CS4397 dac

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Originally Posted by alb

Richard.

Sorry for the poor photo but this will show you how mine looks with the upgraded caps.

http://i27.photobucket.com/albums/c1.../Baffles-1.jpg

C19 is 1000uf Pana FC.
C21 is 150uf Pana FC.
You can use your 470uf at C19. C21 should be smaller.

C9 is Vishay mkp1837 0.1uf. This was the best i found after trying twelve different caps here. Big ones don't work properly and generally mess up the sound, sometimes in a big way.
C9 is in my opinion one of the most important caps on the board. This also the only surface mount that i removed.

C16,17,20 and 25 are Oscon 150uf 16v. Probably enough Oscons.
C3,C18 are 220uf Samwha caps(gold), but any decent quality cap suitable for purpose would perhaps do.

C8,11,12,13 are 3.3uf Tants.

All lytics are bypassed by 0.1uf film caps.
I think blue Vishays are preferable to Wima, anywhere on this pcb.

This DAC works very well. Hope this is helpful.

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Thanks, I will give that a go if the board returns to a stable state ;)

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Originally Posted by Tripmaster

Thanks, I will give that a go if the board returns to a stable state ;)

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Hi

Late on Tuesday night...

Whilst listening to the DAC last night one of the temporary solder connections attaching the right channel lead to the coupling cap broke away.
I re-soldered the lead and at the same time decided to remove the two blobs of solder from the chip on the base of the board. I fired it up again and only the left channel works. All of the connections seem fine and both channels from my amp operate ok via a DAC MAGIC2 box.
I re-soldered the two blobs next to the chip and now the output is very quiet and extremely distorted.

This is not a good way to finish the evening!


Wednesday

Well...I have removed quite a number of the components previously added but am no further forward with regards to sound, still very distorted.

When I desoldered the small blobs from the base of the board next to the chip I think I may have damaged the solder pads (Solder is not sticking any more and they are barely visible).

Do you think I may have damaged this chip due to excessive heat? Or do you think the board is a right off?

Thanks in advance

Richard

Just send it to me ;)

hey everyone I am trying to bypass the onboard output stage to go directly to my headphone amplifier.

I removed the 4 capacitors in the middle of the board and connected the RCA outputs to where -R and -L caps were.

Now I am reading 2.5V on both outputs :/

What have I done wrong?

http://img386.imageshack.us/img386/9568/img3601di7.jpg

Quote:

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Originally Posted by gurusan

hey everyone I am trying to bypass the onboard output stage to go directly to my headphone amplifier.

I removed the 4 capacitors in the middle of the board and connected the RCA outputs to where -R and -L caps were.

Now I am reading 2.5V on both outputs :/

What have I done wrong?

http://img386.imageshack.us/img386/9568/img3601di7.jpg

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This is normal. You should add a 2,2uF capacitors (polypropylene or so) in series to outputs.

ok thanks. I have some 2.2uF MMK EVOX caps and some 3.3uF Philips MKC caps.

Which would be better? sorry I'm new at this....

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Originally Posted by gurusan

ok thanks. I have some 2.2uF MMK EVOX caps and some 3.3uF Philips MKC caps.

Which would be better? sorry I'm new at this....

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You should use this one which sounds better.

gotcha. thanks :)

I have been playing around with some of the recommend cap values (I know the caps are a bit large)

I have tested the output from the psu and I am getting 12v & 5v

How do I check when connected to the board?

Hi

I have checked all of he solder joints and I cant see bridging. I also checked the Digital voltage from the CS8416 and I am getting a reading of 3.33v on pin 23 and 21. I also have a reading of 13.24v from pins 4 and 8 on the opamp.

I have not yet checked all of the tracks for continuity.


After some considering my options I decided to remove the chip from the base of the board.

Can anyone advise which pads I need to short for bypass?