H-Pi Instruments has anounced that it’s now shipping the microtonal Tonal Plexus keyboard, in two and four octave versions, with and without a built-in General MIDI synthesizer option. Tonal Plexus keyboards feature 211 keys per octave, 32 user programmable tuning tables, and a default master tuning based on the limits of human pitch perception.

You can preview the Tonal Plexus in action below.

The smaller keyboards also feature octave transposing buttons, allowing realtime full navigation of 8 octaves of each tuning table with sustain pedal support. DIP switch settings allow for a global pitch-bend mode in which the modulation control affects the global pitch in the same way as a standard pitch bend control, allowing global control of gliding pitches.

A velocity bandwidth feature allows the non-velocity sensing keys to produce natural sounding output by varying the key velocity with a choice of three bandwidths as specified by the user. Fully compatible with GM equipment, each Tonal Plexus keyboard can be used to control external synthesizers, for full pitch control of favorite synth sounds on existing gear.

The synthesizer option includes a 22-watt stereo amplifier with speakers, and hardware control of synthesis waveform envelope attack, decay and release, as well as a 3-band equalizer, panning, volume, modulation, and key velocity.