Analog Modular

PugixWelcome to my DIY synthesizer website. The name Pugix (and the graphic toon) belonged to an online gaming character that I used to play and has nothing to do with synthesizers.

My most recent activity:

Sonic Sanctuary at the MTA

I gave a solo performance at the Mission for Temporal Art in Marshall, NC, on November 14th, 2014.  Thanks go to Wendy Owens, who organized the event, and to Claire Elizabeth Barratt and David Linton, curators at the MTA.

Sonic Sanctuary Magic teaparty FUNdraiser @ MTA

Lately I have started a working method in which I create a patch especially designed for a specific performance, then load the modules into a portable rack cabinet for transport to the event venue.  I now have a cabinet that can hold 10U wide of MOTM format modules.  Here’s what it looked like loaded for this performance.

sonic-sanctuary-performance-rigFrom left to right:

The patch consists of the four oscillators going into the two filters, then the HP, BP, and LP outputs of the filters going into a three-channel mixer and through the Veeblefetzers to the PA system.  Two additional patch cords were used in the performance:  Triangle out of one 258J into the Linear FM input of the other 258J, and XY out of the e350 into the Linear FM input of the first 258J.

The e340 was tuned to 264 Hz (one octave down from the 528 Hz Solfeggio frequency).  One 258J was tuned an octave below that at 132 Hz, and the other two oscillators to 66 Hz.  The oscillators were detuned slightly over the course of the piece to produce varying beat frequencies.  The performance was done by manually changing the filter center frequencies and resonance, the mixes of the filter outputs, the depths of linear FM on the 258Js, the Z waveform of the e350, the spread of the e340.  At one point I added a little chaos in the e340.  Occasionally I tweaked the frequency fine tuning on various oscillators.  I used the Veeblefetzers as level meters.

It was a little cold in the room, hence the balaclava.  Well, the ‘ninja’ look was really just for fun.


It’s about 28 minutes in length.

Synthesis Technology E560 Deflector Shield

motm-e560-panelQuantity 1

From Control:

The e560 is a triple-mode effects module: thru-zero frequency shifter, phaser and ring mod. What sets the e560 apart from other DSP effect modules
is the unique carrier wave morphing feature. Traditional frequency shifters and phasers use sine waves as the carrier/modulator, but the e560 has 8 different carrier waves that can be continuously cross-faded to create never-before heard soundscapes. The 8 carriers are specifically selected to give the widest sonic palette, from simple frequency shifts to 64-note ‘pattern sequences’ to extreme harmonic content.

Three Modes of Operation:

SHIFT: A frequency shifter that can shift thru-zero with 2 simultaneous outputs, down and up. Like traditional frequency shifters, a sine carrier will generate a smooth shift but the e560’s 7 other waves will generate a vast array of harmonic content and even patterns of evolving timbral shift. Carrier waveforms: sine, triangle, square, saw, 16-point random phase, 64-point random phase, cross-modulated triangle/pulse and 3x sine.

Frequency Shift Range: 0hz to +-3000hz

RM: A standard ring modulator (4-quadrant multiplying vca) with a twist: the 2 outputs are always forced into quadrature (90 degree phase shift). The 8 carriers can produce everything from tremolo effects to gating to high degrees of distortion.

PHASE: This is an e560 exclusive mode. The audio input is applied to an 8-stage all-pass network. The 2 audio outputs are in quadrature, but in turn phase shifted from 0 to 360 degrees relative to the input. Not only that, the ‘vector’ the phase shift follows is the data in the carrier wavetable. The phase shifting can be linear (saw wave), traditional (triangle) or bouncing all over the place (64-random phase waveform).

Not only do you have full control over the effect, but also the wet/dry mix and applying either positive or phase-inverted (negative) feedback). This introduces peaking at certain harmonics or cancellation of those harmonics. Applying a slow LFO to the feedback CV can produce a wide range of constantly changing spectral content.

There are 4 CV inputs available to control the e560 in real-time. All 4 of the panel controls have a corresponding CV input.

Frequency shift range: 0hz to +-3000hz

Carrier waveforms: sine, triangle, square, saw, 16-point random phase, 64-point random phase, cross-modulated triangle/pulse and 3x sine


  • Addition of five attenuator pots: one for each CV input, plus one for the signal input


Have a look at Dave Brown’s E60 Project page.

Please see my post about the E580 Re-Sampling Mini-Delay for the construction details, which are practically identical.

I suggest searching for demos of the E560, of which many can be found. I’m still learning it!

Sidrazzi Ditty

Something else I’ve been playing around with:  Sidrazzi with Cocoquantus modulating it to get random S&H steps.  Processed by the Deflector Shield and the Re-sampling Mini-Delay.  This is entirely performed.

Big Envelope

Trying an idea from David Linton, who asked, What if you mixed all your oscillators, tuned to the same pitch, in one patch.  I didn’t use all 15 of my 1V/octave music VCOs in this mix, but just 10, each followed by a separate VCF with a fixed cutoff.  During the recording some waveform changes were manually made.  The name comes from the fact that the whole piece is ‘enveloped’ by manual attenuation.  This is a short recording.  If I did it live, I would probably stretch it out.

E560-E580 Drone

Here’s a quick patch I did with my new Synthesis Technology E560 Deflector Shield and E580 Re-Sampling Mini-Delay.  Just those plus two oscillators and one sample and hold.  Recorded on the Zoom H2n in my studio space.

Synthesis Technology E580 Sampling Mini-Delay

motm-e580-panelQuantity: 1

The Synthesis Technology e580 resampling mini-delay emulates the classic sounds of digital, bbd and tape-based delays with four parameters under voltage control. The E580 recreates the pitch-shift modulating of bbds with the variable bandwidth and noise floor without costly bbd ics. In tape mode, wow& flutter, tape saturation and non-linear distortion model classic tape units without the bulk and maintenance.

There are two simultaneous audio outputs: a straight delay and a variable tapped delay. The tap position is a percentage of the main delay time. This allows very short delays (<350us) as well as long delays (750ms). Both tap position (‘offset’) and main delay time are voltage-controlled over a -5v to +5v range.

The feedback is jumper-selectable from either the tapped position or the main delay. This flexibility can generate standard ‘rhythmic’ delays (feedback from main delay) or a series of ‘pre-delay reflections’ (tapped delay) which sound very different from each other.


  • Addition of five attenuator pots:  one for each CV input, plus one for the signal input
  • Addition of a panel switch to replace the PC board jumper to select the feedback source


Please see the previous post for details common to this and the DIY E560 project.

As mentioned in the previous post, the biggest challenge was mounting the PC board to a bracket.  As shown in the following picture, the bracket was fabricated from thin aluminum stock, available at any hardware store.  The bracket mounts to the panel beneath three pots.  Six of the holes which formerly mounted the pots to the board were re-purposed as mounting holes for 3-48 screws.  Although this left the end of the board with MTA connectors a bit cantilevered, after installation there is no pressure on the board.  But one must be careful when plugging in the connectors.

Four pots from the board were installed on the panel, as well as five attenuator pots, each between an input jack and an input on the board.  These attenuators really enhance the ease of use for CV and also especially for attenuating the audio input signal to avoid overloads.  I chose Bourns pots from Mouser, part #652-91A1A-B24-A20L.  The MTA headers and mating connectors are Mouser parts 571-6404543 and 3-640441-3.


Please see Dave Brown’s E580 DIY project for comparison.

Here’s a demo of a little patch I did with it.