Okay, let’s tackle that volume control (“potentiometer” for you geeks out there)! This has some fiddly, little connections to make, but in the end turned out not to be as difficult as I’d anticipated.
Here are the two parts we’re working with: the ALPS volume potentiometer (“pot” for short) and a little PCB to make the connections to the Driver Board easier to sort out.
There are two sets of four pins holes on the PCB, but only six pins – two rows of 3 – on the volume pot itself. You want to position the PCB like so (noting the empty holes on the left):
We’re going to solder three segments of twisted pair wire to the PCB: one set for the inputs, one for the outputs and a third for the ground wires. Here’s how it looks when finished:
The three sets of wires connect to these six, small holes at the bottom of the Driver PCB, just underneath the big Mundorf caps. We need to be careful to make the correct connections and keep the channels consistent. The bottom row is RIGHT, and the top row is LEFT.
And here, at last, is the volume pot bolted in place, next to the Driver PCB. Look carefully and you’ll see the twisted pairs between the two boards.
Guess what? Our final, major assembly step is coming up next: wiring up the input selector switch. It’s one of the more complicated bits in the assembly process and should be interesting to document for you.