3 ms·
Since you have two channels that source current (L and R) it makes sense to have two parallel op-amps for the GND pin to have the same slew rate & maximum curre
by ThePhysicist 8y ago
Since you have two channels that source current (L and R) it makes sense to have two parallel op-amps for the GND pin to have the same slew rate & maximum current, as both L and R channels return current through the GND line (I would assume).
- mannykannot 8y agoI am curious as to why it needs any circuitry on the ground line - would a direct connection not work? (I guess I am assuming that L, R and ground are the only connections made to the headphones.) Do the amplifiers put a DC bias on the L and R outputs that needs to be matched on the ground, and if so, would a capacitor in series with the L and R outputs not be enough to isolate it?
- megous 8y agoYou could just use the middle connection between the two batteries as a ground. I'm not sure why he didn't do it. Perhaps so that the whole thing works longer even if one of the batteries is discharged faster. That would be my guess.
- mannykannot 8y agoAs it stands, 40% of its 23mA current draw is through the 1kΩ x 2 voltage divider... Now I am wondering if a circuit with the between-battery link connected to ground would risk damaging the op amps (or phones) if only one battery was in?