Midi2TRS is a very simple but handy DIY kit. It does 2 things:
• it converts the Midi-DIN input to 3,5mm TRS like it’s used now on many synths and controllers nowdays
• it switches the polarity on the TRS side and by that flips MIDI TRS-A standard (E.g. Korg, RK006) to TRS-B (for e.g. Arturia and older Novation products) and vice versa. You can use this together with any length TRS audio cable and have TRSA and B work together in an elegant way.

Here is a good explanation about MIDI via TRS.

DIY level: easy. Use the pics as reference as there is no assembly manual.

The 7J is a compact joystick controller module. For each axis the joystick can work as an attenuator or attenuverter, selectable via unipolar or bipolar mode switches. The inputs (normalled to +5V) have dedicated attenuators and both X and Y outputs are equipped with continuously variable offset control (-5 to +5V) for fine-tuning the voltage ranges independently. The 7J also has a manual gate generator on board. The joystick itself is without an auto-return to centre spring, perfect for hands-on expression and playful interaction.

Power: 35mA +12V; 25mA -12V

Width: 8 HP

Depth: 38mm

Building instructions can be found here.

DIY level: easy/medium.

The u3A (v1) is a three channel attenuverter DIY kit for the 1U Intellijel format. Useful for scale, add offset, invert or sum signals. As each input is normalled to +5V, with nothing plugged into the jacks, each knob controls a voltage range from -5V to +5V. Each output is also summed to the adjacent channel on the right when no cable is connected.

Power 30mA +12V; 30mA -12V

Format 1U Intellijel

Width 18 HP

Depth 30mm

Building instructions can be found here. You have to solder some SMD parts!

DIY level: easy.

The u1P is a Bernoulli gate. Based on the probability set by the potentiometer, it randomly routes a trigger or gate signal sensed at the input to either of its two outputs. Having three different operating modes (direct, toggle, single), it becomes a useful tool for adding spice and variety to your drum beats or sequenced gates.

Power 15mA @ +12V; 0mA @ -12V

Format 1U Intellijel

Width 10 HP

Depth 30mm

Building instructions can be found here.

DIY level: very easy.

The u2X is a dual buffered multiple DIY kit for the 1U Intellijel format. With bicolor leds for monitoring signals. Each input is copied into three outputs. As the top section is normalled to the bottom section it’s also possible to get 6 copies of the same signal.

Power 20mA +12V; 20mA -12V

Format 1U Intellijel

Width 12 HP

Depth 20mm

Building instructions can be found here. You have to solder some SMD parts!

DIY level: easy.

The 2M is a dual three channel mixer in 6 HP with volume controls over all the inputs as well as the final output. As its design has been specially focused on audio applications, the input potentiometers are audio-taper type while the output ones are linear. Low distortion / high quality audio operational amplifiers have been selected in order to achieve clean audio mixing, but is also DC-coupled, so it can perform CV signal mixing as well. Great for a small system, allowing for submixes or even stereo mixing.

Power: 25mA +12V

Width: 6 HP

Depth: 38mm

Building instructions can be found here.

DIY level: easy/medium.

The 8S is an 8 step sequencer in 8 HP with control over parameters of the sequence as reset, hold, random step and direction. It’s been designed to work with clock related signals like triggers or gates but any type of CV signals can be used at its inputs. The output signal path is completely analog and its range can be set as unipolar (0 to +5 volts) or bipolar (-5 to +5 volts) via jumper on the back.

Power: 55mA +12V, 10mA -12V

Width: 8 HP

Depth: 38mm

Building instructions can be found here.

DIY level: easy/medium.

The 1F is a voltage controlled switch, intended to be ‘one friend’ for your sequencer. Its design has been specially focused on working with sequences, by giving them some randomness, applying transpositions or constant variation over time. For this, 0.1% tolerance resistors have been used to achieve exact unitary gains for precision summing of the v/oct signals. More detailed info on the demo video.

Power: 15mA +12V, 10mA -12V

Width: 4 HP

Depth: 27mm

Building instructions can be found here.

DIY level: easy.

The 4R is a quad random voltage generator in 2HP. It generates two different random stepped voltages per input, each time a rising edge is sensed at TRIG1 or TRIG2. The inputs are independent so they can work at different clock speeds. As TRIG2 is normalled to TRIG1 it is also possible to get 4 random values with just one trigger. The voltage range of each pair of outputs can be set as unipolar (0V to +5V) or bipolar (-5V to +5V).

We did an DIY online-workshop about this module. If you want to build it and need some guidance, watch the video.

Power: 50mA +12V, 30mA -12V

Width: 2 HP

Depth: 50mm

Building instructions can be found here. You have to solder some SMT parts!

DIY level: medium.

New version is here!

This small board is designed for you to easily power your breadboard with the common Eurorack voltages – directly from the bus in your case. The kit includes the PCB and all the parts necessary to supply voltages of -12V, + 12V and + 5V into your breadboard and it is possible to power the board from a 10 or 16 pin ribbon cable. In addition to reverse polarity protection diodes and power filtering capacitors, a point of connection to ground has been also added to solder a terminal to connect an oscilloscope or multimeter.

Please be aware that there are multiple types of breadboards. This kit is designed to fit on 48mm Breadboard!

DIY level: easy. Use the pics as reference as there is no assembly manual.