See my pure "USB 2 SPDIF"

ary · 28th November 2006, 01:05 PM

Since almost everybody here got a PC, since almost everybody here got a DAC.
May everybody here, like me, want a "USB to SPDIF" .

Here, I've present a pure "USB 2 SPDIF" by using the universal PCM2902 ( http://focus.ti.com/lit/ds/symlink/pcm2902.pdf )

ary · 28th November 2006, 01:10 PM

HoHo

It's only inclued the basic elements

See

ary · 28th November 2006, 01:32 PM

Just print it at 1:1 in A4 paper

MWP · 29th November 2006, 12:08 AM

[me = idiot]

Leolabs · 29th November 2006, 12:26 AM

Piao Liang!

ary · 29th November 2006, 01:38 AM

Hi Leolabs,

Yes, it's a real cute.

tivoidethuong · 29th November 2006, 12:03 PM

Great PCB, thanks for your share

hagtech · 30th November 2006, 03:02 AM

You have no decoupling or filtering on the incoming 5Vdc whatsoever?

jh

ary · 30th November 2006, 05:38 AM

Quote:

Originally posted by hagtech
You have no decoupling or filtering on the incoming 5Vdc whatsoever?

jh

Yes hagtech,

maybe adding a filter will be work. but wheather this would be needed is discussing ,and by this simple curcuit, it really perform well.

hagtech · 30th November 2006, 06:01 AM

Sure, it works. But don't you want it to work its best? Have you no desire to bring out the best performance possible? Just because it makes sound doesn't mean you stop there and be satisfied.

Look, you have LDO regulators onboard this chip, and to stabilize them you need some low impedance decoupling at their emitters (or sources). Otherwise the regulators can go wild. Sure, it might still work, but it is not good design to depend on decoupling at the other end of a USB cable. You are also allowing all of the RF noise from PC to enter the audio system.

Suggest you add an LC or a bead-C to filter this incoming 5V line.

jh

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29th November 2006, 12:08 AM	#4
MWP diyAudio Member Join Date: Oct 2002 Location: Adelaide, South Australia	[me = idiot]

29th November 2006, 12:26 AM	#5
Leolabs diyAudio Member Join Date: Dec 2004 Location: Bukit Mertajam	Piao Liang!

29th November 2006, 01:38 AM	#6
ary diyAudio Member Join Date: Jul 2005 Location: HangZhou	Hi Leolabs, Yes, it's a real cute.

29th November 2006, 12:03 PM	#7
tivoidethuong diyAudio Member Join Date: Dec 2004 Location: Ho Chi Minh city	Great PCB, thanks for your share

30th November 2006, 03:02 AM	#8
hagtech diyAudio Member Join Date: Mar 2002 Location: Hawaii	You have no decoupling or filtering on the incoming 5Vdc whatsoever? jh

30th November 2006, 06:01 AM	#10
hagtech diyAudio Member Join Date: Mar 2002 Location: Hawaii	Sure, it works. But don't you want it to work its best? Have you no desire to bring out the best performance possible? Just because it makes sound doesn't mean you stop there and be satisfied. Look, you have LDO regulators onboard this chip, and to stabilize them you need some low impedance decoupling at their emitters (or sources). Otherwise the regulators can go wild. Sure, it might still work, but it is not good design to depend on decoupling at the other end of a USB cable. You are also allowing all of the RF noise from PC to enter the audio system. Suggest you add an LC or a bead-C to filter this incoming 5V line. jh