Monday, 6 June 2022

Some Drums, Some Bass

Here is a short sample of what you can do with Ornament & Crime (OCP) module. I know, I was not very prolific producing music these past months.

Here goes.


OCP euclidian rhythm params
This five-track piece was recorded on a single session.  No detailed patch today but a light description with the links to the modules I used.

Ornament & Crime with the Pique application generates the three envelopes for the drums using the included euclidian rhythm patterns. 

Kick is Ripples filter pinged and modulated by OCP envelope number 1.

Light clap is a sine wave ringed modulated with white noise in A*B+C with OCP envelope number 2.

Hi-Hat is pink noise mixed with triangle into Erica Synth high-pass filter with OCP envelope number 3.

Patterns for clap and hi-hat are controlled via control voltage, hence the variations.  Clap is controlled via sequencer, hi-hat density is controlled by a random source.  

The synth setup
Swoosh effects is white noise into Rings into Beads, with Tides and other sources as modulation.

Bass, clock and sequencer from Novation Circuit Mono Station.

Sources of modulations : Sloth Chaos, Rampage, Turing Machine and Sample&Hold.

Some effects courtesy of Line 6 HX Stomp.

DAW : Reaper.  Additional effects on Hi-Hat include a dotted 8th note delay. Other effects: stereo diffusion, compressor on drums and bass, some reverb on drums, tons of EQ.

Sunday, 16 January 2022

New Year. New Challenge.

Ornament and Crime is one of the Eurorack modules constantly recommended in modular synthesizers forums, along with Math from Make Noise, Batumi from Xaoc or Clouds from Mutable Instruments.

If we add that it is basically an Open Source project, that it exists mainly as a kit and that there are several variations of the firmware, it goes without saying that I needed one. 

Front side
I decided on the Plum Audio version, a kit available from the Thonk online shop.   This improved version has input control in the form of attenuverters with LEDs, output voltage adjustment and a front panel USB connector.  

Let's avoid the financially painful episode of a post-Brexit purchase from a UK site and let's get to the point.

The kit
Ornament and Crime is a polymorphic control voltage generator.  It has four modulation inputs, four trigger inputs, four outputs and a micro-controller to handle them all.  

Bob cheks solder quality

The micro-controller is a standard Teensy 3.2, with an ARM Cortex M4 on board.  It comes pre-loaded with the official firmware.  
Depending on the firmware application, the module can act as an analogue shift register, sequencer, arpeggiator, envelope generator, quantizer and so on.  Hemisphere, one of the alternative firmwares, even offers to choose 2 modes simultaneously from a choice of about 60.

It was the four independent envelope generation function that made me decide that the module was useful for my usage, but I will experiment with the other modes of course.


micro USB parts.
Bob for scale

In the article about the Befaco Rampage, I wrote that the kit was not for the faint of heart.  However, this version of Ornament and Crime is two divisions above.  Not only is the density high, but there are some tough parts, such as the OLED screen, the micro-USB connector and the "pogo" pins (aka spring-loaded pins) under the micro-controller board.





Bob cleans up
The kit is very well thought out.  The two PCBs are well designed and very clear with the part number and value of each component clearly indicated.  The bags are organised according to the progress of the kit. The contents of each bag are listed on the label. The documentation is accessible via a QR code on the box.  It is minimalist and refers extensively to explanatory videos, which are very practical, but sometimes a little fast.

Despite the density and number of components, the assembly went smoothly given the quality of the kit.  As usual, I did many small sessions, methodically, calmly.  It was demanding but in the end I didn't have to correct anything.


Back side
The only anecdote worth mentioning is that the documentation asks to pay particular attention to the orientation of the bicolour red/green LEDs and indicates that some kits have been delivered with reversed LEDs (red instead of green and vice versa).  I did a quick check with other LEDs I have and concluded that this be the case.  I decided to solder only one of the 8 diodes legs before a final check.  Once the front panel was assembled, the test clearly showed that my diodes were the right kind and therefore assembled backwards.  Unsoldering everything, turning the LEDs over, re-soldering...
If I had been really smart, I would have tested with *one* diode *before* placing the front panel. 

