The instrument
Yamaha offered eight new analog, monophonic synthesizers of the CS series in 1977-1979: CS-5, CS-10, CS-15, CS-20M, CS-30, CS-30L, CS-30D and CS-40M. They follow on from the company's first synthesizers SY-1 and SY-2. The CS devices offer similarities, but have individual components and tonal differences. The CS-15 offers two VCOs, two multimode VCFs, two VCAs, two envelope generators and an LFO, two CS-5s in one device.
Details
The two VCOs offer triangle and sawtooth waves in six foot positions, as well as a square wave that can be adjusted in pulse width (50% - 90%) and modulated by the LFO. Tuning potentiometers can detune VCO 1 by +/- 75 cents and VCO 2 by +850/ -750 cents. The two two-pole VCF multimode filters can be operated either as 12 dB high pass, 6 dB band pass or 12 dB low pass, have cutoff and resonance controls and can be modulated by the LFO and one of the two envelopes. Envelope 1 or 2 can also be selected for both VCAs, whereby the modulation depth is set for both VCAs and supplemented by amplitude modulation with LFO. With the EG section (Envelope Generators), the time values of the attack, decay and release of both ADSR envelopes can be extended fivefold to achieve very slow progressions. The LFO can output a modulation signal from a sine wave, a sawtooth wave or from the sample and hold circuit. There is also portamento, brilliance and a pitch bender. (Source: amazona)