Adding Co-ax Out to CDP

I have a Sony XE510 CDP with an optical out but I want a co-ax one.
I've built a TTL to 0.5V convertor, but now I'm struggling to know where to connect it. The connections to the optical transmitter are labelled 'dig out', 'dig +5V' and 'dig gnd'.

So is 'dig +5V' the TTL output or 'dig out'? What will happen to my dac if I guess the wrong one?

Thanks for any advice,
Phill

 

You don't need that !

just two wires from digital sig and dig ground to the RCA.

I've done this to a number of sony's with great effect.

Either scrape a track to copper or go from the optical out. Make certain you don't uses the supply of the optical out.

You should be able to tell which is which, if not I see if I've a service manual that helps.

 

Cheers Zanash, two minute job then.

 

I didn't say that, but its not hard!

Looking at the curcuit diag I've got there looks to be a ceramic cap across the voltage supply and ground....which means the other is the dig sig. Now looking at things if you place a 75ohm res across the dig sig and dig ground and a 1k in the digsig line this will emulate what sony have done in other units. I have not do this in the units I've done, rather I've inserted a pulse transformer across the output.

 

Won't have time to get to my player until later this week, so I don't know if mine has that cap. Should have taken some photos whilst it was apart I suppose.

How do I go about adding a pulse transformer, I mean what do I have to do to give 75ohms at the socket? (I'll be using a BNC)

I'd be interested in trying that as I remember you raving about your ic with the transformer.
What transformer did you use, will any old 1:1 job do?

Cheers, Phill

 

No it needsto be a digital pulse transformer RS do a couple and farnell as well I think.

These are the only ones that will have the band width and not compromise the signal [too much].

If you have a problem getting hold of one PM me.