Ring-Mod Round-up

An overview of five balanced-, or ring-, modulators: the Intellijel μMod, Makenoise ModDemix, Fonitronik mh-31, Doepfer A-133 and Cwejman VCO-2RM.



RingMod Roundup by navs

These modules have a different approach, feature set and, as you can hear, sound. The Cwejman is a classic two-input, one output affair and I included it as a reference as it has good rejection and headroom.

On the face of it, the additional features offered by each manufacturer set these modules apart. However, given that the basic concept is the same, these differences might not be that wide. The μMod's 'Q' function, for example, seems to be a bipolar offset, something that could be patched externally with the Cwejman or by increasing the manual gain on the A-133. Similarly, the auto-AM/ pseudo-SSB modulation offered by the ModDemix's normalizing could also be covered by a dual module like the Doepfer. Incidentally, it's a shame neither of these dual modules can be used as a mixer out of the box. Pre-patching a signal to one of Maths' attenuverters and using the uni-polar OR output as modulator would yield a function similar to the μMod's rectification switches. The mh-31 utilizes rectification as part of its 'RM' process which might explain its characteristic sound.

Two technical points to note: when used as a VCA, the μMod I tested displayed a small amount of carrier bleed (audible in the example above), but I'm sure this can be corrected by calibration of the 'Q'/ offset. The A-133 suffers bleed too, but this is understandable due to its lack of centre-indent pots. At low 'strength' amounts, the ModDemix displays an unusual response - the processed waveform seemed more typical of AM than the 'attenuated' RM I'm used to from the A-133. Both the Makenoise and Doepfer are DC-coupled, so I wonder if this difference is down to the circuit employed.

In terms of sound and function, I saw the closest parallels between the VCO-2RM & μMod one the one hand, and the Doepfer & Makenoise ModDemix on the other. The mh-31 is the most unorthodox design and doesn't easily fit in either camp.

To my ears, the Cwejman and Intellijel have the cleanest tone, with the Makenoise and Fonitronik well-suited to more abrasive timbres. While not as transparent as the VCO-2RM or μMod, the A-133 can be both clean or driven to distortion.

Thanks to Schneidersbuero for the loan of the Intellijel & Makenoise modules.

Patch Tips #15 - Non-Linear Distortion

I recently stumbled across the Nord Modular's exponential shaper module while looking for something to bend a signal. The ShpExp works with transfer functions to generate non-linear distortion. This can give a sound edge, without totally shredding it. Of course, my next thought was whether it would be possible to patch something similar with my system. As usual, Rob Hordijk had the answer.



The trick involves generating a signal at twice the frequency of the source, which will then be used to modulate the amplifier. The easiest way to do this is to patch multiples of the source to both inputs of a ring modulator, effectively multiplying the signal by itself. This performs full wave rectification and, in the case of sine waves, frequency doubling. Patched to a linear VCA, a sine wave is bent like this:



Here's how it sounds:


Mono- then Duo-phonic signal. Clean Cwejman signal path (MMF-1 sine, VCO-2RM RM, VCA-2P)


Mono- then Duo-phonic signal. Dirty Doepfer signal path for added crunch (MMF-1 sine, A-133 as RM, A132-1 VCA)

Feeding the rectified, frequency-doubled signal back to the source, rather than the VCA, will bend the sine into a triangle, albeit with a different pitch. Try varying the FM-CV amount, other VCO waveforms or even polyphonic signals for seriously warped shapes.

I used the VCO-2RM and A-133 which, being dual, allows one to cascade and further multiply the modulator. Frequency doubling or rectification can also be achieved by feeding +ve & -ve signals to a min/max analogue logic module like the A-172 & Maths' OR processor or Doepfer's A-119 ext. input module, as per this Patch Tip. Like the A-133, Fonitronik's forthcoming mh31 and Makenoise's modDemix provide one-stop solutions.

I'm not sure if this process is in fact single-sideband modulation as the modDemix description suggests, but it's certainly closely related to Amplitude Modulation which will be the subject of the next Patch Tip.

Fonitronik mh31 VC Modulator

A look at the Euro-prototype of Fonitronik's unconventional ring modulator.



See this thread at the electro-music forum for the background to this project and Kevin Kissinger's excellent demo.

"Harry Bissell once recommended Irvine's design for a ring mod. I changed the resistors to our common values, and added two VCAs to the inputs, thus giving a voltage controlled ring mod. Makes a lot of fun."

