audio over USB v. optical

**turbocad6** · 02-07-2007, 01:25 PM

Originally Posted by RedGTiVR6

the Drive Rack has been used in numerous cars in competition. Converting it to 12v has been done before without issue.

you know of any that I could look at.... I haven't been in the competition circuit since putting ranes in the trunk was cutting edge

**RedGTiVR6** · 02-07-2007, 01:27 PM

Doug Winker did his.

I'll see if I have his email address. The guy is brilliant!

**durwood** · 02-07-2007, 01:59 PM

If you want the economy version, the Behringer unit has been modded and done before too, although the driverack is a much better unit.

Back to multiple DACs...
I have a USB Xitel that might be considerd a DAC, I think. IF we can't find documented proof this has been done, maybe if we pool some external DACs together and give them to one person. Then we could get this tested once and for all. I'd be willing to ship this to someone to try out as long as they ship it back when done testing.

**Psyfact** · 02-07-2007, 02:07 PM

Originally Posted by RedGTiVR6

I'm not sure on the multiple USB dacs.

I'm asking because I'm tossing around the idea of looking into having an outboard DAC built that would have multiple RCA level outputs with high voltages. Something that has replaceable opamps and possibly other components.

I'm wondering if it would be better to go over USB or over optical.

Seems to me that USB would be the best bet since not all computers have optical outputs.

What options would you think would be desireable for something like this?

I'm thinking about 10 outputs (5 pairs).

Heck, maybe even making the board it's self but making it a project type board. That way, if I wanted to use the WBT sockets, but someone else didn't want to spend that much money, it's all an option. Same with the DACs and with the other components.

Something where you can pick the RCA sockets you want to use. The caps, the opamps, etc.

But since I know literally nothing about doing somehting on this level, it's going to take some collaboration.

This would be something that's an audiophile upgrade for most folks with CarPCs. Once something like this is done, we could approach a developer about integrating all of the software into one program...or something that could be integrated into a front end.

Is having 5 pairs in the setup so that you can have frequency band separation?

**durwood** · 02-07-2007, 02:10 PM

Originally Posted by Psyfact

Is having 5 pairs in the setup so that you can have frequency band separation?

Yes.

**RedGTiVR6** · 02-07-2007, 02:15 PM

many times, at this level, folks are running multiple amps...one amp per pair of speakers.

we're going to be running a 3 way front stage and a sub.

we need at least 7 RCA outs for our set-up...or 4 pairs.

**durwood** · 02-07-2007, 02:19 PM

I just though of another issue with the mutliple single DAC's strung together idea. How would volume be controlled as a whole?

**RedGTiVR6** · 02-07-2007, 02:27 PM

**durwood** · 02-07-2007, 03:00 PM

A little quick research found this...another problem using multiple single dacs.

http://www.diyaudio.com/forums/showt...threadid=38786

They don't share the same clock. In theory though if the same clock was sued it might work. This was gearded more towards using a specific chip.

ADDED: At least he said ASIO worked with that chip

**Psyfact** · 02-07-2007, 04:28 PM

Solution - usb in to FPGA, FPGA does an FFT and splits the frequency bands, FPGA then drives either parallel inputs dacs or serial input dacs. Dac output through nice set of opamp line drivers.