http://www.pcrecording.com/wcpci.htm

another converter is the tango 24 by frontier design circa 1996-1998

Tango24 Specifications

    8 analog I/O, 24-bit, 48kHz (Crystal CS4390 Inputs/CS5360 Outputs)
    1/4" TRS jacks, jumper selectable +4dBu or -10dBV levels
    Switchable input/output level meters
    ADAT optical in/out/thru
    Internal (44.1 or 48 kHz) and external clock modes
    Frequency response: +/- 0.05 dB, 20Hz-20kHz
    Dynamic range: 105 dB A-weighted
    THD+N: 0.002%
    115 dB signal-to-noise-ratio
    1U Rack-mountable external converter box