I feel like I'm talking to myself here...
Anyhow, I went shopping for supplies today. It's one of those things where I figure probably shouldn't have (and saved my money for buying an actual working amp), but sometimes I just gotta see if my wacky ideas work right?
So thus, proof of concept: (it's ugly, I know)
Using method 2:
to generate G*: opamp LT1352, input resistors 390 and feedback 150 (I also tried it with 39 and 810 as well just to see what happens)
to generate L*/R*: opamps AD8352, resistors and feedback 390
also ran G* through another AD8352 (resistors 390) to invert it again
power was supplied by 3 AA batteries (measured about 4.8V)
Results: well... it works, but it's not pretty right now. It works mechanically (uh, electrically?) but I've got static/buzzing and crosstalk pushing through which is disrupting things. I've also got the physical limitation of cheap parts. The breadboard is kinda spotty at times (especially the power rails) and I got a big box of cheap resistors that are 5% tolerance, so the matching is rather poor. Plus outside EM interference (heck, I can pick up radio signals if I listen closely). I'm guessing there's a bit of time delay/phase shift too, which means some of the signals don't quite perfectly cancel when they're supposed to.
I also compared connecting the headphones to G* vs original G. Connected to G, my channels were mixed (as expected). Connecting to G*, they were "normal" except for the static.
But what do you guys think? Is this worth pursuing? I'm really at the limits of my knowhow right now. I'm sure capacitors somewhere would help, or fitting it all onto a protoboard and reduce the clutter, or increase the resistors?
What happens when I tap an output multiple times? Does the signal decrease or does it stay the same? (I assumed that tapping voltage signals doesn't affect the signal strength, only current, which I *think* isn't a concern if we keep everything small enough)
Edited by Armaegis - 1/5/11 at 8:49pm