Elizabeth, you addressed the issue of impedance mismatch between the source and poweramp. Can you explain what kind of impedance mismatch? In terms of electronics, what does a preamp do with the signal before it enters the poweramp?
why does preamp improve sound quality?
I recently listened to a Mark Levinson no.390s CD processor directly connected to a pair of Quad II-forty five tube amps. When a matching Quad preamp (much cheaper than the Levinson) was placed between the Levinson and the amplifier, the sound improved dramatically even at moderate volume- it became much more clear and transparent. Why would this be the case? Wouldn't adding an extra piece of equipment add more distortion?