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ProTone

RackmountAnalogMonophonic

Back in 1996, this Swiss-made gem emerged from a small factory, delivering pure analog monosynth tones in a compact 1U rackmount format that's perfect for squeezing into any setup without dominating space.

At its heart are two voltage-controlled oscillators offering waveforms like square, pulse, dual sawtooths, triangle, sine, random, noise, and external input, with VCO2 syncable to VCO1 for tight leads and a ring modulator to add metallic bite through sum-and-difference frequencies. The signal hits a versatile multimode filter—switchable between low-pass and high-pass at 12dB or 24dB/octave slopes—with resonance, paired to a single envelope generator shaping amp and filter, plus a speedy LFO reaching audio rates for waveforms including random. Controls are dead simple and fully hands-on across the 19-inch front panel: dedicated knobs for tune, pulse width, waveform selects, slide/portamento, mixer levels, cutoff, resonance, envelope attack/decay/sustain/release, LFO rate/depth with button-routed destinations like pitch, PWM, and pan. MIDI handles notes, velocity, pitch bend, volume, sustain, accent, and filter control, with CV/Gate inputs for modular integration.

Vintage enthusiasts prize its raw, beefy sound for bass, leads, and effects, often highlighting the filter's character and intuitive layout, though some note the single mod amount knob limits nuanced routing. Even discontinued, it holds cult appeal in analog circles for that unfiltered '90s vibe.

Released

1996

Status

Discontinued

Synthesizer
Format
Rackmount
Type
Analog, Subtractive
Internal Battery
-
Voice
A/D
Analog
Polyphony
Monophonic
Oscillators
2
Oscillator Type
VCO (Voltage Controlled)
Voices
1
Filter
Lowpass, Highpass, 12dB/oct (2-pole), 24dB/oct (4-pole), Resonant
Envelopes
1
LFO
1
Effects
Slide (portamento)
Expression
Aftertouch
No
Velocity
Yes
MPE
No
Additional
-
Software
-
I/O
Audio In
-
Audio Out
Stereo Output
Headphone
-
MIDI
In, Out
MIDI Type
DIN (5-pin)
Ports
CV/Gate
Wi-Fi
No
Workflow
Arpeggiator
No
Sequencer
No
Mod Matrix
-
Memory
None
Measurements
Dimensions
-
Weight
-
Last updated Mar 22, 2026