Phase Inversion in Preamplifer?

I have a preamp that allows for inversion of phase by remote control. Yes, one can hear a difference quite readily. But, with most recordings, the difference is subtle, and it is not entirely clear which is the preferred setting (e.g., with one setting the vocals may be more realistic, while the piano becomes unnaturally phasey).

Because recordings seem to be all over the place, there is no reason to really worry about phase if you don't have the means (and will) to switch on a recording-by-recording basis. That kind of switching is only practicable with a phase switch, preferrably, one switch by remote.

The fact that the phono stage does not invert is meaningless. The signal still passes through the line stage after leaving the phono stage, so even when using phono your output will be inverted when leaving the AI, period. You have what is called an integrated preamp, which is similar to an integrated amp. Instead of a preamp and amp in one box, you have a phono stage and line stage in one box. As you become more familiar with seperates, you will realize that the phono stage runs through the line stage and then on to the amp.

Bottom line, everything coming out of your AI will be inverted. The only concern you would have is if the phono stage also inverted, which would then cancel out the line stage's inversion. However, it does not, so you have no worries.

So change the polarity of your speaker cables only once, either at the amp output OR at the speaker input. Note that if you change polarity at both ends you will defeat the purpose.

Hopefully this helps.

Regards,
John

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.

FWIW Jmcgrogan2 is absolutely on point. Most sources that you will attach to your pre-amp won't have "inverted phase". Probably the description arrises out of the fact that tube phono preamps often do invert phase, especially the little one tube cheapies. I have noticed that the inverted phase issue arrises most often in tube equipment with a single tube per side. Perhaps those that use a second tube as a cathode follower correct for the initial inversion. Just a thought.......

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.