HWJ - PROTO/NU - idée fixe #KACCUMULATOR

video upload by FL3SHB4CK

"Hardware Jam Challenge: PROTO/NU

One of my very first patch with the almighty K-ACCUMULATOR, what a beast!
Fancyyyyy K-ACCUMULATOR, NLC Splish & Sloth, MI Beads

Make some noise!

‪@fancysynthesis‬ ‪@cirtcele‬"

nonlinearcircuits Dichotomy Paradox 1

video upload by cirtcele

"Updated version of Divine CMOS. Wonderful module for harmonically rich sounds or use as a complex CV patter and gate generator. Thought the LEDs were superbright purple but turned out to be a mild light blue."

via nonlinearcircuits

"This module has been thru a few cycles. The original idea for the design is from an article in Electronotes EN#98 by Lester Ludwig, spectacularly titled ‘A Square-wave Frequency-division Sub-octave Cross-product Module, it’s relationship with Lie algebra, and other related processes’ or more simply known as The Cross Product Module.

The frequencies of two VCO signals are separately divided by /2, /4, /8 & /16 ratios. The corresponding divisions are ANDed together and the results, along with all the raw divided frequencies are mixed together in various ways. You end up with a very harmonically thick, animated sound.

I did a full bloat CMOS (Ludwig’s design was TTL) version for a 4U panel back in 2008 or so, but changed the AND gates to XOR gates for a more ring-modulated effect. Then a minimal, slimmed down eurorack version, called Divine CMOS. This just used the XOR’d signal and outputted a signal determined by the pots.

After some requests for an expanded version, I re-visited the design.

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7555VCO 1

video upload by cirtcele

"Wide ranging sawtooth VCO with the hardest hard sync around."



via nonlinearcircuits

"Not the most exciting name, I simply wanted a 4HP sawtooth VCO to sit next to the Spectrum Shaper.

It is based on the Utility VCO in Electronotes EN67, which was based on designs by R. Tenny (Electronic Design 11/10/75), J.L. Brice (Wireless World (6/76) and others.

It tracks very nicely, turn the CV pot to max for 1V/oct, ranges from approx 10Hz to over 100kHz and supplies 10Vp-p sawtooth and square waves.

The Sync is the hardest of hard syncs around. I left out the capacitor usually used to turn sync signals into a pulse, so if you feed a gate or slow CV signal into Sync the VCO simply stops, think of it is a bonus VCA. Of course, if you use an audio rate sync signal, it works as normal.

It is a pretty easy build. not many parts. Do not mix up the BCM847 and BCM857 dual transistors, see the build notes for where to install a 1k tempco."

nonlinear circuits Winnits

video upload by cirtcele

"triple reverse sigmoid chaos in 8HP."

via nonlinearcircuits

This 8HP module contains three reverse sigmoid chaos circuits, these are the same as those used in 1U reverse Sigmoid and How’s the Serenity.

This version exists because not everybody has 1U and How’s the Serenity is quite large and more focused on very slow CV generation. This version is limited to 0805 capacitors to set the timing. Tayda sell 22uF caps and you could stack these to get to 44uF easily enough. Generally, a lot of fun can be had using 1uF, 470n and 220n caps.

The syncing between the stages works very nicely with this module as the frequency ranges are closer together than How’s the Serenity, so they have a more obvious effect upon each other.

Please note if you install caps less than 470n, the 62k on that section needs to be changed to 68k. This prevents the circuit locking into a periodic orbit after CV is applied.

The caps for each section must be the same. So you will see three pads marked C1, install the same value cap in all three.

The LEDs should be very bright to shine thru the panel, a low value for RL helps too, say 2k2 or 3k3 which you are installing elsewhere on the PCB anyway. The panel renders below do not show the LEDs but they are there.

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nonlinear circuits spectrum shaper

video upload by cirtcele

"I'm still learning how to use this thing but here are some excerpts from a patch with Tinkle and FM OP via Product wavefolder both fed into the Spectrum Shaper."

via nonlinear circuits

"36 channel voltage controlled comb filter aka string filter.

