The tests were done using the analog input/output (the card also has spdif) by Kjell Olav Aalmo. The operative systems Win98 and Win2000 were used for the test. Win2000 did not work in 24 bits mode. It worked fine in Win98.
The sensitivity can be set to +4dBu and -10dBV on both input and output. The card also has an extra input amplifier that can be set in the range 0 to +18 dB. Supported sampling frequencies: 8000, 9600, 11025, 12000, 16000, ,22050, 24000, 32000, 44100, 48000, 88200, 96000. The buffer size can be adjusted to optimize.
http://www.terratec.net/products/ewx2496/ewx2496_details.htm