First Build: Almost There!

[shaunq]

Hey all,

I just finished up my first build, with much help lurking this forum and it is so close to being a success.  The only issue I cannot resolve is a pretty serious hum occurring when the circuit is bypassed (fuzz circuit).  It sounds just like normal single coil hum, but far louder.  I suspect I have some grounding issue.  I've omitted the LED and ran the top center lug of the 3PDT to the DC jack ground, which I'm not sure was necessary.  I can't find any information on how to treat that lug if you do not want a LED on your pedal.  Aside from the hum, the fuzz sounds GREAT.  Anyway, I'll attach some photos and any help is appreciated!  Here is the circuit in question (also omitted the 2K2 LED resistor and the connection from the board labeled LED+): http://tagboardeffects.blogspot.com/2010/10/dam-meathead.html

Thanks!

[GibsonGM]

Hi Shaun, welcome!

Nice first build.  These kinds of problems happen, esp. when we're new, so hang in there.   

Do you have a pic of how you wired up the switch? I'm going to guess that's where your problem lies.  An open ground on bypass or something like that.

This document shows like 10 ways you can wire the switch - check your wiring. Download the PDF:  http://www.tonepad.com/project.asp?id=35

If no LED, you can omit the whole 'run' and lugs that it uses, provided that ground isn't used to also ground something else.  "Option 5" is what I use.

Let us know what you find!

[Cozybuilder]

First off, welcome to the forum Shaun. It looks like you modified the layout quite a bit, but if it works as intended, great.

For off-board wiring, this article provides some easily understood explanations and drawings, I hope it helps.

http://gaussmarkov.net/wordpress/thoughts/wiring-up-a-1590b/

Since you are not using an indicator LED, you could do this with a DPDT stompswitch instead.

[duck_arse]

also welcome. where does that centre top black wire go? if it is a ground, you shouldn't be switching it, it should be connected to ground.

also, you get extra points for the sleeves on the long cap leads. but, you loose points because you need to clean those board edges. when you cut them, run some P400 sandpaper across them tiil they are straight and smooth, and they'll be tikkety-boo.

[shaunq]

Thanks for the warm welcome and help, all!  That center top black wire is running to the positive lug on the DC jack (this is connection I'm most uncertain of, but if I remove that wire I get no signal).  I have grounds running from the circuit board to the DC jack and from the pot, center lug on the switch, and the input jack to the output jack.  I pretty much did use the method that Cozybuilder linked in his comment.

[Jdansti]

Welcome! Have you tried comparing the hum when using a battery vs power supply?

[peterg]

Thanks for the warm welcome and help, all!  That center top black wire is running to the positive lug on the DC jack (this is connection I'm most uncertain of, but if I remove that wire I get no signal).  I have grounds running from the circuit board to the DC jack and from the pot, center lug on the switch, and the input jack to the output jack.  I pretty much did use the method that Cozybuilder linked in his comment.

Shaunq - sounds like we've got a couple components wired incorrectly. All your grounds except for the power jack neg should run to the input jack ground lug and it appears that the battery's 9+ is going to your input jack. Can you take a picture of the whole project with the wired laid out so we can trace them? Also take a shot of the power jack showing the lugs head on if you could.