Yamaha CS15D

Yamaha CS15D

Yamaha CS15D dual channel synthesizer

The CS15D was released in 1979. It has two independent channels, each having its own preset selectors and inputs/outputs for cv/gate control. There are two audio outputs which are normalled to the channel one output. If this output is used as mix out, the crossfader blends between the two channels. If channel two output is used, each channel is put out at its respective jack.
Channel two features a manual control. If selected, one can shape the sound with the controls on the right side of the panel. Limited as they may seem they reveal the potential of the synth. The filter has its own envelope, as opposed to many other synths at the time, where the one and only envelope is shared by filter and amplifier. The two waveforms can be crossfaded, and there´s a separate noise mixer. Modulation is shared by the two channels. There is only one LFO, but it can be routed to either pitch, filter or amp.
What should be mentioned about the filter: On the one hand the filter is not capable of self-oscillation, but on the other hand the low end of the sound is not eliminated by the filter resonance. Most filters make the sound thinner with rising resonance, not this one.
I love my CS15D and will never give it away!

Related posts:

  • CS15D channel 1 modification mainboard

    This is a follow-up to the general modification article.

    In an effort to come up with a more detailed documentation for the mod I made an annotated picture of the mainboard followed by some explanations:

  • CS15D channel 1 modification

    Since I got my CS15D I´ve always known that one day I would make a certain modification to it, and this day has finally come: Manual control for channel 1.

    Mod design

    When I opened the synth the first time I was pretty surprised by what preset meant before the time of (affordable) digital memory! Each preset ...