This is the Pro-1 Computer Audio Interface Board.  It is designed to interface between your computer sound card input and output and provide professional quality audio.  The circuit receives a stereo un-balanced audio input and provides a Stereo 600 Ohm Balanced audio output.  Each channel has a output level control which is adjusted for '0' db at the time of testing.

The PRO-1 is designed to offer a convenient audio interface between any consumer level audio equipment and professional or semi-professional gear requiring a 600 ohm balanced source.  The PRO-1 provides professional quality audio suitable for use in recording studio or commercial broadcast applications.

Specifications:
Input Impedance:  10K (Stereo)
Output Impedance:  #1 - 10K Mono Unbalanced
                              #2 - 600 Ohm Mono Balanced
Audio Response:  +/- 0.5 db - 20 Hz to 20 KHz
Total Harmonic Distortion:  < 1%
Power Requirements:  9 VDC - 14 VDC
Power Jack:  2.1mm
Size:  3.8"X2.4"

Price:  $149.95