2. amps-preamps
  3. 1143621906

Phase Inversion in Preamplifer?

I just bought a used Audible Illusions 2D here on a'gon. This will be my first venture into separates. I've learned that AI preamps have inverted phase, so it's recommended that I switch +/- polarities at the speaker-amp hook-up. OK. But according to AI literature the phono stage of the preamp is NOT inverted, only the output stage is. So, since I listen to both vinyl and CDs, what do I do? Should I reverse speaker wire polarity or not?

Incidentally, the amp I'll be using is an ATI 1502 -- still haven't been able to find out if it inverts polarity or not. But based on my (limited) research thus far it appears that phase inversion is a design of preamplifiers more than power amplifiers. Is that right?

Thanks,
Rich
winegasman

Showing 3 responses by phd

phd
1,283 posts
 
Preamps by Conrad Johnson all invert phase. I could not tell any difference by changing the polarity to my speakers. It is also interesting to know that many recordings are recorded phase inverted. Since your preamp inverts phase some of these recordings should turn out just right if you can hear any difference at all.
phd
1,283 posts
 
When both speakers are not wired in phase this will of course effect the sound, more noticeably the bass. But if all minus & plus connections between your amp & speakers are correct, and you insert a phase inverting preamp, at this point it will take a very good ear to hear the differences because some recordings are phase inverted (as mentioned above). Personally I would not be too worried over a phase inverting preamp & making corrections. I was told that in order to manufacture a phase correct preamp it will require additional sound degrading circuitry.
phd
1,283 posts
 
Clio09, a test CD to make phase corrections is a very good investment. If there are no other components in your system inverting phase other than the preamp than reversing polarity on both of your speakers will correct this. I am just saying it is difficult to hear the difference if this is the case. Good deal.
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