flipped phase in rack gear

[theblotted]

this is just a hypothetical Q that popped in my head while wiring my gear today -

suppose say that i wire a comp to/fro my converter. if the phase is flipped on both cables (pin3 hot and pin2 cold), it will return as showing no phase flip..

but what are the repercussions of signal going on inside the comp in flipped phase? does the comp behave exact same as if pin2 was hot anyway? or would there be a difference (possible degradation of signal)?

how about other rack gears such as reverbs, delays, etc.?

please help my curious mind.

 

[Sorr]

If the input is flipped and so is the output, then it will still be in phase.
I dont think there will be a difference.
Except perhaps if you introduce unbalanced equipment.
Best to keep everything as standard, ie pin 2 hot etc

 

[clintrubber]

I've never seen any specific 'anticipation' in circuitry of incoming signal polarity (let's use that word here). Response may differ in case of say a comp/lim with a sidechain that doesn't use full-wave rectification, but which ones do that actually ?

It may/will matter for playback: say a pos peak coming first (as it sounded & was recorded) also be be played back that way (so no polarity inversions in the complete chain), but even in that case the debate is still going on about how noticable it is. But if you can (and we can), keep it unaltered.

Regards,

Peter

 

[keefaz]

There was a thread about the signal polarity and the change in sound:
Is there an audible difference in these two soundfiles?

 

[emrr]

Broadcast limiters with asymetrical detector circuits would of course sound different.

 

[theblotted]

thanks for all the replies. and yes, i should have known better, phase for audio and polarity for wires..

my studio is all wired correctly, thanks.. it was just one of those "what if" things that popped in my head.

emrr, interesting you bring up broadcast limiters, b/c not too long ago i acquired a Urei BL40; but i took the phase optimization board out so i don't run into problems you mentioned.

 

[SSLtech]

There are a few -generally academic- issues with clipping that I'll broach.

With a symmetrical waveform, nothing matters. Voice, trumpet violin, oboe etc are highly asymmetric however.

With a typical class AB, bipolar, op-amp design, there is often STILL no resultant difference...


BUT...


With a single-rail, class A circuit with a predisposition to clipping or 'rounding' one edge of the waveform well before the other, there would indeed be an easily discernible sonic difference on an asymmetrical waveform, if the unit were pushed into asymmetric distortion...

...Think a lot of Neve 1272 type circuits.

There you go.

Keith

 

[Guest]

[quote author="SSLtech"]There are a few -generally academic- issues with clipping that I'll broach.

With a symmetrical waveform, nothing matters. Voice, trumpet violin, oboe etc are highly asymmetric however.

With a typical class AB, bipolar, op-amp design, there is often STILL no resultant difference...


BUT...


With a single-rail, class A circuit with a predisposition to clipping or 'rounding' one edge of the waveform well before the other, there would indeed be an easily discernible sonic difference on an asymmetrical waveform, if the unit were pushed into asymmetric distortion...

...Think a lot of Neve 1272 type circuits.

[/quote]

Though asymmetrically "rounding" stages may add some DC and sub-harmonics, the sound is more natural for our ears, i.e. distortions are perceived as indistinguishable from what we expect in real life with mechanical systems that sound, transfer, and reflect. And however in this case significance of polarity increases.

With class AB devices you'll find wider specter and increased level of harmonics on lower signals (decay of strings, reverberation), and non - exponential, abrupt decay that sound very unnaturally and is easily detectable by any individual even if he / she can't say what is wrong consciously. However, noise gates and compressors mask such effects so modern gear and modern records match well... But they add more of artificialities...

Here you go:

 

[SSLtech]

[quote author="Wavebourn"]Though asymmetrically "rounding" stages may add some DC and sub-harmonics, the sound is more natural for our ears, i.e. distortions are perceived as indistinguishable from what we expect in real life with mechanical systems that sound, transfer, and reflect. And however in this case significance of polarity increases.

With class AB devices you'll find wider specter and increased level of harmonics on lower signals (decay of strings, reverberation), and non - exponential, abrupt decay that sound very unnaturally and is easily detectable by any individual even if he / she can't say what is wrong consciously. However, noise gates and compressors mask such effects so modern gear and modern records match well... But they add more of artificialities... [/quote]

Not disputed...

But nothing to do with the original topic, I feel.

Keith

 

[CJ]

as always, the most innocent and simple questions can somtimes provide thought proviking arguments within fertile imaginations, on simple issues such as what would happen if a guy mis wired a UTC and some chick with a soldering iron could not see inside the three layers or mu metal, so the amp comes out a bit different, if a tree halls in the river, does a kayaker get killed?
Yes! On many occasions, search Waly Blackadar, thw most famous yaker in the world, also a doctor in I-da-ho.

OK, I divide it into two camps:

1) Loud speakers are involved

2) Loud speakers are not nvolved

if you are taping, a swap will effect ambient mic noise,

if you are jamming, a flip will afect the low end response if using a Fender and a Marshall togeter, since A Fender and a Marshall are wired out of phase from each other.

The speakers can mess with this, if you recab a Celestion with a Jensen.

use the 9 volt batt trick, anybody know it?

 

[Guest]

[quote author="SSLtech"][quote author="Wavebourn"]Though asymmetrically "rounding" stages may add some DC and sub-harmonics, the sound is more natural for our ears, i.e. distortions are perceived as indistinguishable from what we expect in real life with mechanical systems that sound, transfer, and reflect. And however in this case significance of polarity increases.

With class AB devices you'll find wider specter and increased level of harmonics on lower signals (decay of strings, reverberation), and non - exponential, abrupt decay that sound very unnaturally and is easily detectable by any individual even if he / she can't say what is wrong consciously. However, noise gates and compressors mask such effects so modern gear and modern records match well... But they add more of artificialities... [/quote]

Not disputed...

But nothing to do with the original topic, I feel.

[/quote]

I feel when phase is flipped; of course if low frequencies were recorded properly. I did not know about that before Mediatechnology mentioned that he feels well, so I've experimented and found that I feel as well.

 

[theblotted]

[quote author="CJ"]

1) Loud speakers are involved

2) Loud speakers are not nvolved

if you are taping, a swap will effect ambient mic noise,

if you are jamming, a flip will afect the low end response if using a Fender and a Marshall togeter, since A Fender and a Marshall are wired out of phase from each other.

The speakers can mess with this, if you recab a Celestion with a Jensen.

use the 9 volt batt trick, anybody know it?[/quote]


but doesn't the above concern with one cable flipped? i was talking more about double flipped, and in between is the gear in question.


btw, 9 volt trick = connect the battery to speaker and see which way it protrudes = which terminal is +/-? if not, sorry for popping your cone...

 

[chrissugar]

Theoreticaly there should be no audible difference between absolute phase and inverted phase because in both situations we have the same spectral content. But on some materials there is an audible difference.
There was a research on this subject at the University of Waterloo, and the explanation is that the basilar membrane in our ear is sensitive to the direction of the first movement. That is the reason why on some materials we can perceive some differences.
So the right thing in acoustic recordings is when the microphone membrane moves inwards, the speaker should move outwards so the wave front that reaches the ear should move the membrane inwards.

chrissugar

 

[JohnRoberts]

Yes, absolute polarity is audible for assymetrical waveforms like human voice and brass, but it's pretty subtle.

FWIW, back in '80's I sold a phono preamp with polarity switch, because prior to then there was no standard and recordings were random. I can't say I heard a difference on most recordings.

JR