Install the two 50k Trimmers installed, they should snap fit into the PCB.

Now for the Two slide switches – the inner legs may need slight forming to fit.

Fit the 3.5mm AUX IN mono socket to the reverse of the board.

Next fit the three snap fit 3.5mm mono sockets, making sure to remove the nuts – we’ll need them later.

Note: It is critical that these are really tight to the PCB and the flat edge behind the thread is aligned with the edge of the PCB or slightly set back from the edge.

Now place the ICs in their sockets paying special attention to the chips part name and orientation markers.

Carefully snap the panels apart along the score lines.

*Ahhh, satisfying* 

Thread the wires from the piezo disc on the front panel through the hole and poke them into the pads and solder. 

The silkscreen is marked on the top side + (red) and – (black).

The tape applied to the piezo disc helps with strain relief and stops components shorting out on its metallic body.

Identify your potentiometers before pressing them into the PCB.

DO NOT solder them yet.

B102 = 1k linear

B103 = 10k linear

B504 = 500k linear 

A104 = 100k log

Place the potentiometers and switches in their footprints but DO NOT solder them yet. We will solder them after a few more steps

The potentiometers should snap into the PCB, sometimes the mechanical legs need pushing outward slightly to get a tight fit.

Place the top panel on.

Sometimes the switches need a little help to poke through.

Snap the sides into place. Try not to put too much sideways force on the potentiometer shafts.

This stage can often be made difficult or impossible if the mono jacks are not properly fitted or the legs of the mono jack are bent outwards. 

Screw the nuts onto the mono jacks.

Make sure all the sides look square with respect to one another and the unit has very little play.

We’ll solder the potentiometers before the switches.

Apply a small amount of solder to one mechanical (large) pin of the potentiometer.

Place a finger firmly on the potentiometer and reheat the joint, as the joint melts you will be able to feel the potentiometer move into place.

Test the potentiometer before soldering the rest of the pins. The potentiometer shaft should not rub on the panel when turned, if it rubs repeat the reheating of the joint but apply gentle pressure away from the rubbing point.

When you are happy with the fit solder all the pins and repeat the process for the others.

Note: rubbing will not cause the metal synth to not work, but will cause the potentiometer to have a shorter working life and be more difficult to turn.