Seven Years

This blog is now more than 7 years old. The case is complete.  It’s time to look where we stand and have a bit of retrospective.

It’s been three years now since I bought the Tiptop Mantis case to host my modular synthesizer.  A fine decision.  It is a nice case with a good power supply with plenty of room.

Here is the current situation with what’s what.

 

This post is the 54th. The blog has now close to 78000 views. 

 

Along those years, Bob was always there to help me with the Do-It-Yourself aspects. Thanks Bob.

 

 

 

 

 

 

Some highlights of the last years :

- Beads, a granular texture synthesizer, Emilie’s Last stand : April 2021

 

 

 

 

- Tiptop Mantis, a better case for the synth : October 2021
 

 

 

 

- Ornament + Crime, the multi-purpose module : January 2022

 

 

 

 

- Beatstep Pro, the versatile sequencer : April 2024

You’ll find other highlights of this journey in the blog's 3 years retrospective.

The soundcloud playlist was growing as well. Mostly as illustrations of the function of a module for the blog, but not only :
- 14 sound examples of the module at hand;
- 12 sound illustrations of the state of the synthesizer;
- 2 participations to the monthly KVR Music Cafe;
- 1 participation to Audiofanzine Inspired Composition (Compos Inspirées).

 

 

Jay F. · Modular Suitcase

My Own Input Module

To close the 4HP gap at the bottom left of my synth case, I added a last input module. It will allow me to enter some external signals and bring them to the voltage level of the modular synth.  Moreover, it has its own piezo microphone.

It is modelled along the lines of Music Thing Modular Mikrophonie and Mutable Instruments Ears.

Input module

One input, an amplifier and an envelope follower for good measure.

The design is based on the original schematic for Ears from Emilie Gillet.  I kept the input gain stage. Due to space constraints, I had to simplify the envelope follower. I’m still doing pass through breadboard here, so this is not dense enough to have the same features as a full fledged Ears (or Microphonie Mk2 for that matters).

It took me a while to figure out the details. I had one operational amplifier available. The other being used by the gain stage. I was going for a short attack but not so short release with the right amount of filtering. Still not perfect : the shape is good enough but I fear that without the proper buffer at the end, I may not be able to drive any type of circuit.

 

 

Breadboarding the circuit : envelope follower output on top.

Piezo attached, other for scale

As I wanted to have some bumps to be able to scratch the surface above the piezo, I went with a different technique for the front panel.  It is the technique I used for the previous 2HP modules I made : dremel some lines and blacken them.
 

Bob helps with the panel

 

 

 

 

 

 

Mistakes I made include cabling the potentiometer in reverse (was expected), having a diode badly placed (more problematic) and connecting the piezo to the output instead of the input (confusing left and right duh !).

Debugging

Finished PBAs

 

 

 

 

 

 

 

 

 

 

 

This is the densest design I made this way. I begin to feel the limit and a desire to do things differently. I will change the technique for the next designs. In fact I might revisit the first modules I made, shrinking them in the process.
 

On the side

Here it is. Bottom left.

The completed case

 

And here are some sound examples where the module microphone is used for sound effects. Electric bass and synth pads are treated by the synth through the jack input.

Jay F. · Should I Come In

Finally, should you be interested, the schematics and layout.

A new sequencer

I haven't mentioned it on this blog yet: I bought a second-hand Beatstep Pro from Arturia.

Beatstep Pro

Beatstep Pro is a triple sequencer: two melody sequencers and a dedicated drum sequencer.
It has MIDI and USB inputs and outputs, but above all CV/gate/modulation and trigger outputs, which are useful for driving a modular synthesiser.
My now-ancient Korg SQ-1 pales in comparison. The Beatstep Pro can be used as the master sequencer in my setup.

This machine is cool, very playable and goes perfectly with a modular synth. Not much else to say about it.

Synth setup

Here's an illustration of a song in which the 4 tracks are controlled by the Beatstep Pro and generated (in part) by the synthesiser in a single take.

Jay F. · Beatstep Pro + Volca Sample + Rings

Drums and percussions : Korg Volca Sample (808 samples) MIDI-driven by the Beatstep Pro and two synth-generated percussions (Pony VCO+noise -> Multimode filter -> Percall). One of the sound is treated with Beads.
Bass : Doepfer VCO (PWM) -> Ripples 12db/oct How Pass Filter -> VCA (enveloppe from Rampage) -> Twin Drive
Melodies : Rings (polyphonic mode -> Left output in a reverb / Right output in a delay.  In polyphonic mode, when both Rings outputs are used, one trigger triggers one output, next trigger triggers the other one. Two melodies in one.
FX unit : Line 6 HX Stomp
DAW : Reaper with EQ and compressors added

OCP Update

After two years and barely much use, I decided to upgrade my Ornament and Crime module with one of the latest firmware.

Ornament and Crime being an open source platform means there are several alternative firmwares out there.

I reckon that the original firmware is a bit daunting : lots of applications with pages and pages of parameters.  Moreover, each application uses all the inputs and outputs. I do not need, for example, a 4-channel ADSR envelope generator.  One or two is enough. I wanted less comprehensive applications, using less resources and be able to mix some of them (i.e combine a Sequencer and an LFO generator)

Why would I need 4xADSR envelope generators with 20+ parameters ?

Update in progress

And that’s what firmware like Hemisphere promises. It is an "alternate firmware for the Ornament and Crime Eurorack module, featuring a dual-applet framework with dozens of different modular functions".  Each applet is simple with an handful of parameters. And two can be combined at any given time.

