or suggestions for changes


 # Descr .................................................. .......... Digikey Part #..........Price / min quantity

 1 x PCM2902 (SSOP28) ................................................. 296-12986-5-ND ........ $9.00 / 1
 1 x 74HC04 (SO14) .................................................. . 296-12883-1-ND ........ $0.44 / 1
 1 x TPS793 4.75V (SOT23-5) <-- pain to solder! ....................... 296-12160-1-ND ........ $1.14 / 1

 1 x 560µF 6.3V Panasonic FC .......................................... P12705-ND ............. $0.48 / 1 (backordered)
 2 x 22µF 10V OS-CON SC (or equivalent similar, FCs are fine) ......... P11213-ND ............. $0.32 / 1 (inexact match - 25V (6.3V available))
 4 x 1µF Wima MKS-02 (or similar, tantalum should be ok, 2.54mm pitch). 399-1337-ND ........... $0.41 / 1 (tantalum - 25V)
 5 x 100nF 0805 ceramic capacitors .................................... PCC1843CT-ND .......... $0.06 / 10 (panasonic ecg)*
 1 x 100nF 5mm (0.2") pitch capacitor (Wima MKS-2 or similar) ................ 495-1103-ND .... $0.17 / 1 (EPCOS INC)*
 1 x 10nF 0805 ceramic capacitor ...................................... PCC1991CT-ND .......... $0.09 / 10 (panasonic ecg)
 2 x 33pF 0805 ceramic capacitors ..................................... PCC330CGCT-ND ......... $0.05 / 10 (panasonic ecg)

 1 x 1M 0805 resistor ................................................. RR12P1.0MDCT-ND ....... $0.15 / 10 (sasumu 0.5%, .1W)
 1 x 1K5 0805 resistor ................................................ RR12P1.5KDCT-ND ....... $0.15 / 10 (sasumu 0.5%, .1W)
 1 x 91R 7.5mm resistor (Vishay Dale appropriate, or generic 1% metal film) ... P91.0CACT-ND .. $0.17 / 10 (Panasonic - ECG)*
 1 x 360R 7.5mm resistor (Vishay Dale Appropriate, or generic 1% metal film) .. P360CACT-ND ... $0.17 / 10 (Panasonic - ECG)*
 2 x 22R 0805 resistor ................................................ RR12Q22DCT-ND ......... $0.15 / 10 (sasumu 0.5%, .1W)

 1 x 12MHz HC49 crystal oscillator .................................... CTX058-ND ............. $0.94 / 1
 1 x 10µH 1210 inductor ............................................... DN10103JCT-ND ......... $1.02 / 1
 1 x USB B-type connector ............................................. WM17109-ND ............ $1.94 / 1
 1 x 3mm low voltage LED .................................................. .. HLMP1700-ND .... $0.35 / 1 (Fairchild Opto)*
 1 x generic resistor for LED, V ~ 4.5V ...................................... 4.32KXBK-ND .... $0.10 / 5 (Yageo -- you should check my math to see if this is actually appropriate, I just guessed 
	

	
	
		
		

		
		
	


	




 )*
 1 x RCA socket
 1 x case
 1 x USB cable


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## guzzler

looks good dsavitsk; 6.3V capacitors will be fine for the electrolytics.

 g


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## dsavitsk

Any chance that the newest layout will allow the use of the 10V version of the 560uF cap? It looks like there might be some room there, but I don't know if it's enough.

 -d


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## Nisbeth

If there isn't enough room, you could consider using the 470uF/6v3 instead (p/n P11169). I don't think the slightly lower capacitance is a problem and if you order in a hurry, DigiKey still has some available 
	

	
	
		
		

		
			









 /U.


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## aswils

I would like 4 please,
 Thanks,
 Adam


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## individual6891

Quote:


  Originally Posted by *Nisbeth* 
_EDIT: Andy, perhaps you can post the in the thread at diyaudio? 
	

	
	
		
		

		
		
	


	


_

 

Done


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## BradJudy

This looks like an easy fun thing to play with. Does it require any particular driver/software to put out PCM under WIndows XP or Mac OS X?


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## dsavitsk

Quote:


  Originally Posted by *BradJudy* 
_This looks like an easy fun thing to play with. Does it require any particular driver/software to put out PCM under WIndows XP or Mac OS X?_

 

The drivers are builtin to win2k, winXP, win2003, winME, OSX, Linux, FreeBSD, and NetBSD. I don't know about OpenBSD, MacOS9, Solaris, etc. Win98, WinNT, and anything older don't work out of the box, and there may or may not be drivers available (there probably are for 98, but it is less likely for NT, 95, 3.1, etc.)

 Windows will put out a 48khz pcm signal (asio may fix this to 44.1, but I don't know -- check the computer audio forum), OSX a 44.1khz, and I think *nix is probably 48, but you'll have to check this too.

 -d


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## mansfield

Hi,

 Im just starting to put together an music server and this looks like a great first project. Are SMDs used on this and if so, how many. Sorry but Im not really familiar with alot of the parts listed and SMDs and I havent gotten along very well.

 Thanks, Mansfield


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## dsavitsk

Quote:


  Originally Posted by *mansfield* 
_Hi,

 Im just starting to put together an music server and this looks like a great first project. Are SMDs used on this and if so, how many. Sorry but Im not really familiar with alot of the parts listed and SMDs and I havent gotten along very well._

 

By my count, fully half of the parts are SMD -- I count 73 smd soldered connections 
	

	
	
		
		

		
		
	


	




 While the projects is not too complex, it does require pretty decent soldering skills.


