Need Help with Second Build - Not Working

Box_Stuffer · May 16, 2023, 09:52:07 AM

Hey guys

I just started building pedals at the beginning of this year. I have successfully built one Bazz Fuzz circuit into a pedal, but it was in a cheap plastic box for an enclosure, but it works.

So I have been breadboarding and I have put together a tweaked version of the Bazz Fuzz that I call the Filthy Gringo Fuzz and I made a really good distortion that I call the Dirtbag Distortion. I have the perf boards wired up point to point. I checked both of them by hooking them to the breadboard and played through them and everything worked as it should. Then, when I put them into the aluminum enclosures, they do not work! Nothing seems to be touching or shorted.

They are both transistor based circuits and both seem to have the same problem. Using probes, I can tell that there is signal up to the base of the transistor, but not out of the collector. What might cause this issue? Where else should I start checking? It just makes no sense that it works outside the box, but not inside. It must be something relatively simple - I just have NO experience with troubleshooting.

antonis · May 16, 2023, 10:02:21 AM

Hi & Welcome..

1. Could you plz sent some pics of your build..??

2. Is BJT placed on socket..??

GibsonGM · May 16, 2023, 10:02:41 AM

Welcome, Stuffer.

Maybe touched the enclosure and shorted (died)? Does it still work when NOT in the box anymore? Do you know how to test a transistor using the diode function on your DMM (you do have a DMM, right?)

https://vetco.net/blog/test-a-transistor-with-a-multimeter/2017-05-04-12-25-37-0700

I always insulate the box w/cardboard, I just glue some inside so the board cannot possibly contact metal. Or I use non conductive foam on the back of the PCB if it is facing toward the lid and I can get to it.

Now, if it worked on the bench, and you later added switch, jacks etc to it - they may well be the culprit. If you can post some pics of the build, that would be helpful, too! The more info the better.

duck_arse · May 16, 2023, 10:56:04 AM

also welcome.

how are you powering the boxed, battery or external supply? what kind of DC jack if external? most important of all, what voltages are you getting on the boxed version? but yes, photos and circuit diagrams, please.

Box_Stuffer · May 16, 2023, 11:24:31 AM

They work in bypass mode and I get the signal up to the base in "on" mode, so the jacks and switches should be good. I have not really got into checking components with the multimeter yet. I am just learning from Youtube videos and I got a book about DIY effects, but it lacks in the troubleshooting section.

These are rough prototypes, so the boards are facing different ways. They are suspended by the pots which have PCB legs and are soldered to the board, so they should not be touching anything. I put thick clear Gorilla tape on the top and back of the box for insulation.

Box_Stuffer · May 16, 2023, 11:41:01 AM

Quote from: duck_arse on May 16, 2023, 10:56:04 AM
also welcome.

how are you powering the boxed, battery or external supply? what kind of DC jack if external? most important of all, what voltages are you getting on the boxed version? but yes, photos and circuit diagrams, please.

I have not gotten as far as testing voltages yet. I am going to watch some videos and see what I can learn. So far, I have just made a tester with an old guitar cable, but that just tells me if I am getting a signal or not.

I am only using a power jack (no battery circuit) with a 9v 1A power source - same thing I use for the breadboard.

GibsonGM · May 16, 2023, 03:25:11 PM

Do you have and know how to use a meter?

antonis · May 16, 2023, 04:44:05 PM

Just to have a reference..

Quote from: Box_Stuffer on May 16, 2023, 09:52:07 AM
Using probes, I can tell that there is signal up to the base of the transistor, but not out of the collector. What might cause this issue?

1. Collector grounded (either DC or AC wise)..
Check for any short between Collector and GND or Collector and +9V

2. Collector open (floating)..
Check for continuity between Collector and 10k resistor

3. Collector resistor (10k) not powered..
Check for continuity between 10k resistor upper leg and +9V

4. Emitter open (floating)..
Check for continuity between Emitter and Dirt pot upper leg (lug 3)

5. Dirt pot not grounded..
Check for continuity between Dirt pot lower leg (lug 1) and GND

All the above measurements (continuity checks actually) should be realized with power off..

P.S.
All the above checks are essential requirements for a potentially working transistor..
For a happy working one, there should be needed some voltage verifications..

Ripthorn · May 16, 2023, 04:54:55 PM

My best guess is you are using a metal DC jack so that, now in the enclosure, your voltage supply is getting shorted so that your transistor can't amplify anything. Check your voltages and replace the DC jack to a plastic one.

Box_Stuffer · May 16, 2023, 08:32:30 PM

Quote from: Ripthorn on May 16, 2023, 04:54:55 PM
My best guess is you are using a metal DC jack so that, now in the enclosure, your voltage supply is getting shorted so that your transistor can't amplify anything. Check your voltages and replace the DC jack to a plastic one.

I think you may be right because I am getting 0 volts while it is plugged in and there is 9.16V at the tip of the power supply. It IS a metal jack. I will have to order some plastic ones. I was hoping to use the metal ones because they would be more durable.

bluebunny · May 17, 2023, 03:06:56 AM

While you wait for your order, you can test this quickly by undoing the nut securing the DC jack and pushing it through so it's no longer touching the enclosure. Then go and curse BOSS for their choice.

Govmnt_Lacky · May 17, 2023, 07:42:27 AM

Why couldn't you just swap the wires on the DC jack? You are not using a battery so no need to have the switching. This way, the GND will go to the enclosure and the DC will go to the circuit.

duck_arse · May 17, 2023, 10:04:29 AM

Quote from: Govmnt_Lacky on May 17, 2023, 07:42:27 AM
Why couldn't you just swap the wires on the DC jack? You are not using a battery so no need to have the switching. This way, the GND will go to the enclosure and the DC will go to the circuit.

but then the plug from the supply would be reverse - a different set of problems.

Govmnt_Lacky · May 17, 2023, 02:14:52 PM

Quote from: duck_arse on May 17, 2023, 10:04:29 AM
Quote from: Govmnt_Lacky on May 17, 2023, 07:42:27 AM
Why couldn't you just swap the wires on the DC jack? You are not using a battery so no need to have the switching. This way, the GND will go to the enclosure and the DC will go to the circuit.

but then the plug from the supply would be reverse - a different set of problems.

Huh

If the supply is sending DC to where it is supposed to go and sending GND to where it is supposed to go (by swapping DC jack wires inside the enclosure) then how would this figure in?

duck_arse · May 18, 2023, 11:22:41 AM

well, the plug attached to the cable from the plugpak may well be connected centre negative, barrel positve, for example. in that case, in matters not what you do with wires inside the box, the only way any style of DC jack can then deliver correct polarity to the internals is if the jack is also wired centre negative. swapping wires internal doesn't affect the plug wiring.

ohh. it strikes me you might be referring to the battery switching contacts. I guess that would work, depending on which contact was connected to the body of the jack, obvs.

Box_Stuffer · May 19, 2023, 08:59:44 PM

Quote from: Ripthorn on May 16, 2023, 04:54:55 PM
My best guess is you are using a metal DC jack so that, now in the enclosure, your voltage supply is getting shorted so that your transistor can't amplify anything. Check your voltages and replace the DC jack to a plastic one.

You were right! I had one left so I switched it out and it's working. I ordered a bunch more plastic ones. Thanx bro!

News:

Need Help with Second Build - Not Working