Matthias's opening description in that thread might lead one to believe that this circuit is indeed just another ring modulator with the added benefit of voltage control, something akin to Doepfer's A-133 VC Polarizer. Irvine refers to his design as a 'frequency mixer' and, while I'm not sure of the the semantic difference, the sonic results certainly are unlike 'normal' RM.

Here's a comparison between the Cwejman VCO-2RM, the A-133 and then the mh31:

mh31a.mp3

The Cwejman and Doepfer (0:26) exhibit 'classic' RM, with the latter distorting at higher CV levels. The mh31 (0:54) produces a harsher, more metallic tone that, while having RM characteristics, doesn't yield the expected sine-on-sine bell-tone. Here's what the waveforms look like:



Irvine's circuit sums the inputs, then inverts, rectifies and doubles the amplitude of the sum. This offers a clue as to why this circuit sounds different. In the following example, I've modulated an audio signal with an LFO. Using a traditional DC-coupled RM, the amplitude is attenuated as the LFO nears 0V and is then polarized. To the ear, flipping the polarity of an audio signal should make no difference:

mh31b.mp3
(VCO-2RM, A-133 @ 0:11, mh31 @ 0:25)

This last clip highlights the difference in Irvine's approach. Rather than simply changing the polarity, at slow speeds, the waveform seems to 'change direction'. This reminded me of the type of soft sync that is implemented in some VCOs or mixing waveforms in a min/ max analogue logic module like the A-172. Here's what it looks like:



The term 'ring modulator' might be misleading, but that shouldn't detract from the possibilities of this circuit, both in terms of timbre and function generation. The build quality is excellent and, taken as an alternative to the classical DC-coupled ring mod, the mh31 offers new sounds and surprising results when processing control voltages.

Patch of the Day - Automation Uncertainty

Three VCOs running as External Instruments in Logic, random CCs & pitch information generated by a Sequentix P3 to various plug-in parameters.


Automation Uncertainty

The patch:
1) Livewire AFG linear FM'd by Cwejman MMF-1,
reverb depth modulation.
2) Cwejman VCO-2RM > Plan B M13,
delay time & level modulation.
3) Cwejman VCO-2RM > Doepfer A-105,
flanger feedback-level modulation.

Shame there aren't any decent, fully CV-able stereo effects in Euro format yet, as I'd far rather do this in the modular realm than faff around with assigning CCs. But in terms of flexibility and price, it's a good compromise for adding some modulation madness to your patches.

Silent Way CV Input - Digital Ghost Tracks

Ever wanted to record CVs to your DAW? Expert Sleeper's latest 'Silent Way' plug-in makes this possible.

'CV Input' brings Buchla and Subotnick's Ghost Tracks method into the digital age. The plug-in can handle bipolar CVs (LFOs etc.) and the 'recovered' CV can be output live or recorded for rearrangement or further processing.

To get the most out of 'CV Input' you'll need a DC-coupled Ring Modulator although for unipolar CVs (envelopes etc.) a standard linear VCA will do.

In beta testing, I tried a Doepfer A-133 VC Polarizer, Cwejman VCA-2P and the DC-coupled ring modulator in my VCO-2RM. The latter gave me the best, most accurate results. The A-133 is a good, cheap option but the lack of centre-indent on the manual offset pot made it tricky to zero the output precisely and meant the returned CV was asymmetrical. The VCA-2P was not as accurate because its 'linear' mode is in fact semi-logarithmic. Os at Expert Sleepers suggested that a calibration function to address these issues might be a possible future update.

So, does it work? The short answer is a resounding yes!

The caveat is that you might need to spend a few minutes setting up the plug-in for your system, but this is swift and painless. For example, you want to find the 'hottest' carrier level your audio interface can handle and balance that against the strength of the modulating CV to avoid clipping your VCA or RM. Then you will need to use the 'scale' knob to get a 1:1 match between 'original' and 'recovered' CV. Bear in mind that you might need a negative scale to counteract any anomalies in your system.

Here's a short clip featuring three tracks of one VCO following the same bipolar random CV. For each successive 'harmony' track I adjusted the decoder's scale.



Nice one Os - now all we need is a pitch to CV converter!

For more Silent Way tips and tricks read this post.

Patch of the Day - Long Way Down

Something gentle for a Sunday afternoon:

PotD_longwaydown  by  navs

Live, four-voice patch with manual tweaks.

