HiFi over WiFi

[toptip]

Have you found a solution to your wireless SPDIF transmittal question?

I recently bought the Rocketfish wireless transmitter / amplifier combo. These have only analog input and outputs. However, when you open the boxes up, inside there are five-pin jacks marked with standard digital notation like bitclock, L/Rclock, +5V, etc., as if someone intended there to be SPDIF inputs and outputs.

The chipset used on this (also on the Acoustic Research wireless headphones) works well with almost no latency. It may be worth investigating how to add SPDIF. Interestingly the more expensive AR headphone does have an SPDIF input but, obviously, nothing on the actual headphones.

[xenob]

this is what you are looking for

http://www.elv.de/Digitale-Audio-Sig.../detail2_16757

instructions(only german)

http://www.elv-downloads.de/service/..._TIR100_km.pdf

[Sandor]

xenob,
thank you, the device you suggest is the closest thing to what I need. I have no time to experiment with the Elektor circuit, which also uses IR, so having a try with that commercial S/P-DIF to IR converter may be worthy. My digital source has only a coaxial S/P-DIF output, so I need a coaxial to toslink converter. Can you suggest a simple circuit?
Best regards.

Paul

[dangus]

I've read that a wireless video transmitter/receiver set will handle S/PDIF signals. Use the RCA video jacks, not the audio jacks.

[toptip]

"I've read that a wireless video transmitter/receiver set will handle S/PDIF signals. Use the RCA video jacks, not the audio jacks."

I doubt that...SPDIF is not a waveform.

It would work though if the SPDIF is first changed into a Y/C signal, the way original Sony PCM F1s did (so that they could use the Betamax system for recording). I have been meaning to experiment with this by buying a pair on Ebay but they are somewhat rare and only one model has a SPDIF I/O, the rest are analogue.

[stevecole]

I've also read somewhere that an AV sender can be used for SPDIF transmission, using the video section only. If I remember correctly, it was being used to send the front audio channels from the source components in an AV setup at the back of a room, to the front amp & speakers, at (no surprise really) the front of the room.

I have a similar application myself, but would like further comfirmation that such a device can be used for this purpose, before I shell out my money only to find that it either doesn't work at all, or that you need to buy a specific type of sender, not just one picked at random.

Is there anyone out there who has such a device and is willing to run a trial for us?

[jrwhite]

Yes, you can use the video channel of an AV sender to send S/PDIF. The coax S/PDIF signal is just under 1v, and likes a 75ohm load, so it's electrically similar to a composite video signal.

I've used these to send multichannel 1.5Mb/s DTS streams and 780Khz Dolby Digital streams across a room, and between two adjacent rooms with wood walls.

You get best results if point to point distance is less than 20 feet. The main problem is signal drop-outs caused by someone walking in the path between the transmitter and receiver will cause the Dolby Digital or DTS decoders in your receiver to un-lock, and drop-out for a second or so while it re-syncs to the stream. You get the best results if you can 'lock' your receiver to a specific stream type ( raw stereo, DTS, DD ) as the stream re-aquisition time is faster ( the receiver doesn't have to spend time figuring out what type of signal it is. )

If you can have both the transmitter and receiver up high and line of sight, then you should orient the directional antennas so they face each other. If you can't do this, and must have the transmitter and receiver within the walking path, you can still get acceptable results by experimenting with antenna orientation on the transmitter and receiver. Often times orienting the antennas to 'bounce' off a suface in the room ( like the ceiling ) gives the best results.

I've tried quite a few senders ( X-10 / Radio Shack ), but have had the best luck with the RF-LINK 5.8Ghz sender.

Remember, it will never be 'perfect' .. you will always get the occasional drop-out.

A better solution is the Nordic chip mentioned in an earlier post. I found one site that has modules that 'appear' to be based on the Nordic NRFZ1, and can transport S/PDIF. They're a bit expensive at 95Euro a module. I haven't tried them myself.

atific spdif module

Hope this helps.

Jonathan

[stevecole]

Thanks Jonathan, that's useful info. I've tried asking various manufacturers whether their device can do this, but without any luck so far. I think I'll go striaght to the 5.8Ghz option rather than try some of the more common 2.4Ghz units, as I've already found out there are issues with both microwave oven & wireless network interference at this frequency.

Regards

Steve

[wakibaki]

Originally posted by stevecole
I've already found out there are issues with both microwave oven & wireless network interference

It seems to me a bit strange to launch off into an experiment involving who knows what compromises in quality when you could get assured quality by making some compromises elsewhere in your requirements.

w

[Sandor]

Hello wakibaki,
can you, please, make some examples?
Best regards.

Paul