Hi,
I
have successfully tested the E-MU 0404 USB
2.0 Audio/MIDI Interface:
http://www.emu.com/products/product.asp?category=610&subcategory=611&product=15185&nav=features
It's
frequency response is flat up to 90 kHz. Unfortunately, it is not BUS-powered,
which means that it requires an external power adapter.
The
frequency response and anti-aliasing characteristics of such audio
interfaces are primarily determined by the A/D converter chips in them. The
above unit employs the AK5385A chip, whose pass-band filter characteristics (at
fs=192 kHz) can be found at page 10 of the data sheet: http://pdfdata.datasheetsite.com/pdf1/AKM/AK5385A.pdf.
Regards,
Raimund