A preamplifier is unnecessary when using your Wadia 521 Decoding Computer. The Wadia 521 Decoding Computer provides all the necessary control functions of a preamp while the signal is still in the digital domain. This avoids the sonic degradation caused by og circuitry, switches, and wire. The Wadia 521 Decoding Computer output stage can drive any power amplifier and any interconnects, even at very long lengths. Does the Wadia Volume Control