Push-Pull Amps

[el mo]

well, the gimmick is that, as far as i know, you can't bridge two amps that have partial current
feedback implemented. so i was wondering if it could work like this.( the obvious method would be paralleling them, i guess )

[joecool85]

You can parallel or bridge LM3886 chips, it just depends on what ohm speaker you want to run.

[SECONDandBOWERY]

Running the input into one op-amp's + inupt and to the other op-amp's - input will put the signals out of phase, correct?

Rock'n'Roll,
--Andy

[el mo]

Running the input into one op-amp's + inupt and to the other op-amp's - input will put the signals out of phase, correct?

-basically  yes, but the op-amp needs to be biased slightly differently, depending on whether the+ or -input is used. so the regular approach is to use a phase-inverter to make the
actual halves of the bridge as identical as possible.

[SECONDandBOWERY]

Oh, ok.  I'm just going out of the .pdf file that teemuk posted.

Rock'n'Roll,
--Andy

[SECONDandBOWERY]

Will the schematic I've posted along with this post work as a unity gain phase inverter?  Would I ever need to apply power to the dual opamp, or since it's unity gain, could I just use it as a passive phase inveter?

Sorry if those are stupid questions, I guess i just got used to seeing 12AX7 long tailed phase inverters in tube amps that when I think "phase inveter", that's the only thing that pops into my head!  :duh

Rock'n'Roll,
--Andy

[el mo]

yes, i guess it would have to work, although you could omit the noninverting system- it doesn't amplify anything and the phase is the same as at the input.
you need to suplly power to the opamp though, ptherwise it won't do a thing.

[el mo]

there may still be some merit to using a dual opamp, under certain circumstances, for example if you decided that you wanted an arrangement similar to the PI of a tube amp in order to reproduce certain characteristics like voicing etc.