Msg: 2754 *Conference*
06-16-92 02:53:03
From: DAVID FIRTH
To : DREW BLANCHAR
Subj: REPLY TO MSG #2731 (ACOUSTIC COUPLER)
Thanks. I forgot that M100 owners are well versed in some computer techniques that my PC-only buddies consider to be a lost art (especially those who grew up in the cheap RAM, big disk era). No offense intended, of course. I now have the pin-out and the circuit diagram from the Inside the M100 book. The circuit shows the mic taking power from the M100 via a resistor in the coupler. The author was less specific about the amplifier. He shows op amps, but doesn't specify type. I plan to use a low power audio amp chip (LM386) in the first rendition of the design. I plan to determine the necessary gain by tweaking the circuit while viewing the output on an o'scope.