diyAudio

diyAudio (https://www.diyaudio.com/forums/index.php)
-   Digital Line Level (https://www.diyaudio.com/forums/digital-line-level/)
-   -   PCM56P-K replacement (https://www.diyaudio.com/forums/digital-line-level/343441-pcm56p-replacement.html)

Javik50k 2nd October 2019 08:29 PM

PCM56P-K replacement
 
Hello everyone.

There is an old Yamaha CX-1000 DAC/preamp. I'm currently restoring one. Analog part working like a charm, but i have a problem with digital part. It uses PCM56P-K as a DACs. Sounded ok, but i tried to replace them with PCM61P-K, as they are totally pin-to-pin compatible and replaceable (so said datasheets), and PCM61 have better noise and DR specs. But all i got was crippled noise with no sound. Am i done something wrong or i just got faulty or fake PCM61P-K chips?

Can anyone, please, give me an advice to do this correctly? I want to use this restored preamp as a main DAC in my Hi-Fi system. Source is PC (E-MU1212m), power amp is Yamaha MX-600, speakers are NS-1000M.

P.S. Also can DAC part somehow be modified to use PCM1704? (my favourite multibit DAC chip).

weissi 2nd October 2019 08:57 PM

Ad1856 would be a second source replacement for pcm56.

rfbrw 2nd October 2019 09:17 PM

YM3414 = 16bit
PCM56 = 16 bit.
PCM61 = 18 bit.
PCM1704 = 24bit
You need the YM3434 for PCM61.

euro21 2nd October 2019 10:10 PM

Replacing PCM56 is a mistake.
This is one of the best (after PCM63) tonality R2R DAC chip.

Javik50k 3rd October 2019 12:30 PM

Quote:

Originally Posted by euro21 (https://www.diyaudio.com/forums/digital-line-level/343441-pcm56p-replacement-post5932478.html#post5932478)
Replacing PCM56 is a mistake.
This is one of the best (after PCM63) tonality R2R DAC chip.

As for me, PCM61 a bit better than 56 (of course, both must be K grade). But if replacement will fail, i'll simply use original japanese 56-K, they are fine too.

starbender 3rd October 2019 12:45 PM

pcm56 is 16bit, pcm61 18bit.

I was using pcm56 in nos mode with logic. One of pcm56's damaged while unsoldering, I had to use pcm61's for both channels, but i modified logic for 18bit.

You cannot use 18bit chip in 16bit position without modifying things...

Javik50k 3rd October 2019 01:02 PM

Quote:

Originally Posted by starbender (https://www.diyaudio.com/forums/digital-line-level/343441-pcm56p-replacement-post5933021.html#post5933021)
pcm56 is 16bit, pcm61 18bit.

I was using pcm56 in nos mode with logic. One of pcm56's damaged while unsoldering, I had to use pcm61's for both channels, but i modified logic for 18bit.

You cannot use 18bit chip in 16bit position without modifying things...

Can you please be more specific? What needs to be done? Maybe - clk adjustment somewhere? Digital IO is YM3623B, filter is YM3414.

starbender 3rd October 2019 01:17 PM

Afaik 3414 is not compatible with 18bit dacs.

Javik50k 3rd October 2019 01:27 PM

Maybe 61P will just operate as 16bit with lower noise?
Anyway i need to order new set of 61P-Ks (from Japan preferrably), as mine are really suspicious ones. 56P-Ks are real japanese ones. Using them now.

merlin el mago 3rd October 2019 09:01 PM

Quote:

Originally Posted by euro21 (https://www.diyaudio.com/forums/digital-line-level/343441-pcm56p-replacement-post5932478.html#post5932478)
Replacing PCM56 is a mistake.
This is one of the best (after PCM63) tonality R2R DAC chip.

+1:)


All times are GMT. The time now is 03:32 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 17.65%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio

Wiki