How to Build the AI026 DIY Eurorack Line Interface

This is the build guide for the AI026 Eurorack Line Interface

1. Resources

2. About the AI026 DIY Eurorack Line Level Interface

The AI026 Eurorack Line Interface converts between +/- 2V Line Signals and +/- 5V Eurorack signals. This allows for the best headroom and highest quality when processing Line signals with Eurorack modules, and vice versa. The kit is not a dificult build, so long as you are able to manipulate small SMD parts. They have been chosen to be as large as possible given the size constraints.

3. Tools Needed

For testing:

Multimeter WITH Continuity Testing

4. BOM

Category	Part	Quantity	Designation
Capacitor	10uF Capacitor	2	C1-2
Capacitor	.01uF 805 Capacitor	4	C 3-6
Capacitor	1uF 4x5.5mm Capacitor	4	C7, 10, 11, 16
Capacitor	10pF 603 Capacitor	8	C8-9, 12-18
Diode	1N5817	2	D1-2
Hardware	Shrouded Power Header	1	Power
Hardware	Jack	8	Line In L, Line In R, Line Out L, Line Out R, Euro In L, Euro in R, Euro Out L, Euro Out R
Hardware	Nut	8
Hardware	6 Pin Plug	4	J1, 3, 6, 8
Hardware	6 Pin Socket	4	J2, 4, 7, 9
IC	TL074	2	IC1, 2
Potentiometer	9mm Alpha Dual Potentiometer A100K	2	Line In, Synth Out
Resistor	100K Ohm 805 Resistor	4	R1-3, 5
Resistor	330 Ohm 1206 Resistor Code	4	R8, 13, 17, 20
Resistor	27K 1206 Resistor	2	R9, 14
Resistor	680K 805 Resistor	2	R4, 10
Resistor	10K 805 Resistor	8	R6, 7, 11, 12, 15, 16, 18, 19

5. Build Guide

As usual, we solder from “low items to high items.” First solder the two TL074 ICs. The EXTREME close up (gross) above shows the orientation of the ICs. Start with one pad, and then hit the others. View the video if you have any questions.
Now solder the four 100K resistors.
Now solder the four 330 Ohm resistors.
There is two 27K Resistors.
There are two 680K resistors.
Now solder the eight 10K resistors.
There are four .01uF capacitors. Your kit bag may say 10nF – they are the same value.
There are eight 10pF capacitors.
Now solder the four 1uF capacitors. These are polarized and must be orientated per the image above.
Now solder the four sets of 6 pin sockets and headers. These pass signals between the two PCBs.
There are two 1N5817 Diodes to provide reverse power protection to the module.
There is a 10 pin box header for power on the Rear PCB. Ensure that the Key (gap) faces as shown in the image above.
There are two polarized 10uF Capacitors for power filtering.
There are 8 i/o jacks on the Front PCB. I start from the bottom and solder the ground lugs (the ones that stick out) and move up the PCB.
There are two stereo A100K pots on the Front PCB for controlling volume. I place them in, loosly place the panel over the pots and jacks, and then solder all the lugs.
Now perform a Continuity Test, insert ICs if you haven’t allready and power on.