User Interface board.
LEDs are reversed.

Once assembled, the module still needs to be calibrated.  The firmware guides all along the way but it is quite tedious to measure the 50 or so calibration points.  It took me almost an hour, including the time when I had to remember how to use the measurement ranges on my multimeter.  Fortunately, this is a one time thing.

Now I just have to get used to the beast.  We are far from the "one function per button" philosophy of analogue modules. Since this is a geeky project, parameter pages abound in each firmware application

Module is alive. 
Testing various options of the envelope generation.
The screen refresh is visible in the picture.


Sunday, 19 December 2021

ModWiggler Odd Meter Remix Challenge

I'm no stranger to participate to some Internet forum challenges or contests.  Some of them are being illustrated in this very blog.  I participated in about ten One Synth Challenge sessions, some other KVR contests and more than my share of Audiofanzine contests.  Lots of these can be found in this Soundcloud playlist.

But this was different.

Some admins from the site ModWiggler decided to have a contest between them to create an odd meter track.  The challenge here was be to ‘remix’, or ‘re-mangle’, or ‘reimagine’ the winning track (whatever that means) and use at least two of the provided multitrack files in some sort of manner. 

The principle gear used must be modular or semi-modular and patchable with pins or cables. 

It was fun and I learned a lot. I had to do things I was not used to. Performing a track and not arranging clips in my DAW being one of them.

Synthesizer in action with both sequencers

Mixing section with the old synth suitcase

I assembled and looped the two files I selected on a computer and kept them in synch with the sequencers as best as I could.  They can be heard untreated at least once.

I really stretched myself here. Literally, as I brought another table to support the mixer and my old synth suitcase.
I went out of 3.5 mm to 6.35 mm adapters.
I used modules that I previously stored because they couldn't fit in my main rack.
I allowed myself to have the kick drum out of modular but I used an analog mono synth anyway : a Novation Circuit Mono Station.



My main concern was sequencing. I do not own a lot of sequencing capacities. I used my Korg SQ-1 as well as the main sequencer and the third auxiliary sequencer on the Mono Station. The later has the possibility to directly output control voltage and gates signal to a modular synthesizer.

Anyway, I'm not used to use only the modular and to mix outside the box. For the sake of the challenge, I refrained from arranging and mixing in my DAW, so the mixing took place inside my good old Berhinger MX802. It's written 'eurorack' on the faceplate, so that counts I guess.  

Only treatments in DAW are a bit of EQ, compressors and a limiter.
To be fair and accurate, I did a little copy-paste to correct a technical issue at the end. The issue is present somewhere else on the track but it was too loud and clear on the ending.

So enjoy :

Full documented patch :

Wednesday, 1 December 2021

Facing the Tides

 Tides was the new module I slipped in the new case.

Tides unboxed

Now that I have more space in my case, I reckon I can accommodate another Mutable Instruments module.
Some might argue that this was the main reason to get the new case in the first place.

Cause or effect ?  Whatever.

The Mutable Instruments modules in the rack.  Tides on top.

Mutable Instruments Tides checked a lot of boxes.  

I felt I needed more modulations.
Tides is a LFO and an envelope generator at the same time.  Waveform parameters like shape, smoothness and slope are modifiable via control votage.  So there are a lot of waveforms available.  The module accepts an external clock as well.
It has multiple outputs and, depending on the mode, they are either different shapes, different amplitudes, different times or different frequencies.
Frequency range can go up into audio range, making this my third VCO.

In action


In the following piece, Tides plays the role of LFO, envelope generator and oscillator.  I have displayed the patches to demonstrate how it is done. 

The first part is a four-track drone. Each animated by a dedicated LFO from Tides in « different frequencies » mode.  Lots of effects (from Reason rack) added in the DAW (Reaper) as well.
Then two « bass » tracks played with the Korg SQ-1.  Tides is now the VCO.  Same patch, different settings.  The variations are either the Ripples filter frequency or the shape and smoothness parameters from Tides.  These have a dramatic effect on the sound obviously.
Finally, Tides serve as one of the Attack-Decay envelope from the drum part.

