Test Platform question

[jwyles90]

Hey all!
First off, I just wanted to say how awesome this forum has been. I'm new to making pedals, so whenever I've run into a problem I didn't really know how to fix or something I didn't quite understand, you all have been super helpful and nice about responding to my questions. So thanks again!

I bought one of these test platform boards from Pedal PCB: https://www.pedalpcb.com/product/pcb365/ (A little expensive, I know, but I liked how tidy and compact it is). If anyone has experience with using test platforms, I have a couple of questions about how they work.

1) Once I have the wires soldered onto the PCB do I just stick them into the openings on the terminal box and then tighten the boxes to secure the wires?
2) As far as pots go, I'm assuming you generally want to have the pots connected to the pcb before you test everything out, correct? I'm just trying to wrap my head around testing a pcb that has mounted pots vs wired pots. The builds I'm currently planning on testing are all PCB mounted pots, so any insight regarding how to go about doing that would be greatly appreciated.

Thanks!

[Kevin Mitchell]

1) Yup!
2) Without pots in-circuit it'll be an incomplete circuit. The guitar signal will end where the pot's missing, oscillator's won't work correctly and so on.

Without picking things apart too much, I'd like to ask what you're expecting this PCB to do for you? The reason I'm asking is because your question of "pots or no" is irrelevant to the "Test Platform" pcb itself. It looks like it's simply a PCB that puts your effects in, out and power supply on one board. For tinkering and testing, this only saves you some soldering to test it before you go to... well... solder it during final assembly.

Is there a point to this PCB that I don't understand?

[jwyles90]

Yea that's a fair question. I guess I just wanted something that I could use to make sure everything is working as it should be before I go through the process of wiring everything up to the enclosure itself. The last build I did I accidentally lifted the pad off of the track on one portion of the board, I thought I'd maybe fixed it but when I wired it all up it sounded pretty gnarly, so I think that gave me a bit of PTSD about wanting to make sure it all works before I go through the work of wiring everything to the enclosure.

I also have a build that I'm doing that has a few JFETs that need to be biased, so the platform feels like it could be an easy way to do that before putting it into the enclosure?

That whole idea of "rock it before you box it" makes sense to me, although now that I think about it, if I've soldered everything correctly and wired it up properly then theoretically it's kind of a redundant step. 

[Kevin Mitchell]

With this board you can hold off on soldering the wires to the jacks (in, out & power) for the "rock before box" method. Otherwise it's really not saving you much effort. You would still need to solder components & wires to the PCB.

These will be your best friend when trying out components - especially those bias resistors.
Breakaway SIP sockets

[ElectricDruid]

That whole idea of "rock it before you box it" makes sense to me, although now that I think about it, if I've soldered everything correctly and wired it up properly then theoretically it's kind of a redundant step.

That's a big IF though, isn't it? At least, it still is for me. I would never assume that the thing was working *before* testing it. Even in a professional electronics environment, QA is a big deal and stuff *has to* get tested before you move to the next step. Of course, as you get better at it, failures get less frequent, but that doesn't mean that the need to test disappears or that the likelyhood of a screw-up ever reaches zero! (Oh! If only life were so!! )

My advice is to get into rocking it before you box it and do whatever makes it easiest for you to do that - including test boards like the one you have, whatever. I've built similar things for specific jobs in the past, if I thought I was going to need to do it few times. The extra work soon pays back.

HTH

[jwyles90]

That whole idea of "rock it before you box it" makes sense to me, although now that I think about it, if I've soldered everything correctly and wired it up properly then theoretically it's kind of a redundant step.

That's a big IF though, isn't it? At least, it still is for me. I would never assume that the thing was working *before* testing it. Even in a professional electronics environment, QA is a big deal and stuff *has to* get tested before you move to the next step. Of course, as you get better at it, failures get less frequent, but that doesn't mean that the need to test disappears or that the likelyhood of a screw-up ever reaches zero! (Oh! If only life were so!! )

My advice is to get into rocking it before you box it and do whatever makes it easiest for you to do that - including test boards like the one you have, whatever. I've built similar things for specific jobs in the past, if I thought I was going to need to do it few times. The extra work soon pays back.

HTH

That was my exact thought process! Sure, it might add an extra step or two in the building process but it seems like it sould save me a lot of time in the long run if I knew it was working before I wired it all up (which to me is the most tedious, frustrating part). So I guess I'm just trying to wrap my head around how exactly to do that since I've never done it before. I'm assuming the PCB basically needs to be complete (pots soldered and all that) in order for me to wire it up to the test board?

[ElectricDruid]

I'm assuming the PCB basically needs to be complete (pots soldered and all that) in order for me to wire it up to the test board?

Yep, get the whole PCB complete with pots done so that all it's missing is "In" and "Out". Then you either hook it up to a test board like the one you have and give it a go, or you temporarily solder some jacks to it so you can check it works (in which case you still don't have any in/out switching, which is a nice plus on your test board - lets you check bypass and effect levels are similar) and give it a run through. Once that's done and you're happy the board is doing what it's supposed to, you can go ahead and wire up the proper jacks and the 3PDT switch and the LED and whatever else. If it doesn't work after that process, you can be fairly sure it's because you screwed up the wiring, not because the board doesn't work. And since probably *at least* 50% of problems come from the offboard wiring, that's a big help.

[jwyles90]

I'm assuming the PCB basically needs to be complete (pots soldered and all that) in order for me to wire it up to the test board?

If it doesn't work after that process, you can be fairly sure it's because you screwed up the wiring, not because the board doesn't work. And since probably *at least* 50% of problems come from the offboard wiring, that's a big help.

Ok awesome! I finally got the components I need to put together the test board and finish up a couple PCBs from Tayda today, so I'll fire those guys up and see how it goes. Thanks for the help!