CS-15 is an analog monophonic synthesizer released by Yamaha in 1977(perhaps, in Japan). The list price was 105000 yen. CS-15 has 2VCOs, 2VCFs, 2VCAs, 2EGs and 1LFO. Cheaper CS-5 and CS-10 have only one oscillator. CS-15 was gorgeous compared with them. There were more expensive CS-30 and CS-30L. They were not in range for synth boys. Competitors are Roland SH-2 and KORG MS-20. CS-15 has 2VCFs and 2VCAs. That was unique. My friend owned CS-15. He played sound effect with noise, one filter and one amp. Simultaneously he played musical notes with 2 oscs, one filter and one amp. It was amazing. In other hand, CS-15 filters were 12dB/Octave often said "dull". No filter oscillation. No delay vibrato.
CS-15 has CV/Gate(Yamaha calls "Trigger") inputs. The CV is Hz/v. Then Yamaha and Korg used Hz/V standard. Other manufacturers adopted Oct/V. Hz/V circuit is simple, so, tuning is stable rather than Oct/V. But we cannot expect wide key range. I own some Kenton's MIDI-CV/Gate converters(Pro Solo, Pro Solo mkII and Pro 2000). I tried Pro Solo with CS-15. The key range is about 3 octaves. Adjusting is not easy.
I tried to use Korg MS-20 Kit as a MIDI-CV/Gate converter for CS-15. It was nice.
No adjusting, wide range(about 5 octaves). Please listen the sample sound below. But, MS-20 Kit converter has no pitch bending, no LFO. It is not easy to say which converter(Kenton or Korg) is nice.
CS-15 has two CV inputs. One is for VCO1, another is for VCO2. 2 gate inputs. One is for EG1、another is for EG2. If you have two CV/Gate sets, you can play two notes with your CS-15. In 1980s, I fed two sets of CV/Gate from Yamaha CS-40M to CS-15. It worked. Now, you may want one CV/Gate to control whole CS-15 modules. You should use two Y-cables like the photo below.
| Sound | Comment |
|---|---|
| Triangle HPF Lead | One of CS-15 uniqueness is that VCO, VCF and VCA have independent "LFO MOD" knobs. Vibrato, growl and tremolo can be added with own depth. Nice shaking. |
| CS-15 played by MS-20 Kit CV/GATE | KORG MS-20 Kit has Hz/V MIDI-CV/Gate conterter. It matches well to CS-15. But no pitch bending, no modulation and no portamento. If you want them, try Kenton's converters. |
| Triangle Solo | CS-15 is commented "Electone sound". In 1980s, the comment damaged CS-15. But now, analog Electones do not exist. I love CS-15's beautiful and gentle tones. I miss my old Electone D-30. |