[rw@cn]

Learned something new, but why would a preamp be designed where you need to wire your speakers out of phase?  In other words, what is the advantage?

Jim

It does seem nuts, but a lot of equipment is that way. More than one would think. Especially some tube units. Jim Smith, in his book takes time to discuss this.

[medium jim]

It does seem nuts, but a lot of equipment is that way. More than one would think. Especially some tube units. Jim Smith, in his book takes time to discuss this.

I've owned several tube pre's and none were as such.  Books are great for knowledge, but listening is the ultimate arbriter....

Jim

[SteveFord]

When in doubt, go to the source.
From Kara Chaffee (UV refers to UltraVerve):

Any tube in a  normal gain stage will invert phase. It made no sense to add a second gain stage to the UV to reverse phase once more --with that as its only goal.  The simplicity and directness of the design far outweigh the phase issue, and furthermore many traditional tube power amps also invert phase for the same reason. So a lot of the time it is of no consequence. 
I have observed that a lot of people have accepted complexity as a proxy for quality.  Look at loudspeakers in the tall thin format--do I want a speaker with three bass drivers or one good one , for the same price ? Yet people think three (cheap)  drivers must be better!

From me:
I've stumbled upon a very smart cookie.

[medium jim]

Steve:

I'm all for simplicity, that is why I prefer two way magnepan's with true ribbons. My tube pre allows me to change the speaker phase via a switch, yet it still is a direct path in the topography.  I still think those guys back in the 50's had it right!

Jim

[Davey]

Fellas,

The proper term is not "phase" but "polarity."  In most discussions "phase" refers to some sort of frequency-dependent behavior.  "Polarity" refers to a simple 180 degree reversal that is not frequency dependent.
I'm surprised how many "industry types" still seem to be confused by this basic concept.

Anyways, it's sort of a red herring to be concerned with how many polarity reversals your playback equipment implements because there's no way to know how many were contained in the recording chain.  Your only option is to utilize some sort of easily reversable polarity switch somewhere in your playback equipment and evaluate every recording in your collection to see if one "way" sounds better than another.  And then note that position on your CD jewel box or album cover or whatever. 

I believe the prevailing thinking on audibility of absolute polarity swaps is related to the even-order distortion exhibited by your speaker system.  Transducers that have some asymmetry in their construction will probably make this effect more audible.......assuming it's audible at all. 

Cheers,

Dave.

[medium jim]

Fellas,

The proper term is not "phase" but "polarity."  In most discussions "phase" refers to some sort of frequency-dependent behavior.  "Polarity" refers to a simple 180 degree reversal that is not frequency dependent.
I'm surprised how many "industry types" still seem to be confused by this basic concept.

Anyways, it's sort of a red herring to be concerned with how many polarity reversals your playback equipment implements because there's no way to know how many were contained in the recording chain.  Your only option is to utilize some sort of easily reversable polarity switch somewhere in your playback equipment and evaluate every recording in your collection to see if one "way" sounds better than another.  And then note that position on your CD jewel box or album cover or whatever. 

I believe the prevailing thinking on audibility of absolute polarity swaps is related to the even-order distortion exhibited by your speaker system.  Transducers that have some asymmetry in their construction will probably make this effect more audible.......assuming it's audible at all. 

Cheers,

Dave.

Dave:

Sorry for the confusion, but now I understand why on my McIntosh MX-110, as well as my Marantz 9's, I have the ability to change the polarity 180 degrees.  When ever I encounter a CD that sounds less than desirable, I will flip the polarity and see if it makes it sound better....

Thanks,
Jim

[kevin360]

The trick to conquering audio nervosa is to throw money at it.
The last piece of the puzzle showed up today, details to follow...

No, the indicator of audio nervosa is one's throwing money at 'it'.
The problem with 'last pieces' is that they often inspire another 'last piece'.
One cannot conquer this disease and to attempt to do so is to spoil part of the fun. There's nothing wrong with what we do as long as we aren't ignoring a hole in the roof while buying this stuff. It's enough to acknowledge that some would consider it nutty.

A friend of mine just bought a new pair of wheels for his bicycle - at $5,600. He doesn't compete professionally. Is he insane? Are we? Nah, we're okay. We're having some fun while we're on this earth. I'm okay; you're okay.

Enjoy

[SteveFord]

Well, I did order a service manual for my dead Sherwood S-2000 this morning to replace the Carver TX-11a for the MMG system and I'm waiting to hear how this one phono stage which is under construction progresses...
You're right, it never stops!

[medium jim]

Everyone needs to count to ten and then stop

Jim

[josh358]

I believe the prevailing thinking on audibility of absolute polarity swaps is related to the even-order distortion exhibited by your speaker system.  Transducers that have some asymmetry in their construction will probably make this effect more audible.......assuming it's audible at all. 

Cheers,

Dave.

Cool, I'd wondered if that might be the case. Has anyone done any formal experiments to verify this hypothesis?

[SteveFord]

Where the heck is AVNerdguy? 
He has (or had) a schematic of my SFL-2 and flipping the phase switch on that didn't do much at all.
Swapping the speaker leads had a tremendous impact with the UV3. 

