Looking for Polarity Invert Feature...

The PS Audio GCP-200/GCPS is an outstanding value, discrete balanced pre, XLR/RCA- I/OS PLUS polarity control(though it is misnamed phase) on the remote!

IMHO, one needs polarity on the remote because many records/CDs are mixed up, and one needs to hear it from the listening position.

Another choice that's twice as much (MSRP) is the newish Parasound JC 2

The focus seems to be on preamps, but I'll ofer that the Marantz SA11-S2 and SA7-S1 SACD/CD players have a polarity switch. They are excellent palyers for the money too.

Spectron Musician Signature III MK2 Amp

The Tube Audio Design TADAC has polarity switches for each channel. It helps that it's a wonderful tube output DAC with adjustable gain and "tubyness" control.

One of the first preamps to have the invert feature was the original Atma-Sphere MP-1 (1989). It is the one signal processing feature that we have on our preamps (easy enough to do since our preamps are internally fully balanced).