Recording via optical from DAT deck - unwanted QT compression?

Question

Hello
I was trying to import from a DAT deck the other day, using the optical input on my G5 Dual 2Ghz. I was surprised to find that I could not get SoundTrack to see the incoming stream, nor BIAS Deck, that I am also using for recording. The optical connection was visible in the Systems Audio Prefrences, however.
After looking around a bit I remembered that QuickTIme now can record. It worked well, but I was very surprised when I saw the file size. A 30 minute recording was only 6 MB!
I asked at the Genius bar in Ginza here in Tokyo, and was told that QT is compressing very hard, and that GarageBand would be more suitable, which also will see the optical data coming in. But I think I read somewhere that GareBand do not support the full 48Hz that the DAT is using, and can only handle 44Hz.
The sound of the QT file was actually quite good. But how can I make sure that I get all the data of the original DAT recording? What is the proper software to use? At what settings?

Answer 1

If it's clipping somewhere, you'll have to adjust the gain in the analog domain. Either at the output of your DAT or at the input of your audio interface. Adjusting the gain in the software won't be useful because the clipping occurs at the analog-to-digital conversion.