----------------------------------------------------------------- | ATARI/NAMCO ASSAULT STEREO SPEAKER HOOKUP | ----------------------------------------------------------------- COPYRIGHT 2001 REVISION NUMBER: 1.0 REVISION DATE: 8 August 2001 CREATED BY: Tom McClintock STANDARD DISCLAIMER: -------------------- REMEMBER, NO WARRANTEES, EXPRESS OR IMPLIED, ARE GIVEN. USE THIS INFORMATION AT YOUR OWN RISK. I AM NOT RESPONSIBLE FOR ANY DAMAGES THAT MAY OCCUR TO YOUR PERSON OR PROPERTY. GENERAL OVERVIEW: ----------------- The NAMCO System 2 Assault board has a standard JAMMA connector, which allows for one channel of audio (MONO). However, the Assault game code produces STEREO sound. The NAMCO engineers were nice enough to provide an additional output for the second channel (as well has headphone outputs among other things). INGREDIENTS: ------------ 1 - Working NAMCO System 2 Assault PCB 1 - 8 Ohm speaker 1 - 48-pin edge connector PROCEDURE: ---------- Near the audio amp on the PCB you will find a set of jumpers marked "JP1". Make sure the shorting block is in the STEREO position, not the MONO. From the factory, the Assault PCB outputs the left channel audio stream on the JAMMA edge connector. Pin 10 is the left channel "+" and pin L is the left channel "-". Next to the JAMMA connector there is an unused .10" spaced 48-pin connector. Pin A1 is the right channel "+", and pin B1 is the right channel "-". The connector is clearly marked so you can't miss it. Now all you need to do is route the right channel audio off the board to your new speaker! The 48-pin connector is notched and I wold highly suggest installing a plug in your edge connector to ensure you can only insert it one way. Once you've wired up the new speakers connections, you can test the left and right orientation with the game's test mode. Play the FM sound #20 as it will play a sound on left and then the right channel. Note that the volume control knob behind the coin door only affects the (original) mono speaker. You can install an additional volume control in-line with the new speaker to control its volume. TROUBLESHOOTING: ---------------- - Watch the speaker phasing, i.e., make sure the speakers are wired identically: "+" going to "+" on the speakers, connectors, PCBs and so on. This will keep the speakers in phase, and give you the maximum bass response. - Never connect any part of a speaker system to ground - even through another speaker. Audio amps don't like it very much! There should always be outputs marked "+" and "-" for the speakers. --------------------------------------------------------------------- | END | ---------------------------------------------------------------------