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## mansfield

Well then I guess I will need two. One for practice and one to give to my friend to do if I kill the first.

 mansfield


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## guzzler

Regards compatibility; it will work with any OS that natively supports USB. WinXP, Win2K, Linux, Mac OS-X etc.... It will work on the second edition of Win98, but not the very original without the USB patch. I don't know much about the various Mac OS', but if a USB device is plug and play in it, it will probably be fine...

 Nearly at 75 guarenteed. 100 is the next target 
	

	
	
		
		

		
		
	


	




 1 week left!

 g


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## BradJudy

Count me in for 4.


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## JHouser

Ill take 2

 Jonathan-


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## tommak

I might have missed it, but is there as schematic posted? If so, could someone please direct me to it? If not, could one please be posted?

 Thank you!

 tommak


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## PYROTAK

i'll take 2.


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## individual6891

Quote:


  Originally Posted by *tommak* 
_I might have missed it, but is there as schematic posted? If so, could someone please direct me to it? If not, could one please be posted?

 Thank you!

 tommak_

 

Read the first post, click the link


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## individual6891

Guzzler, is there any chance you can order some of the SMD devices and ship them with the boards for an extra fee? Most places in UK have a min quantity of 100 for these things


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## guzzler

It should be okay to order the passives and include them. I'm ordering from Rapid fairly soon and I'll use most of them up anyway. That would mean you'd still have to obtain everything else though, like semiconductors and hardware. As a rough guess, I'd say SMD passives would add ~20p to the cost, not including the inductor which would be about 40p itself.

 edit: PYROTAK and JHouser, could you PM your PayPal details to me? Thanks

 g


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## tommak

Quote:


  Originally Posted by *individual6891* 
_Read the first post, click the link 
	

	
	
		
		

		
		
	


	


_

 

I'm sorry but I still don't see a schematic. Even though I'm probably staring right at it. I do see the board layouts, but no schematic. Could someone please tell me the "post number", or where else I could find the schematic?

 Thank you!

 tommak


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## individual6891

There is a schematic at:
http://focus.ti.com/lit/ds/symlink/pcm2902.pdf

 Where DOUT goes into a hex invertor.

 Guzzler, if you could include the capacitors/resistors, that'd be great. Rapid has a 100 min quantity limit, and RS has a 50 min quantity limit.


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## guzzler

Regards the schematic; it's the basic implementation from TI as above. All the control lines, and analogue section have been removed. The buffer is a standard TTL to S/PDIF converter using a hex inverter as stated. See the bottom of Rob Elliots project at http://sound.westhost.com/project85.htm. It's the one marked TTL to Coax converter.

 G


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## Voodoochile

I'll take one please.


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## guzzler

Could people please remember PayPal addresses in PMs? Thank you. Posted the price for 125 as well 
	

	
	
		
		

		
		
	


	




 g


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## guzzler

^ 4 days remaining bump ^


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## james902

what? on the second page? 

 ^
 ^
 ^
 bump

 fine. since the price is dropping, i'll take 3 instead of 2! i dunno what the third board is for, but this needs to be on the first page!


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## roibm

pm sent for 5 instead of 3...


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## endia

count me for two please, thanks.


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## dsavitsk

You can now add all of the DigiKey parts to an order with one button click. Just go to http://www.ecp.cc/dk.html

 You should still proof the list to make sure it is correct. Quantities are the higher of necessary or minimum order number

 -d.


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## randytsuch

Quote:


  Originally Posted by *dsavitsk* 
_You can now add all of the DigiKey parts to an order with one button click. Just go to http://www.ecp.cc/dk.html

 You should still proof the list to make sure it is correct. Quantities are the higher of necessary or minimum order number

 -d._

 

Very cool. Thanks for doing it.

 Randy


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## clarke68

Quote:


  Originally Posted by *dsavitsk* 
_You can now add all of the DigiKey parts to an order with one button click._

 

Very cool indeed! Total came to $33.96 for me, excluding shipping, tax, duties, etc.


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## individual6891

Is it ok to use a 330uF 6.3V OSCON instead of the 560µF 6.3V Panasonic FC?


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## BradJudy

Awesome webpage for Digikey purchasing. It looks like $82 to make 4 of them.


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## guzzler

Quote:


  Originally Posted by *individual6891* 
_Is it ok to use a 330uF 6.3V OSCON instead of the 560µF 6.3V Panasonic FC?_

 

Yes, the value of that cap isn't critical. Just don't go too high 
	

	
	
		
		

		
			





 g


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## individual6891

Is the +5V from from the USB lines stable enough to put a 6.3V oscon in here? The oscons are very sensitive to overvolting, even small pulses. Also, will the lower ESR of the cap affect the USB? Read something back there which talked about USB hubs seeing the line as a short if the value of the cap isn't right..


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## guzzler

There is an inductor in the path that will provide sufficient resistance to prevent shorting on most capacitors. There is no way the USB will put out much over 5V either as it must maintain a standard, which I think is +/- 500mV. If you're worried, don't do it!

 g


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## vpolineni

guzzler,
 i tried sending you a pm but received a message indicating you're not accepting pm's. is it still possible to order these? please let me know. thanks.


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## motherone

Guzzler,

 I pm'd you a few days ago.. Can you confirm that you got my order?

 Thanks!


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## guzzler

Sorry about that folks, I tried to change my email address to my university account and it didn't send me the verification email so couldn't post or recieve.

 vpolineni; please resend; still available 
	

	
	
		
		

		
		
	


	




 motherone; yes, you're on the list (check top post for all involved)

*ADDITIONAL: could people who would like the passive SMDs included let me know ASAP so I can include them with my order*

 Also, have sent PMs to all I haven't got a PayPal address for

 best regards, and my apologies

 Gus


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## shiggins

Okay, I just realised I have a use for one of these - I'll take 3 please. With SMD's if possible. PM about to be sent.

 Cheers,
 s.


