phase control on BAT VK pre amps

A point to keep in mind is that when the setting of the phase switch is changed, not only is the polarity of the recording being inverted, but the configuration of the circuitry in the preamp is being changed. That in itself can be expected to sometimes affect the sound, to a greater or lesser degree depending on the specific design.

Also, seconding Jfrech's point, my understanding is that most recordings in most genres are produced via heavy multi-mic'ing (i.e., a lot of microphones) together with subsequent mixing and processing in elaborate electronic consoles. With the result that neither polarity setting stands much chance of being correct for all of the performers and/or their instruments.

Regards,
-- Al

The following CD has a test that will enable you to tell if you can actually hear the Wood Effect. It also contains test for proper sound stage(left and right imaging), the LEDR test, etc: (http://www.amazon.com/Chesky-Records-Sampler-Audiophile-Compact/dp/B000003GF3) Notes on the Wood Effect here: (http://mariobon.com/Glossario/Fase_Assoluta.pdf) LEDR info here: (http://www.stereophile.com/features/772/)

You will only hear the effect of inverting the phase if you have a recording with only 2-3 mics in true stereo.

50% of recordings are out of phase anyway, so this can get really tricky.

The Chesky disc has two demos, in which phase is reversed. The first with one trumpet(actually two tracks, one reversed). The next with a full jazz band, which they reverse the phase on, without telling you at what point. My son and I both noted the exact moment of reversal, different days, no prior discussion. I own a number of recording(CDs and vinyls) that I have marked for reverse phase playback. As Ralph mentioned; there are many more in which no differences will be noticed.

"My son and I both noted the exact moment of reversal, different days, no prior discussion. I own a number of recording(CDs and vinyls) that I have marked for reverse phase playback. As Ralph mentioned; there are many more in which no differences will be noticed."

Keep in mind that the Chesky CD is made for demos. Most likely, they selected tracks that emphasize whatever quality they want you to hear.