Fix or replace Accuphase DC 91 DAC?

ACCUPHASE DC-91

16 x PCM63P-K – SM5842AP

This one of the great R2R multibit dacs, that does justice to Redbook .
 I'd buy it off you if you were in Australia.
 
http://www.ebay.com/itm/1X-PCM63P-K-20-Bit-Monolithic-Audio-IGITAL-TO-ANALOG-CONVERTER-PCM63-/120827998139?hash=item1c21e8efbb:m:mqWgY3j6zmxl-vpzTM4vQ5w

Or you'll have to purchase an old cdp on ebay to get hold of a PCM-63 chip if one of them is playing up.

Here is a list of cheaper players that used them, there are many many more very expensive ones, but just get a cheap one for the part.
 AKAI CD-79
Creek DAC-60
Monarchy Audio Model 22, 22A, 22B, 22C, 24 and  33
Parasound 1500 and 1600
Pioneer PD73, PD93

Cheers George

definitely worth repair but not $1500. $1500 is definitely inflated price and you must shop around. accuphase equipment does not drop value just like mcintosh. 

I agree and I spent time today swapping cards in the unit and seem to have determined (as George suggested) that it most likely is a defective BB PCM63 chip. 

Thanks for the response!

Hey George,

Thank you for that post and information.

I’m not much of a tech at all but was able to swap cards around to narrow down the problem to one of the cards that has 8x BB63P chips.

I see the chips are available for sale on Ebay but don’t know if one is bad or even if an other component on the board is causing the problem.

Do you or anyone reading this have suggestions as to the next step? I do know someone who has the ability to simply swap out chips but don’t think they would be able to determine which might be the culprit.

But bottom line, I am relieved to have isolated the problem and the idea of packing and shipping this unit to California for $1500 plus shipping was not something I was looking forward to!

Thanks again!

I see the chips are available for sale on Ebay but don’t know if one is bad or even if an other component on the board is causing the problem.

I thought in your original post, that you already knew it was the Accuphase, and that the qualified audio guy narrowed it down to the dac chip (D to A Convertor) chip.
My mistake, as just a swap of the channels would have indicated the Accuphase.

Yes it may not even be the PCM63’s maybe the i/v stage or the l/p filter stage or the output buffer. Yes these card/s house the PCM63’s and the I/V and maybe the buffer.
https://s-media-cache-ak0.pinimg.com/736x/9c/8e/7c/9c8e7ca238a92ee114616a00b3203796--professional-audio-le-son.jpg

As czarivey said $1500 is a bit steep, seeing it’s so easy to remove the faulty card I think in the order of $200 -400 would sound about right, the parts will be no more than $50.
I have a passion for R2R multibit as it’s the only conversion around that converts Redbook (pcm) "bit perfect" all other coverters only give a facsimile.

Better still give it to me, it's 22 years old now and I’m poor and needy.

Cheers George

haha..thanks George!

If I hit the lottery, the Accuphase is yours!

Meanwhile, I have no idea but will start to look for a replacement card, which I doubt I find very easily.

Who fixes this stuff anymore? I'll start a thread!

thanks again!

I have no idea but will start to look for a replacement card, which I doubt I find very easily.

That will be like finding rocking horse s**t!

Who fixes this stuff anymore?

Guys like me, who can't stand to see good stuff stay broken in the cupboard.

Cheers George

"That will be like finding rocking horse s**t!"

lol true of course...

I'll let you know (about lottery!)

I really like a lot of modern DAC's a whole lot, but the BB's in the old Theta Digital gear were among the best.

Same time, several dac's introduced in last 5 years or so are simply outstanding and affordable.

Best,

E

Hello,
you knew to 100% it  is R Ladder Error in BB PCM63 that makes 
the Distorsion?
Many Times it is the incorerect Voltage of the Outputstage(  Caps)
i had three Dacs here a Sonic Frontiers ,Theta and Proceed
with the Same Problem...
You need the Shematic of Accuphase

Best Regards 

It very well could be. In the meantime, I am expecting a Brooklyn DAC..But...interestingly, I got my hands on an Arcam D33 and it sounds amazing.

The pressure is off now and all I have to do is find some strong packing material and get the DC91 repaired.

It will be interesting to compare it to the Arcam!