My Pedal Build failure thread.

[McHaven]

I recently spent money I shouldn't have spent on a GGG tuned muff kit. It arrived this morning and I've spent the last 5 hours working on it. I put it all together according to their instructions and now, it does not work. I've checked my solder joints. I don't see any bad cold solder joints, I don't see solder touching two points together anywhere. Of course, I'm practically blind and I may be wrong.

Point is, this is the 3rd pedal I've worked on. I failed attempting to rehouse another muff clone. It broke in the process somehow. I tried to build a Parapedal clone. Never happened. I tried this GGG muff, and even with the great instructions I was give, I failed.

Some people just aren't meant to do things, and I guess I'm not meant to build effects. I'm going to give this pedal to my friend, if he's willing, and see what he can do with it. Maybe he can see what's wrong and fix my mistake. Otherwise I've wasted 70 dollars.

Only thing I've succeeded in is burning myself.

[Toasted]

It's almost definitely an off-board wiring problem, or a transistor put in the wrong way around.

[J. Crawford]

Originally Posted by Toasted

It's almost definitely an off-board wiring problem, or a transistor put in the wrong way around.

KoRn knows a thing about Twisted Transistors.

[dannybuoy]

Check the orientation of your diodes and electrolytic caps too. I'm about to dive into the DIY scene too, we'll see how it goes! Persevere, as you get more experienced you'll spot the common mistakes more easily and learn how to avoid them.

[B.C.]

Originally Posted by dannybuoy

Check the orientation of your diodes and electrolytic caps too. I'm about to dive into the DIY scene too, we'll see how it goes! Persevere, as you get more experienced you'll spot the common mistakes more easily and learn how to avoid them.

+1, diodes are quite easy to mistake orientation, and knowing a muff clone, there is atleast two in opposite orientation. These are the clipping diodes, so you might try flipping both of them.

Trust me, its an art.

[The Lurker]

Originally Posted by B.C.

+1, diodes are quite easy to mistake orientation, and knowing a muff clone, there is atleast two in opposite orientation. These are the clipping diodes, so you might try flipping both of them.

Trust me, its an art.

Or if not an art, at least an iterative process

[seanm]

Originally Posted by The Lurker

Or if not an art, at least an iterative process

+1 I assume you don't have an oscilloscope, so you need an audio probe and a signal source.

The signal source can be a radio, CD player, anything that can produce a continuous signal. Plug that into the input of the effect.

You also need a probe:



The probe needs to plug into some sort of amplifier with a speaker. The blue wire needs to go to a ground. Then you touch the exposed cap to various parts of the circuit and listen to the result.

Now you just walk through the schematic and see where the problem is. For example, in your case the output of C3 is a good place to start. So you get a signal there? Then try C4? Then try C7? C12?

When you find the point where it works, and the point where it doesn't, the problem is in between. Simple.

[B.C.]

Wow, thats pretty clever, I like

[Jammin'ForJesus]

What is a "GGG tuned muff kit"?

[dannybuoy]

Seek and ye shall find!

It's a kit produced by General Guitar Gadgets to make a tweaked version of the Big Muff Pi fuzz pedal. More gain and more mids than your typical muff, 99% the same as the Sanford & Sonny Bluebeard fuzz that is much loved by the players of the doom/stoner genre.

[rcubed]

Coming from the Double Muff, it's a pedal I really liked. But after trying some bass fuzzes, I felt it still lost too much lowend and I didn't like the scooped mids. So a change in the tonestack and the addition of a mids knob has really made this pedal work for me.

McHaven, don't give up on it. It's going to be worth it if you can figure out your mistake, not only for potential future projects but you'll also have a new fuzz pedal. Sounds like you checked the board but not the off board wiring. As mentioned, that's probably where your mistake is.

Do you have a volt meter? Check to see if the transistors are getting a voltage. You should see less than 9V (I'm guessing ~4.5V) at the collector of each transistor in respect to ground. Also check for DC voltage before the coupling capacitors and AC voltage after the coupling capacitors. Take a look at C3, C4, C7, C12 and C13.

[grygrx]

Originally Posted by seanm

+1 I assume you don't have an oscilloscope, so you need an audio probe and a signal source.

The signal source can be a radio, CD player, anything that can produce a continuous signal. Plug that into the input of the effect.

