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Help With Mockingboard Amplification



Hi Guys,

I decided to add the LM386 amplifiers to my Mockingboard that I posted
about a few weeks ago. Prior to adding the amplification, the board
was working fine with powered speakers. This might be another case of
"if it aint broke, don't fix it", but I wanted to hear the difference
the amplifiers would make, and I had already bought them as well, so
the temptation was too strong.  ;-)

I completed the amplifier add-on and have got it working as such, but
with *heaps* of bus noise being output. I can play music, and I know
the amplifiers are obviously working as the sound is loud even on un-
powered speakers. The trouble is, as soon as I turn on the Apple II, I
can hear fairly loud bus noise.

Now I've used the circuit as described in the AY-3-8910 data manual
which can be seen here:
http://apple2.sytes.net/Mockingboard/images/AY-3-8910_Interfacing.jpg