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NEW AJH Synth MINIMOD Modules, plus V-SCALE – in stock now

AJH Synth News 15.01.17

Exciting news for AJH Synth fans! Allan Hall has designed some new high-quality Eurorack modules to complement and expand his incredibly popular Minimod range: DUAL LFO & VCA, DH-ADSR ENVELOPE, CV MIX-OFFSET-VCA and GAIN SWITCH MULTI along with the V-SCALE VARIABLE BUFFER.

We have a limited stock of these, and all are in the DARK EDITION – with the exception of the GAIN SWITCH MULTI and V-SCALE, of which we have a couple of standard silver panel versions. More stock will be arriving in early/mid-February, once Allan has recovered from NAMM 🙂


Here’s an overview of the designs from the man himself:

  • Dual LFO & VCA – This has two LFOs, each with variable waveshape from Saw to Triangle to Ramp waveforms, or variable Pulse width on the Square wave output. LFO 1 has the addition of a low range and a Sync input. Also included is a DC coupled VCA, the input of the VCA is normalised to the output of LFO 2, so a 0 to +5V input to the VCA CV input gives control of the LFO waveform amplitude. It can also be used as a stand alone VCA. This module is very useful for controllers such as the Waldorf KB37 where the modulation wheel gives out 0 to +5V, this can be routed to the VCA CV module so the level of the modulation waveform can be easily controlled. This makes it very easy to add VCO vibrato or filter ‘wah’ with control of modulation amount from the modulation wheel or other controller.
  • DH-ADSR Envelope – Available in Silver or Black. We have had quite a few requests for a variant of MiniMod contour generator with Release added to the envelope so that it is full ADSR but still with the characteristics of the Model D -so this is what we have done! The DH-ADSR is exactly the same circuit as the original Model D envelope and therefore features the same contour shape and retrigger behaviour, but with the addition of a release control. However, we have also added a pulse delay and pulse stretch circuit, along with a re-trigger facility (both of these can be switched out of circuit so that the envelope is a simple ADSR unit). The addition of pulse stretching and retrigger makes it into an LFO module and it can perform in a similar way to the EMS Synthi A and VCS3 Trapezoid generator, with a variable delay between each retrigger and a variable “on” time – however it can also have full ADSR envelope on each retrigger too!
  • CV Mix-Offset-VCA – This useful module is a Bipolar Mixer, DC voltage source and Linear DC coupled VCA –  With no input to channel 1 the Input 1 pot becomes a voltage source with a range of +/- 6V. The control pot and input for channel 4 can be switched  to become an offset control and/or a second CV input for the VCA.  Input 3 has 2x gain, so it can amplify lower level CV’s too. All of the inputs are bipolar, which means that either non-inverted or inverted version of the input signal can be added to the mix depending upon the Input control being turned clockwise (non-inverting) or anti-clockwise (inverted). The 12’o’clock position is zero.
  • V-Scale Variable Buffer – This is a precision active buffer and multi– this module has outstanding performance, it features very high input impedance, very low output impedance and an offset voltage of <1mV. Not all active multi’s are born equal, some designs do not fully solve impedance mismatch and tracking problems or they apply offset voltages to the output and in rare cases can cause more problems than they solve!  We have added a very useful (and unique) feature to cure tracking problems – four of the five outputs can be adjusted up or down by +/-5% from the front panel, so that VCO’s and VCF’s that don’t track 1V/Oct exactly can be easily compensated to track correctly without having to re-calibrate the VCO or VCF themselves.
  • Gain Switch Multi – We have had quite a few customers asking if we can make the gain jumpers on the MiniMod VCF and VCA modules accessible from the front panel, so this 2HP module has two switches which connect to the gain jumpers on the VCA and VCF. Switch “up” is the same as having the gain jumper in place, switch “down” is the same as removing the jumper, and gives higher gain. Using these switches gives a similar effect to the old “headphone out to external input” trick on the original Model D but with a much wider overdrive range, particularly from the VCA. We have also included a six way passive multi.