Hi Ryan,

The LM358 will require a pulldown resistor on its output, otherwise it
runs class B and will distort real bad.

Also you will need to get the bases of your transistors a little further
than 2 diodes apart. Put a third diode in there, and it should sound
great but use too much current. Make that third diode a Schottky and you
should be golden.

Cheerful regards, Bob=20

On Tue, Mar 17, 2015, at 09:36 PM, Ryan O'Connor wrote:
> Hi guys, I've bread-boarded the following circuit, but its not playing
> audio. I get only DC current at the base of the 2N4401. I've had it
> playing audio briefly while screwing around. For example if I remove
> the 0.01uF cap from the non-inverting input of the left-most opamp and
> plug it back in, I hear a distorted version of the song I am playing
> as input for about half a second (actually the cap value is polar
> 47uF). Then silence, DC voltage. Could it be because I am using
> electrolytics for these two caps? I can't find any "103" bipolar lying
> around, or even close to it. I tried a 0.47uF bipolar but I only hear
> about 0.05 seconds of audio when I plug/unplug that one. Have double
> checked all the wiring twice.
>=20
> Circuit below:
>=20
> http://www.techlib.com/electronics/graphics/audioa14.gif
>=20
> Cheers,
> Ryan

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