[qusp]

yes youre right, though implied, I missed one word there Steve, symmetrical, but well you know I was set on using the words that were used to say it wasnt balanced

 

[Chris J]

Quote:

 
in simplest terms
this^

 
Yep, thanks, Bob's yer uncle.
 
Quote:

 
hahaha, you are right, the odd person actually does say that down here, but around here only for comedy.
 
yep all 3 amps i'm using at the moment are lowZ, the lowest 12.5 mOhms and the highest ~30 mOhms. I think you would agree doubling that is of no consequence. I use multidriver IEMs a lot and they thrive on these amps

 
30 mOhms!
Good grief, man!
Ridiculously high!
Sell it!

 

[Chris J]

Quote:

Ok, simply put, balanced means equal impedances with respect to a reference point which is typically, but not always, ground.
 
The voice coils in a loudspeaker or headphone driver are typically symmetrical which makes them inherently balanced. Same with the windings on an audio transformer for example. The reference is the center of the winding. It doesn't matter if there's not a physical center tap to force balance. If the windings are symmetrical, it's balanced. Period.
 
se

sounds like one of your weird se definitions
may as well say a resistor or an inductor is balanced.

 

[Steve Eddy]

Quote:

sounds like one of your weird se definitions
may as well say a resistor or an inductor is balanced.

 
No. That's what "balanced" has meant in terms of audio interfaces and signal transmission for over a century. It's what makes balanced interfaces work with regard to common-mode rejection which is its whole raison d'etre. Any imbalance in impedances leads to a reduction in common-mode rejection.
 
It's the so-called "high end" audio industry that's come up with its own "weird" definitions. Many don't understand just how balanced interfaces work, which is why you'll see such follies as "balanced" gear with two completely separate signal paths per channel from input to output.
 
se

 

[qusp]

Quote:

 
Yep, thanks, Bob's yer uncle.
 
 
30 mOhms!
Good grief, man!
Ridiculously high!
Sell it!

indeed what was I thinking? that last 15-20mOhms makes the difference between heaven and complete poop lol. thats the balanced one BTW. also the circlotron, which is discrete power jfet has quite massive damping factor too, though I dont know exactly how high. playing with an F3 headamp along with the F5 and possibly F6 all P2P at the moment for as bit of flavor with HD600

 

[Chris J]

Quote:

 
No. That's what "balanced" has meant in terms of audio interfaces and signal transmission for over a century. It's what makes balanced interfaces work with regard to common-mode rejection which is its whole raison d'etre. Any imbalance in impedances leads to a reduction in common-mode rejection.
 
It's the so-called "high end" audio industry that's come up with its own "weird" definitions. Many don't understand just how balanced interfaces work, which is why you'll see such follies as "balanced" gear with two completely separate signal paths per channel from input to output.
 
se

 
It seems that you are confusing a symmetrical device with a balanced device and are stretching the definition.
An example of a balanced device may be a transformer with a centre tap on the secondary. Obviously you could use it to create a balanced signal from an SE signal. 
Then you would use this to drive a balanced cable i.e. a cable with two conductors, both conductors having the same impedance WRT to each other and the same impedance to common point (usually ground).   
 
It makes no difference to a headphone or a speaker whether it is driven balanced or SE as the headphone or loudspeaker will not reject common mode noise if it is driven with a balanced signal.
A loudspeaker is not a differential receiver.
 
A transformer may be symmetrical, but this will not make it reject CM noise. 
 
Judging by your tone there is no further point to arguing with you so.......I. AM. OUT.
 
thx, Chris

 

[Steve Eddy]

Quote:

 
It seems that you are confusing a symmetrical device with a balanced device and are stretching the definition.

 
No, I'm not.
 
Quote:

An example of a balanced device may be a transformer with a centre tap on the secondary. Obviously you could use it to create a balanced signal from an SE signal.

 
There's absolutely no requirement for a center tap on the secondary in order for it to be balanced and to produce a balanced output from an unbalanced source. This is done routinely using transformers. Without center taps.
 
Quote:

It makes no difference to a headphone or a speaker whether it is driven balanced or SE as the headphone or loudspeaker will not reject common mode noise if it is driven with a balanced signal.

 
Yes, they will.
 
Quote:

A loudspeaker is not a differential receiver.

