A/D and D/A converters

  • Thread starter Thread starter David Katauskas
  • Start date Start date
D

David Katauskas

New member
If I buy an A/D D/A converter such as 'Flying Cow' from M-Audio, and run the Digital Out to my Soundblaster soundcard Digital In, will that eliminate any noise created by the Soundblaster soundcard. IOW, is most of the noise generated from soundcards from the A/D converter?
 
The circuitry of your soundbastard is very cheap, and I believe that is what is causing the noise.

Ditch the card and get a proper interface if you want pristine sound. Even a $100 prosumer card will get you much better results, imho.

For the $300 you'd spend on the Flying Cow, which I have read is overpriced, you could get a much better soundcard that has decent convertors.
 
In theory though - If your conversion is taking place in the Cow, the SB should NOT change it - It should cleanly pass the digital signal, therefore bypassing any noise due to the noisy conversion in the SB.
 
I tried this myself with consumer level cards - they still add noise even through spdif.

A while back, for giggles, I tested this out on a Sound blaster live and on an audigy. Noisy as heck. I also tried a Turtle beach Santa Cruz, which was a little better, but still noisy.

The same through my emu 1820M was really quiet.

I now go direct to digital mixer and to my computer via firewire, which is extremely quiet.

This is not gospel, of course, just my own experience.
 
The SBLive and Audigy are only 16 bit on the input. If you run a 24 bit signal to them, they will truncate the last 8 bits.
 
Farview said:
The SBLive and Audigy are only 16 bit on the input. If you run a 24 bit signal to them, they will truncate the last 8 bits.
Click to expand...

That's true :) While I would like to think I was testing at 16bit, but the truth is, I don't remember.
 
The Soundblasters resample at 48Khz on digital input - that's probably the source of noise/distortion. It's cleaner if the external A/D is set for 48K and you record your project at that rate. No soundcard electronics can add noise to a digital signal, provided it passes it straight through but unfortunately, Creative cards do not.

A better pci card is the M-audio Audiophile2496 or even the cheaper Delta DIO2496 - the s/pdif on these run at the rate of the external converter - a clean passage.

Another budget a/d-d/a is the Behringer SRC2496 which despite it's name, is not just a sample-rate converter.
I've just bought one but yet to test it.
More bang/buck that the Flying Cow, at least here in the UK.
 
I'm now aware of a limitation of the Behringer SRC2496. In its a/d-d/a mode, it cannot provide a master audio clock. What this means is...

Audio interfaces with s/pdif inputs either have to use the audio clock in the incoming signal, or use sample-rate conversion to match to their own internal clock. The former is prefered in Pro and Semi-pro interfaces as the conversion is a potential source of error, noise and distortion. These interfaces require switching to the incoming external clock ( or maybe automatically switch on detection) , in order to recieve anything from an s/pdif input. If your external converter cannot produce the clock, but relies on that recieved from the audio interfaces s/pdif OUTPUT, then it cannot work! You will only be able to use the DAC of the SRC2496 on your s/pfid out.

So, it'll work with something like a Creative card which converts the incoming s/pdif but NOT such as an M-audio Delta; which has to be switched to the external clock arriving on the s/pdif input in order to recieve any audio from it.

Hope this clears up what is a potential pitfall!
;)
 
You must log in or register to reply here.
Back
Top