Alchemical Eurorack Touch Controller Assembly Instructions

Thank you for choosing Rat King Modular!  We want to give you the best step-by-step instructions as possible to assist you in a successful build.   Please make sure to follow these instructions in order and take your time!  If you have limited experience please try and get some experience/help before attempting something that you are uncomfortable with.  With that said, let’s begin!

Here is the bill of materials:

Take a look at the partially completed PCB/Controller Panel:

AA Touch Controller Rear
AA Touch Controller Rear
AA Touch Controller Front
AA Touch Controller Front

TOUCH CONTROLLER LEDs 

Take your LEDs and bend them as shown below.  Make sure that the cathode (shorter leg) of each LED is oriented with the negative pad marked with the “-“.  You can now proceed to solder the LEDs in place.

AA Touch Controller LED's
AA Touch Controller LEDs

Carefully clip the excess leads.

AA Touch Controller LED lead clipping
AA Touch Controller LED lead clipping

3.5mm Jacks

You can use PJ301M-12 (“Thonkiconn”) or PJ301BM (“Erthenvar”) jacks with this circuit. Both style of jacks are shown below.

PJ301M-12:

Flare out the 3.5mm jack lead as shown below on all four 3.5mm jacks.

AA Touch Controller 3.5mm Jacks
AA Touch Controller 3.5mm Jacks

Now place the 3.5mm jacks into the board as shown below.

AA Touch Controller Jack Placement
AA Touch Controller Jack Placement

Turn the project over and gently tighten down the nuts on all four jacks. 

Now solder both the bent SLEEVE pin onto the board and the TIP pin onto the PCB.  The TIP pin will require some of the provided wire in order to install.

AA Touch Controller Jack Soldering
AA Touch Controller Jack Soldering
AA Touch Controller Jack Soldering
AA Touch Controller Jack Soldering
AA Touch Controller Jack Soldering 2
AA Touch Controller Jack Soldering 2
AA Touch Controller Jack Soldering 3
AA Touch Controller Jack Soldering 3

PJ301BM:

Erthenvar Jack Wiring 1
PJ301BM Jack Wiring 1
Erthenvar Jack Wiring 2
PJ301BM Jack Wiring 2

DIN MIDI Jack

Insert the DIN MIDI jack into the PCB as shown below and secure it with two 3mm screws and 3mm square nuts.

AA Touch Controller DIN MIDI JACK
AA Touch Controller DIN MIDI JACK
AA Touch Controller MIDI Jack Installation
AA Touch Controller MIDI Jack Installation

Solder the DIN MIDI pins to the PCB via the provided wire as shown below.

AA Touch Controller DIN MIDI Jack soldering
AA Touch Controller DIN MIDI Jack soldering

POWER JACK

Now solder the DC power jack to the PCB with the provided wire as shown below.  Start by finger-tightening the DC Jack Nut.  Rotate the jack before soldering then finally tighten the nut

DC JACK WIRING
DC JACK WIRING
DC JACK NUT
DC JACK NUT

POTENTIOMETER

Now gently tighten down the potentiometer nut.

AA Touch Controller Potentiometer 2

Now take the potentiometer and solder it into place as shown below.

AA Touch Controller Potentiometer

SWITCH

Insert the switch into the board, tightening the nut on top (orientation on this switch does not matter).

AA Touch Controller Switch Nut

Solder it in with wire as shown below.

AA Touch Controller Switch Installation
AA Touch Controller Switch Installation

VOLTAGE OUTPUT TRACKING ADJUSTMENT

Voltage-Octave-Adjustment
Voltage-Octave-Adjustment

Calibration steps:

  1. Connect a volt meter (switched to DC) to a patch cable coming from the CV OUT jack.
  2. Power the unit off, then power it back on.
  3. When you touch the highest note on the keyboard (C), the Touch Controller will output C5, or 4V.
  4. Adjust the V/O trimmer (on the back of the unit) with a fine-tip screwdriver until your volt meter reads exactly 4V.

You’re done! Make some music!