Re: Help Needed to Identify Sound Option

[supertimer@aol.com (Supertimer)]

Alan Tuttle <news001@macgeek.org> wrote:

>I have two of these guys, so I'd like to find out what they are.
>
>It's a 1.5" by 2" printed circuit board with a mounting bracket for the
>Apple IIgs backplane. It has two cables. One of the cables connect to
>the audio port that's located at the front of the IIgs (7 pins). The
>second cable plugs into the fan connector on the back of the machine (2
>pins). And, it has the audio and fan connectors on the circuit board so
>probably you can plug a fan or a Sonic Blaster into it.
>
>The IC chip has the inscription "CA 324E", "H 9036", and an "H" which
>looks very much like the Honda logo. On the solder side, it says "1988
>Roger Wagner Publishing, Inc." and "FCC ID: HYORWIIGS"
>
>Thank you for any info you could provide!

Hello.  That's a sound digitizing pre-amp card.  It amplifies the audio
input (from an audio source such as a mic or a cassette recorder or
a CD player) to the levels needed by the Analog to Digital Converter
(ADC) on the IIGS motherboard.  The pre-amp gets power from the
fan connector and outputs the pre-amplfied audio signal to the
motherboard Ensoniq connector.

You'll get the cleanest recording if you choose 26.32kHz (or a
multiple or half of it) because that's the frequency the power supply
operates at.  By synching digitization with this frequency, you
virtually eliminate interference.