This module has some history. In 2018, I was part of a team putting on a show with CellF at the Todays Art festival in Den Haag. I popped down to Rotterdam to visit Dennis (aka Mono-Poly) and his studio of vintage lab gear. Dennis had an incredible patch going centred around a Bruel & Kjaer 36 channel Spectrum Shaper. Listen to his album Testlab to hear how it sounds. I just knew I had to make something like it one day. This type of filter is often called a ‘String filter’, used to emulate stringed instruments tho don’t feel limited by that.

Fast forward to 2026, I read an AES paper by R. Burhans describing his 36 channel comb filter. It reminded me there were some designs in Electronotes, so I looked them up and discovered they were both inspired by and heavily influenced by Burhans, particularly in terms of the comb filter frequencies and spacing. One was a 40 channel version by Ian Fritz using transistor based filters. He had an interesting mod, originally suggested by Lester Ludwig, where each set of 6 filters had a feedback pot. Some screenshots from these articles are at the end of this build guide. The relevant Electronotes issues 107, 115 and 116 can be found online.

The Bernie Hutchins design used 39 regular op amp based filters, along with Ian’s feedback per 6 filters mod and added an inverter so the feedback could be positive or negative (so, centre off). Negative feedback ‘flattens’ the peaks somewhat and smears the sound, positive feedback makes the peaks narrower and higher (if tuned for it, you can make them self-oscillate, see notes). Bernie also added a noise gate on the output, summing 39 channels is always going to be noisy.

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BURHANS TIMBRE 1

video upload by cirtcele

"Multi function module for creating timbre, simple or complex CV/gate patterns and pseudo random noise."

via nonlinearcircuits

8hp

This module can be used in a number of ways:

Timbre generator

CV Pattern generator/sequencer

Controllable pseudo-random noise generator

It is based on ideas presented in an AES article by Ralph W. Burhans

Using the switches, pots and signal input, you can create patterns as simple or as complex as you like.

It is not a 6 stage sequencer as most settings enable more than one channel to be active at once and the CV output is a sum of the voltages set by the pots connected to the active stages.

The switches enable extremely long patterns to be generated. The signal input allows you to change and randomise patterns on the fly, but it fun to flick the switches back’n’forth (centre is off); sometimes you might even return to a previous pattern. It is also fun to feedback a gate output into the signal input to create shorter loops that can be altered with the switches as well.

As a timbre generator, it can add harmonics to sine waves or step in and out of pseudo random noise as the signal and/or clock are CV controlled. It might be good to feed the output to a VCF to smooth some of the edges, but it depends on how noisy you want it.

New FREQY, EPILOGUE VCF, & Rong Mid modules by nonlinearcircuits

FREQY video upload by cirtcele

"Frequency Shifter without dome filters"

EPILOGUE VCF

video upload by cirtcele

"Low pass filter with some unusual feedback paths"

Rong Mid

video upload by cirtcele

"Ming Rodulator with VC phase control"

How's the Serenity?

video upload by cirtcele

"Quad reverse sigmoid chaos module with CV inputs, sync controls and mixed outputs
https://www.nonlinearcircuits.com/mod...

single 1U version - https://www.nonlinearcircuits.com/mod..."

"This module is a set of 4 reverse sigmoid chaos circuits, running at different frequencies, there are pots to feed each section into another and influence, sync – sort of, the action. There are also CV inputs for each section which affect the reset or crossover timing, for the faster ones the results are obvious. For the slower ones, give it a few hours.

The reverse sigmoid circuits are similar in concept to the mackey-glass based design used in the NLC Frisson, but are greatly simplified to a bare minimum of parts. Simply an integrator, two all pass filters and a nonlinear stage with two feedback paths. The nice thing about them is you can use any capacitors you like, so long as all three are the same, and the circuit will work with no other mods required. The sections in this module use 1uF, 10uF, 2x 1000uF in series (so 500uF) and 2x 2200uF in series (so 1100uF).

They work quite differently to the Sloth chaos circuits, with a number of ripples or rolls between each attractor, also the three outputs track each other, the faster ones are delayed by a few seconds, the slower ones by minutes. The intent of having 4 different circuits running together with pots to get them to influence each other is to have a module that can create longer tracks with many different but related musical events happening and, of course, weird delayed CV effects. Think of a band where the members all do their own thing but every now and then the sounds and patterns connect and achieve structure, which slowly scatters and reforms in new ways.

