• TETRAPHON is a rare experimental analog drum machine based on Metasonix D-1000.
• TETRAPHON is sold individually and as part of Tube Bundle.

The TETRAPHON is an extremely rare, experimental analog drum machine that relies entirely on real vacuum tube circuitry instead of digital processors or standard solid-state electronics.

Drum 1 & Drum 2: Driven by self-resonating vacuum tube ringing bandpass filters. They are highly flexible and tunable from below 20 Hz (for deep, thunderous kicks) up to 2 kHz.

Snare: Utilizes a similar tunable filter structure but is voiced with a much harder, sharper, and more aggressive tone.

Cymbal: A highly unconventional circuit where an internal white noise source is gated through a pentode tube. The attack is variable via a knob and Control Voltage (CV), allowing it to morph from a sharp transient click into a soft, textured "whoosh".

All four voices are routed into a master, overdriveable vacuum tube preamp via individual mix-level controls, allowing users to drive the signals into pure sonic chaos.

8-Step Toggle Sequencer: Rhythms are programmed using raw mechanical toggle switches (flip up to activate the hit, flip down for silence).

Tempo Control: The internal master clock runs from a standard 60 BPM up to an incredibly fast 1000+ BPM. It also includes independent built-in roll clocks for each voice.

It relies on parallel external trigger inputs (0-5V) and pitch CV inputs for melodic sequencing or interfacing with other modular gear. A basic clock input to sync external gear.

Outputs: Features a main mix output alongside individual physical drum voice outputs. Note that plugging into individual outputs does not automatically subtract that voice from the master mix output.