Slew-rate performance of M-Audio Fast Track USB, and iMic info

[kilowatt]

"Hello, I'm kilowatt, and I'm a gear-o-holic". :ahem:

From a purely output point-of-view, has anyone measured the performance of the M-Audio Fast Track USB? I'm looking to use it in my playback/qc rig. Any recommendations for sub-$100 usb audio adaptors would be greatly appreciated.

If anyone has access to an oscilloscope and can run some square waves through it, I'd be most gracious for the results.

On the topic of the iMic:

I benched my powerbook's OEM audio against the latest iMic revision (the one in the white plastic case), and the powerbook totally blew it away, slew-rate-wise. But the powerbook was a few dB down around 10K. My older, silver-cased iMic, which recently broke, must have sounded good enough that I wasn't ever tempted to bench it.

So recently, after the old iMic broke, I purchased a new one. And when I got home from the local Apple retail store, I noticed the output level of the new iMic was considerably lower than the older one I was used to. Once I compensated for the level difference, I quickly realized something else was different.

The latest iMic USB adaptors really suck. Wasn't even close to passing a square wave at 2KHz. Also be warned, the newer iMics don't send audio at 24-bit (the older ones would).

On the up-side, frequency response was decently flat, and the new iMic includes a female RCA pair to 1/8" stereo adaptor.

Thanks for listening!