PWM Mantis Hybrid Analog Duophonic Synthesizer

With DSP-based oscillators and an analog signal path, the PWM Mantis hybrid duophonic synth exhibits serious stability and deep sound shaping capabilities.

Mantis is a unique duophonic hybrid-analog synthesizer with dual filter, 200 patch memory and full USB-C MIDI control.

This project is a collaboration between the late Chris Huggett (Gnat, WASP, OSCar) and PWM (Paul Whittington). In development over the last period of his life Chris threw everything he could into the Mantis. Although incomplete when he passed away he handed his part of the project over to Paul to continue and to see what, if anything, could be made of it - he really was so humble in his work! Those at PWM, with the support of Chris' estate, think this synthesizer is totally amazing and deserves to be born into the world for everyone to enjoy, and know Chris would be really proud too!


The OSCs are generated at boot-up using complex mathematics. They run on a DSP chip that gives ultimate stability and control without compromising the unique sound. This is what makes the synth a hybrid but don't be fooled - everything after that through the mixer, gain staging and the filter is analog.


The Filter is a multi-mode state variable VCA Filter with overdrive. It is built using the SSI2164 chip in special configuration designed by Chris Huggett. There are two filters - one for each analogue signal path. They can be combined in series or parallel and used with the width control and width modulation to create that distinctive sound only heard on the OSCar.


The Mantis has two simple digital effects: Reverb and Chorus. Reverb has a time read more and level adjustment but also a high and low pass filter that can be switched into limit unwanted lower mud and/or higher bouncy twinkles (!)


Mantis has 2 ADSR envelopes but each has an additional 'Sustain Fall' parameter and negative and positive velocity modulation level hardwired for convenience. 'Sustain Fall' allows you to create a drop before release even while a key is held for greater sound design possibilities. Each envelope can also be put into repeat mode to act as a pseudo LFO if you wish.


The gain staging on Mantis is, of course, all analog and is run through the SSI2164 VCAs - we have a few of them in the design! The signal is actually twice amplified to ensure the overdriven sound is warm and clips naturally.


- Duophonic with 2 discrete analogue signal paths
- 2 Oscillators + sub oscillator per voice
- 2 Envelopes with sustain fall and envelope repeat
- 2 LFOs with 4 waveform types and sync
- 2 Multi-mode filters with drive, keytrack and frequency modulation
- Dual filter mode with width and modulation
- 37 note full sized keybed with aftertouch
- Multi-function joystick and octave shift
- Arpeggiator with 6 modes, tap tempo, swing and sync & unique duophonic arp mode
- Reverb with low & high pass filtering and 4 chorus modes

- Additional Features (beyond the top 10)
- Mixer with Noise and Ring Modulation
- Oscillator density and drift
- Modulation Routes with fast configuration
- Selectable triggering
- Powered via DC PSU
- Sustain pedal input
- Controller pedal input
- 1/4" Stereo master outputs
- 1/4" Stereo headphone output

- Power Supply (9V 600mA)
- USB C lead
- Getting Started Guide
WARNING: Cancer and Reproductive Harm -
read less

200 Patches:
- All patches in RAM so can be overwritten
- Bank A: 100 Factory presets
- Bank B: 100 User presets (all set to initial patch)
- Compare function
- Initialize patch function

Duophonic with 2 analogue signal paths:
- Mathematically generated oscillators designed by Chris Huggett
- Analogue signal path designed by Chris Huggett

2 Oscillators plus sub-oscillator per voice:
- Sine / Triangle / Saw / Pulse plus additional wave types
- Shape control and shape modulation input
- Will create pulse width modulation on the pulse waveform with perfect square at the center
- Pitch modulation control
- Octave selects per oscillator
- OSC 1 SUB follows oscillator 1 parameters

Oscillator Drift:
- Creates random pitch variations between oscillators

Multi-mode state variable VCA filters with overdrive:
- 2 Analogue filters - 1 per signal path
- Low Pass / Band Pass / High Pass in 12dB and 24dB configurations
- Additional WBAND (series) and WSTOP (parallel) types
- Filter Cutoff
- Filter Cutoff Modulation
- Filter Resonance
- Filter Width
- Filter Width Modulation
- Filter Keytrack

LFO (Low Frequency Oscillator):
- 2 LFOs
- 4 waveshapes per oscillator
- Fade In / Fade Out parameter
- SYNCable
- Rate control

- 2 Independent envelopes
- ENV 1 normalized to amplitude
- + Sustain Fall parameter for shaping during key-down
- + Repeat which can be used to create looping envelopes
- Velocity positive and negative control

Ring modulation:
- First mix: OSC1 and OSC2
- Second mix: OSCillators and noise
- Third mix: OSCillators + noise and Ring modulator

VCA (Voltage Controlled Amplifier):
- All amplification is done in the analogue domain in multi-stage VCAs

Modulation Routes:
- Control - 6 choices of modulation parameters
- Source - 6 choices of effectors from envelopes and LFOs
- Scale - choices of controls used to scale the effect of the modulation

- Glide amount
- Auto-glide mode

- Indicator LEDs:
- Two LEDs for Voice
- LED for Keyboard activity

Master tune:
Master volume:
- ENV 1 Legato
- ENV 2 Legato
- LFO Keytrig
- LFO Keytrig

- Master power switch
- DC 9V input
- Sustain pedal input (switch)
- Pedal input (continuous)
- Stereo 1/4" line Outs: L/Mono and R
- Stereo 1/4" headphone out

Multi-function Joystick control:
- Left / right for pitch bend
- Performable vibrato
- Latching hold mode

- 6 arpeggiator types
- Up, Down, Up/Down 1, Up/Down 2, Played & Random
- Sync rates control from 2nds to 32nds
- Tap tempo button
- Swing including positive and negative swing
- Auto clock sync
- Detects MIDI or USB-MIDI clock and synchronizes the arpeggiator automatically
- Latch via joystick HOLD
- 6 Octave range

Dedicated tempo control:
Duophonic mode control:
- Duo mode
- Duo mode with simple filter
- Pan control for duophonic voicing

Digital Effects:
- Reverb time
- Reverb level
- Reverb High Pass Filter
- Reverb Low Pass Filter
- Chorus level
- Chorus type

Keyboard Control:
- 37 Full-size semi-weighted velocity-sensitive keys
- Channel aftertouch
- Octave shift

Weights and Dimensions (product unboxed): 24.5 x 12.5 x 4.5" / 11.5 lbs
Dimensions and Weight in Packaging
Base Item
Shipping Weight: 16 lbs
Shipping Dimensions: 32 x 16 x 8 in
Manufacturer Part Number (MPN): PWM-MNTS

For support or warranty questions, please contact the manufacturer:


  • 18 x
  • 12 x
    $112.42 with zZounds
  • 8 x
    $168.63 with zZounds
FREE -Day Shipping!
Get it  for
Get it by if you order within
Shipping to