Need help with a DIY pedal

[StuckItToYa31]

I've built an loop-style pedal similar to this one, but the pedal I built chokes the volume out of my signal when I run my guitar in and amp out, either with power or no power for the LEDs.

 

I'm not sure if it's the wiring, since it is a little messy and long. I wish I could post some pictures, but I'm at work right now and don't have the ability to do so. I know the solder joints are fine - so no issue there - and the parts I used are fully functional.

 

This other thread describes my schematic a little - I'll post the one I drew up when I get home.

 

I'm going to describe the features that differ from the above schematic, and post pictures after. I need as much help as I can get solving the problem(s) (thanks in advance):

 

1. The wire gage is 22. Is this too much for the audio path? Is this my problem, in combination the with the "spaghetti" look?

 

2. I had to wire up the center of the power jack positive because the metal jack I used (after my plastic one was partially melted by the solder gun's heat) had to have an opposite barrel polarity than the box so the LEDs would light. So the box is part of the grounding, but I know this isn't the signal issue since I had the volume drop when I had the plastic, center negative jack wired up.

 

The switch is flipping between the two loops just fine. I'm sorry if this post is long, and appreciate anyone taking their time to go through it.

[Sporky McGuffin]

Wire is wire. Unless it's ridiculously thin it doesn't make a difference.

[WRGKMC]

Wire thickness and the power shouldnt affect the signals at all. This box should run without power if its a true bypass like in the diagram

 

From what I see there its a looper pedal not an AB box. You could add an A/B into the same box but the function is different that whats in the diagram.

If you are using and AB box, simply switch the 2 chords going to the 2 amps around. Unplug from the box and swap, then unplug from the amps and swap. This should isolate if its the Box, Chords, Or Amps. swapping chords at the amp, and problem doesnt move, its the amps, If it doesnt moves when you swap the plugs at the box, its a chord, If it does move swapping chords at the box, its the box.

From there on if its the box, I would disconnest all the outputs and test the signal wires for continuity, Bleed to ground, and switch continuity. Overheating a switch soldering has bad results on the contacts.

 

I would also check to make sure none of those LED resistors or battery lines contact any signal lines. That part of the circuit is for switch position identification only. They arent there to do anything to the signal path and can be completely removed without affecting the signal.

 

Lastly, if this is a looper circuit, and you just mis-stated what it does in your post, Turning on any one of the loops and having a voltage drop

is dependant on the pedals in those loops.

You need to set the gains and outputs so they match the bypassed signal. This is where a pedals tone sucking or boosting bypassed signal becomes apparent. Some pedals have buffers and boost the bypassed signal, some suck the signal down. Making the proper adjustments, Changing the order, Adding buffers or preamps, and even getting a different pedal for the loop may be required.

For example If I had a Crybaby wah in a loop, I would expect a drop in volume for that loop because those pedals arent true bypass and suck the signal down. It may not have been noticed because it would normally have been switched off using the pedals switch which isnt true bypass.

Hope this helps.

[StuckItToYa31]

 

Wire thickness and the power shouldnt affect the signals at all. This box should run without power if its a true bypass like in the diagram From what I see there its a looper pedal not an AB box. You could add an A/B into the same box but the function is different that whats in the diagram. If you are using and AB box, simply switch the 2 chords going to the 2 amps around. Unplug from the box and swap, then unplug from the amps and swap. This should isolate if its the Box, Chords, Or Amps. swapping chords at the amp, and problem doesnt move, its the amps, If it doesnt moves when you swap the plugs at the box, its a chord, If it does move swapping chords at the box, its the box. From there on if its the box, I would disconnest all the outputs and test the signal wires for continuity, Bleed to ground, and switch continuity. Overheating a switch soldering has bad results on the contacts. I would also check to make sure none of those LED resistors or battery lines contact any signal lines. That part of the circuit is for switch position identification only. They arent there to do anything to the signal path and can be completely removed without affecting the signal. Lastly, if this is a looper circuit, and you just mis-stated what it does in your post, Turning on any one of the loops and having a voltage drop is dependant on the pedals in those loops. You need to set the gains and outputs so they match the bypassed signal. This is where a pedals tone sucking or boosting bypassed signal becomes apparent. Some pedals have buffers and boost the bypassed signal, some suck the signal down. Making the proper adjustments, Changing the order, Adding buffers or preamps, and even getting a different pedal for the loop may be required. For example If I had a Crybaby wah in a loop, I would expect a drop in volume for that loop because those pedals arent true bypass and suck the signal down. It may not have been noticed because it would normally have been switched off using the pedals switch which isnt true bypass. Hope this helps.

 

 

It is a loop box, but people for some reason weren't sure what I was talking about unless I qualified it as an A/B.

 

This post is very helpful, and I'm starting to think it's either the switch (because it had too much heat) or that the resistors are touching a signal line. There is no pedal volume drop, and the volume through the pedals is the same as all of them completely bypassed. My rig is completely fine, cables, pedals, amps and all.

 

It's the box itself. I bet 10-1 it has something to do with the way the grounds and LED resistor lines are connected. I didn't think I crossed something, and everything is working, but something is limiting the signal, whether it be here or the 3pdt switch itself.

 

I still haven't had a chance to post any pictures or draw my schematic. I'll toss that up after I check out the box and see what the hell is going on around the resistors.

[StuckItToYa31]

Oh, and fantastic info. Hopefully the parts I don't need can help someone else out.

 

Very well stated and easy to follow throughout.

[ZachBMTH]

yes, wire gage shouldn't matter unless it's an extreme

[StuckItToYa31]

Wow. Looks like it took me quite awhile to post these pictures.

 

This first one is my schematic. I had to make the center of the power jack positive because the jack was metal and I needed to ground the enclosure.

 

 

The input, output and loop jacks are wired and grounded properly, and each piece of the pedal is passing the signal. It's just a very weakened signal - barely audible until my amp is set to 12, at which point I can still drown it out by talking loudly. 12 on my amp would normally shatter windows.

 

Here are a couple shots of the mess inside. I have tested the signal chain, and everything is passing through.

 

 

I also redid those exposed parts, shortened the wiring a little and masked off any exposed wire you see with electrical tape. Anyone have suggestions or see my error?

[Sporky McGuffin]

Rewire that from scratch, keeping all the wires short and neat. I'd suggest using different coloured wires too so you can more easily see what's going where.

[Noise...]

 

Rewire that from scratch, keeping all the wires short and neat. I'd suggest using different coloured wires too so you can more easily see what's going where.

 

 

+987894352351.62

 

Seriously. Keep your wires neat and color coded. Otherwise, you end up with issues and it makes it near impossible to trouble shoot.

 

I usually use red wire for the signal path, black for grounding and small jumpers, and white or green for various other things (IE, hooking up a potentiometer or simple switch).

 

Hold up a length of wire between the two points you'll be connecting, and cut it a small bit longer. You want to make the wiring extremely easy for you to follow. If it's color coded and nice and neat, you'll not only understand the signal path better, but also be able to spot where problems are easier, and have an easier time working on the pedal.

[Sporky McGuffin]

I go far more complex than that!

 

Wire from the input jack is yellow. Wire from the output jack is orange. Send is grey, return is green. Ground is black and 9v is red. I then have purple, pink, brown and white for other stuff. Pots get wired with coloured ribbon cable.

 

Rather over the top, perhaps, but it makes tracing things incredibly easy.