The Dave Smith Instruments TETRA is a standalone, four-voice, analog poly synthesizer with four banks of 128 programs and separate outputs.
Tetra’s voice architecture is the same as Mopho’s, but with a couple of notable differences. There is no external audio input, but input gain is now programmable for total recall of feedback settings. Other features include separate outputs for each of the four voices and, for the first time ever on a DSI synth, USB support.
Tetra is expandable. Up to four units can be chained for 16-voice polyphony. Or add one or two units to a Prophet ’08 for 12- or 16-voice polyphony. The Prophet ’08 factory programs are included.

MPN: DSI-1204

- Multitimbral four-voice analog synthesizer

- 100% analog signal path

- Two oscillators per voice (sawtooth, triangle, saw/triangle, square with variable pulse width) with hard sync

- White noise generator

- One classic Curtis low-pass filter (switchable 2- or 4-pole) per voice, self-oscillating in 4-pole mode

- Analog VCAs

- Three envelope generators (ADSR plus delay) per voice

- Four LFOs per voice

- Two sub-octave generators (one octave down and two octaves down) per voice

- Feedback loop per voice with programmable level and gain

- Four assignable performance controls per program

- Gated 16 x 4 step sequencer (one sequence per program)

- Arpeggiator

- Fully programmable (free downloadable software editor for Mac OS and Windows)

- 512 programs organized into four banks of 128; 128 combos

- I/O: USB 2.0 (type B receptacle), MIDI In, MIDI Out/Thru, Poly Chain Out, Audio Outs 1/Left, 2/Right, 3, and 4 (1/4" unbalanced), 1/4" Headphone Out

- 7.9in L x 5in W x 2.7in H (20.07 cm x 12.7 cm x 6.86 cm)

- 1.8 lb. (0.81 kg)