Self-oscillating Cwejman MMF-1 dual-peak sine modulated by WB smooth out. A-Sol SH-NZ noise to Plan B Model 12 HPF, VCA VC'd by Doepfer A-147 VCLFO sine, itself VC'd by the output of a A-156 Quantizer. Ring Mod output of a VCO-2RM filtered by a Malekko/ Wiard Borg, envelope from Bananalogue/ Serge VCS VC'd by Woggle out. M15 VCO (linFM) gets WB stepped, gated by M10 envelope which is triggered by WB burst and VC'd by stepped out. M10 EOC to A-142 envelope which provides the voltage which is then quantized by the A-156.

Patches. They always start out simple, don't they ...

PotD - Polystyrene / Buchla Lust

Today's Patch of the Day was inspired by Morton Subotnick's Sidewinder.

PotD_Polystyrene  by  navs

A Plan B M15 VCO running through the bandpass section of a M12 filter provides the polystyrene, the ring mod output of a Cwejman VCO-2RM the glassy tones.

On a side note, the following was recorded in response to this thread over at sequencer.de discussing how one would go about cloning a Buchla Music Easel with Euro-format modules.

All sounds were created with Plan B models 10, 12, 13 & 15 plus one modulating oscillator:


Buchla Bore

Sure, I'd love a vintage Buchla too, but I don't need one. Honest.

Welcome to Navs Modular Lab!

Welcome to navs.modular.lab, a resource for Euro format module reviews and samples.

Over the past year, I've tested more than 20 different VCOs, VCFs, VCAs, Modulators and Manglers and posted the results over at the Canecutters website. I'll be moving the tests from their old home during the next couple of weeks and adding some new ones. You can look forward to Plan B's Model 10 Polyphonic Envelope, Doepfer's Source of Uncertainty and some lovely examples of the Livewire AFG's FM capabilites.

This site will also be home to Patch of the Day, my modular patch diary which has just celebrated its first birthday.

But to kick things off, I've got some demos of Bleep Lab's Thingamagoop which I bought here in Berlin at General Robots - a great shop full of things you didn't know you needed.



Not exactly modular, but fun nonetheless!


Thingamagoop Rises


Thingamagoop Flies


Thingamagoop Modulates

Thingamagoop did his thing through Cwejman's MMF-1 filter and a Roland Space Echo. On track 3 I ran him through an envelope follower and took the signal to stimulate a pair of ring modulating VCOs (Cwejman's VCO-2RM).

Hope you enjoy the sounds & site and look forward to your comments!

Cheers,

Navs

Patch of the Day - Harmonyhertz

I twisted my knee and had to undergo an MRI scan this week. For those of you who haven't had the pleasure, this is what it sounds like:

Harmonyhertz-PotD  by  navs

Having entered the machine, you're given a pair of noise-canceling headphones. The classical music that is piped through these is supposed to calm and distract you from the grunts and buzzes generated by the scanner. Don't know which device was responsible, but the kick and hi-hat pattern was a bizarre counterpoint. Sort of like a Clockwork Orange warehouse party. Someone with a sense of humour at Siemens, the company that built the contraption, decided to call it 'Harmony'. The nurse told me that the larger unit is called 'Symphony'.

THE PATCH

The patch features four voices: kick and hi-hat, ring modulated squarewaves, FM klunk and some 'ducked' classical music. Although I managed to use up nearly all of my patch cables, it was actually fairly straightforward.

Drums: MMF-1 sine wave kick, M12-filtered-noise hat. LFO provides rhythm, VCS provides gate delay for 'swing'.

Buzz: Wogglebug stepped out provides slow pitch changes for VCO-2RM. Two square waves, with a touch of XMod and manual pitch and PWM tweaking, are output from the ring modulator. Timing is generated by the burst out of the WB which is patched to a clock divider. The /8 gate signal triggers one Maths channel. An inverse /8 gate is fed to a second Maths EG so that the klunks are timed to occur after each buzz has sounded.

Klunk: M15 & AFG lin FM plus some pitch woggle and envelope thwapping from Maths and the mix out of an A-143-1. Maths' EOC used to trigger the Doepfer, klunk gated by M13 LPG.

Classical: Borg-filtered with a bit of FM from the combined buzz & klunk CVs. Vactrol speed in evidence as the CV takes a while to fade away from it's peak.

Ducking: this was achieved by sending the classical sample to the first channel of an A-134-2 VC Xfader, the audio mix of buzz and klunk to the second and applying the combined buzz and klunk CVs to the (asymmetrical) Xfader.

Hope you enjoyed the sounds and remember to look after yourselves!

This PotD dedicated with thanks to the docs and nurses.

