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anyone mod CDp to include S/PDIF?

U

Uzinusa

Happy Chappy
Has anyone around here modded their CD player so that it can output to S/PDIF and a external DAC? Cheers, Uzi
 
Most cheap players do it as stock - why not just buy something?

With a decent modern DAC that is jitter immune, there is no point having a fancy name-brand (or even Naim-brand) transport.
 
I think the Buffalo design is (except under extreme cases, where it loses lock).

I think designs that use a RAM based data buffer are as well; I can't bring a brand name to mind, but google should be your friend.

It isn't a big deal - you run the DAC off a clean local clock, rather than deriving the clock from the data source, and just use the data as data. It is just unfortuneate that common engineering practice for 20 years has been dead wrong.
 
Thanks for comments all. I wanted to work on my slightly modded CD5, the goal being to be able to use it as either a straight CDP or through a DAC.
 
I seem to remember reading somewhere that the data handling chipset that one of the Naim players uses (it might be the CD5) is a very standard one, and that it was, in principle, capable of SPDIF output. However, to do this it needs to be initialised differently, so you would need to replace the stock firmware with custom firmware, as well as wiring the appropriate output pin to a buffer and transformer.

Sorry, I can't remember where I saw this, nor exactly which player it applied to.
 
You can't add SPDIF to the CD5.

Naim players with the SAA7220 digital filter (CDS, CD1, CD2, CD3) potentially can - you could pick-off the DOBM output from pin 14 and use that to drive an SPDIF output via a buffer; but the 3.5, 5 and all other models have DOBM output from the decoder suppressed in Nim's own operating software for reasons of clock performance. HTH
 
Anyone ever done the opposite?

Spend a long time modding a CD Player, and rather than have an extra box I want a DAC input ala recent Cambridge ... Have your squeezebox output into your Arcam 5 etc ...
 
I think the term 'jitter immune DAC' should be banned - IE no such DAC exists :)

Seriously though, my Benchmark DAC-1 sounded markedly (and I mean markedly) different when tried with various bit-perfect digital sources, yet it is claimed to be jitter immune. The better the source, the better it sounded.

Mr Tibbs
 
trancera said:
Anyone ever done the opposite?

Spend a long time modding a CD Player, and rather than have an extra box I want a DAC input ala recent Cambridge ... Have your squeezebox output into your Arcam 5 etc ...
Click to expand...

I suppose it is possible, but it would be hard and it would be invasive.

The interface between Digital Filter and DAC is, I think, in a signal format called I2S. You would need to generate this. You can get kits for SPDIF receivers, like this one http://www.twistedpearaudio.com/digital/wm8804.aspx

So in principle, you just need to break the tracks to the DAC chip, run them through a switch, with the receiver outputs on the other pole, then into the DAC. The extra wiring and the switch will wreck havoc with the jitter, unless done very carefully. Receiver needs power supplies and case will need to be modified to allow for switch, and SPDIF input socket.

Don't fancy doing it, but it is a free world.
 
Trichord used to do a thing called a Digital Output Board. I had one fitted along with one of their Clock 2 upgrafes in a Sony battleship CDP 337ES players many years ago and it improved things a lot. I'm still using it into a Bel Canto DAC 2.

Not sure about the possibilities with the Naim boxes but it might be worth giving Graham at Trichord a call he is very helpful

eddie
 
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