The Tuber Synthesizer is a valve, subtractive, monophonic, semi-modular synthesizer. It uses a Phantastron based voltage controlled oscillator and a four valve Sallen-Key voltage controlled filter.
The modular system allows for modules to be rearranged along the signal path, but without the need for patch cables. The current system has a keyboard controller, two Phantastron oscillators, a noise and percussion generator, two envelope generators, a 12dB voltage controlled Sallen-Key filter and a voltage controlled amplifier. A third oscillator will be built in the future.
The diagram below describes how the modules interact on the backplane. Each module either adds to the audio signal (such as the oscillators) or intercepts it and changes it (filter, amplifier). The same applies to the control busses. A signal may be replaced with another along the bus. Any signal that is unused by a module is passed through.
