Different ways to transport SPDIF Audio signals
media clients are en vogue today with all their advantages and disadvantages. I was looking for a simple way (without media client) to transport digital audio from the PC in my workroom to my audio system in the living room. I had no free coax between those two rooms so transporting SPDIF seems to be impossible.
Looking around I found out that the professional AES/EBU-standard transports digital audio via twisted pair. Accidentally I found a twisted telephone wire in the wall from my workroom to the living room with a length of approximately 15 meters.
From Neutrik I ordered a NADITBNC-FX (female) and a -MX (male) for aprx. 100Euro. Those units have a transformer inside converting 75Ohm coax to 110Ohm twisted pair (see here).
At the wall I installed XLR connectors which I connected to two twisted wires inside the 10 wire telephone cord. I ONLY connected those two wires (pin 2 and 3), NO ground to get galvanic isolation between the workroom and the living room. In the wall outlets I plugged the Neutik transformers and in the transformers 75Ohm coax wires with one side BNC and the other Cinch. The signal arriving in the living room has visible jitter (eye diagram) but still inside the AES-specification (10%).
Now it strongly depends on
the playback hardware. Restoring the D/A clock from this signal will be
inacceptable. I tested it with my improved
digital input stage for the Behringer DCX2496. I made A/B-test with
SACD sampled on the PC in my workroom (telephone line) and the SACD direct
via Straight Wire Silverlink II from
my modified Pioneer 578A. The ensuing listening test gave no difference between a SPDIF
signal coming directly from the CD-Transport and that coming from the PC in the