[medium jim]

Where the heck is AVNerdguy? 
He has (or had) a schematic of my SFL-2 and flipping the phase switch on that didn't do much at all.
Swapping the speaker leads had a tremendous impact with the UV3.

Steve,

I'm still dumbfounded that taking or wiring the speakers out of phase makes sense, as you are cancelling the bass...

Jim

[SteveFord]

No lack of bass, that's for sure.
There was actually too much of it with the EH tube but it's just right with the RCA.
I don't know enough so someone more knowledgeable will have to chime in.

[TONEPUB]

Fellas,

The proper term is not "phase" but "polarity."  In most discussions "phase" refers to some sort of frequency-dependent behavior.  "Polarity" refers to a simple 180 degree reversal that is not frequency dependent.
I'm surprised how many "industry types" still seem to be confused by this basic concept.

Anyways, it's sort of a red herring to be concerned with how many polarity reversals your playback equipment implements because there's no way to know how many were contained in the recording chain.  Your only option is to utilize some sort of easily reversable polarity switch somewhere in your playback equipment and evaluate every recording in your collection to see if one "way" sounds better than another.  And then note that position on your CD jewel box or album cover or whatever. 

I believe the prevailing thinking on audibility of absolute polarity swaps is related to the even-order distortion exhibited by your speaker system.  Transducers that have some asymmetry in their construction will probably make this effect more audible.......assuming it's audible at all. 

Cheers,

Dave.

Good post.  And if you really want to drive yourself crazy, I've talked to more than one recording engineer that has said sometimes, one or two mikes in the chain ended up being out of phase during the recording, which really wreaks havoc with things..

But my experience most of the time is getting absolute polarity correct yields slightly bigger dynamics.  I've never had it be terribly dramatic.

[Davey]

Cool, I'd wondered if that might be the case. Has anyone done any formal experiments to verify this hypothesis?

Not that I'm aware of.  I don't think "formal" experiments are easily possible since this would primarily be a subjective evaluation.  And of course, subjective evaluations would require some sort of double blind testing. 

On this forum, talk/discussion of double blind testing gets you in hot water. 

However, it certainly seems intuitive that transducers with a very large asymmetry would accentuate any audible effect with regard to absolute polarity.

Me thinks Magnepan is probably aware of this as well.  The MG 20.X's obviously address this aspect.....among other things.

Cheers,

Dave.

[josh358]

Not that I'm aware of.  I don't think "formal" experiments are easily possible since this would primarily be a subjective evaluation.  And of course, subjective evaluations would require some sort of double blind testing. 

On this forum, talk/discussion of double blind testing gets you in hot water. 

However, it certainly seems intuitive that transducers with a very large asymmetry would accentuate any audible effect with regard to absolute polarity.

Me thinks Magnepan is probably aware of this as well.  The MG 20.X's obviously address this aspect.....among other things.

Cheers,

Dave.

It would be an interesting experiment for someone who has a push-pull ESL or planar and some ABX software. Actually I should try a web search, I can't believe that someone hasn't done a study of this at some point.

[TONEPUB]

No, the indicator of audio nervosa is one's throwing money at 'it'.
The problem with 'last pieces' is that they often inspire another 'last piece'.
One cannot conquer this disease and to attempt to do so is to spoil part of the fun. There's nothing wrong with what we do as long as we aren't ignoring a hole in the roof while buying this stuff. It's enough to acknowledge that some would consider it nutty.

A friend of mine just bought a new pair of wheels for his bicycle - at $5,600. He doesn't compete professionally. Is he insane? Are we? Nah, we're okay. We're having some fun while we're on this earth. I'm okay; you're okay.

Enjoy

Couldn't agree with you more.

I've managed to acquire more than my fair share of "last pieces" yet I am still amazed that things can be pushed further.
Am I spending more money?  Nope.  But it is fun to investigate.

[Davey]

It would be an interesting experiment for someone who has a push-pull ESL or planar and some ABX software. Actually I should try a web search, I can't believe that someone hasn't done a study of this at some point.

I've google searched previously, but much of what I read were ill-conceived testing configurations where conclusions were made from questionable data.

I think you have to start with some sort of reference test (maybe performed with the proper headphones) to identify recordings where (possible) absolute polarity changes are audible.  If you can use that program material to audition with speakers and correlate the results with the headphone testing then (maybe) you can make a conclusion. 

Of course, that won't conquer audio nervosa.  But it would be entertaining discussion. 

Cheers,

Dave.

[josh358]

I'm not even sure about headphone testing, since most headphones use asymmetrical transducers . . .

[kevin360]

You know, Dave, I think a lot of folks mentally transfer the neat electrical signal to the wave traveling through the air, where things really get 'messy'. Of course, what's in the air is quite tidy when compared against our perception of it.

I'm perched on the fence on the polarity issue, but consider it pointless to fret about it. It would be interesting to investigate seriously, but what utility would be gained from the discovery? My DAC has an 'invert' switch. For fun, I think I'll fiddle with it in search of material that I perceive to be better one way or another. It should be quite simple for me to have another individual select one or the other and test me on it.

This, however, points up an example of how messy this stuff gets in our heads when we get analytical and listen 'critically' - especially in a comparison setting. On the other hand, if the result is a confirmation that I can tell the difference, I will have given myself a serious outlet for anal behavior - I don't need any more outlets for that.