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:

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

Enhancements

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

Construction

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 E360, 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.

Enhancements:

  • 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

Construction:

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.

e580-assembly

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

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

 

E560-E580 Project

I was late to make DIY builds of the Synthesis Technology e560 and e580 modules.  A post on the Synthtech email list alerted me to Dave Brown’s builds.

E560 Deflector Shield

E580 Resampling Mini-Delay

I had heard about these DSP modules when they came out about three years ago in Eurorack format.  I didn’t know that Paul Schreiber was still offering the DIY kits in summer 2014, but he was and I purchased one each.  I obtained the excellent Front Panel Express panel files designed by Dave Brown and ordered those, too.  The only remaining parts for the project were panel jacks,  attenuator pots, knobs and one switch.  Here’s a photo of the assembled and tested boards, as delivered from SynthTech:

e560-e580-boardsFour pots and one switch are soldered onto the board and serve to mount it behind the standard Eurorack panel, like so:
e560s

Putting these into 5U panels required removing the switch and pots from the boards. After a struggle with the first pot, I developed a technique to suck solder out of the holes around the mounting table and then rock them out gently, after desoldering or cutting the leads. Like Dave Brown did, I installed 3-pin MTA headers to make all connections to the panel, so that no wires would have to be soldered to the PC boards.

The trickiest part was finding a way to mount the board to a bracket, since the boards have no mounting holes. Dave had drilled corner holes, but I deemed that too much risk of damage to the multilayer PC board. Instead, I used six of the holes that formerly held the pot tabs and found that size 3-48 screws from Ace Hardware were just small enough to tap into them without much fuss. (A 3-48 screw is in between a 2-56 and a 4-40 in diameter.)

Here’s a photo of the empty panels:
e560-e580-panels

Here are all the parts laid out, prior to assembly.
e560-e580-big-parts

Subsequent posts will describe each of these modules in detail.