XLR output: pins 2+3 > different amps?

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Suppose we have an active (not passive nor transformer based), buffered, variable audio balanced XLR output. If the answer potentially changes for SS or tube circuit, please explain.

I propose pin 2 to drive a sub amp with 12k input Z, simultaneously while pin 3 drives a main amp with almost certainly higher input Z (estimate 30k to 100k).

Pin 1 ground shorts to amp 1 and 2 input grounds. Let's presume the output has enough current to properly drive each load. I realize pin 3 is inverted, easily fixed by inverting speaker cable polarity. Sub amp volume fixes sensitivity differences.

Tx!
 
Not sure why would you do that.

It will *electrically* work but both preamp out and (active) cabinet inputs will be incompatible with anything else on the Planet.

And you will have to split Preamp out buffers , injecting proper frequency range to each of them.
 
The preamp I consider buying has only one XLR output. The sub amp has unbalanced input only. The only other known solution is to use an active balanced to unbalanced circuit (or transformers).

It seems like the proposed solution is the simplest and least costly, both financially and in signal degradation, unless I miss something, which is the reason for the post.
 
The preamp I consider buying has only one XLR output. The sub amp has unbalanced input only. The only other known solution is to use an active balanced to unbalanced circuit (or transformers).

It seems like the proposed solution is the simplest
not simplest at all because you have to correct for second ampbeing out of phase.

Does your preamp **only** have an XLR out and **nothing else?**
Not any RCA/Jack/terminal block/minijack?
I find that hard to believe.
and least costly, both financially and in signal degradation,
not least costly once you correct the inherent problems.
And you end up messing with signal.
unless I miss something, which is the reason for the post.
None of us is backing your idea, maybe that mkeans something.

Please state which preamp and power amp(s) are we talking about for more focused answers.
 
Others have said it, I'm concurring.

The problem with using one pin of the XLR-OUT for driving one amplifier, and the other pin for driving the other — while admittedly conceptually simple — is that pin 2 is the phase-inverse of pin 3.

For your bass speaker, it is important to figure out which pin is 'going the right direction' when the speaker cones need to push OUT. Typically. If 'the other pin', the inverse signal goes to your mid-to-treble speaker, the phase inversion is of almost no importance.

So, either you'll “accidentally get it right”, or just the opposite. In the “right” case, bass 'punch' will seem to hit you slightly in the chest, just as it does live. If wrong, it won't have that effect, and your ears won't perceive the bass as very accurate.

HOWEVER, the other equally simple solution (which still requires “getting it right” in choosing pin 2 or pin 3!) is to make a splitter cable off a SINGLE pin. The inputs to your other amplifiers typically are fairly high impedance (high resistance ≡ low load), so even driving 2 of them “in parallel” is almost certainly of little loading consequence to the XLR driver.

So… there you are.

⋅-=≡ GoatGuy ✓ ≡=-⋅
 
I appreciate the help. I'm sure the posters understand how a balanced signal works better than myself. One professional technical person, and EE, disagrees with all the replies above, saying he/she has not tried it, but knows no reason why it would not work.

The only point in trying it is that I have had experience with load impedance dropping so low that it negatively impacted audio performance. I just wanted to know if this option existed.

The 2 sub amps power a sub woofer array: 2 subs toward the L wall, 2 subs toward the R wall. L subs tuned to 45 degrees, R @ 135 degrees, to further damp bass modes beyond the array's already superb mode damping effects. The center is @ 90 degrees to damp modes in the pass band with the mains. As per Dr. David Griesinger, Dr. Earl Geddes, and Dr. Robert E. Greene, Todd Welti, and Dr. Floyd Toole. You guys should post how stupid is this philosophy to correct their public errors.

It sure is difficult to invert a red and black speaker wire, BTW! Thanks for saving me from that! Whew!

Thanks again.
 
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With all due respect, while the hot and cold side of an XLR, pins 2 and 3, commonly have the same signal, with the cold side phase inverted, it is not necessarily so. The only requirement is that the incoming signal difference is used. The X part of the circuit is intended to go to chassis ground and not necessarily circuit ground.
 
With all due respect, while the hot and cold side of an XLR, pins 2 and 3, commonly have the same signal, with the cold side phase inverted, it is not necessarily so. The only requirement is that the incoming signal difference is used. The X part of the circuit is intended to go to chassis ground and not necessarily circuit ground.

Is there ever a case where a normal XLR/source to RCA/load adapter does not work? When and why? Is it not true that in every single such case, pin 1 (chassis ground as you describe it above) drives the circuit ground of the load?

If that's a yes to the last Q, then my suggested application is no less likely to work than any application where someone uses an XLR/source to RCA load adapter.

Besides in their imagination, does anyone reading this have a manual or text forbidding the use of an XLR/source to RCA/load adapter. I ask for a friend.
 
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You came with a pet idea looking for confirmation.

You did not get it, but answers addressing multiple errors/problems with it , at the same time trying to find ways to help you.

You reacted like a despised child, rejecting advice and dropping as many respected names as you could find trying to awe and impress us.

That you dropped names fully out of the blue and out of context is actually worse: quoting not a single line backing your pet idea speaks volumes about it.

FWIW
a normal XLR/source to RCA/load adapter
has absolutely no relation to your pet idea which was
I propose pin 2 to drive a sub amp with 12k input Z, simultaneously while pin 3 drives a main amp with almost certainly higher input Z
 
James (RO9397), you have managed to insult just about everyone who read your original post and attempted to give sanguine ideas that you could constructively use to accomplish what you seemed to originally desire.

I know you might be frustrated or possibly even angered by a few of the followup postings.

It isn't likely that you will continue to follow this thread, now that you've shat upon its community. Just know this … while there is every likelihood that your idea will work, because it is simple and convenient, and because at least with a few of our posts, it is supported by solid theory … you also shouln't be too surprised if it does not work either.

In helping quite a few of my younger friends understand technology (and XLR connectors' idiosyncracies are just as much a 'technology' as USB cables, optical audio, vinyl record RIAA spectrum shapers and all the rest), I seem always to come around to one unshakeable principle: it is really hard to debug things that are not working, if one is unclear on the principles that were used in the design of “the thing” to begin with.

Again, as before, I wish you good luck.
With all the talking and writing and so on we have done,
… by now you could have TRIED IT OUT.
So, break out your soldering iron, and get to it!

⋅-=≡ GoatGuy ✓ ≡=-⋅
 
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