Feel free to change the 1uF caps to a higher or lower value, similarly for the 10uF. Stack capacitors on top of each other to get 20uF, or use Tayda 22uF caps and stack them. See pictures on pg6 for info on which caps to change. Make sure the capacitors have at least a 25V rating or higher.

If you want to use larger values than 1000uF and 2200uF, make sure they will fit on the PCB and/or thru the panel holes (1000uF on PCB are 10mm diameter, 2200uF panel holes are 16.8mm)

There are also two difference rectifier circuits which output complex mixes of the individual chaos circuits."

1U REVERSE SIGMOID
DESCRIPTION/USAGE

6hp

This module is a reverse sigmoid chaos circuit; it can be built to run as a fast or slow CV source, or even as an audio/noise source. This is a single version of the four chaos circuits in the NLC How’s the Serenity module.

The reverse sigmoid circuits are similar in concept to the mackey-glass based design used in the NLC Frisson, but are greatly simplified to a bare minimum of parts. Simply an integrator, two all pass filters and a nonlinear stage with two feedback paths.

The nice thing about this design is you can use any capacitors you like, so long as all three are the same the circuit will work with no other mods required. The capacitors are marked ‘C’ on the PCB, 1uF is a good mid-range value to install, but 10uF, 22uF are good too albeit much slower. Lower values than 100nF get you into audio rate territory. Make sure the capacitors have at least a 25V rating or higher.

This works quite differently to the Sloth chaos circuits, with a number of ripples or rolls between each attractor, also the three outputs track each other, the faster versions are delayed by a few seconds, the slower ones by minutes.

The Input expects a positive CV, negative going CVs won’t hurt but will have no effect. The CV signal feeds into the first all-pass filter stage via 10k and a diode, this is different to the method used on How’s the Serenity. On slower builds, using 10uF caps, the effect of the CV will be washed out to some extent. It will still have an effect but not as noticeably as on the faster versions.

SCJS#82 THE HITCH-HIKER [HWJ Full Jam]

video upload by FL3SHB4CK

"Small Case Jam Sessions #82 THE HITCH-HIKER [HWJ Full Jam]
It is the full jam of Hardware Jam Challenge: Soundtrack
• HWJ THE HITCH-HIKER (excerpt) A modular so... [below]

GITGUD, TABOR, 8BIT CIPHER, EFI, ZERSTORER, BATTERING RAM, AHH

Recorded live thru Syntakt delay & reverb

‪@Jolin_wbs‬ ‪@cirtcele‬ ‪@ShakmatModular‬ ‪@alizondevices‬ ‪@xodesnet‬"

HWJ THE HITCH-HIKER (excerpt) A modular soundtrack

video upload by FL3SHB4CK

"Hardware Jam Challenge: Soundtrack

GITGUD, TABOR, 8BIT CIPHER, EFI, ZERSTORER, BATTERING RAM, AHH

Recorded live thru Syntakt delay & reverb

‪@Jolin_wbs‬ ‪@cirtcele‬ ‪@ShakmatModular‬ ‪@alizondevices‬ ‪@xodesnet‬"

JAMUARY26#22 CHAOS IN COSMOS

video upload by FL3SHB4CK

"HAPPY NEW YEAR! HAPPY JAMUARY26!
One brand new jam everyday in this Jamuary 2026, enjoy!
https://fl3shb4ck.bandcamp.com/follow_me

Pam, Hyperchaos Deluxe, Algo, Beads

Make some noise!

@RYKModular @busycircuits @cirtcele"

nonlinearcircuits Introduces 4HP NEURON

video upload by cirtcele

"This module is a 4HP version of the NLC 8HP Neuron & Difference Rectifier.

The differences are half the panel real estate, SMD components, LEDs to indicate activity and one less input on the Neuron (2 instead of 3).

From the original version description -

The Neuron was inspired by a paper on neural computing and is a variation of a typical analogue neuron circuit. It can be used as a complex audio waveshaper, gate or pulse generator, CV shaper or to generally mess things up. The diff-rect is a hybrid of two basic op amp ‘building blocks’ – a difference circuit and a rectifier. Not sure if I have ever seen the two merged together before. It is probably a bad idea except for synth use, where it is a wonderful idea!

