Noob question... testing before putting guts in pedal

[lordradish]

Hey, folks...

I'm just about to wrap up my second project (actually, third, but I just couldn't get #2 going after two tries), and I had a question about testing the actual pedal... can I test it without putting it in the enclosure, meaning, plug everything in and see if it works, before final assemble?  Hope this isn't too silly question.

[rocket88]

not a silly question. what you want is a test box, link. this will allow you to hook everything up and run the pedal to ensure it's working right before boxing. many people use one.

[lordradish]

Good to know, I didn't know about this. Thanks.

[lordradish]

I am curious, though (I almost have this one done)... if I ensured that no components were touching each other, this should still work if I tried firing it up, right?

[motterpaul]

Another thing you can use is a breadboard.  

Or you can do this: take a DC jack (if you have a DC power wart) or a battery clip and solder on some alligator clips (+ and -), and then take two guitar jacks and attach wires with alligator clips to the tip and ground, or use a terminal block like I did in the pic below;

Just remember you have to connect ground from the power source to the circuit and the guitar jacks



Your circuit should work as long as it is wired right. You will be surprised how much "abuse" a circuit can take and still work, but there are also things that can go wrong and burn out a component if it is not wired right. I recently learned that tantalums fry if the DC was connected backwards - which was good to know because it helped me troubleshoot a problem I was having.

[tabbycat]

@lordradish,

i would say the two most important first lessons i learned when i started building pedals were:
1. always test before you box, and
2. always socket transistors.

so your instincts jangling and putting the idea in your head to test before boxing may mean you are a natural builder, which is a very good sign.

others have suggested stuff already like testing boxes and boards, also worth noting that the almighty fuzzdog has just released 'The Ultra Mega Testing Contraption' which you (or others here) may find a use for at some point.

http://shop.pedalparts.co.uk/Ultra_Tester/p847124_15700704.aspx

i'm old school and use a breadboard, but that's more because that's what i'm used to using rather than being the best solution. if i had known of other options before i tried it i may well have gone that way instead. it's all down to what feels right for you. low-fi, hi-fi, cheap or fancy. all get the job done.

[lordradish]

I'm getting better at this, but I still suck.

I wired up my circuit (not in the box), had throughput when off, but when I turned it on, the LED wasn't working. Seemed I was a bit over-eager with the soldering iron (that's something I'm trying to get better at), and fried the switch. Replaced the switch... now the LED lights up, and when I turn the volume knob all of the way, I can hear some sort of change (hiss gets louder) but something still isn't right, as I'm still not actually hearing my guitar or the fuzz.  It has germanium transistors, and I'm trying to identify what is what, with no luck. Can I fry a transistor if it's not wired right (I am using a socket)? It has two OC71's and 1 OC44. The OC44 has a red dot on one side, but the others don't. I got them from Mammoth.

I have checked the switch, and all wires going to the board, and there are no continuity problems across the switch. This is a hard hobby to get into, to say the least, when one has almost no knowledge of electronics.

[motterpaul]

unfortunately, with THOSE older germanium transistors you can burn them out by wiring them up wrong. (Newer silicone parts tend to take more abuse without burning out).

I highly recommend you look into a making a test box for circuit first - so you don;t have to worry about LEDs, footswitches or guitar jacks when building a new effect.

I understand this is not an easy thing to get started doing - but you will get the hang of it. But I suggest that you not try to use any more expensive parts before you know more about what you are doing.

[Marbles]

You'll be ok, trust me!

Just keep doing it. I'm a noob myself, but have done about 25-30 builds by know, and the frustration gets less. Really. I didn't use a testbox before because, well, I thought it was a waste to use parts for a thing that doesn't make my guitar sound awesome, right?

After finishing a build, I would box it, check everything very carefully, cross my fingers and fire it up. When it worked: Awesome! But a lot of times: Nothing. Then the sweating started: %$^*& What could it be! I checked everything! Trying to lift the circuit a bit to see if I could spot bridges, if the wires would let me. reaching out to people here, wiggle things around in a small enclosure, getting more frustrated: Why the &%$^& doesn't it work etc. Major frustrations. It discouraged me to build for a few months even.

I then decided to make a testbox. I had misdrilled an enclosure before and that was perfect for it (a BB). Mine is not nearly as fancy as the boxes mentioned above, I can post a pic if you want. It's basically a 3pdt switch, a led, 2 jacks. I have 4 wires coming out with alligator clips. 1 for 9v, 1 for ground, 1 for input and 1 for output. When you wire it directly in the box, like you experienced, your switch could be a problem or the led, miswiring of the jacks etc. You don't have to worry about those things anymore, cause you know that works. That's a huge timesaver. And cause that's out of your mind, you can focus on your real problem more easily (at least, it works that way for me, makes room in my head).
It's really worth making. I think everyone will say: I wish I made it sooner. Cause eventually most people will.

Apart from that: Just keep building! Like I said, I'm a total noob, but the more you do, things start to fall into place. You'll start to recognize some problems and what the most likely cause is. I have no knowledge of electronics whatsoever either, but you pick something up with every build. Just hang in there and keep building despite the frustration sometimes :D There's a lot of nice and helpful people with a lot of knowledge on this forum that have your back ;) (Lord knows they helped me a lot)

[Travis]

Just FYI, the germanium transistors from mammoth are new production, and totally different than the original parts. They're expensive and generally not that great.

You can buy NOS germanium transistors from smallbear and on eBay. You have to watch out on eBay too. You can also buy the same reproduction germaniums from mammoth on eBay. Don't buy the DSI brand transistors if you're looking for NOS stuff.

Regarding testing before boxing, I use my breadboard. I mounted jacks to my breadboard to make plugging it into my amp easier. The wires from the jacks are left long so that I can plug them in anywhere on the board. Instead of soldering the wires from the boards to the pots, I just plug the wires into my breadboard, and use a trimpot or PCB mounted pot so that I don't waste or ruin any pots if I don't end up boxing