Unbalanced and Balanced Clarification

[Speedskater]

Well no.
A balanced interconnect system is a 2 wire system.
XLR pin#
2 is normal.
3 is invert.
1 is shield
The shield may or may not be connected at the receive end. Now we are seeing more unshielded Cat5/6 used in balanced interconnects.

 

[pinnahertz]

Balance transmition use 3 wires : 1 hot (normal), 1 cold (invert), 1 ground.

Balanced transmission uses 2 wires. The shield is grounded, but not part of the signal circuit, and in many cases not present at all.

Typical jack is XLR3 in which pin 1 is ground, 2 is normal, 3 is invert.

For output 2 channels XLR4 is use, pin 1 is L-, 2 is L+, 3 is R+ and 4 is R-
Base on that you can diy any interconnect cable balance or unbalance. Ex 6.3mm TRS to XLR4 or 2.5 ttrs to dual XLR3

There are a few others you can't do too, like some XLR3 outputs to unbalanced require pin 3 grounded (transformer outputs) while others specifically won't work well that way (active differential outputs).

 

[TYATYA]

Balanced transmission uses 2 wires. The shield is grounded, but not part of the signal circuit, and in many cases not present at all.


There are a few others you can't do too, like some XLR3 outputs to unbalanced require pin 3 grounded (transformer outputs) while others specifically won't work well that way (active differential outputs).

I did diy cable for my demand, I known some case but dont know other case.
2.5 trrs balance (for A&K) to dual XLR3 balance, no grounded works okay signals, but when stop playing can heard AC noise (just play even near zero volume of source, no noise any more). 6.3 TRS unbalance to xlr4 unbalance, rewire hp to be balance...
Each company has their pin map so one cable using ok on this device can not work correctly w/ other device may be their pupose to sale accessories

 

[Speedskater]

How could a TRRS have 2 balanced channels?

 

[pinnahertz]

How could a TRRS have 2 balanced channels?

Not sure....S used for signal and no ground?

But noise on the A&K with balanced and no shield had nothing to do with the lack of a shield.

 

[Speedskater]

Not sure....S used for signal and no ground?
.............................................

That's possible. Do any manufactures wire them that way?

 

[pinnahertz]

That's possible. Do any manufactures wire them that way?

Seems unlikely. But then, the whole idea of balanced headphone wiring and driving seems unlikely. And they do that anyway, so....

 

[Speedskater]

Well headphones never need a shield connection, so a TRRS would work for balanced headphones.

* * * * * * * * * * * *
We seem to move back and forth from interconnect to headphone cables.

 

[castleofargh]

yeah the problem here is probably about how freely the consumer audio world uses the term "balanced". I've had a portable "balanced" amps that didn't even have balanced input. and it was indeed a simple 4 pins on the output.

 

[pinnahertz]

Well headphones never need a shield connection, so a TRRS would work for balanced headphones.

* * * * * * * * * * * *
We seem to move back and forth from interconnect to headphone cables.

Yes, well as you say, headphones don't need s shield. It just seems a study in non-standards. For interconnects at least there are some conventions and standards as to wiring and connectors, even if the actual circuits connected don't match the definition of what balanced means.

I think the term "balanced" is a marketing warm-fuzzy. Positive connotations, good feelings, if it's good for tires and diets then it has to be good for audio too. "Unbalanced" just sounds wrong.

That's why we have "single-ended".

 

[TYATYA]

How could a TRRS have 2 balanced channels?

TRRS is configuring differently depending in manufacturers. For Astell $Kern it is R+R-L+L- in order TRRS.
For hp, no need ground or shielding.
For amp connecting, it also work no shield but if stop playing can heard AC noise (multiple of and incl 50/60Hz) if charging the dap which is playing.
For AK, ground by 3.5 trs jack.

 

[pinnahertz]

TRRS is configuring differently depending in manufacturers. For Astell $Kern it is R+R-L+L- in order TRRS.

That's the non-standard part that makes TTRS a situation-specific and non-universal solution.
For hp, no need ground or shielding.

For amp connecting, it also work no shield but if stop playing can heard AC noise (multiple of and incl 50/60Hz) if charging the dap which is playing.

...which means that balanced input has failed as a balanced input in the one aspect that makes balanced connections an advantage: common-mode noise rejection.

 

[TYATYA]

That's the non-standard part that makes TTRS a situation-specific and non-universal solution.
(1)

For hp, no need ground or shielding.
...which means that balanced input has failed as a balanced input in the one aspect that makes balanced connections an advantage: common-mode noise rejection.
(2)

(1) yes
(2) no. Just try playing a silence track to make clear. I did. No AC noise transfer to hp, at max gain.
IMO, when stop, balancing transmittion none active (dont know how) that is why AC noise happen. AC noise is gained by the amp during stop/pause because it goes other way. I think so.
Quality is no different when ground or not when playing, as I can heard

 

[pinnahertz]

(1) yes
(2) no. Just try playing a silence track to make clear. I did. No AC noise transfer to hp, at max gain.
IMO, when stop, balancing transmittion none active (dont know how) that is why AC noise happen. AC noise is gained by the amp during stop/pause because it goes other way. I think so.
Quality is no different when ground or not when playing, as I can heard

Your observations do not eliminate the failure of the balanced input to reject common mode noise. If you connected the amp to the same device but unbalanced, do you have the same problem?

 

[TYATYA]

Your observations do not eliminate the failure of the balanced input to reject common mode noise. If you connected the amp to the same device but unbalanced, do you have the same problem?

Oh nice question. But how can I transfer in rca (unbalance mode) w/o grounding?
Ofcouse unbalance mode did face that problem, bcs it has grounded wire.
Edit : I think balance mode is term of eliminate signal noise comes from out side environment, acts to the line.
AC noise in my post was from the charger.