Phase Inversion in Preamplifer?

I have to say that the whole phase inversion thing leaves a bit to be desired. Much good advice has already been posted. From my perspective, I have a Joule Electra LA-100 MkIII that inverts phase and a Hagerman Trumpet phonostage that has a polarity switch. I recently acquired a passive preamp that does not invert phase. My system is set-up so the digital front end runs through the passive and the analog front-end runs through the Joule. So I don't have to keep swapping the speaker leads back and forth, I just leave them wired + to + and - to -, using the polarity switch on the phonostage to reverse phase to compensate.

The funny thing about all this is that I really can't tell the difference. I have a few test discs, two CD and one LP. Using the voice phase tests swapping the speaker leads made no difference to my ears. However, swapping IC leads did. As for the Rives CD, they use a track with solo piano followed by solo bass. Again, I could not tell the differnece. Although Larri's point about the piano seems to make some sense now that I think back on it. I may have to revisit that test track.

Newbee - At least in my experience, the Joule LA-100 MkIII and Cary SLP-98 use cathode (in the Joule's case it is a Mu) followers and both inverted phase.

Sugarbie - you're correct about phase inversion and polarity. In my case, while it is called a polarity switch on my phonostage, the manufacturer suggests it is used to invert phase.

Autio, re-reading my post I did not make myslef clear. Swapping the speaker leads at the amp binding posts (+ to - on each channel) I could hear no difference, meaning the voice on the test CD stayed centered and was well imaged. However, with the speaker leads wired correctly, swapping the RCA leads at the amp inputs so that L from preamp output goes to R amp input and R preamp output goes to L amp input, I could hear a difference. The voice on the test CD was not centered, instead appearing as if it were coming from different areas.

Then a test CD that uses a voice to do phase testing seems to be flawed. Something like the Rives CD where piano and bass are used would be more accurate. Correct? On that CD the bass was fine in both tests. However, I think Larryi may still be on to something with the piano, and I'm going to revisit that.