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:

Phil Kline Unsilent Night Ashevile 2014

Unsilent Night is an original composition by Phil Kline, written specifically to be heard outdoors in the month of December. It takes the form of a street promenade in which the audience becomes the performer. Each participant gets one of four tracks of music in the form of a cassette, CD, or Mp3. Together all four tracks comprise Unsilent Night. The fact that the participants play different “parts” simultaneously helps create the special sound of the piece. Participants carry boomboxes, or anything that amplifies music, and simultaneously start playing the music. They then walk a carefully chosen route through their city’s streets, creating a unique mobile sound sculpture which is different from every listener’s perspective.

I participated in this year’s event in Asheville, NC. I carried in my right hand a portable amplifier (Roland Mobile Cube) connected to my iPhone running the Unsilent Night app, and a portable recorder in my left.  Here is an excerpt.

Don’t miss the saxophone at the end, courtesy of an Asheville busker, playing Happy Birthday!

Stereo Input Module

stereo-input-front-panelSometimes you cannot find a PC board with just the right circuit.  This was one of those times.  I work with a lot of stereo sources, such as the Ciat-Lonbarde instruments, that output line level audio.  I needed a way to bring those into the modular at full levels, so I designed a circuit and built it myself.  It features

  • Stereo input mini-jack
  • Quarter inch left and right inputs
  • Left and right outputs
  • Mono mixed output
  • Clip indicator LEDS
  • Master gain knob

The Circuit

stereo-input-schematicThe mini-jack inputs go through the normal switching on the quarter-inch jacks so that either can be used, but not both simultaneously.  Each channel has a unity gain buffer with AC coupling and a 470K terminating resistor.  This is followed by an inverting buffer with 20X gain max.  A dual-ganged audio taper pot allows the gain to be adjusted from zero up to 20X.  The panel dial is marked to correspond roughly to the gain.  At the lower settings, a full synthesizer level input can be processed.  It’s not a mistake that the last two markings both indicate 20X.  This is due to the fact that the maximum resistance of the pot is reached a bit before the maximum rotation.

Each channel is monitored by a comparator that lights an LED whenever the signal passes 4 volts peak to peak.  An inverting unity gain mixer provides a handy mono output.





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.