At the risk of asking a dumb question here goes.
Is there more than one type of digital coax/rca cable out there?

I have a generic Coax cable linking my M audio AudioPhile USB device to my Pioneer CD recorder.

When Coax is selected on the recorder, the recorder recognises the 48Khz signal coming from the M Audio device SPDIF outputs but when the signal is sent from the computer its flatline.

I think the CD recorder works because the analogue inputs are fine from the same source.

Trying to eliminate all possible causes here so I thought I would ask if Coax Digital and SPDIF Coax are one and the same? If not I will go buy a SPDIF cable, matching the M Audio output.

I don't have another SPDIF input device to cross-check this.

If they are the same then maybe the problem is in the recorder.

Thanks

Coax applies to the physical construction, not the electrical characteristics. The proper cable for S/PDIF is 75 ohm impedance. For shorter distances, regular audio interconnects work with no problems, but at longer distances (8 feet? 12 feet? I don’t recall, and there isn’t an exact crossover anyway) the correct impedance is important. As length increases, you will eventually start getting errors.

You have coax and coax: http://en.wikipedia.org/wiki/Coax
And you have S/PDIF: http://en.wikipedia.org/wiki/Spdif

Any well shielded 75 ohm coax cable should do the job

Maybe you computer sends something with a rate you recorder can't cope?

SPDIF is a lot more robust than many people give it credit for. I've run SPDIF over about 50ft of very cheap and thin COAX cable (certainly not 75ohm) between a CD player digital output and an M-Audio AP2496, and there were no problems.

I reckon the OP's problem is more likely to be a routing issue within the M-Audio Delta Control Panel. Perhaps whatever he's playing isn't being routed to the SPDIF output? Or maybe the mixer panel has the SPDIF muted?

I don't know if this is true for all soundcards, but mine definitely only outputs a S/PDIF signal when set to two channel operation in the soundcard mixer. Maybe the OP isn't aware of this or has overlooked it?

Cheers, Slipstreem.