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## individual6891

Would like mine with SMDS if the cost is just a few extra pence


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## james902

how much more is the passive smds?


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## motherone

Quote:


  Originally Posted by *guzzler* 
_
 motherone; yes, you're on the list (check top post for all involved)_

 

Sorry Guzzler, I totally missed that on the first page 
	

	
	
		
		

		
		
	


	




 Thanks for the quick reply!

 I, too, would be interested in SMD's if it's not too much more.


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## guzzler

SMDs are 60p per board. That is all the SMD resistors, capacitors, and the inductor

 g


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## Nisbeth

Quote:


  Originally Posted by *guzzler* 
_SMDs are 60p per board. That is all the SMD resistors, capacitors, and the inductor

 g_

 

At that price I'll definitely want SMD's with my boards - all seven of them 
	

	
	
		
		

		
		
	


	





 /U.


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## individual6891

Yeah me too


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## guzzler

Updated top list with SMD people. Just check to make sure I've not messed up, or left your name off.

*ORDERS CLOSE 23:59 GMT TOMORROW FRIDAY 18th*

 (I might take some a little after that time 
	

	
	
		
		

		
			





 )

 thanks 

 gus


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## Icy006

YGSMDPM


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## roibm

^_^


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## Bas Horneman

I'd like to order 1 please!
 TIA.


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## bg4533

I want 2. Sick and need to lay back down. Will send PM in a bit.


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## Botch

Can I put in an order for 2 with SMD components. Guzzler, when do you want payment (by PayPal I guess)? Just saw this thread 5 minutes ago and wanted to make sure I got in before midnight. 

 Nice work,

 Botch


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## Garbz

Eh... curses for not paying attention. Any chance i can get the SMD components with my board still or are we closed already?


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## guzzler

Garbz, sure that's fine... didn't get to a computer till now so you're lucky 
	

	
	
		
		

		
		
	


	




 [size=large]Orders are now closed. Could people who had optional orders please get in touch to confirm if they want them or not.[/size]

 Thank you all; please check the list on the first post to make sure I've not made any mistakes. The order will be placed on Monday morning, so you have until then to get back to about optionals and mistakes

 best regards

 Gus


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## flush2000

YGM regarding the off chance that the order hasn't gone in yet and me being two days late.


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## nleahcim

Dammit - been so busy that I missed this post. Any chance I could get a couple boards?


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## james902

just checking to see if you sent out paypal requests yet


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## guzzler

PayPal requests will go out this evening (tuesday). Boards have been ordered, hopefully about 2 weeks until postage, so no rush on the payments. 

 ALL BOARDS ARE ACCOUNTED FOR, NO MORE WILL BE MADE

 g


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## guzzler

Dear All, PayPal requests have been sent. If I'd made a mistake (not impossible by any means 
	

	
	
		
		

		
		
	


	




 ), please get in touch and do not pay the request...

 regards

 Gus


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## endia

if anyone want to sell any spare one, i take...
 thanks.


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## eastside504

payment sent, thanks


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## individual6891

Quote:


  Originally Posted by *guzzler* 
_Dear All, PayPal requests have been sent. If I'd made a mistake (not impossible by any means 
	

	
	
		
		

		
			





 ), please get in touch and do not pay the request...

 regards

 Gus_

 

Haven't received invoice


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## dsavitsk

Payment sent for 12. Thanks again.

 The beginnings of a project page are up at http://www.ecp.cc/usb-spdif.html I'll add more info as it is available, and as boards are built.

 -d


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## Garbz

Payment sent, I'm surprised how cheap it worked out. I expected the SMD components to be a lot more.


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## Icy006

Payment sent. Thanks!


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## PappaSmurf

AHH!!

 I cant believe I've missed out on this by under a week! 
	

	
	
		
		

		
		
	


	




 If anyone has ordered any spares which they would part with please let me know. I was just refered to this webpage from Overclockers Australia -- http://forums.overclockers.com.au/sh...d.php?t=359877 but it looks like I'm too late 
	

	
	
		
		

		
		
	


	





 If I cant possibly still get in on this somehow, I'll have to go ahead and do it on my own, except that its going to cost me $25AUD in shipping for a <$3 PCB and who knows what gastly shipping for all the components 
	

	
	
		
		

		
		
	


	




 damn Australian remoteness!!

 Bugger 
	

	
	
		
		

		
		
	


	




 If anyone can help (unlikely I know) please let me know.


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## guzzler

Folks, 00940 and Matt have pointed out a small error just found in the other DAC thread. It turns out that pins 8 and 9 should be driven high for stability. Unfortunately, this isn't done on the current board, but is easily fixed. You'll need to carefully create a solder bridge between 8,9, and 10. 10 is the regulated input, and is high enough for logic levels. If you don't include the regulator, be sure to bridge those connections too. My apologies on this, thankfully the fix is easy. See attached image for details

 regards

 Gus


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## uzziah

<shamelessly begs for someone to have pitty on him, and send him a board>

 "will work for pcb"


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## sft

Payment sent, thanks for your effort.


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## Garbz

k thanks for that. What exactly happens if this isn't done? Like unstable how?


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## needlz

Hey Garbz,

 I noticed the mod'd transit in your equip list. What exactly did you do to it?

 thanks.

 nix that question... I found your thread discussing it.

 And to get on topic... Payment was made. I am stoked to get my boards.


----------



## flush2000

a wee bit off topic, i know, but would anyone be willing to modify this to have analog in/out or link me to something similar? I'm looking for something to use as an external soundcard with a mic port on a mac mini, and need a project to work on. Thanks for any help!


