Sound circuits on the 11A and 11B CPU boards
System 11A and 11B CPU boards carry a cut-down sound section: a 68B09E, a 55536 speech chip and an MC1408 DAC. System 11C CPU boards leave this out and the D-11581 sound board does all the sound.
Systems
Related tips
- CPU sound diagnostic switch SW1 results
- How System 11 makes sound
- Which System 11 sound board each game uses
- Using a D-11581 sound board in other System 11 games
- Power-on sound tones and what they mean
- The D-11581 sound board: chips and ROMs
- Constant hum instead of sound: shorted capacitor C26 on the sound board
- Loud constant hum that the volume control does not change
Source: Repairing Williams System 11 Pinball 1986 to 1990, Part Two, Clay Harrell (pinrepair.com)