General Testing/Debugging question:

[tracer03]

So, I built a basic test box. Finished a couple of circuits. And by far the most frustrating part of it all is the testing: connecting everything, a mass of spaghetti wires and clips and pots and power and...

So, with my reasonably limited (and old) electronics knowledge, I was trying to simplify the testing, and I can't seem to find answer to a question that's been bugging me...

With the exception of the output/volume pot in most circuits, is it necessary to have the pots attached/in the circuit when testing? Or is there a simpler way to test a circuit without hooking up everything in order to determine if an effected signal is being output?

I realize that in most cases the pot values contribute to the tone/fuzz/what have you - but I just want to test if a circuit 'works' without the extra time of hooking everything up, testing, unhooking, etc.

[alltrax74]

A pot is 2 connections via 2 resistors, so if you omit it you will not have continuity so no output signal.
You need to wire the pots

[Marbles]

Yeah, I wire the pots as well.

Do you mean you clip all the pots with clips? In that case I can imagine.

I wire the pots before I box it. Which means I only clip 4 leads:

- Input
- Output
- 9v
- Ground(s)

Ofcourse sometimes you have more wires if it uses a lot of pots. But I solder them at about the length they will need in the enclosure. Either using the enclosure or, (well, most of the time cause my timing is shitty and about this time the enclosure is drying or spraypainted) a piece of cardboard with holes where the pots should be.

[tracer03]

I have a test box I built that has 4 connections: 9v, ground, signal to effect, signal from effect - all on alligator clips. Simple DPDT toggle to engage the circuit, and when building and testing 'smaller' circuits (Meathead Dlx, etc.) it's worked fine.

One problem for me is that I'm still having difficulty judging the wire length from board to pots, and so I have a couple of finished builds where the wiring turned into a spaghetti mess.

I'm just trying to figure out ways to make the testing and boxing part of building less frustrating. Guess I will just have to keep building and practicing...

[purity]

Are terminals 1-2 and 2-3 not shorted when the pot is rotated fully counter-clockwise or clockwise, respectively? Then you ought to be able to simplify pot connections by shorting the wires going to the pot. For controls like tone, gain and the likes it should work, but its not a good idea to have a volume control set to minimum for debugging purposes, or to maximum to keep your ears blood-free. Or am I missing something here?

I can add that if you are worried about heating up the pot too much from (de)soldering, just whack a trimmer in there. The 3362p-style trimpots are my favourite for this purpose.

[tracer03]

purity wrote

Are terminals 1-2 and 2-3 not shorted when the pot is rotated fully counter-clockwise or clockwise, respectively? Then you ought to be able to simplify pot connections by shorting the wires going to the pot. For controls like tone, gain and the likes it should work, but its not a good idea to have a volume control set to minimum for debugging purposes, or to maximum to keep your ears blood-free. Or am I missing something here?

I can add that if you are worried about heating up the pot too much from (de)soldering, just whack a trimmer in there. The 3362p-style trimpots are my favourite for this purpose.

Not worried about overheating pots, really: since i'm still very much an electronics rookie, I'm just trying to verify that a circuit I built makes *some* noise close to what I was aiming for. And I'm not too worried about bleeding ears: my bench test rig is a little Blackstar Fly 3w amp. I use that to test before I box it up.