First Patch of the Year

Dusting off the cobwebs after a week on the Baltic Sea island of Rügen

Der Rasende Roland by navs

Another P3 driven track featuring four elements: VCO-2RM cross-modded and 'thwapped' by a VCS to a Model 13 LPG and gated by an A-143-1, AFG FM'd by an A-105, MMF-1 dual sine pinged & VC'd and some white noise sweeps.

Happy New Year to all!

PotD - Toppo Banjo & the Wonky Beat

Two patches/ applications featuring Toppobrillo's Triple Wavefolder: first as a traditional audio waveform multiplier, then processing an LFO to generate syncopated rhythms.

Toppo Banjo

Although the TWF is capable of creating more extreme sounds, especially when fed with polyphonic or FM'd material, in this first recording I've kept the settings fairly tame.

For the plucked banjo sound two stages of the TWF processed a single sine wave which was then filtered by a Wiard/ Malekko Borg. The bias was modulated with an envelope. The guitar sound was similar, with the exception that I modulated the DC offset with an LFO. The Hammond/ Leslie-like sound was the result of three stages folding an exp. FM sound from a Cwejman VCO-2RM, an oscillator the TWF seems to love.

In this second example I used the TWF to multiply an LFO to mess with an otherwise straight rhythm:

BeatFolder

The kick drum is triggered by the pulse out of a Doepfer A-147 VCLFO, the FM click sound by the folded signal and the FM klonk by a subdivision of the same (A-160). In the first 40 seconds I adjusted the bias settings of the three folding stages, thereafter I altered the DC offset. This was a lot of fun and the results are certainly useable.

The Toppobrillo Triple Wavefolder has been a revelation to me - despite having built my own CGS Lockhart Wavefolder and tried Doepfer's A-137 and the Bananalogue/ Serge WVX, I never quite 'got' wavefolding/ multiplying. The Toppo sounds fantastic - to my ears, the best of the bunch - and its open nature makes it a flexible tool: you could, for example, tap the output at stage two, send it to a resonant filter it and then return it to stage three for some final folding. I managed to coax subtle plucked harp sounds through to aggressive sync-like 'digital' basses from this module, all with minimal fuss. Its taken me a while to cotton on, but the Toppo has opened my ears to wavefolding and got me inspired.

Thanks to Herr Schulz at Schneiders for his almost missionary zeal in recommending the TWF!

Cwejman DMF-2 Dual Filter Demo

A demo of Cwejman's DMF-2 dual filter.

Drones created with the DMF-2, a VCO-2RM, Wogglebug and Bananalogue VCS.

Cwejman DMF-2 Demo by navs

This was the first time I had the opportunity to process an audio source with two, matched filters. With the cutoff frequencies offset and, fed with different CVs, this module is capable of some great sounds.

Patch Tips #12 - More Mixed Envelopes

Mixing envelopes for tailor-made transients. A follow-up this post.



Today's Patch Tip aims to overcome the limitations of the simple ADSR envelope when used to open a filter or VCA. I often find that in addition to controlling the time it takes for an envelope to reach it's peak value, I also want to control the level of that stage. This is especially true of the attack portion when I want more 'bite' without increasing the overall modulation depth of the D, S & R stages. Mixing an ADSR with an AD envelope solves this problem:

envmix1.mp3

Cwejman VCO-2RM (+ sub ex A-160) > Borg filter, ADSR-VC2 + Bananalogue VCS > Fonitronik polarizing mixer > Borg. Gate to both envelopes. Pitch CV > VCOs + Borg 'key in'. Makenoise Pressure Points row 1 offsets pitch of oscillator 2, row 2 > VCS VC rise.

This is a simple but effective solution without getting into the complexities of patching-up a time/ level envelope as found on the Korg Poly 800 or Roland JD-800. If you did, however, want to try this, the Maths, Brains/ Pressure Points and Doepfer A-143-1 manuals all offer examples.

PotD - Mutant Horse 2

A gentle gallop into Basic Electricity #5 on Friday. This is a take on the patch Tom & I played at BE#4, likened by Ian Boddy to "riding a mutant horse".



A Sport Modulator provides both timing information and CVs, driving Maths, a VCO-2RM, Triple Wave Folder, A-112 Sampler/ Delay and VCA-2P panner. The oscillators are FM'd before being gated, folded and sampled. A stepped and manual CV controls the rhythm, delay time and panning. Flipping between track- and sample-and-hold on the SM delivers the final crack of the whip.