----------



## Nisbeth

Where are you located in the world? If you are in UK/Europe, Elektor Electronics published a design using the PCM2902 some years ago (issue 12/2002) which has both analog input and output. That might be just what you need and the last time I looked you could still buy ready-made PCBs directly from elektor (a bit expensive though) 
	

	
	
		
		

		
		
	


	





 /U.


----------



## paologatto

Quote:


  Originally Posted by *flush2000* 
_a wee bit off topic, i know, but would anyone be willing to modify this to have analog in/out or link me to something similar? I'm looking for something to use as an external soundcard with a mic port on a mac mini, and need a project to work on. Thanks for any help!_

 

Hi flush2000,
 I made a similar project.. but sorry, I have already all the units assembled. Initially I thought about making it in form of kit but since there are some SMD components I realized that many didn't like this.. 
	

	
	
		
		

		
		
	


	




 Still speaking of the analog input and output of the PCM2902 and PCM2906, may be interesting some measurements that I performed on them. The plots are obtained from the FFT of the impulse response of a loopback measurement (output --> input), so they include both the response of the output and of the input converters.













 (click on the thumbnails to view the full image)

 Edit: forgot to tell, the input and output buffer in my project are realized with the R/R Opamps Burr-Brown OPA2353.


----------



## flush2000

nisbeth, that sounds good, would it still work since i'm in the US?

 paologatto, do you have project page or something? I'd love to take a look at the schematics and board layout if you don't mind.

 Thanks again for all the help!


----------



## Nisbeth

It still works in the US, I'm just not sure you can get the article 
	

	
	
		
		

		
		
	


	





 /U.

 EDIT: Here's the project page on elektor's website http://www.elektor-electronics.co.uk...h=12&art=50774
 I just noticed you can actually buy the article as pdf for 1.00 GBP


----------



## paologatto

Quote:


  Originally Posted by *flush2000* 
_paologatto, do you have project page or something? I'd love to take a look at the schematics and board layout if you don't mind.
_

 

The schematics are very similar to the one suggested in the Evaluation Board of the PCM2902.. 

 Instead, you can take a look inside of my project in this Head-fi post:

http://www6.head-fi.org/forums/showp...2&postcount=67


----------



## flush2000

nisbeth and paologatto, thank you very much. I've just downloaded the schematic from Elektor, and am thinking about picking up the board as well. I'll be sure to post a thread when i'm done


----------



## paologatto

There are online also some similar projects here:

http://monterdiy.com/karta_muz_usb.htm

http://monterdiy.com/karta_usb_3.htm

http://monterdiy.com/karta_usb_4.htm

 All is written in a language that I don't understand.. but the schematics don't need translations 
	

	
	
		
		

		
		
	


	




 In this site http://monterdiy.com/konstrukcje.htm there are also other very interesting things...


----------



## agentpt5

Still have not received invoice. Can you resend. Thanks.


----------



## Tohex

Before i go putting my name down, anyone know if you can get all the parts here in AUSTRALIA...

 Also, i am hoping you'd ship down here guzzler? Maybe this has all been answered...lol, but i didn't read all 6 pages...

 Thanks


----------



## james902

i think the group buy closed


----------



## Tohex

Fair enuf...so does that mean that there is NO way i can get my hands on one of these if i want? (still based on the fact that i need to be able to get parts and delivery here in AU)


----------



## dsavitsk

read the project page at http://www.ecp.cc/usb-spdif.html If you are up to building it, and you can get the parts, contact me via pm in a few weeks. I may have an extra board or two, and there is a queue forming for it (them.)

 -d


----------



## Tohex

Indeed, i reckon i could solder most of it...looking at that soldering page, i just dont have all the right tools (well i dont have a 'solder sucker'....)...i will have a look a bit more and see what i think.....i'll PM you i'f i'm interested. I may also check out the F/S thread...might be some on there at some point (i saw dooboloo had one i think....expensive tho...nice case )

 Thanks


----------



## individual6891

Quote:


  Originally Posted by *alucrep* 
_Indeed, i reckon i could solder most of it...looking at that soldering page, i just dont have all the right tools (well i dont have a 'solder sucker'....)...i will have a look a bit more and see what i think.....i'll PM you i'f i'm interested. I may also check out the F/S thread...might be some on there at some point (i saw dooboloo had one i think....expensive tho...nice case )

 Thanks_

 

dooboloo's wasn't this board.

 This is a USB -> SPDIF/COAXIAL/DIGITAL RCA (Whatever you want to call it)


----------



## guzzler

Boards have been shipped, should be with me on Monday, and I'll try and get them out on tuesday... thanks for payment from (almost) everyone!

 g


----------



## BradJudy

Cool. Thanks for your work g. I guess I should order some components.


----------



## Bas Horneman

Yahoo! Good news Guzzler...I just ordered all the parts from DigiKey...thanks to that wonderful parts list of DSAVITSK!!!


----------



## dsavitsk

in case anyone hasn't seen it, parts list, etc., is at http://www.ecp.cc/usb-spdif.html


----------



## Garbz

Just going to try and save time by asking if someone here already know this or not. (was that even a sentence?)

 Are all these parts available from mouser too? Because that would save me $26USD on shipping if I can combine that with another order.


----------



## DaKi][er

everything apart from the TPS793 and pcm2902 ic's


----------



## ~n00beR

Cant wait to get my boards : 
	

	
	
		
		

		
			





 Thanks again Gus


----------



## guzzler

Folks, there's been a bit of a disaster:

 the courier has delivered the package to somewhere that isn't my house! I emailed Eurocircuits last night as I was worried, apparently it was delivered to someone called Moore on Monday; considering I don't know anyone (apart from the local butcher) called Moore and it's no one around here, I'm worried.... It's Friday, I can't get in touch with TNT till Monday (18th), but just a heads-up. Of course, if it's lost, I'll be refunded and I can either order another batch, or refund current purchases. 

