The TRAX RetroWave MIDI-Controlled Analogue Synthesizer

The TRAX RetroWave is an analog desktop monosynth, designed for musicians ‘who want the warmth and raw power of classic analogue sound, created by a real analogue instrument, as opposed to a digital system or computer emulation’.


  • True analogue oscillators, filter, sample and hold, noise generator, VCA and signal path
  • Log VCO with square, ramp, triangle and sine outputs, and PWM control of square wave
  • 24dB/octave, 4-pole lowpass filter with oscillator function, log response
  • Two triangle and square Low Frequency Oscillators with waveshape controls
  • Built-in MIDI to CV unit, with 5V gate and velocity output, 1V/octave CV response
  • Built-in overdrive circuit for epic distortion effects
  • No menus, no software, just switch on and play
  • Supplied with 1/4″ patch and output jack leads

The TRAX RetroWave is a boutique synth and is available in limited quantities, via eBay, priced at GBP 325.00 (Approx. US $525).

If you’ve used the TRAX RetroWave – leave a comment with your thoughts on it!


Connect any keyboard or sequencer with a 5-pin DIN MIDI out socket to the R-1’s MIDI input socket, and you have an complete analogue synthesizer system for live gigs and recording. Add a USB to MIDI lead for computer control, and the possibilities are endless – automatic play-along with recorded music, complex and rapid sequences, etc.

The Internal Modules

  • 1 x Voltage-Controlled Oscillator (VCO), true analogue, with 1 volt per octave response. Square, ramp, triangle and sine outputs. The square wave can be pulse-width modulated by other internal modules (low frequency oscillator 2, ADSR sweep) or an external source, oraltered manually for dynamic searing leads and  fat bass lines.
  • Frequency modulation comes from 2 x LFO’s, sample and hold, ADSR sweep or external source, either separately or all together. An octave selector switch and master tune control give you flexibility when playing along with other instruments, and can be used to give pitch shifting effects while playing.
  • 1 x MIDI/CV and Gate Converter. 12 channels to choose from, instantly selectable via a rotary switch. CV, gate (+5V), and velocity output jacks are provided, so that the R-1 can drive other analogue equipment. Glide control for “Rick Wakeman” style blurring of one note into the next.
  • 1 x 24dB/octave, Four-pole Voltage-Controlled Filter (VCF), low-pass, with 1 volt/octave response. Create all those classic dynamic filter sounds, including auto-wah, ADSR sweeps and keyboard CV tracking. Cut-off frequency can be modulated by LFO 2, ADSR, sample & hold, MIDI velocity, or external signal, together or separately.
  • The filter can also be put into oscillation mode to track the MIDI CV output, effectively acting as a second VCO. Comprehensive signal input mixing combines VCO, sub-octave 1, sub-octave 2, noise and external input to give a composite filter signal.
  • 2 x Low-Frequency Oscillators (LFO), with triangle and square outputs. Wave shape controls to give ramp, sawtooth, and pulse variations – great for sirens, sci-fi sounds, trills and vibrato effects. Low (sub-audio) and high speed (audio) range switches give effects that vary from a subtle vibrato, through to a dirty hyper-modulation that will send the cat running for cover!
  • Each LFO has a clear, high-brightness yellow LED monitor, so you can see at a glance the running speed and approximate shape of the output waveform.
  • 2 x Sub-Octave Generators, each with a square wave output.  One octave below, and two octaves below VCO frequency. Fatten up the VCO output to give deep bass and organ-like sounds, with full level control of each sub-octave.
  • 1 x Sample and Hold Circuit. Supplies random voltages, for programming the VCO and VCF. The random note effect is just the thing for creating a “psychotic” lead line, and the random VCF modulation will add some sparkle to any performance.
  • 1 x White Noise Generator. Noise can be mixed in with oscillator, sub-octaves and ext. signal. Essential for creating whistle edge-noise, drums, wind, rain, surf, and explosive sound effects.
  • 1 x ADSR/VCA, combined four-stage envelope generator and voltage-controlled amplifier. Attack – decay – sustain – release circuit features a low and high range switch – use the low range for short and punchy effects (blips, organs, machine-guns) and the high range for sounds with extended decays, such as drones, thunderclaps, etc.
  • The ADSR can be bypassed for easier sound set-up, and a repeat switch is provided which allows LFO 1 to repeatedly trigger the ADSR. Features a high-brightness yellow LED indicator, which illuminates on receipt of each gate pulse, and glows in proportion to the contours of the set envelope.
  • The linear VCA has a rear panel jack socket for an external CV input, or an internal patch, to give amplitude modulation if required. It also has an overdrive stage to add some aggressiveness to the final output signal – use it for growling solos and incredibly messy distortion effects!

 Case and Controls

The retro-styled aluminium case has a powder-coated, black and white paint finish, and a tough laminated polycarbonate front panel, so the panel legends will not wear away through repeated brushing by fingers. The controls and switches are laid out as ergonomically as possible, making programming rapid and easy. All potentiometers are robust, full-size units, and toggle switches are used in preference to the unreliable and fragile slide type.

 Inputs and Outputs

The rear panel has inputs for 24V dc power supply, MIDI (via 5-pin DIN socket), gate, VCO CV, VCO PWM, VCF CV, VCA CV and external audio (all 1/4″ jack sockets). Output jack sockets for CV, gate +5V, velocity and audio.

The jack sockets can also be used in conjunction with the supplied patch leads, for extra interconnections between modules that are not catered for by the internal patching arrangement.

Power Supply and Accessories

The unit is supplied complete with a universal 24V dc power unit that will work on any mains supply from 100 to 240V ac,. There are three interchangeable plug tops – just attach the plug pin assembly that matches your local power supply socket.

A long 1/4″ (6.35mm) mono jack to jack output lead is supplied, for connection to an external audio amplifier.

Two short patch leads are also included, for making extra connections between internal sections as described above.


  • Type: monophonic analogue synthesizer.
  • MIDI channels: 12
  • Power supply: 24V dc.
  • VCO control characteristic: 1V/octave, logarithmic
  • VCF control characteristic: 1V/octave, logarithmic
  • VCA type: linear
  • Gate input range: 2 – 10V.
  • Gate output from MIDI: 5V
  • Velocity output from MIDI: 0 – 10V nominal
  • Output level: 0 – 3V p/p, variable.
  • Dimensions: 436 x 230 x 100mm overall.
  • Weight: 2kg approx.
  • Hand built in the UK.


7 thoughts on “The TRAX RetroWave MIDI-Controlled Analogue Synthesizer

    1. All you need is an existing keyboard with MIDI out; you could get a compact one. Personally I already have 3 of those so a synth with no keyboard is preferable.

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