Bugbrand - DRM2
Here comes the DRM2 - a mighty analogue synthesizer, primarily aimed at percussion duties due to the choice of decay envelopes but, as will be seen, only a step away from traditional subtractive synthesis roots. The DRM2, built around high specification circuit blocks, internal modulation routing and diverse CV I/O, is quite possibly the most powerful dedicated analogue drum voice ever produced!
"Back in 2014 I brought out the DRM1 Major Drum and its DRM1X Expander - I built a good few before, in quite typical manner for me, deciding I wanted to revise just a few aspects... Cue a 2 year hiatus, numerous prototypes and some different approaches - where the DRM1 was more additive (Osc & Filter sections were independent) the DRM2 follows a more subtractive approach and comes fully tricked out as standard (ie. no expander)." -Tom Bugs
The DRM2 can be seen as two main parts - sound & control - with internal and external routings built around the circuit blocks. (Check the Block Diagram)
- Sound Section - made up of Oscillator -> Filter -> Amplifier
- Control Section - Input Preamp / Trigger Processor / Bend Envelope / Amp Envelope / Sample & Hold
Oscillator - A voltage controlled Triangle core Oscillator (VCO) that is wide ranging (c.1Hz to 10kHz from panel controls - wider still with CV modulation), accurate & stable. It features internal modulation from the Bend Env and White Noise or Sample & Hold, and two exponential 1V/Oct external inputs (one with attenuator and switched inversion).It can be swept between Triangle and Square waveshapes.
Filter - A voltage controlled 12dB/Oct State Variable Filter (VCF) offering Low/Band/High pass outputs. It is accurate & stable and capable of self-oscillation. Again it features internal modulation, but this time from S&H or the Oscillator, and two exponential 1V/Oct external inputs like the Oscillator. It can be fed by the VCO, an external source from the Preamp, or the input can be switched off for sine-generation when self-oscillating.
Amplifier - The linear VCA feeds into a shaping circuit which can be switched to either Saturation or Wave-Folding - low modulation depth keeps the VCA in clean range, while driving it harder brings in the effects of the shapers. The VCA is controlled by the Initial control along with modulation from the Amp Envelope and external modulation (again with attenuator & invert switch). There is a final master output control before the impedance balanced 1/4" output.
Input Preamp - External signals can be used either as an alternate input to the VCF and/or to create Trigger Events. The unbalanced 1/4" input has a Drive control with gain up to 20dB.
Trigger Processor - This sums three sources to produce the global Event Trigger pulse -> the Trig input, the manual Trig button and, with To Trig switched On, an external audio signal via the preamp. The Event Trigger passes on to the two Envelopes, the Sample & Hold (S&H) and also syncs the VCO.
Bend Envelope - This is a simple instant attack, variable decay Envelope (range approx 10mS to 1.5S) which primarily feeds the Bend controls of the VCO and VCF to give them an initial thwack.
White Noise / S&H - Transistor based White Noise is generated for modulation and to feed the S&H circuit - clocked by the Event Triggers it creates random step voltages with each trigger.
Amp Envelope - This is similar to the Bend Env but adds voltage control to the decay and longer decay times (up to c.10S).
The DRM2 is capable of quite a variety of sounds, often with subtle variances possible - the manual gives a range of examples. It can, of course, talk with other equipment via its 4mm banana sockets - indeed, you can play it like a monosynth with a CV/Gate interface (even more so if you patched in an external ADSR envelope). See the video below for some sonic snapshots.
As with other Red designs, it comes 'cased' as standard but can be also be supplied as a module to incorporate into a larger Bug system using Powered Frames. In standalone form it measures approx 5.25" x 7.5" x 3.5" and is supplied with an external worldwide (90-260VAC) 12VDC power pack (300mA, 2.1mm centre-positive).
Module current draw: 75mA per side