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Anyone use XLR to RCA interconnects? - Page 2

post #16 of 26
1/11/10 at 7:09pm
Quote:
Originally Posted by linuxworks View Post
I don't follow this; can you explain?

what about electro. drivers 'need' balanced drive? why can't they be driven by 2 SE ground-floating amp sections?
Every single electrostatic driver in existance needs balance drive. In the case you've outlined, there wouldn't be a way to supply the high voltage bias to enable the driver to function.

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post #17 of 26
1/11/10 at 7:12pm
Quote:
Originally Posted by linuxworks View Post
what about electro. drivers 'need' balanced drive?
The animation on this page says it better than I ever could: Electrostatic - Wikiphonia

You absolutely have to have balanced drive to make it work.

Quote:
why can't they be driven by 2 SE ground-floating amp sections?
Electrostatics are an entirely different load. To my understanding they are far more capacitative than dynamics, run close to no current (technically it is an open circuit), yet require hundreds of volts swing. In addition to the inherent need for balanced drive, dynamic amp designs are completely inappropriate.

[EDIT] Gah, beaten!
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post #18 of 26
1/11/10 at 7:16pm
I knew about high voltage needed but I was not aware that they need 3 wires per element. is that what I'm seeing in that diagram? truly 3 wires per element??
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post #19 of 26
1/11/10 at 7:17pm
Quote:
Originally Posted by linuxworks View Post
I knew about high voltage needed but I was not aware that they need 3 wires per element. is that what I'm seeing in that diagram? truly 3 wires per element??
yes, pinch yourself it's true! long live balanced! burn the SE ranters!

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post #20 of 26
1/11/10 at 7:21pm
Quote:
Originally Posted by linuxworks View Post
I knew about high voltage needed but I was not aware that they need 3 wires per element. is that what I'm seeing in that diagram? truly 3 wires per element??
Yes, a high voltage bias is applied to the diaphragm (230V for old Stax, 580V for modern day Stax, 620V for Koss ESP950, amongst many other options) then balanced drive for the two stators.

And it is more than 'just' the high voltage. Even if you could somehow make a B22 swing 1000V, it just would not be suitable to drive the phones directly.
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post #21 of 26
1/11/10 at 7:34pm
that pic really clears it up (lol).

I used to have electret headphones but never had any 'statics. my ATH6 electret needed step-up trafo box but it was not active/powered and I don't remember seeing 3 wires per element. so I was thinking that the 'static was not too different but I guess it really is..

btw, balanced does not need 3 wires, so that was another area of confusion. you can run balanced over 2 wire (implying a ground reference; phone POTS wires are like this, in fact) but it clearly looks like the statics need all 3 wires and not just 2. very interesting.
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post #22 of 26
1/11/10 at 7:42pm
Quote:
Originally Posted by linuxworks View Post
btw, balanced does not need 3 wires, so that was another area of confusion. you can run balanced over 2 wire
Conversely, just because you have three pins doesn't mean you need to use them. Lots of XLR applications float pin 1...

For extra credit, anyone know how to do true balanced on any 3 pin connector without any rewiring of the headphone?
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post #23 of 26
1/12/10 at 3:07am
Thread Starter 
I wonder if I can disassemble those monoprice cables to make sure they're wired correctly? Might be a simple task of just breaking the pin 3 connection to make sure it doesn't short to ground. Anyone ever try that?
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post #24 of 26
1/12/10 at 4:13am
Quote:
Originally Posted by luvdunhill View Post
For extra credit, anyone know how to do true balanced on any 3 pin connector without any rewiring of the headphone?
Yes. Two ways in fact. But maybe you don't want me to spoil it so I'll keep quiet for now.

se
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post #25 of 26
1/12/10 at 1:17pm
Quote:
Originally Posted by Koyaan I. Sqatsi View Post
Yes. Two ways in fact. But maybe you don't want me to spoil it so I'll keep quiet for now.

se
Feel free to spoil things, perhaps it deserves its own thread even. I'm not interested in taking the heat from the fanboys on this one. It's the headphone audio equivalent of a Copernican revolution
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post #26 of 26
1/12/10 at 2:25pm
Linux, sorry for blowing up
Quote:
Originally Posted by luvdunhill View Post
For extra credit, anyone know how to do true balanced on any 3 pin connector without any rewiring of the headphone?
I can also think of a couple ways that *may* work.

The first would be to build your standard differential amplifier with an output transformer (Push-Pull or depending on your mood & methods bridged). Hey-o the actual amplification stages are actually balanced, and you get the characteristic distortions & PSRR from that (I know, I know why not build a better amp to start... this amp was designed to be differential from the start anyone who wants is welcome to build a better differential amp). Ground the secondaries for safety and tie them together.

Plan B would be to use whatever gain stage you like with an OPT. FLOAT the secondaries on the OPT. *DO NOT* ground them. Assuming that "losses to ground" define the balance CMRR through 6ft of cable into your 32ohm headphones should be acceptably high.

Was the goal of balanced amplification good CMRR between a power amp and a low impedance load with no gain, or some hope of reduced distortion through better design of active stages?
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