Yamaha CS15D SN 1784

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"The CS15D is two synths in one, with separate controls for each (including two sets of cv & gate and two audio outputs) but with the ability to mix, blend and modulate the two together. This gives loads of possibility for creative programming.

The 'preset' section is made up of two channels. Channel 1 has 15 funky 'instrument' sounds and Channel 2 has 14 'synth' sounds plus a button to activate the 'manual' section of the synth. There is a slider to mix between the two channels and channel 2 can be detuned.


The Preset synth has controls for the VCA envelope via the Sustain knob and the Brilliance slider gives you control of the filter. You can also apply the lfo via the modwheel to either the VCO, VCA or VCF of the preset sounds. These controls gives you scope for some big tonal changes.

The separate manual synth section has variable control between saw and pulse waves for its VCO, which can be mixed together. There are also controls for pulse width modulation, noise, tuning and 5 octave settings. You get two punchy ADSR envelopes for the filter and the VCA. The beefy filter is a 2 pole lowpass, with full controls over resonance and cut off and envelop depth.

The mod wheel can also be applied to the manual synth section, as can the Brilliance slider.

The LFO has a number of waveforms including sample & hold and repeat and goes up to audible level, which is great for ringmod style and other weird effects.

Where it gets really interesting is the ability to mix the two synths (channel 1 & 2) together via the mixer slider. Then, this two vco synth really comes into its own, with some rich and complex tonal possibilities."