does sample rate matter to a coaxial/optical converter?

H

hawaiianshirt

the jerk at the board
So I have a Fostex D2424LV with an optical out, and an Audiophile 2496 with a coaxial in. I need a converter (until I can get an ADAT capable soundcard anyway...).

Less expensive converters don't mention sample rates at all. M-Audio has a $50 bi-directional solution in this category that would suit me just fine.

But Hosa has a bi-directional converter that mentions a 24bit 96k maximum for $75. What gives?

Does sample rate even matter to a converter? Or does Hosa just know that if you slap "24bit/96k" on any product, you can charge more for it. Could I sell a 24bit/96k milkshake for $8?

Any help would be much appreciated.
 
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That's certainly what Dan Lavry thinks at least with reference to Sampling rate:

http://www.lavryengineering.com/documents/Sampling_Theory.pdf

I'm no expert on this by any means but having messed around with recording at different bit lengths and sample rates and having read around the subject a fair bit I've come to the following conclusions:

There is a noticeable difference recording at 24 bit over 16 bit. I find that I get good levels without having to record too hot so the noise floor is lowered and the risk of clipping is reduced.

There is nothing to be gained from recording at a sampling rate above 44.1hz. This is backed up by the research paper written by Dan lavry.

Hence I tend to record at 24/44.1
 
If you need ADAT-optical (lightpipe) to coax, you're looking for something more complex than an optical-coax converter, which is only intended to convert between simple stereo TOSlink (optical) and S/Pdif (coax). Something to select which 2 tracks in the ADAT stream to convert is needed. I confess I don't know what will do this, just a hunch that something like the RME4DD can?

Given suitable componants, format handling should be automatic - what goes in, comes out, just on a different type of cable. Although in the case of ADAT, something more inteligent is needed to seperate and re-code the data streams.

There are reasonable cost pci ADAT soundcards from Marian (Marc A), E-mu (1212M) and I think there's a new one from Esi.
 
yeah thats what i was thinkin too: to use ADAT from your ecorded, you would need an ADAT capable soundcard, not a converter to s/pdif coax. The above mentioned ADAT cards seem good. i would also recommend the echo GINA to check out. it has a good price tag and comes with a lot.
 
No, no... I didn't mean that I was trying to convert ADAT to coaxial. I'm trying to convert S/PDIF optical to S/PDIF coaxial. My recorder has both S/PDIF and ADAT outs, and right now I just happen to be stuck with the S/PDIF.

I know I need a converter for this. It's right in the Fostex manual.

What I'm asking is: why does the expensive Hosa optical/coaxial converter mentions having a 24bit/96k maximum, while the less expensive optical/coaxial converters don't mention a sampling rate at all?

Is it because the less expensive converters won't support 24bit/96k? Or does the sampling rate not matter to these converters at all?

Thanks alot.
 
You mentioned ADAT!!!

The M-audio Co2 specs says upto 24/96. I should think they can all do it as it's inherent in the s/pdif spec?

Which converter have you seen doesn't have a spec?
 
My bad. All the advertising for M-Audio CO2 has no mention of the sample rate, so I skipped right to the manual-- which also doesn't mention the sample rate. But upon further investigation, the official M-Audio product page DOES mention a 24 bit/96k maximum.

Thanks Jim. That's why I love this BBS. It sees all the details I'm too thick to see. :D I'm on the hunt for a CO2 now.
 
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