optical S/PDIF

[Richard Monroe]

I couldn't figure what forum to post this in, so here goes: I'm just starting to use some optical I/O options that I wasn't using before. Prior to this, all my digital transfers were by coaxial S/PDIF, with the Digi002 by firewire. I use a Roland VS1824 for a remote unit, and I often use the Digi 002 to send or receive
digital signals to and from the Roland. Now I've added Behringer ADA8000, just to add a bunch of cheap channels by optical ADAT to the 002. I have also begun using the optical outs on the Joemeek twinQ. Here's some basic questions:
Given that the transfer is photo-optical, is it immune to electromagnetic interference, such as power cables? Secondly, I note that cables and jacks have dust caps, presumably to prevent dust on lenses. How critical is that? Does every cable and port have to have the dust cap on at all times, or do they just ship them that way? Is there any special care and feeding for optical cables? How critical is cable quality for this type of data transfer, and who makes good cables of this type? I doubt the DIY'ers just solder up an optical cable.-Richie

[Track Rat]

Yes, it's immune to EMF and such as it's light. The TOSLINK cables and sockets should be kept clean but they're not near as critical as true fiber optic connections (it's an LED rather than a laser). I keep a can of air to blow out the TOSLINK jacks and dry optical wipes (same thing you clean reading glasses with) to wipe the ends on the connectors with. The fiber I use at work is about 3 microns in diameter. A single spec of dust will take it down. The TOSLINK is much less finicky.

[AlexW]

As far as cables go--get good ones; but there's not the same spread in build quality as say for a balanced analog cable. One thing I've found is that the bulkier cables with the larger end connectors tend to lose their fit in the terminals due to their weight. I've had better luck with the very thin cables with small ends. The ones I'm using now I purchased at Fry's Electronics; though they look very similar to the ones sold at Guitar Center made by Hosa.

[Richard Monroe]

Track Rat and Alex- Thanks for the tips! There's always new ground to break. Go figger- I've found the VS1824 to be a solid hard drive, mixer, processor, FX box. It's pres suck, and A-D/D-A conversion is mediocre at best. If you feed it a good digital signal, it can be a really good recorder. I'm considering a SIAB upgrade in the future, just for improving connectivity. The Roland is a pain to export tracks- Look ma, no WAV file. It has served me well, though.-Richie

[Paj]

Rich:

(1) I've been using an ADA8000 for about 1.5 years now, most for live recording from the stage---no problems, great sevice, good results. It was a bargain. I figure about 6dB of headroom to go when the peak LED's start to flash. Don't forget that you can use it in reverse to get 8 LoZ track feeds for mixdown.

(2) I agree with the thin cable statement for short (3-10ft) runs. On longer (or stage floor) runs, I use a thicker, coated cable.

(3) Interference? Interference? You don't get no stinkin' interferece!!

(4) I also carry a can of dry air, since I lost one of the square dust caps and can't seem to find a replacement source. Never had a lost/no signal message.

Paj
8^)