B-B PCM63 Demo Board as DAC...any Mods?

[Diogenio]

Group:

I have a DEM-PCM63 demo (evaluation) board that was sold by Burr Brown in the mid 90's. It is in fact, a complete stereo DAC that just needs +/5 V supplied to it. The chip lineup is: Yamaha YM3626B receiver, B-B DF1700P 8x filter, pair of PCM63 DACs. The I/V uses OPA 2132s. I plan to scrap the I/V section and replace with either a tube I/V or a resistir I/V followed by a tube gain stage.

Specific Questions:

1. Does anybody have the original ap notes for this demo board, and also for the DF1700 filter chip? They are NOT available on the B-B (now TI) website!

2. Are there any pin-compatible chips that I can use to replace either the YM3626B or DF1700P? Great advancements have been made in these two areas since this demo board was designed.

3. Any other mods suggested? What about the clock? B-B uses a a 16.9344 MHz crystal for the filter chip. I undersatnd that there are small, highly-stabilized oscillator modules available that could reduce jitter. Any recommendations?

I realize this is an OLD ladder DAC and that many of you will scoff at it's implementation. However, I have heard some wonderful DACs using the PCM 63, even by today's standards, so please spare any abrasive comments. The demo board was free, and newer does not automatically translate to better sound. Vacuum tubes are a case in point.

Looking forward to any discussion this thread might promote...

[rfbrw]

Originally posted by Diogenio
Group:

I have a DEM-PCM63 demo (evaluation) board that was sold by Burr Brown in the mid 90's. It is in fact, a complete stereo DAC that just needs +/5 V supplied to it. The chip lineup is: Yamaha YM3626B receiver, B-B DF1700P 8x filter, pair of PCM63 DACs. The I/V uses OPA 2132s. I plan to scrap the I/V section and replace with either a tube I/V or a resistir I/V followed by a tube gain stage.

Specific Questions:

1. Does anybody have the original ap notes for this demo board, and also for the DF1700 filter chip? They are NOT available on the B-B (now TI) website!

http://www.abcelectronique.com/simul...ts/DF1700P.pdf

2. Are there any pin-compatible chips that I can use to replace either the YM3626B or DF1700P? Great advancements have been made in these two areas since this demo board was designed.

No.

3. Any other mods suggested? What about the clock? B-B uses a a 16.9344 MHz crystal for the filter chip. I undersatnd that there are small, highly-stabilized oscillator modules available that could reduce jitter. Any recommendations?

http://www.tentlabs.com/ProductEntities/XO/XO.html

or for a more comprehensive clock upgrade

http://httpd.chello.nl/%7em.heijlige...tml/dactop.htm

and for those with idiosyncratic hearing

http://www.geocities.com/nonospcm1704/

I realize this is an OLD ladder DAC and that many of you will scoff at it's implementation. However, I have heard some wonderful DACs using the PCM 63, even by today's standards, so please spare any abrasive comments. The demo board was free, and newer does not automatically translate to better sound. Vacuum tubes are a case in point.

Compared to the TDA1543, thats all the rage at the moment, the PCM63 is right out there on the leading edge.

[Cobra2]

Originally posted by Diogenio


2. Are there any pin-compatible chips that I can use to replace either the YM3626B or DF1700P? Great advancements have been made in these two areas since this demo board was designed.

3. Any other mods suggested?

The old HDCD chip PDM100 shiold be pin-compatible, if you can find it.
Keep the YM...but look for clock-mod (search the forum).

A new discrete I/V stage would not be wrong...(PassLabs D1 type or similar).

Arne K

[rfbrw]

Originally posted by Cobra2



The old HDCD chip PDM100 shiold be pin-compatible,

Not on this planet.

[Cobra2]

Originally posted by rfbrw



Not on this planet.

Then on mine ;-)

Please check PDM-100 datasheet, page 21.

Arne K

[Diogenio]

Originally posted by Cobra2


Then on mine ;-)

Please check PDM-100 datasheet, page 21.

Arne K

Many thanks to all whom have responded so far! The low-jitter clock links are exactly what I have been looking for!

Arne, I've heard good things about the HDCD filters (as used in non-HDCD mode), but it is very hard to get data on the Pacific Microsonics products. Can you please give me a link to the data sheets for this chip, or possibly email me a scan of the main pages?

What is the best way for me to get one of these chips? Does anybody have a stock, or must I buy an old DAC on EBAY and gut the chip out? Which popular (and cheap enough to butcher) DACs used this chip?

Thanks again,
Dennis

[Nicke]

Originally posted by Diogenio
I plan to scrap the I/V section and replace with either a tube I/V or a resistir I/V followed by a tube gain stage.

2. Are there any pin-compatible chips that I can use to replace either the YM3626B or DF1700P? Great advancements have been made in these two areas since this demo board was designed.

3. Any other mods suggested? What about the clock? B-B uses a a 16.9344 MHz crystal for the filter chip. I undersatnd that there are small, highly-stabilized oscillator modules available that could reduce jitter. Any recommendations?

Originally posted by Cobra2


The old HDCD chip PDM100 shiold be pin-compatible, if you can find it.
Keep the YM...but look for clock-mod (search the forum).

A new discrete I/V stage would not be wrong...(PassLabs D1 type or similar).

Arne K

For the I-V stage you could try something like the one Jocko wrote about here:
Jocko´s simple I-V stage

I use it myself together with a pair of PCM63´s...

As for the PCM1700 I think it is pin compatible with NPC SM5813.

And last about the reciever:I use the YM3623(haven´t checked the data sheet for 3626 so I don´t know how similar it is),but the clockmod Arne K is writing about is probably this one:http://www.diyaudio.com/forums/showt...012#post281012

Haven´t tried that in my DAC...yet....

BTW:Arne,didn´t you use Jocko´s original I-V stage in your DAC?

[Nicke]

As for a clock upgrade this one looks really promising.
Guido Tent´s low jitter clock for DAC´s

[rfbrw]

Originally posted by Cobra2


Then on mine ;-)

Please check PDM-100 datasheet, page 21.

Arne K

Yes, so long as you disregard the odd control pin or two. Put the DF1700P pinout alongside the PMD100 pinout and then tell me they are pin compatible. Standalone or Program mode, it would need major surgery to fit the PMD100 in place of the DF1700P.

[jean-paul]

Originally posted by rfbrw

and for those with idiosyncratic hearing

AFAIK everyone has idiosyncratic hearing.