Acoustic & Electronic Instruments, Musicians, News, Tutorials, Videos & Interesting Finds
Acoustic & Electronic Instruments, Musicians, News, Tutorials, Videos & Interesting Finds

MiniMod Keyz is Moog Model D reinvention

AJHSynth has launched the MiniMod Keyz synth as a modular mono synth featuring much acclaimed MiniMod modules, recreating the vintage circuitry and sound of the early Moog Model D in a Eurorack modular format.

It can be used as a standalone keyboard synth or expanded further by patching it to other Eurorack modules. It uses a Cre8audio Niftykeyz controller keyboard featuring custom-designed American Walnut end cheeks, 49 full size keys and outputs including Pitch CVs, gate CVs, velocity and aftertouch CV, and multi-mode arpeggiator for a high degree of expression and sound control.

The MiniMod Keyz has three VCOs, two shaped sine sub bass generators, classic 24dB vintage ladder filter, 6dB and 12dB high pass VCF, dual cascaded VCA, dual contour generators, glide noise module, ring modulator, tap tempo VC-LFO, and onboard second multi-function modulation LFO.

Glide Noise

Glide with added Up/Both/Down function, including correct glide slope profile, along with Hold function that recreates the “Glide only when key is depressed” behaviour. Noise generator with White, Pink and DC Red noise CV modulation source.

Discrete Transistor VCO x 3 

Three Discrete Transistor Core VCO’s, much acclaimed analogue design featuring the circuitry of the early and very rare RA Moog oscillator which is often acknowledged as the fattest analogue VCO in Eurorack.

Ring SM

Our hugely versatile three-in-one module, with fantastic sounding ring modulator based on the EMS VCS3 discrete transistor design, two Sub bass generators with our unique, shaped sine waveforms to add -1 and -2 octave waveforms, and last but not least, a five channel DC coupled vintage Moog CP3 transistor mixer. 

Transistor Ladder Filter

The Moog Ladder Filter is renowned for its beautiful creamy sound, and the Transistor ladder Filter from the early Model D was the pinnacle in terms of sound, with its unique overdriven circuitry and roll off of resonance at low frequencies. It has featured on countless recordings over the last 50 years or so.

Low Fat Filter

Voltage controlled High Pass filter with 6dB and 12dB slopes. It can be used standalone, or can be combined with the MiniMod Ladder Filter to create a fully customisable band pass filter, allowing the range of passbands to be cherry-picked rather than fixed.

Discrete Cascaded VCA

The Model D cascaded VCA is an essential part of creating the classic MiniMoog sound, because in addition to it’s VCA function, it adds harmonic distortion and further character to the sound. There were three different gain configurations used in Model D, with the very early RA Moog and Musonics models having the highest distortion and most sought after sound, so this is the circuitry that we use here. It is actually two VCA’s in series, hence the cascaded label. The second VCA is normally unused, however by patching to the Master IN we can use this second VCA here to control Velocity from the keyboard.,

Dual Contour generator

The contour generators play a larger part in the sound of the Model D than many people realise. There are two factors that make them unique, firstly the exponential slope when it’s used in conjunction with the (near) linear slope of the original VCA, which is responsible for the famous Model D “punch”.  Secondly, the re-trigger behaviour is quite unique, as multiple re-triggering increases the output level. We have faithfully reproduced all of these essential characteristics in the MiniMod Contour Generators.

Tap Tempo VC-LFO

A considerable limitation of the Model D was the lack of any LFO’s for modulation, so VCO 3 had to be switched from Audio to LFO mode to provide modulation. As the MiniMod synth benefits from a full open modular architecture we have added two LFO’s, the first being the onboard LFO that is hard wired to the Modulation wheel, and the second and much more powerful addition being the Tap Tempo VC-LFO. Its huge specification includes built in VCA for CV control of modulation amount, tap tempo and CV control of LFO rate, 16 different modulation and random voltage waveforms, each with a unique PWM style twist function. Clock in and out, and CV control of all parameters.


  • High quality full size 49 key synth action keybed with CV outputs for both Velocity and aftertouch.
  • Five mode arpeggiator, including swing control, latch and sequencer mode. Range control allows Arpeggiator span to be varied from one to four octaves.
  • Two mode modulation wheel that can output either a variable CV voltage or control the level of the LFO 1 waveforms.
  • Internal LFO 1 that can generate Ramp, Saw, Triangle, Square or Random waveforms
  • Front panel octave switch -1/ 0 / +1 octaves
  • Transpose up or down in semitones by up to one octave.
  • Selectable pitch bend range, either +/- 2 semitones or +/- 1 octave.
  • Clock input and output
  • Two active multi’s for splitting CV and audio signals
  • Switchable between Gate retrigger or legato (no retrigger when second note is pressed) modes.
  • Dual outputs, each with 2 x mix jacks, so four signals can be routed to outputs
  • Aftertouch and expression pedal smoothing adds a glide to slowly increase the effect with time, selectable from 0 to 5 seconds.
  • Four Pitch CV outs and 4 Gate outs allows four voice modular polyphonic control and keyboard can be split into two zones.
  • Autochord function.
  • Works as a fully featured polyphonic Midi controller for DAW or other Midi instruments, with 5 pin Din and class compliant USB sockets
  • Sustain Pedal input triggers arpeggiator latch function
  • Expression pedal input, this generates either a 0 to +5V or 0 to +10V range to the Expression CV jack.
  • Two outputs, both with 1/4″ and 3.5mm jacks, and output level controls
  • Headphone output to full size stereo 1/4″ jack, with separate headphone level control.
  • Midi In with 5 pin Din socket and class compliant USB socket. Incoming Midi Velocity and Aftertouch dataCV jacks, and CC#1 is routed to Modulation CV
  • Midi out over USB and 5 pin Din allows it to be used as a polyphonic midi controller keyboard fro your DAW or otherMmidi synths, with local off capability.
  • Generates midi clock from internal arpeggiator and recieves Midi clock in.

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