The Difference Rectifier has 4 inputs (two + & two -) and two outputs. The Neuron has 3 2 inputs and one output, the pots control when the neuron will react to incoming signals and how much it will react."

nonlinearcircuits IMMIX 1 | googoomux 1 | demux phaser 1 | path filter 1

video upload by cirtcele

"SSI2190 based VCA/mixer with inverting and non-inverting inputs"

googoomux 1

video upload by cirtcele

"DG408 based mux / demux; either feed one input and route to 8 outputs or 8 inputs routed to one output"

demux phaser 1

video upload by cirtcele

"gate controlled pahser"

path filter 1

video upload by cirtcele

"Unusual path filter, somewhere between a phaser and switching filter."

SCJS#45 LEVIATHAN II

video upload by FL3SHB4CK

"Small Case Jam Sessions #45 - LEVIATHAN II

Battering Ram: kick & bass
Trepanator: main voice & clock
8bit Cipher: gates & cv
Mini Drive: overdrive & light
AHH: close & open hat
µGR2: random & gates
Beads: reverb & grains

Recorded live into Syntakt delay and reverb.

@zlobmodular @cirtcele @xodesnet @ShakmatModular"

SCJS#44 LEVIATHAN I

video upload by FL3SHB4CK

"Small Case Jam Sessions #43 - LEVIATHAN I

Battering Ram: kick & bass
Trepanator: main voice & clock
8bit Cipher: gates & cv
Mini Drive: overdrive & light
AHH: close & open hat
µGR2: random & gates
Beads: reverb & grains

Recorded live into Syntakt delay and reverb.

‪@zlobmodular‬ ‪@cirtcele‬ ‪@xodesnet‬ ‪@ShakmatModular‬

Nonlinearcircuits MACRAME | LOGORRHEA | VCF 1

video upload by cirtcele

"Macrame is a 6 channel mixer with voltage controlled level and panning. It uses two SSI2190 chips to do all the work.

You can use the SET pots to operate the level and pan manually, or use CV to get things moving around and up and down.

It has two synth level outputs, two line level ¼” jack outputs and a stereo line output (which works fine with most headphones too).

For some reason, probably because I was slightly askew on post-op painkillers when designing this, the panel is 21HP. I guess this means I need to release more odd HP modules to avoid gaps in cases."


LOGORRHEA

video upload by cirtcele

"Logorrhea is kind of a vocal filter; basically it is the back half of a vocoder crammed into 8HP. There are two inputs, 10 filter channels, a white noise channel and a thru channel, to feed thru the original signal(s). It uses two SSI2190 chips to do all the work.

There are no knobs.

To use, patch in one or two audio signals. Ones with lots of harmonics sound best, pulses, squares or wave-folder outputs, not sinewaves.

Patch in a bunch of CVs to set up your sounds, it expects 0-5V CV signals.

OUT is all channels mixed together.

OUT A is thru, LP (low pass), BP2, BP4, BP6 and BP8 (BP = bandpass).

OUT B is noise, BP1, BP3, BP5, BP7 and HP (high pass).

Using OUT A and OUT B in a stereo mixer (such as NLC Macramé) is nice with panning to move the sounds around."


FAST AND BULBOUS VCF
video upload by cirtcele

"This module uses the SSI2140 chip which is based on the SSM2040 VCF, tho with a few updates.

My first thought when I read the datasheets was that it would be great to design a module that could switch between a phaser and a VCF. Looking back at old SSM2040 designs, it seems most of the usual suspects (T. Henry, J. Blacet, C. Anderton et al) had much the same idea.

This module is based on Anderton’s design in Device 1-6 (yes, I spotted the error) with modifications to suit the SSI2140 and Eurorack.

There are 4 switches, one for each OTA stage, to select between (all pass (phaser) and low pass filter mode. You can have quite a lot of fun with 2-3 switches in one mode and 1-2 in the other.

There is a dry mix pot to mix the incoming signals into the OUT signal, which is taken from the 4th OTA stage. This is probably more commonly used in Phaser mode, but there are no rules, so do whatever you like.

POLES is a weighted mix of the outputs of each pole, it is a bit shy when all switches are turned to Low Pass but perks up very nicely when one or more switches turned to Phaser.