 
A loudspeaker driver is indeed a differential receiver, just as a balanced primary on a transformer is a differential receiver. Both will only pass the difference between its two terminals.
 
Quote:

A transformer may be symmetrical, but this will not make it reject CM noise.

 
Yes, it will. In fact that's precisely what makes transformers so good at rejecting common-mode noise, their extremely high common-mode input impedance.
 
Think for a moment.
 
Both dynamic loudspeaker/headphone drivers and transformers require current to operate. In the loudspeaker/headphone driver, it's the current through the voice coil which produces the varying magnetic field that interacts with the fixed magnetic field of the driver's fixed magnet motor system to move the driver/diaphragm back and forth. In a transformer, it's the current flowing through the primary windings which produces the magnetic field that couples to the transformer's core and from the core to the secondary winding inducing a voltage across the secondary.
 
Apply a voltage of the same magnitude and polarity to each of the driver's or transformer's two terminals, as is the case with common-mode noise.
 
How do you end up with any current flowing?
 
The differential voltage across the two terminals is 1 - 1 = 0. No voltage, no current. No current, no output.
 
Quote:

Judging by your tone there is no further point to arguing with you so.......I. AM. OUT.

 
So instead of trying to learn something, you're just going to stomp off mad?
 
Your choice.
 
se

 

[qusp]

balanced audio is only referenced to ground/reference through the power supply (and not even always), what would the signal do with a center tap? what would even be present on the center tap if fed a symmetrical signal?
 
Chris mate, Steve isnt being combative here, I know what that looks like =) where else would common mode cancellation from the amp output happen, other than the loudspeaker?

 

[maxmays1]

Quote:

balanced audio is only referenced to ground/reference through the power supply (and not even always)....
 

are you referring to "ground" as being the negative signal or ground as ground to neutral? 

 

[Chris J]

Quote:

are you referring to "ground" as being the negative signal or ground as ground to neutral? 

 
Ground as in "Ground to Neutral".
In typical residential, the ground which is tied to earth.
Assuming your equipment is grounded, of course, i.e. the AC power cord has the third pin:  the ground pin.
 
Or in mobile audio, the ground is tied to the frame.
 
The "negative signal" is actually an Inverted Signal: 180 degrees out of phase with the "positive signal" which is really the Non-Inverted signal.

 

[maxmays1]

I'm aware. some people just refer as the negative signal as ground. and since there is this ambiguous argument of what balances really is i thought i'd clarify.

 

[Chris J]

Quote:

I'm aware. some people just refer as the negative signal as ground. and since there is this ambiguous argument of what balances really is i thought i'd clarify.

 
ooops.
Then I shall weasel out of this by saying that I post my comments not just for myself, but for the good of all mankind, sort of like Thor, or Captain America or Iron Man or Batman.   Or Wonder Woman.

 

[Steve Eddy]

Quote:

 
Ground as in "Ground to Neutral".
In typical residential, the ground which is tied to earth.
Assuming your equipment is grounded, of course, i.e. the AC power cord has the third pin:  the ground pin.
 

 
Just to clarify a few things.
 
First, a rod stuck in the dirt (i.e. earth ground) has absolutely no relevance whatsoever to an audio system with respect go "ground." The rod stuck in the dirt is only there for lightning protection.
 
Second, the third pin on the AC power cord also has absolutely no relevance whatsoever to an audio system with respect to "ground" other than being the leading cause of ground loop problems.
 
The third pin is there purely for safety purposes. It's tied to neutral back at the service panel and provides a return path for fault currents in the event that a failure should cause AC hot to contact the equipment chassis. This prevents you from being the return path and getting electrocuted. Sadly, it's not terribly difficult to design equipment chassis to meet Class II specs (i.e. "double insulated") in which case the third pin is not required. However these things get slapped onto everything, even equipment which does meet Class II specs. For some reason, people have come to believe that equipment with a 3 pin IEC 320 receptacle on the back is a sign of "quality." But as I said previously, outside of safety purposes, all it does is create ground loop problems.
 
The only "ground" that is relevant is the equipment's own internal ground.
 
se

 

[mikeaj]

Too bad "ground" is such an entrenched part of the terminology.  Maybe we'd be better off if everybody just called it something else in situations where earth ground is not meant, like the 0-reference.

 

[Steve Eddy]

Amen!
 
se