Adding a coaxial digital output on Sony CDP

[rabbitz]

I am going to add a PD's NOS DAC to a Sony CDP990 and need to add a coaxial digital output to use instead of the existing Toslink as shown in the schematic.

Researching has found some simple circuits that I think could be suitable.

http://www.andrewkilpatrick.org/mind/spdif/spdif_circuits.gif

http://sound.westhost.com/p85-f6.gif

Dout comes from pin 60 on a CXD2500Q and part schematic of the Toslink output is shown in the pic.

Am I on the right track? I need something simple as I'm digitally challenged and want to keep away from transformers (I believe they also offer protection) in the circuit but op amps would no problem if required?

The cap at C1 on the links can be MKT or ceramic?

 

[DragonMaster]

Hi, you could try Andrew's or Rod's scheme, but DOUT is only 2.5v from the scheme so I don't know if they will work, since they need a TTL input.

You can even put nothing at all, it works ;-) (Done it a couple of times)

For a transformer, yes, it's recommended, but almost every SPDIF equipment have no transformer at all so I don't know if it makes a real difference.

Why don't you take the EIAJ output to an EIAJ -> I2S converter to plug it in your DAC? Still simple, sounds better.

 

[georgehifi]

Rabbitz, pin 60 is correct for the digital out on the CXD2500 , then you could use one of Tentlabs XO3 and that gives you a spidf (digital coax) out and at the same time improving the sound of the player greatly because of the new clock. Just a simple thought.
Just so happens that I'm the Aussie agent for Tentlabs also, wonder if that constitutes an add, maybe, whoops.
Cheers George

 

[rabbitz]

Thanks for the replies.

Speakers and amps are fine but I'm a digital dummy and have no idea what you are talking about in regards to EIAJ etc. I'll give the 2 options a go plus the direct route.... whatever works.

If I bought the Tentlabs as well as PD's NOS DAC, I'd get strung up by the you know whats I just need a simple output to try the NOS DAC as I'm very curious about it's sound.

Yep George, you got your add in

I'll have to get one in as well. If you want to buy a .........

 

[DragonMaster]

EIAJ is like I2S, but with a different timing. There is a circuit here to convert it but I'll have to try it myself with my CXD2500 CDP before that...

 

[zanash]

Hi......

I added a digi out to mini disc. The service manual showd the us edition with the coax out, where as my unit was a uk one without one. All they had done was take the digital to the centre pin of the rca socket and ground to the ground of the optical. I tried it and its fine its been in operation now for 5 years !

 

[rabbitz]

Ended up using the simple one on the ESP site and worked a treat. All the required inputs came from the optical section except the DGRD which came from the digital section of the PCB.

http://sound.westhost.com/p85-f6.gif