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USB - ADC

Posted: Thu Jun 30, 2011 9:22 pm
by sebgar
Hello,

I'm working on building my own USB analog-to-digital converter to work with Audacity, what would be the best output to match the highest quality in audacity?

Thanks

Re: USB - ADC

Posted: Fri Jul 01, 2011 9:00 am
by steve
96 kHz 32-bit float format, (but most chips are designed for 44.1 / 48 kHz 16 bit integer, unless you are intending to build it from discrete components).

Re: USB - ADC

Posted: Fri Jul 01, 2011 10:10 pm
by DVDdoug
Ummm... There no 32-bit or floating-point ADCs. You can feed-in 32-bit floating-point data, but it would have to be converted to 16 or 24 bit integer (in firmware) before being fed into the ADC.

Of course, it doesn't help to have higher resolution than your audio files... And, the guys who do blind ABX tests have pretty-much shown that there's no audible difference between 44.1kHz, 16-bit (CD quality) and anything 'better". But... If you have 96/24 files and a 24-bit ADC, you might as well take advantage of it. ;)

Re: USB - ADC

Posted: Sun Jul 03, 2011 9:11 pm
by steve
DVDdoug wrote: Of course, it doesn't help to have higher resolution than your audio files...
sebgar asked about "analog-to-digital".

Answering his question literally, "the best output to match the highest quality in audacity" would be 32-bit float, but an accurate 96 kHz 32-bit float A/D converter would be exceeding the standards of the current state of the art audio converters. To take full advantage of greater than 16-bit with the current version of Audacity would require building Audacity with ASIO support and using an ASIO driver for the USB device.

In practice it is unlikely that an individual would be able to build a sound card that performs as well as a commercially produced sound card without spending a great deal more time and money on the project. There's a choice of high quality (24/96) USB sound cards designed for music production for less than $100 US.