 This is a pain in arse, which I hope to get sorted as soon as possible

 best regards, and thanks for your patience

 Gus


----------



## james902

i can only imagine the guy saying "What is this? wafers? what am i going to do with this?"

 lol


----------



## BradJudy

Gus,

 That sucks. Thanks for all of the work you are putting into this. At least if they are lost, maybe the board can be tweaked for that missing bridge.


----------



## guzzler

All sorted out; boards will ship either Monday or Tuesday.

 Still awaiting payment from

 vpolieni and JHouser... 1 week and then the boards are free

 Gus


----------



## individual6891

Quote:


  Originally Posted by *guzzler* 
_All sorted out; boards will ship either Monday or Tuesday.

 Still awaiting payment from

 vpolieni and JHouser... 1 week and then the boards are free

 Gus_

 

So the butcher stole the boards huh, damn him!!


----------



## guzzler

Quote:


  Originally Posted by *individual6891* 
_So the butcher stole the boards huh, damn him!!_

 

 It was the butchers dog, honest 
	

	
	
		
		

		
		
	


	




 Most boards have been shipped, I ran out of cellotape when I was packing them. 

 g


----------



## Bas Horneman

Quote:


 Most boards have been shipped 
 

Groovy baby yeah!


----------



## ~n00beR

Got my boards this morning Guzzler.

 Thanks again 
	

	
	
		
		

		
		
	


	




 n00beR


----------



## Magsy

Mine too 
	

	
	
		
		

		
		
	


	




 Why is stuff always smaller in the flesh!! Can't believe the size of the things, well nifty. Will fit in a box with a dac nicely or make a keyring size digital out!

 Thanks Gus, much appreciated!


----------



## Bas Horneman

Anyone have pictures yet? Next to a matchbox maybe?


----------



## ~n00beR

Quote:


  Originally Posted by *Bas Horneman* 
_Anyone have pictures yet? Next to a matchbox maybe? 
	

	
	
		
		

		
		
	


	


_

 

Lol it would fit in a match box, with room to spare if you found the right capacitor.
 I think i may have just found my temp' case for this little gadget.

  Quote:


 a keyring size digital out! 
 

Ooooooh that gives me an idea


----------



## Bas Horneman

Quote:


 Ooooooh that gives me an idea 
 

What...you are going to build it into your hearing aid?


----------



## ~n00beR

Quote:


  Originally Posted by *Bas Horneman* 
_What...you are going to build it into your hearing aid?
	

	
	
		
		

		
		
	


	


_

 

Lol thats an even better idea


----------



## Magsy

Didn't have a matchbox sorry!


----------



## Bas Horneman

Thanks! The battery is a great reference also!

 Mmmm now..how am I ever gonna solder that PCM2902!


----------



## james902

that's awefully small... i may have to buy a new solder tip...


----------



## Magsy

Gotta buy a new camera, this thing needs like 10inches distance to stay in focus :|






 Hardest part is placing it straight! Flux on the pads, place it and hold it with something. Solder the pins at the corners, then put a little solder on a small tip and just wipe it across the pins. S'all I did on my last Guzzler USB Dac!


----------



## guzzler

Build page courtesy of dsavitsk

http://www.ecp.cc/usb-spdif.html

 Don’t forget to bridge 8,9,10 and connect 10 to V+ if you’re not using the regulator 
	

	
	
		
		

		
		
	


	




 edit: idea for key ring S/PDIF... do it like those USB pocket drives with an A connector instead of a B connector (have to be some creative mounting), and then it would just slot straight into the side, no cable needed! 
	

	
	
		
		

		
		
	


	




 And finally, GOOD LICK!

 g


----------



## randytsuch

Quote:


  Originally Posted by *Magsy* 
_





 Didn't have a matchbox sorry! 
	

	
	
		
		

		
		
	


	


_

 

OK, but what's the rolling paper for? 
	

	
	
		
		

		
		
	


	




 Randy


----------



## Bas Horneman

Thanks Guzzler! Got my board yesterday! Just waiting for digikey now. Do they send a mail when they ship? 

 There are many like it..but this one is mine 
	

	
	
		
		

		
		
	


	




 Shown here on it's custom made jitter reducing ceramic de-resonator! Ha Just kidding ofcourse it's a generic part!


----------



## walangalam

got mine. Thanks guzzler.

 My pile of PCBs to do just got a little larger... hehe.


----------



## phobus

Got mine too! Thanks!


----------



## Garbz

eagerly still awaiting mine thanks guzzler


----------



## dsavitsk

Boards have arrived to the States. Thanks Gus.


----------



## shiggins

Got 'em. Thanks Gus.

 Did we all get our boards taped to part of a script? I got page 42 - maybe we can club together and get the whole play?


----------



## guzzler

Quote:


  Originally Posted by *shiggins* 
_Got 'em. Thanks Gus.

 Did we all get our boards taped to part of a script? I got page 42 - maybe we can club together and get the whole play?_

 

haha, yes it's part of our scrap paper pile, dads old scripts end up there 
	

	
	
		
		

		
		
	


	




 g


----------



## eastside504

got my boards + page 117. Thanks for the read.


----------



## jamont

Got mine today, thanks again Gus!


----------



## PYROTAK

got mine but i have no idea where to get the parts for it


----------



## Pappucho

Quote:


  Originally Posted by *dsavitsk* 
_You can now add all of the DigiKey parts to an order with one button click. Just go to http://www.ecp.cc/dk.html

 You should still proof the list to make sure it is correct. Quantities are the higher of necessary or minimum order number

 -d._

 

Edit: Sorry, didn't realize that link doesn't work anymore..... 
	

	
	
		
		

		
		
	


	





 Got my boards in today, thanks Guzzler!


