2. amps-preamps
  3. 147027-10803

Why do some manufacturers reverse preamp polarity in the first place?

My Rogue RP-5 reverses polarity, so I switch the pos / neg at speaker terminals. The manual does not mention this, however, I wrote the company and they the amp does reverse the polarity. 

Now my question is...why? I would say 98% of buyers of this amp do not know to reverse the cable connections. I would say most reviewers did not as well. Yes, I realize, polarity reversal is not noticable in most instances. Especially, since many recordings are all over the place when it comes to polarity (at least that is what I've read).

So the question remains...why...why not just have the amp terminals set up so the buyer can just plug in as normal?
aberyclark
mr_m
1,900 posts
 
Of all the thousands of recordings I have had over the years, the only recording in my collection that called for reversing polarity (at the speakers), was a LP of Dave Grusin- Discovered again. Seffield Labs.

I couldn't hear any difference in sound quality, at the time. That was many systems ago. Maybe I should re-visit that experiment and see if I hear any difference now.
geoffkait's avatar
geoffkait
23,365 posts
 
Well, Sheffield Labs recordings are actually on the Polarity List as R Reverse Polarity.

+1 for George Louis. On a sour note, FIM recordings also appear on the Polarity List as R. 

A discussion of the Polarity List somewhere in cyberspace prompted this comment. 

I know everything I've done for FIM has correct polarity.

Bruce A. Brown
Puget Sound Studios
Stereomojo reviewer
Seattle, WA

snapshot of Polarity List

Reprise – Joni Mitchell – Blue N
Rhino R
River North Records N
Rounder R
SANSTONE MUSIC – MEL TORME – THE LONDON SESSIONS R
Sheffield Labs R
SHILOH RECORDS – Greg Harris – Acoustic II R
SIRE – Talking Heads – Stop Making Sense R
Solid Air R
Solid Air Records – Grove Masters R
Sony R
Sony – Miles Davis – Kind of Blue R
pops
2,275 posts
 
He does and presents no evidence whatsoever. He came into our room one time and insisted that our room was in reverse polarity. I flipped the polarity switch on our preamp. Then he insisted that you couldn't hear it on LP- only CD. So I played the same track on CD as I had it on hand. Then he insisted that you couldn't hear it if the source was analog...
And then he left the room hastily, leaving behind only our impressions of him, with which we made jokes from for the rest of the show. 

Thanks Ralph - priceless!  
pops
2,275 posts
 
OK Geoff and calendar - go ahead and resume the interesting slap fight.
celander's avatar
celander
1,503 posts
 
Rupert Sheldrake was a respectable biochemist and plant biologist before he became a parapsych crackpot. PEAR is debunked.
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