Modifiying the frequency range of the vibrato
DISCLAIMER : Any modification to any MiniBrute will immediately void its warranty. Arturia or any of its affiliates will not accept responsibility for any damages, personal loss or injury that may result from any modification to the device. Should you apply any of the hacks and modifications described on this site, your own responsability alone is engaged.

Aim of the modification:
The idea is to add a lever switch at the back of the MiniBrute that makes it possible to toggle between the normal vibrato range and an extended audio range. With the audio range the vibrato turns into a FM modulator for the main oscillator. With this one can create bell sounds and other crazy FM modulations.

Difficulty : For experienced DIYers. Requires a good experience in soldering and drilling.
Principle of the modification

Schematics of the Vibrato oscillator
Modified schematics
                                                                          
Required parts : two 33cm (13") long wires, one 1µF non polarized capacitor, one 33nF capacitor, one mini lever switch SPDT. A euro-cent coin gives the scale. And a small length of shrink tubing.
Finding the Vibrato on the PCB










Mechanical part: drilling the MiniBrute's case

Let's find a place on the back of the case. The only place with room left for drilling and installing a switch is located at the level of the Arturia's logo.





Let's stick a piece of paper tape on the region to be drilled at the back of the case and also inside the case. The tapes protect the paint from small scratches that may occur when positionning the the drill. It is also used to draw a mark (cross) for drilling.




A 5 mm hole is required, but in order to be accurate I first used a 2 mm drill bit to make the pilot hole then a 5 mm bit to make the final hole. Note that the aluminum of the case is quite easy to drill through and I recommend using a rather low speed for the driller.
 



The mini-lever switch fits perfectly at the back of the case...




... and is fairly accessible from the inside of the MiniBrute.

Electronic part: assembly and connections

Solder one of the wire to the middle lug of the switch. Protect the connection with shrink tubing (white tubing on the photo below).
Solder one leg of the 1µF capacitor to one of the external lugs of the switch.
Solder one leg of the 33nF capacitor to the other external lug.
Next solder the free legs of the capacitors together.
And finally solder the second wire to the connection between the two capacitors.




Install the switch on the back of the MiniBrute.




Now comes the hard part we must unsolder C83 from the PCB, as it is a SMD component we must use a small tip solder iron. .

Locate C83 on the PCB (brown component).



Unsolder C83. One must be careful not to overheat the soldering pads



Now solder the two wires on the solder pads of the former C83




That's it, now let's re-assemble the MiniBrute and enjoy this new feature.