----------



## steel

got mine today, thanks...


----------



## DaKi][er

so, anyone got one working yet?


----------



## Garbz

settle grettle, most of us haven't got our boards yet


----------



## DaKi][er

Quote:


  Originally Posted by *Garbz* 
_settle grettle, most of us haven't got our boards yet 
	

	
	
		
		

		
		
	


	


_

 

I count 12 on this page alone; surely someone has soldered one up

 I’m interested in results to gauge what to expect somewhat from the one I got on my upcoming DAC


----------



## Bas Horneman

Quote:


 I count 12 on this page alone; surely someone has soldered one up 
 

...still waiting for digikey to deliver the parts...thats my excuse anyway


----------



## dsavitsk

Turns out that while I seem to have gotten the parts list right for everyone else, I ordered myself a SMD 91R, so I am waiting for $0.05 worth or parts 
	

	
	
		
		

		
		
	


	




 Hopefully it will get done this weekend.

 -d


----------



## bg4533

My stuff arrived (I got a USB DAC kit too). Both of these are a lot smaller than I expected. They should be fun to build. I won't be able to start for a few weeks though.


----------



## Botch

Arrived in Zurich today with a USB DAC kit also. Thanks for all the hard work Gus. Just happy there is professional smd soldering station with a microscope at work. Those DAC IC's are tiny.

 Botch


----------



## Icy006

Got mine in Worcester, Ma on Monday (4/25) - thanks! Now to buy a very small soldering tip and/or cyborg super-eyes...


----------



## 00940

For all those worrying about the size, check Guzzler's website. The trick he explains works really well to solder those chips. And no need for a fine tip.


----------



## MattN

Got my boards a couple of days ago - thanks.

 I've just put one together and it seems to work fine.


----------



## Garbz

Mine arrived. Any tips for telling the caps appart


----------



## Garbz

For guzzler and any others who are currently building I'll post a pic of all SMD parts for the board that guzzler shipped, + dac + regulator. I have the inverters, however because I will run the signal directly into an ISO150 i won't use it.

 Despite how it looks it appears as though it will work. The method to get the IC on in the absense of any soldering flux was to simply gob the legs full of solder, then use a desoldering braid over all the legs, that left that brown stuff. But no solder bridges remain (except the ones that need to be).

 Here's my effort:





 /EDIT: SMDs were done using a 13watt pencil. Guzzler the heat relief connections on the bottom 2 caps were way too large for my liking. The iron did not like working with that at all, and it was very hard to make the soldier stick to the pad.


----------



## guzzler

Easiest way to tell the caps apart is to count them 
	

	
	
		
		

		
			





 100nF in multiples of 4
 33pF in multiples of 2
 10nF in multiples of 1

 g


----------



## Garbz

Do i need to point out I already assembled the board, it doesn't take a genious to count caps.

 Although on ur website the count says 5 100n caps were needed, but I only got 8 with my order of 2 boards. That took a bit of extra thinking


----------



## guzzler

Quote:


  Originally Posted by *Garbz* 
_Do i need to point out I already assembled the board, it doesn't take a genious to count caps.

 Although on ur website the count says 5 100n caps were needed, but I only got 8 with my order of 2 boards. That took a bit of extra thinking 
	

	
	
		
		

		
		
	


	


_

 

 I know, I was just passing on the knowledge 
	

	
	
		
		

		
		
	


	




 There were 5 SMDs needed originally, but I changed one of them for a box type cap in the coax conversion stage

 g


----------



## dsavitsk

Quote:


  Originally Posted by *Garbz* 
_Although on ur website the count says 5 100n caps were needed, but I only got 8 with my order of 2 boards._

 

Don't blame Gus, he has no control of the website. I'll fix it one of these days.

 -d


----------



## phobus

Is there anywhere other than digikey where I can buy a 2902? They won't have them in stock until 5/31


----------



## Garbz

My bad i thought Gus ran it.

 The 2902 is available from Digikey as well, or directly as a sample from texas instruments if you qualify.


----------



## individual6891

Quote:


  Originally Posted by *Garbz* 
_The 2902 is available from Digikey as well, or directly as a sample from texas instruments if you qualify._

 

 Quote:


  Originally Posted by *phobus* 
_They won't have them in stock until 5/31_


----------



## aswils

Sorry to be such a feeb but where exactly do the spdif leads attach?


----------



## Bas Horneman

Quote:


 Sorry to be such a feeb but where exactly do the spdif leads attach? 
 

Check out http://www.ecp.cc/usb-spdif.html

 my guess is that they would connect to the out connectors. (not being sarcastic. it's just that I don't have the schematic. And that seems the likely place)


----------



## aswils

Dope slap to head. Thanks Bas I looked and looked but obviously overlooked the "out" arrow.


----------



## Garbz

Sorry i meant Mouser but that would have been a load of crock too. Just disregard my rambelings.


----------



## dsavitsk

I can't believe nobody has mentioned this yet ...

 The suggested USB jack included in the original parts list (DigiKey part WM17109-ND) does not fit the board ... or rather, it fits the board but extends back and touches the pins of the voltage regulator and 3 resistors. As you might imagine, this is not good. It is possible to lean it forward to avoid this, but it has been replaced on the pats list by a part (AE1085-ND) that fits better. Here is the technical drawing if you want to convince yourself that this part is the better choice.

 -d


----------



## Garbz

well my order from mouser was only just released today, but a quick show of hands will probably indicate that not many people have finished it yet


----------



## dsavitsk

A couple more things ...

 The parts list suggested using 2 22uF caps while the board says to use 10uF caps. If you already have the 22uF caps, they should not cause a problem, but they have been replaced on the parts list with 10uF panasonic FC's.

