Each gain stage inverts polarity. A phono amp generally needs 2 amplification stages for gain and RIAA and an impedence matching buffer stage to drive the power amp. 3 stages = inverted polarity. 3 stages are better than four -less is more- so they leave polarity inverted. I believe they leave it like that for 2 reasons. It works fine with their amps. It doesn’t make a big difference to SQ.
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?
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?
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And in some pre-amps that contain a phono stage (or in a separate phono amp), that stage (or amp) may be of inverted polarity while the line stage is not (or visa versa). What are you gonna do, reverse your speaker leads depending on whether you are listening to an LP or CD? And since, as atmasphere points out, most recordings are made without respect to absolute polarity, album mixes are made from recordings (done on a 16 or 24 track---or more---multi-track recorder) in which the channels may be a mix of both inverted and non-inverted signals (some microphones also invert polarity! Some effect boxes---EQ, reverb, compressors, etc.---do as well) ). Of that there is no solution. And of course, many multi-driver loudspeakers have one or more of those drivers in polarity opposite to one or more of the other drivers. Of that you DO have control---don’t own such a loudspeaker! |
A single gain stage always inverts polarity, would you have the manufacturer add a second gain stage to change it back again? And do you change the polarity of your speakers for each recording the you play? That would be necessary if the goal is to always be in correct polarity. In fact, many recordings that use spot mikes on different instruments will have the sax in negative polarity while the keyboard is in positive polarity, so I would suggest that you change the polarity of your tweeters, midrange and woofer as called for by the specific recording. |
Several answers above as to why some preamp invert polarity. With last years big upgrades I can better than ever hear recording polarity. Lucky for me, my main preamp has a polarity switch easy at hand. Also with dipole speakers it is easy to hear a difference. Since reverse polarity the soundstage is larger and behind the speakers, with correct polarity the soundstage is more in front and between the speakers. Plus with correct polarity vocals are clearer. Bass is slightly more defined. There is not only correct and reverse. All sorts of angles.. Also some records multi tracked, some instruments one polarity some the other.. some 90 off due to running through gizmos.. One of the reasons plenty of Rock (in particular) recordings you cannot hear any real polarity... since in one recording it is all over the place. |
given so many reputed recordings are 'all over the place' regarding polarity/phase.... What then is the correct way to not adversely stress the power train when re ordering polarity? mute the sound, then switch? or just switch polarity on the fly as it won't matter for neither the speakers or amps will encounter undue strain or stress? ... just wondering |
It actually doesn’t matter to the average person whether the preamp is Reverse Polarity or Correct Polarity because so many recordings are in Reverse Polarity. So, what’s the difference? Since there are no technical standards for Polarity in the industry one should first establish whether his system is in Correct Polarity in the first place and go from there. |
Ralph, I respectfully disagree. Well over 2 decades ago I learned 2 things (that were only accessible at a reasonable price from PS Audio), things that should be universal if a product is to be called ’High END" * differentially balanced AND * either the preamp or dac has remote Polarity control Individual songs on discs have long been mastered in various facilities, moreso on Greatest Hits, but still. Most of the time "I" have no problem hearing when polarity is in/out. Over the years I find bass is the greatest offender. When it’s out the music lacks clarity, space is more homogeneous, loses the speed of the initial attack |
My preamp has a polarity switch and it can be flipped with music playing no problem. No pops or clicks... Agree reverse phase the music lacks clarity, and yes the bass is messed up a bit. As far as the comment that equipment with reversed polarity is 'cheap'. hah hah ha hah etc. Try purist.. way more appropriate than cheap. |
A point that hasn't been mentioned is that when the setting of the polarity switch that is provided on some components is changed, in addition to the polarity of the music signal being inverted the sonics of the component could conceivably change, at least slightly, depending on the specific design. I'd expect that to not be the case with a fully balanced design, such as Ralph's (Atmasphere's), since polarity in such a design can be changed by simply interchanging two signals somewhere in its internal signal path. But with a design having an unbalanced internal signal path it is not necessarily that simple, and in some designs I wouldn't be surprised if sonic side-effects were to occur when the position of the switch is changed. Perhaps in some cases that is one example of how easy it can be in audio to attribute a perceived difference to the wrong variable. Regards, -- Al |
A question about the internal sonic effects in Al's theoretical 'some' preamps. Now if the actual electronics were creating the change. Then it would 'always' be one position which gave the apparent sort of signal. And the other position also would have a specific signal sound. So if the differences do not follow the switch, but rather follow the source polarity.. Then the suggested problem almarg discussed does not exist in the preamp in question. If on the other hand it did follow the switch, then yeah your preamp polarity switch is messed up. I have several preamps into the main one. And one of them inverts. (Conrad Johnson ACT2) so with care adjusting the controls with the same signal to several, I can switch the main preamp fro the Threshold FET TEN to the ACT 2. inverting with the selector switch, let alone the Bryston polarity switch. No matter how it is done. the results match. |
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Here is all you need to know about polarity. http://www.6moons.com/industryfeatures/polarity/polarity.html Cheers. |
I get an uncomfortable feeling when the 6 Moons author states, “there’s a 50-50 chance a given recording features Inverted Polarity.” I’m mean how does he know?” I would sincerely like to see someone, anyone, compile a list of say fifty audiophile recordings, LP and CD, with Polarity for each. That doesn’t seem too difficult. So far all we have is George Louis’ Polarity List. Which is great that he compiled that long list, but I have trouble buying into it, primarily because he concludes the percentage of CDs that are in Reverse Polarity is so high. But 50-50 assumes no audio engineers or mastering engineers check for Polarity and I don’t buy it. I’m not saying it’s impossible, just the probability is low. |
