Phase inverting preamps

Thanks, Phild. Does this in any way compromise sound quality? And, why would the maker of a preamp produce a unit that inverts phasing? Is there something specific they are trying to achieve that is negated by reversing the phasing elsewhere? Seems like it would be easier just to make the preamp without inverting the phase. Is it a cost savings measure?

If it's inverting phase, it's inverting push/pull (+/-) signals. To correct this, you need to change your speaker connections.

KP

I don't get it either, but I know someone here will have the answer for you. I've read an explanation before, but I forgot what it was. I vaguely remember someone saying that it was a design choice. I don't think it's a cost saving issue as much as it is a way to keep the circuit simple (but I'm not positive about that). I really don't think there's any adverse effects. It's a clean switch, so you're okay as long as you switch it back. Most people wouldn't even notice the phase problem, but the correct phase should sound noticeably better when you compare the two. It should sound more natural. To confuse things even more...some recordings (or mic'd instruments within a recording) are out of phase. That's out of your control, but you can sleep soundly knowing you did your part to fix your system phase. :-) You may want to ask the manufacturer of your preamp...they should be able to tell you if your's in phase inverting. You could also pick up a test record or CD (Hi-Fi News and Record Reviews, or others) that have a phase test...usually just a voice saying, "Yo...dis be da right chanel" and "Yo...dis be da left". If you're hearing the voices from the wrong speaker, you should check all of your connections and make sure they're correct. If they are, you know that some component is inverting the phase. My CD and LP source were both backward, so I assumed it was my preamp.

Hi Killerpiglet...I won't bet my life on this, but I think that what you're talking about (inverting push/pull) is signal polarity, which isn't the same thing as phase inversion.

Ouch, guys, it isn't left and right that are inverted. It is as KP said above, pos and neg. Just connect each pos speaker terminal on the back of your amp to the neg terminal on the speaker. They say they do it to save a gain stage necessary to flip the signal 180 degrees back to positive polarity. "Phase inversion" is commonly used to refer to reversed polarity.