 If you are using tantalum 1uF caps instead of the Wimas, please note that the tantalum caps are polarized. To figure out how to install them, each position has one leg toward the 2902, and another to the ground plane. Connect the positive (+) leg of the cap toward the chip and the negative (unmarked) to the ground plane.



 I built one and plugged it into the computer. No errors, no smoke, etc. I didn't hook it up to a DAC yet to see if there is a signal as I am waiting on some wire to do this with.


----------



## guzzler

Hi all, just to clarify ds' post above

 The tantalum +ve side goes to the side from which the traces come from the 2902 (not a via), and obviously the negative side goes to the other pad (which is a via, and is cross-hatched underneath)

 g

 PS, anyone working yet??


----------



## MattN

All five of mine are working.


----------



## mfive

ICY -

 If you have not put the PCM2902 down yet, I have Zephpaste and a rework station and I live in Shrewsbury. I use the PCM2902 in one of my products and the paste / rework station method works like a champ.


----------



## dsavitsk

Quote:


  Originally Posted by *MattN* 
_All five of mine are working._

 

Mine works too.


----------



## guzzler

Quote:


  Originally Posted by *dsavitsk* 
_Mine works too._

 

Excellent news 
	

	
	
		
		

		
			





 hope everyone enjoys their board

 gus


----------



## dsavitsk

And, it is probably worth mentioning, it sounds pretty good too. I think the digital signal is of higher quality than that from either the sonica or the xitel -- at least it sounds better than those plugged into my Cal Sigma.


----------



## Garbz

I wonder what attributes to that. Does the sonica resample the audio?
 Another thought does this chip work with any ASIO drivers?


----------



## dsavitsk

I didn't do anything specific in the setup -- no asio, or anything like that. The sonica is at 44khz with its drivers while the xitel is at 48 with the win32 drivers. I assume that this is at 48, but I did not check it yet. My guess is that it is either that I used better connecting wire (I used a 4 inch piece of wonder wire where as with the other cards I have used actual 75ohm cable -- about 2m of it) or that the 2902 does a better job of converting than the chips in the other cards (which I have not opened recently, so I don't know what they are), or that the curcuitry to ensure a clean signal works, or that I made it all up. 

 As someone with an interest in the project, you should take my views as suspect, but I think it works pretty well thus far. It certainly isn't worse, anyway.


----------



## Garbz

I take everything with a grain of salt don't worry.

 On the one side i'm expecting wonders from Guzzler's little board since i'll be connecting it directly to a dac via an ISO150, so there's no nasty cable or anything to go over it. Also since it's fixed at a certain bitrate / frequency I assume it would do a good job at thoes frequencies.

 While my M-Audio Transit is on paper better being a 24bit 96khz solution, I need to run a software resampler to use that which doesn't really help. I also need to use optical interconnects. However where it may trump the Guzzler dac is that it supports ASIO on the software side bypassing the windows screwups of directsound.


----------



## 00940

the pcm2702 supports asio. I don't see any reason why the PCM2902 wouldn't


----------



## paologatto

The PCM2902 as well as the PCM2906 work perfectly with the ASIO4ALL generic driver.

 Read this my old post on diyaudio:

http://www.diyaudio.com/forums/showt...477#post464477


----------



## Garbz

ahhh thanks i didn't know about the generic driver!


----------



## needlz

Anyone here using a mac with this usb board? When I plug in the board to my mac, the LED lights up but that's it. Do I need to install a driver or is there probably something wrong with my board?

 thanks.


----------



## paologatto

Quote:


  Originally Posted by *needlz* 
_Anyone here using a mac with this usb board? When I plug in the board to my mac, the LED lights up but that's it. Do I need to install a driver or is there probably something wrong with my board?

 thanks._

 

http://www6.head-fi.org/forums/showp...&postcount=116

 A friend of mine is using daily a soundcard made by me based on the PCM2902 on Mac and is very satisfied.

 He had only a problem lately: attaching it to a specific USB port of its Mac he obtains a bad sound output, like it was downsampled/distorted and with lot of noise in background.. Attaching the device to other USB ports of the same Mac the PCM290x works perfectly, also to a PCMCIA card --> USB and to a USB hub. 
	

	
	
		
		

		
		
	


	




 We tried to analyze the problem using an oscilloscope.. the USB port gives the right voltage, the D+ and D- signals seem ok, there is no more noise than in the other ports and there are no ground loops (tests done with an headphone). So the thing remained a mistery.. My idea was a _software_ problem of that USB port, but it's hard to say.

 A Mac mistery..


----------



## bg4533

Quote:


  Originally Posted by *needlz* 
_Anyone here using a mac with this usb board? When I plug in the board to my mac, the LED lights up but that's it. Do I need to install a driver or is there probably something wrong with my board?

 thanks._

 

What OS are you using? From what I understand it shouldn't need drivers or anything to work with OSX. Don't know about previous versions.


----------



## randytsuch

Just finished my first board, finally. It did not work at first, my PC would not recognize it. Then, I read this thread, and saw I needed to short pins 8,9 and 10. 

 Hooked it up again, and PC installed it, and it works fine. 

 Thanks again Gus. 
	

	
	
		
		

		
		
	


	




 Randy


----------



## dsavitsk

fwiw, I finally got around to checking and I am getting bit perfect output. In fact, HDCDs ripped to flac show up on my DAC as HDCD sources.


----------



## Garbz

excellent, look forward to finishing my dac before the end of the year then. Btw which dac do you have that has hdcd decoders builtin?


----------



## dsavitsk

Quote:


  Originally Posted by *Garbz* 
_Btw which dac do you have that has hdcd decoders builtin?_

 

Cary 303/200. 

