Stereo  Phono RIAA Preamplifier Module Board.
This item has been assembled, and electrical test passed.
Thickness 1.6mm FR-4 fiber glass PCB (double layer).
HQ terminal blocks easy connection wire.
Low noise and low distortion audio OPAMP LM833-N.
Input resistance and capacitance DIP switch selectable.

Best Operating Voltage:         +/-9Vdc to +/-15Vdc.
 Gain:                                         30 / 50dB, DIP switch on board option.
 Input Resistance:                    12K to 2.2M ohm, DIP switch on board option.
 Input Capacitance:                  0, 22, 47, 100pF, DIP switch on board option.
 Output Impedance:                 47 ohm.
 RIAA Accuracy:                       <1.5dB.
 Bandwidth:                               20 to 20KHz (-3dB).
 Distortion:                                0.05% (at 1KHz).
 SNR:                                         >68dB (two 9V batteries supply).
 Size:                                         78 x 50 x 16mm (L x W x H).

Module spec.:  http://www.audiowind.com/pdf/A-310.pdf, No paper specifications, please download this document.