The latest incarnation of Hemisphere is djphazer’s Phazerville. In the classic open-source forking tradition, it is built on Benisphere, itself a fork from Hemisphere. It still contains a fair share of the original applications, so it makes quite a complete feature set.

My version of Ornament and Crime is based on a Teensy 3.2 micro controller platform.
So I downloaded a Teensy loader, turned my module around in order to access the ‘program’ button, followed the instructions on the Teensy loader webpages and that was it.
As far as I can tell, the installation of a new firmware does not affect calibration data, so I was good to go after the 30 seconds installation.

Now I have a new world of possibilities to explore 

Done

Fixing the random module

This Random module, with its noise generators and sample&hold, is one of the first modules I made in 2017.  It's based on a design by Yves Usson for his Yusynth.

For some time, I had been under the impression that the output of the sample&hold had no influence on the modulations I assigned it to.

After some investigation, it appears that the input jack is at fault.  This jack has a switch so that if no plug is connected then the internal noise feeds the sample&hold. When a plug is connected, it opens the switch and the input signal feeds the sample&hold function.
 
In this case, the jack is of bad quality and its switch no longer closes properly.
 

Access is not so easy

Once replaced, everything works again.
I even changed the clock input jack because I thought we were using the same internal/external function management principle. But it wasn't necessary: the switch is outside.

Fixed !

Percall

Percall is a percussive oriented module that will shape four different sound sources into percussive sounds. Percall has four VCAs with dedicated decay envelopes and a mixer so that you can prepare a percussion submix.  (Source : befaco.org)

Freshly finished

As soon as Befaco introduced this module about 2 years ago, I wanted to have one.

However, at the time, available space in the suitcase and other priorities forced me to hold off.

Using my need for a new VCO and my choice of the Pony VCO, I upped my order to Befaco with a Percall kit.



This kit is qualified as "high grade", the maximum difficulty level at Befaco. And this is not misleading.  It is indeed the densest kit I have ever assembled.

Under construction

The two PCBs come grappled together.  This is unprecedented for me, and actually quite practical.
The instructions are basic and very clear. 

The PCB is dense. You have to be extra careful with the labelling, since some of the designations can be confusing if you are not paying attention. As usual, I proceeded methodically and slowly, in small sessions, highlighting the parts on the instructions as they were placed.

There were no particular issues with the soldering of the components.
 

Bob cuts components leads

 

Assembling the front panel was not as challenging as I expected.  I followed the instructions not to solder the parts before assembly, so that I could fit them precisely.  Small problem: I ended up with too few a black nut to fix the jacks.  Either I lost it or it was not in the kit.
It doesn't matter.  I used a plain old nut that was lying around in a drawer.
Did you notice it in the first picture?  I don't think so.

No empty space. The whole volume between the PCBs and the front panel seems to be occupied.

 

The boards before assembly

The edge

Here it is, mounted in the rack with its little friends. It gives me a nice envelope generation and manipulation section.

In the rack

 

Pony VCO

Befaco Pony VCO

I decided to replace my two Mammouth Boutique modules with two new Befaco kits.
The wooden front panels are very cool, but they contrast a bit with the rest.  Besides, if the modules are okay, I wanted something else.

After much hesitation, I decided to replace the oscillator with the new Pony VCO from Befaco. The other alternatives were two completely different modules: Make Noise STO and Klavis Twin Waves. One for its clean sound and simplicity, the other for its possibilities. In the end, the Pony VCO was chosen for its size (only 4 HP) vs its possibilities. And it's a kit ... well ... kinda.

Pony VCO is a very complete oscillator. It can generate over 7 octaves a sine, a triangle, a sawtooth or a square. It can also be used as a low frequency oscillator if need be.
There is a Thru-Zero FM input, which means that when the modulation signal falls below zero, it continues to oscillate, reversing its phase. This technique should make for some nice metallic sounds. It has a timbre control in the form of a wavefolder for more sonic possibilities. Small but powerful.

The kit

The kit is quite simple: two switches have to be mounted and adjusted with the front panel.  You assemble the front panel.  And that's basically it. The rest are surface mounted components already mounted.

Given the narrowness, the ten or so soldering operations needed require some dexterity and attention.

 

 

Bob calibrates

Then comes the calibration. The kit includes a small card with a QR code leading to the manual. Great idea. Except that the manual is incomplete and does not contain the necessary illustration to know where to measure the reference voltage. Fortunately, the complete manual is available on the product page.

The calibration does not pose any particular problem.

 

 

In the rack

With the two Music Thing Modular modules, the bottom row is starting to take its final shape.
Note that I took advantage of my purchase at Befaco to order a synth Duster, a handy anti-static duster and bananuts, those coloured minijack nuts to change the look of my Befaco modules and my Erica Synth filter. Befaco has a new colour code, with black nuts for the inputs and red for the outputs. Beautiful and practical.

My bottom row is getting complete.

Nearly finished botom row

And finally, a small sound illustration.  It is made of two main parts. The first is the sine output of the Pony VCO, modified by its timbre and the Twin Drive, filtered by Ripples and animated by Tides and Rampage. This is about the first minute of the sound bite. It is detailed in the patch notes below.
For the second part, a PWM wave is split into high and low frequency parts by a multi-mode filter and animated by Tides and Rampage envelopes. The sum of the two is then passed through Rings, then Beads in stereo mode.

Jay F. · The Machine (Part 2)

 

 

Patch of the first part of the track