You also need a probe:



The probe needs to plug into some sort of amplifier with a speaker. The blue wire needs to go to a ground. Then you touch the exposed cap to various parts of the circuit and listen to the result.

Now you just walk through the schematic and see where the problem is. For example, in your case the output of C3 is a good place to start. So you get a signal there? Then try C4? Then try C7? C12?

When you find the point where it works, and the point where it doesn't, the problem is in between. Simple.

I assume the cap is on the tip port and the ground is the sleeve port

I need to make one of these personally. Looking at the picture I'm confused what the the heck is going on. Is that thin grey line just the tape?

[Chronicle]

MAKE SURE YOU HAVE THE COMPONENTS...


soldered the right way...don't put them on backwards..happens to me

[rcubed]

Originally Posted by grygrx

I assume the cap is on the tip port and the ground is the sleeve port

I need to make one of these personally. Looking at the picture I'm confused what the the heck is going on. Is that thin grey line just the tape?

One lead of the cap is going to the tip, the other is free for probing. That cap is there to block any DC current/voltage from going to the amp. Use tape or shrink tubing so you don't short anything to ground.

[seanm]

I would really recommend that anybody that is looking at building effects buy a scope. For audio use you only need an "obsolete" 2MHz analog scope. These can be bought dirt cheap used. I got mine for $50.

[rcubed]

Originally Posted by seanm

I would really recommend that anybody that is looking at building effects buy a scope. For audio use you only need an "obsolete" 2MHz analog scope. These can be bought dirt cheap used. I got mine for $50.

Good call. I need to do that myself. But for now I have a scope and function generator at work I can use.

[Wren and Cuff]

You probably have a much simpler problem than you realize. Most of the above suggested problems could be it, but with most of those, the pedal would still "work" it would just sound all messed up.

Check your grounds. Check your grounds again. Then after that check your grounds. Make sure every ground on the board, and every jack, and the vol pot ground are connected. It's easy to make the mistake of having a ground point or two connected to OTHER ground points, but not connected to ALL points.

If the kit has the jacks grounded to the enclosure, solder a wire to the jack grounds and hardwire the wires to the board just to be sure.

This is all assuming you don't have a DMM or a simple connection tester (available at any hardware store for about $3). You can build one, but i'd spend the 3 bucks so you can concentrate on the pedal, not the tester.

Thomas Edison tried and failed to get the light bulb to work over 1200 times before he succeeded.

oh yeah, I forget to mention, check the grounds.

best,

matt

[B.C.]

Originally Posted by Wren and Cuff

You probably have a much simpler problem than you realize. Most of the above suggested problems could be it, but with most of those, the pedal would still "work" it would just sound all messed up.

Check your grounds. Check your grounds again. Then after that check your grounds. Make sure every ground on the board, and every jack, and the vol pot ground are connected. It's easy to make the mistake of having a ground point or two connected to OTHER ground points, but not connected to ALL points.

If the kit has the jacks grounded to the enclosure, solder a wire to the jack grounds and hardwire the wires to the board just to be sure.

This is all assuming you don't have a DMM or a simple connection tester (available at any hardware store for about $3). You can build one, but i'd spend the 3 bucks so you can concentrate on the pedal, not the tester.

Thomas Edison tried and failed to get the light bulb to work over 1200 times before he succeeded.

oh yeah, I forget to mention, check the grounds.

best,

matt

Single best piece of advice here. Grounds haunted me in my first builds and to this day I still have to double check all of them. Very good call.

[McHaven]

Thanks for all the support guys. I'm going to resume working on it later this week, once I'm home for Easter holidays. At least then I'll get to have my bass and amp right beside me as well. I had to build, drive to the rehearsal space at school, test it, then drive back to try and fix it. Really inconvenient.

[McHaven]

Also, I'm going to pull out the magnifying glass and absolutely double check that none of my solder points are touching. Its a real tight fit for some of these components IMO and I'm not the best at soldering so....

Reexamining my board, it looks like I may have some points possibly touching and I'm pretty sure that's no good, right? Causing a short of some kind or something.

I had also left out the DC jack, and just wired in the battery, but I'll be going back and wiring it exactly to the wiring diagram to eliminate any possible problems.

Then I'll get someone who knows what he's doing to really take a look at this terrible job I've done.