Preamp inverts phase question:


The owners manual of my preamp indicates that the preamp inverts phase: the circuit is phase inverting. Does this mean that I need to hook my speaker cables up backwards to correct the phase inversion... do I hook the positive speaker cable to the negative speaker binding post and visa versa with the negative speaker cable connections on both speakers?
adampeter

Showing 7 responses by dopogue

Easy test. Play a dozen LPs, CDs, and/or reel-to-reel tapes. After you listen each one, switch the speaker connections left-to-right (+ to -, red to black, whatever) on both speakers. Play again. Do you hear any difference in any of them? If not, count your blessings and forget the whole thing (because your speakers do not reveal polarity* differences). If you do hear a difference, then decide if it's important enough for you to keep switching speaker cables or invest in a polarity-switching preamp like the Aesthetix Calypso.

* I think of this as polarity switching rather than phase switching, but it's probably best not to get into that.
It only matters, Hifiharv, if it's audible. I could never hear polarity differences ("normal" vs "inverted") until I got my current speakers (Gallo Reference 3) which the manufacturer says "are very polarity sensitive." Most of my friends' systems are not polarity-coherent and it's pointless for them to mess with it if they can't hear it. Dave
Benie, again, since many discs are recorded in mixed polarity and the rest are half "normal" and half "inverted," I don't think your argument holds water. On the mixed discs, the polarity setting doesn't matter ( although I have discs where I can pop the vocalist out front with one polarity setting and push him back into the mix with the other). Only a polarity switch or speaker cable switching will "fix" the others. The electronics are basically inconsequential. And the speakers -- the way they're wired internally -- are key to whether the effect is audible or not.
Benie, you're still missing the point that with respect to absolute phase (polarity), you are essentially at the mercy of the recording engineers and how any given disk was recorded in the first place. It would be wonderful if all disks were recorded in absolute polarity, but they're not. For instance, every Deutsche Grammophon record and tape I own was recorded in "inverted" polarity. So the only way you "can achieve absolute phase" when playing a DG disk is to switch speaker cables or have a preamp with a polarity switch. IF, as I keep saying, you can hear the effect at all.
Al, remember that when you switch speaker cables you are also affecting wire directionality, or so I've read. In fact, I remember Doug Blackburn writing an essay on polarity suggesting that the primary audible change you hear (if you hear ANYTHING) is the effect of wire directionality rather than polarity. IME, there IS a more pronounced effect from switching speaker wires rather than changing polarity via the preamp's remote. Anyone for listening to some music? Dave
Al, I switched the cables at the speaker end. The cables I was using at the time were shielded. Doug Blackburn's contention was that the cable-switching affected signal flow directionality of wire and other devices (capacitors, etc.) inside the speakers (soundstage.com/maxdb/maxdb101999.htm) if i understand him correctly. Further, he questions the audibility of polarity-switching per se.

Needless to say, self-proclaimed polarity guru Clark Johnsen ("The Wood Effect") opposes Blackburn's views, to put it mildly. I'm honestly not sure who's right. I only know what I think I hear, and fortunately it's repeatable.

Thanks for the 6moons article. Very interesting. Dave
Faced with a similar situation -- Otari open reel tape deck (pin 3 hot) to Aesthetix Calypso (pin 2 hot), I had XLR cables made that reflected this in the connectors.

You might also have the XLR pin outs on the Marantz player rewired internally, if that doesn't void your warranty. Dave