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

 

Modular Music Thingies

At the end of 2022, I took part in a giveaway organised by Thonk, an online shop for modular synthesizer products. The goal was to raise money for a charity for Pakistan. The prize was a Plinky, an out of the ordinary synthesizer with a very peculiar interface.
Thonk also had the good idea to include 2 modules from Music Thing Modular.
I was lucky to be among the 4 people who won this giveaway. And I am now the proud owner of these two modules: Startup and Twin Drive.

Unboxed

Startup includes a clock generator in the upper part, with a tap tempo and a split control.
The lower part is an audio mixer. The mixer has no knob. Instead, relative volumes are set by patching : loudest on top, quietest at the bottom, one stereo input. Finally, there are two stereo headphone outputs. I would have preferred two mono outputs, but here we are.

Twin Drive is a double overdrive with nice incandescent overdrive bulbs.

They have a temporary place in the rack, because they were not in my plan. But I'm not going to leave such fine modules on a shelf.

Twin Drive

Startup

Avalanche

I bought this module kit from Mammouth Boutique before the shop closed. So it's been a while.

I finally put some time into it at the end of 2022 to start building it.

Finished Avalanche

 

The kit

Avalanche is a rather imposing module with 42 HP (21 cm long). It consists of 8 oscillators with a filter, an envelope generator, an internal clock, a sample&hold and an effect processor.  The latter is based on an FV-1 SMD chip and is pre-soldered onto the board.

It's semi-modular, so you don't need any cable to produce a sound. But you can take advantage of the random generator or the envelope to play with the pitch or the cut-off frequency of the filter.

The kit is flawless like the previous ones from Mammouth Boutique.
There is a single PCB with the electronics on one side and the numerous controls on the other. The black front panel is very classy although a little cryptic.

Since I assembled it after closing the shop and the website, I had no way to download the assembly manual.  I had recourse to the designer who kindly answered me. Considering the complexity of the kit, I couldn't see myself starting the assembly without the electrical diagram in case of a problem. The future will show that I did the right thing.

The construction is done without any particular problem.  
As usual, slowly, methodically, in small sessions. The parts are well distributed in the various bags.  The sorting of resistors, capacitors and transistors required a little attention because of the quantity, but nothing too important.

Fortunately I had the manual. Details like cutting a tab off the 2N4401 or the direction of the switches would have gone over my head. The exact nomenclature of the capacitors was also welcome.

A side

B side

My synth suitcase is almost empty.  It is now used to store the modules that no longer fit in the Mantis. It will do the job well.
At the first power up, the oscillator LEDs light up correctly.  But no sound comes out. From the demo video, I knew that the clock should work.  But it doesn't.  

Crude 5V converter

A glance at the electrical diagram shows me that the audio output is connected directly from the FV-1 circuit, powered by 3.3V from the 5V power supply of the rack ... not present in my synth case: the small Doepfer power supply module bought at the time only outputs -12V and +12V.
So I decided to make the easiest and least efficient voltage converter possible.  With the components I had in my drawers and a piece of board, I made a circuit based on the LM7805 voltage regulator.  Super inefficient: more than half of the power will be transformed into heat; but ready in less than 30 minutes. Given the low power requirement, I doubt it will heat up enough.  The radiator is only there for the principle and the decoration. If you are looking for a serious solution, I suggest this innovative solution from Klavis: NoDrain.

Once this is in place at the bottom of the case, the module lights up cleanly and works the first time.  Happy.

Alive

Jay F. · Test Avalanche