tech : asteroids sound question

hi all..

i am having a most troublesome time with an asteroids board..

here is the problem, my mate has an alca 'planet' machine (bootleg
asteroids) but is using a proper atari asteroids board. after fixing a video
problem, and a sound problem, the board works perfectly on my testrig. The
cabinet however has no audio/regulator board, so there is no audio amp..

so we have tried to put in an amplifier, but i have a problem, asteroids
outputs a push-pull audio arrangement, and the amplifier we have is just a
(normal?) type, so any way we try and hook it up, we just get a loud hum
behind the game sounds.

analogue electronics is not my strong point :)

i am hooking up GND and Audio1 from asteroids into the amplifier.

a friend suggested to put a 1000uf cap across the amplifier inputs in order
to 'cap couple' it? it didn't work, made the humming much more quiet, but
hasn't solved it :)

i'm getting lost, has anybody else succesfully hooked up audio from an
asteroids *without* the aid of an AR1 or AR2??

i suppose the only other solution is to build a push-pull amplifier for it,
but that's a last resort..

many thanks.

Andy Welburn
(P-man)

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Received on Fri Mar 16 09:09:26 2001