Hello,
Yes, you can very well control the "bip-blup-555" Gottlieb board from a different source.
This card is very basic, it has three circuit-based oscillators 555, each triggered by the grounding of a pin.
The three frequencies generated (594 Hz, 266 Hz and 153 Hz) are then mixed and amplified by a LM380.
555sounds (resized).jpg
It require a 24 v DC power on pins 9 and 6/7 (GND).
The tones are activated by grounding one (or more) pin : 1, 2 or 3
- Connected to ground = tone
- Not connected = no tone
The board has been designed to replace directly the xylophone coil controls (similar, activated by grounding).