NKOTB - TTVJ/Millett 307A Headphone Amp

[Dreadhead]

In general you will not want to take the XLR outputs and sum them for the RCA unless you attenuate the signal as well since the balanced output on most gear is operating at more than 2x the voltage of the single ended stuff.

I have never heard the argument that trafo coupled should be better than properly designed balanced gear and I'd need a lot more convincing.

Edit:

Wikipedia to the rescue:

Balanced audio - Wikipedia, the free encyclopedia

"Fully balanced internal circuitry has been promoted as yielding 3dB better dynamic range."

From that it appears that fully balanced amps do not need transformer coupling on the inputs to avoid ground loop issues.

[recstar24]

http://www.thatcorp.com/datashts/1200data.pdf

page 8 - pretty simple enough. bypass caps for the + and - power supply rails. a cap between Cm in to Cm out, pin 5 to 8. Who wants to be a pal?

[recstar24]

Originally Posted by Dreadhead

In general you will not want to take the XLR outputs and sum them for the RCA unless you attenuate the signal as well since the balanced output on most gear is operating at more than 2x the voltage of the single ended stuff.

That is the point - I need the extra voltage. That should be plenty for my integrated and my listening needs.

[grawk]

I don't have many details at all, but your description matches my understanding. input 12v dc, +, -, and output a summed signal.

[n_maher]

Originally Posted by recstar24

If anyone wants to take pity on my, and build me a simple opamp, resistor, and DC source in a small hammond box with an xlr input and rca output, I sure would appreciate it

See your other thread, I don't think you want to go introducing another stage to the output of you source.