Alesis QS4 Quadrasynth -1993 ("Plus" version 1995)(

User Manual: Alesis
Reset Proceedures: N/A
Operating System code:
MIDI or other control protocol: See Manual
Software related Links: QS pages
Patches or knob settings: QS pages
Circuit Overview: below
Scematics/Service Manual:
Common Service Issues/Tips: below
Parts Sources: Keys knobs semiconductors misc
Uncommon chips/modules used: Many
General Info Links: QS Pages or QS Pages for the QS Plus version

Circuit Overview:
     VLSI based digital synth that was a breakthrough in voice/dollar value. 64 voice polyphony and some interesting modulation options. 76 key keyboard. S4 module has same architecture.

Service Tips:
      Always verify power supply voltages if problem looks like it could remotely be power supply related. I have seen some bad solder problems and one intermittent processor reset problem that required a new board in an Alesis product. If you must reset these this is all I've seen:

HOLD DATA BUTTONS '1' and '4' while powering on (Clears edit buffer only. there is no hard reset)

Advanced Musical Electronics has a lot of parts for Alesis stuff. THey only deal with techs though.
I've also seen All electronics carry displays occasionally at low prices. Always feel free to ask or check my Parts
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