The SSI chip is a bit tight to solder, have your bottle of flux ready, otherwise it is a pretty easy build."

Let's Get Fenestrated

video upload by cirtcele

"Triple window comparator, each section has different features.
https://www.nonlinearcircuits.com/mod..."

"This module contains three individual window comparator circuits. They all work slightly differently from each other and somewhat differently from regular window comparators.

These are particularly useful circuits to create gate/timed events from chaos signals, or any other CV signal. It can also be used for pulse width modulation at audio rates, lots of good sounds to be found.

The rather grandiose names for each comparator came from a paper - Some Special-Purpose Comparator Circuits by H.K Verma. The actual circuits are different but two are inspired by the ones presented in the paper.

1. Special Comparison Instant – this is probably the most normal window comparator of the three. The pots can be used to set the high and low voltages between which the output gate will be high. You can also patch in CV signals to alter the high and low settings.

2. Comp for Concurrent Magnitudes – this will output a gate when the signal on Input 1 is compared against the setting of the SET/In2 pot. If no signal is on In 2 then the pot sets a fixed voltage, otherwise the signal on In 1 is compared with the amplitude of the signal on In 2, which can be attenuated by the pot as desired.

The extra feature of this circuit is the Level pot can set the gate level (up to 10V!) or you can patch a signal into the LEVEL input and create envelopes or bursts rather than gates.

3. Comp for Restricted Openings – this one has a pot (WIDTH) or CV control to set and change the gate width. In1 and In2 are summed together and compared with the level chosen with the SET pot.

Building is fairly simple, just be mindful to bend the LEDs slightly upwards to shine thru the windows from the bottom. It is good to use super-bright LEDs in this module as they have to shine thru the PCB panel."

RAZORS

video upload by cirtcele

"Razors is a dual voltage controlled frequency tripler........sort of, maybe best viewed as a harmonic generator for sine and triangle waves or a fuzz/distortion. Out 1 is sent to In 2 to get them running in series"

Sandy Freckle

video upload by cirtcele

"Sandy Freckle was a wonderful villain played by actor Rock Hampton in the Kath & Kim series. He was sleazy and annoying but irresistible and funny at the same time, much like this module."

via nonlinear circuits

"In Australia, there is an entrepreneur called Dick Smith who ran a chain of electronic hobby stores in the 70s and 80s (now he makes breakfast cereal). He used to publish circuit books every year (and sell kits for them), I no longer have the issue but remember the finer points of a circuit for a burp/fart generator.

It was simply 3 transistor based multivibrators running at different frequencies. The trick was that they were loosely connected by low valued resistors causing them to influence each other. This would result in unpredictable sounds that rarely repeated. Don’t expect it to actually sound like gas escaping from an orifice, think of it is a random pulse/burst generator

This version has pots to adjust the frequencies of each section and an input for turning the sound on and off rather than a switch. It can be fed gates or envelopes, which give a more gradual onset and tail as the sound starts and drops off.

Feel free to build it with whatever capacitor values you like. The ones suggested on the PCB (and heard in the demo vid) get into audible frequencies, but in some ways it is more interesting to use larger valued capacitors to get just pulses that will then ping filters and phase-shifters.

It is also interesting to feed it audio rate signals and it becomes a waveshaper/distortion module.

Sandy Freckle was a wonderful villain played by actor Rock Hampton in the Kath & Kim series. He was sleazy and annoying but irresistible and funny at the same time, much like this module."

LDRama 1

cirtcele

Light from the film controls the patch.

"1st attempt to make a demo with this module, using an excerpt from the public domain film Daughter of Dementia to generate CVs. Yes my phone is a bit big (A21) but works fine, the design suits regular 5x2 inch phones.If you want to use your synth for making soundtracks, this module is pretty useful.

The video shown is playing full screen on my phone, which is sitting on a bank of LDRs (light dependent resistors). As the LDRs change corresponding to what is on the screen, the circuit generates a variety of CVs based on different sections of the screen."

nonlinearcircuits BBX291 VCF

Published on Apr 3, 2020 cirtcele

"Vari-bandwidth VCF based on the Buchla 291, tho the CV sections are completely different and it uses a black box between the PCBs instead of dual vactrols.
https://www.nonlinearcircuits.com/mod..."