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

 

Rampage

The second kit from Befaco I built is the Rampage.

And it is not for the faint of heart.

Befaco Rampage

The kit is good quality (as was the A*B+C).  However, with 227 parts (about 560 pins to solder), 3 connectors and around 40 jacks, pots and various switches, I wouldn't quality it as easy.

Rampage kit

I chose this module as an alternative to Make Noise's Math, one of the most recommended module in forums.  With some exceptions, Rampage fills the same roles.  Moreover, it is available as a kit which fulfills my desire to build my synth as much as I can.

Main board close-up

According to Befaco website :
"The module is built around two voltage controlled integrators. Integrators (also known as Lag Processors or Slew limiters) allow you to process your voltages, converting sharp square waves in ramp-like waveforms.
These lovely devices can, for instance, convert a gate signal into a simple envelope, or achieve a “portamento” or “glide” effect when applied to pitch CV."

A properly patched Rampage can assume more than 20 different functions : envelope generator, oscillator, comparator, polyrythmic gate generator, trigger delay, etc…

Before mechanical assembly

Assembly instructions are similar to the previous kit : same advantages, same drawbacks.

With a kit of that size and density, you have to be systematic in order to make sure to be "good first time".  Debugging such a circuit afterwards was not in my intentions.

Calibration of the triangle shape

 
I estimated that the two Schottky diodes of the kit were too large for the PCB footprint and I replaced them by some in my stock.

I also found an oddity in the presence of a solder joint below one of the potentiometer.  I reckon there should be enough room between the back of the pot and the joint when the pot is tightly attached to the panel, but I decided to mask it anyway with some insulation tape.

Better safe than sorry.

Still, I implemented the mod presented in this Muff Wiggler thread to ensure reliable gates by soldering 1M pull-downs resistors at the outputs.

Additional pull-down resistors

Finally, a photograph of the Befaco boys in action and a bit of sound.

Befaco boys in action

Here above, Rampage channel A is programmed as an LFO which frequency is determined by the output of the S&H and cadences the patch.  Channel B is the envelope triggered by channel A and whose attack is also determined by the ouput of the S&H.
A*B+C plays the role of the VCA.   The sound source is the pink noise from the S&H module.
The sound is coming out via Rings (whose parameters are, ... guess what ? ... controlled by the output of the S&H) and the phaser.
Additional effects : NI Supercharger, TAL Reverb II & LoudMax

A * B + C

To complete my synth, I recently bought 2 DIY kits from Befaco.

The first one is called A*B+C.

Finished module

The kit is  good quality and rather simple.

Before soldering

The A*B+C is a dual, four-quadrant multiplier with VC Offset.

It can perform different operations on its inputs :
- amplifier and inverter of A input.
- VCA on A, with envelope CV on B.
- VC offset generation with C input.
- attenuation/inversion of C input
- ring modulation of audio signals in A and B.

Moreover, the output of the the first channel is normaled to the mixer of the second channel.  So the module can serve as CV/audio mixer.

Before assembly

Assembly instructions are good but could have been clearer, especially for the final assembly.
A couple of photos wouldn't have been too much.  But I didn't encounter any major issue.

My only gripe was about some parts that had a larger size than their footprint on the PCB.  I had to replace the two Schottky diodes with those I had in stock and solder 2 couples of resistors vertically. One resistor even had to be soldered on the other side of the board.

Once again, nothing major in my view.

Profile view.  You can see the vertically mounted resistors

Finally, the module suffers from a high level of background noise as indicated in this Muff Wiggler forum thread.   Anyway, it does not seem prohibitive.   There is a suggested mod but it looks like it modifies the potentiometers behaviour, so I didn't want to perform it (and I didn't have the necessary 1/8 W resistors).   Time will tell.