A bit of cut-paste in a sequencer and voilà …

The patches...

The four-part drone waves :


 The basses :


The drums : kick, snare, hihat :




Saturday, 16 October 2021


I thought it would be a good idea to compare the new case with the old one. So here it is.

Before :

After :

More space, better power supply, better ergonomics overall.

Sunday, 3 October 2021

Tiptop Mantis

Close up of the new case

My synth suitcase is very cool.  I enjoyed setting up the inside of the case, spending hours building modules and experimenting on my first patches.  
Final shot of the synth suitcase

But, with the last modules I bought (some of them still to be revealed), it became too small. Also, I reckon the power supply is at its limits.  I find that it starts to heat up too much during long sessions.  Finally, the fact that I don't have a removable lid makes it a bit uncomfortable to use.  Although I have used it a few times as a stand for the sequencer or an additional Volca, it's not very convenient to have the lid in the way.

So I decided to buy another modular synthesizer case.
The Mantis from Tiptop Audio is elegant, widely recommended, of a manageable size and not too expensive.
Assembly, following my Modular Grid plan on my phone

Bob pulls the module

Internally, there is a comfortable power supply (more than twice the power of my previous power supply) with shrouded connectors.  
Some of these connectors are mounted horizontally, freeing up space at the bottom of the case (61mm deep at most).
Not enough space

Despite this, there is not enough space for my deepest modules: in the top part modules cannot be deeper than 50 mm. My sample&hold can hardly fit in there because what is sticking out can slip behind the bus board.


Also, the feet take up some space, which drastically limits the depth of the modules on the left and right of the bottom row. 

I had to revise my plans by inverting the two rows in relation to the synth-valise. For the better I think.  Anyway, no other choice.




I thought I was indifferent to having threaded rails or sliding nuts. Or even that I liked the fact that I could quickly reposition modules with the sliding nuts. I was wrong.  The threaded rails are much more practical.  The assembly went smoothly.  I just had to plan to run two power cables from the bottom modules to the second row, as there is only room for 12 horizontal connectors and there will be 13 modules in the first row.

Bob plugs the cables

Finally, being able to position the box at 45° is a real space saver and is ergonomically pleasing.  On the other hand, at 90°, I am not confident enough in the two plastic legs.

The cable of the external power adapter is too short. The 230V power cord can be changed easily.  But the connection to the box could be 2x longer.  If you want to have the box vertical, the power supply hangs down and it's a shame.

Oscillators, filters, resonator

No sound example today.   But a quiz: a new module has slipped into the set, can you spot it?
The answer will be the subject of the next article.

Friday, 28 May 2021

Passive Modules

Finished guys
It looks like it has been a year since I built my last DIY module.
Time for some passive modules I guess.

I ordered two 2-hp blank.  I needed another multiple to fill the rack and I decided to experiment with some passive functions.

A passive multiple is very basic.  You simple connect the tip and ground of each jack.  In practice the ground connection is established via the aluminium panel.  No need to use wire.

The main difficulty here is at 2-hp, or a bit more than 1 cm width, you do not have a lot of margin to drill your holes.  You do not want the body of the jack to go over the edge.
Not perfect but good enough.
I used mostly very cheap jacks I got a long time ago, except for the one with the switch as the switch on the cheaper ones is really terrible.

Behind the scene

Bob at work with the panel
I also experimented with some minimal panel marking by using my Dremel to carve some traces and fill them with a permanent marker.  This should not age very well. Time will tell.

The second module is the combination of a passive OR and a half-wave rectifier, ideal to combine gates and manipulate control voltages or distord audio.  You’ll find  the layout for both of them at the end of the article.  I got the schematics from unrecordings! blog

In the rack

In the following piece, the Korg SQ-1 produces two tracks of gates and CV for the kick and hi-hat.
I used the multiple to distribute the gates everywhere in the synth and I used the OR function to build a third melodic track from the first one and the output of the Turing Machine,  clocked by the second track.  I know it sounds complicated.  Patch schematics is at the end of the article.
The half-wave rectifier produces some overtones to spice up the sounds.
The variations in the piece is me playing with the sequencer.

Connection layout

Patch of the day