Yamaha CS-15 -1979    Weight = ? Lbs. Number mfg.= ? MRP=$835


User Manual: Yamaha
Reset Proceedures: N/A
Operating System code: N/A
MIDI or other control protocol: N/A
Software related Links: N/A
Patches or knob settings:
Circuit Overview: below
Scematics/Service Manual: fdiskc archive or Manual Manor
Common Service Issues/Tips: below
Parts Sources: Keys knobs semiconductors misc
Uncommon chips/modules used:M51620P/IG00150 lfo chip, M51621L/IG00151 VCA's, IG00153 VCO, IG00156 VCF, YM24800 key assignermux/demux, lots of TC series chips.
Modifications:"DX" Mod!
General Info Links: Vintage Synth Explorer

Circuit Overview:
     A dual oscillator subtractive analog synth similar in many ways to other CS series.

Service Tips:
     Typical problems in CS series are power supply over voltages which blow tantalum capacitors and they short, or the caps just fail over the years. During this various chips may be taken out. I've seen LFO chip, VCA's and dac comparator fail so they might be most susceptable.

Parts:
The knobs for these are a black knob w/white pointer tht I think I have similar ones to if not same. The sliders I don't think I have the same thing for these. Several failures of YM24800 keyer chip have been reported over the years and Mail Dean at Five Star to get on his list because he has successfully created a retro board to replace these impossible to find chips! I believe I should have any electronic part (except assigner) or keys for these save exact transformer, etc. Ask if you have need.
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