 <off topic>
 I made the mistake of opening it last night to see what was inside (I need to stop doing this.) I think the Cary is a nice player, but it has always had a slight edginess (the same edginess that I hear in opamp based amps) that has bothered me and I now think I know why. Looking around the inside, there was a decided lack of things saying Blackgate on them. In fact, the caps and resistors all look like generic stuff from Digikey -- not even Panasonic. The rectifier diodes are all generic 1n400x type, and while there are a couple of opa627's (in a player at this price point, there should not be any opamps), there are also some (i.e., 4) opa234's (I think I am remembering them correctly -- they were BB's that generally get trashed around here and I think that was the model #.) (The least that Cary could have done is socket the opamps.) Output caps were Wimas, etc. All in all, I was amazed. Part of me thinks that there is tons of opportunity for making modifications, but another part thinks I could build something from scratch that is better, and that mods would be expensive and too difficult. We'll see. I have never heard of anyone modding this player, and I am going to guess there is a reason?

_Edit: They are opa2604's_

 </off topic>

 -d


----------



## Jam_Master_J

I completely missed this group buy. I'm interested in getting my PC to feed my DAC, what are my options?


----------



## Nisbeth

Quote:


  Originally Posted by *Jam_Master_J* 
_I completely missed this group buy. I'm interested in getting my PC to feed my DAC, what are my options?_

 

I have a few spares, YGPM 
	

	
	
		
		

		
			






 /U.


----------



## Jam_Master_J

Gonna go ahead and do this project now. Although the SMD soldering scares me.


----------



## Garbz

it scares all who haven't done it before. If you're like me in the end you'll wonder how you could live so long without it.


----------



## dsavitsk

Quote:


  Originally Posted by *Jam_Master_J* 
_Gonna go ahead and do this project now. Although the SMD soldering scares me._

 

There are a number of tricks that will help. First, look at that site linked to from the project page. It will show methods of doing chips. Also, scotch tape helps a lot. tape down half of what you are going to solder and solder the other half. Chips have a tendancy to move, caps have a tendancy to stand on end. Another trick is to get the pad hot and then put a dot of solder on the pad. then, once it is cool, hold the part in place with tweezers and reheat until the solder flows on the part (obviously this last one is for caps and resistors and not chips.)

 -d


----------



## Jam_Master_J

Will my Radioshack 15/30 watt iron be too cumbersome for this project?


----------



## Garbz

No infact I whipped out my 25 watt iron after my 13watt pencil was too weak to solder on the groundplane side of things.


----------



## guzzler

Personally, I use an 18W iron. The thermal reliefs on the groundplane should help the situtation, although 13W is on the low side 
	

	
	
		
		

		
		
	


	




 g


----------



## Lil_JV

Sorry if this has been answered but I was too lazy to read through this thread. Are there any extra boards left? 

 JV.


----------



## guzzler

I've got a few left, someone didn't send the money for their boards 
	

	
	
		
		

		
		
	


	




 give me an email

 awjl3 _at_ cam _dot_ ac _dot_ uk


----------



## seppstefano

Hi,
 I was looking to find a way for playing music from my laptop and feeding a DAC. A dear friend of mine pointed me your project.

 Is it too late to get a card?

 Thanks a lot,

 Stefano


----------



## guzzler

email address above...


----------



## erozsolt

Hi,

 I just finished DIY modding my IBM Thinkpad T40 to be capable of fanless music playing, and using external USB hard drive it is finally a no-moving-part-totally-silent notebook, and I would like to ask you about todays computer DAC solutions.

 a.) use USB > SPDIF > DAC
 b.) use USB-DAC (like AQVOX DAC)
 c.) buy a VIA EPIA board and with a decent PCI card (EMU-1212) (optionally mod the PSU) for DAC purpose
 d.) buy a VIA EPIA board with a cheap PCI card (AV-710) for SPDIF out purpose > DAC

 Which of the above solutions provide the best value for money? I am collecting money for a Stax 4040 setup (after I heard a 3030, I do not want to go dynamic), and I would not want to spend more than 500 EUR for a DAC.

 Is there any good quality USB-DAC avaible or it is not a popular solution yet? I mean native USB-DAC, not a SPDIF DAC with a USB-SPDIF converter built in. If you advice using this board, could it produce better results than EPIA + AV-710.


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## Garbz

If you're willing to put down 500E for a dac then external is definatly the way to go. Arugably though the onboard soundcard should provide less jitter on the digital output curtosy of not having the dodgy USB spec to go throuhg. In practice though these cards are rarely decent, have poor firmware, and don't usually have a bit-perfect output like the USB->SPDIF card using ASIO out.


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## canadiandude

I read that there are officially no boards left, but is it possible that anybody has a spare, or does anybody know anybody that might have a spare?

 if not does anybody know of the cheapest Firewire or USB --> S/PDIF(coax or tos)
 anything i find on google has a bunch of extra "crap" and upwards of $200

 thanks in advance

 edit: I forgot to say that a PC card II would work as well since I use a laptop


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## quicksilver96

The DAC201? Sure its got some headphone and volume control crap that you probably don't want, but its not overly expensive and you might be able to do without populating some things you don't want.


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## canadiandude

ya kinda big for my liking, cant companys make barebones "get the job done" devices. theres that Turtle beach USB-->toslink, but i hear that the softaware is excessive and not very good (not sure though)

 does this PCM2902 send any digital signal eg DD or DTS, PCM (16 24 32 bit; 32 44 48 96 etc) to later be decoded by my DAC.
 and do retail devices such as the turtle beach thing im looking for do the above?


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## doobooloo

Dude from Canada, YGPM.


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## flyhyena

maybe this is too late, just wondering if there are still pcbs left?


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## kfaiman

Any one have a spare PCB to sell me? Populated or unpopulated.

 Thanks!


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