The Pig Butt...from HELL!

[blackedition]

hey all. I'm working on finishing a Pig Butt and have run into a brick wall.

1) the pedal is sans-box... i am in the process of rocking before boxing . I have gone through and verified the values of all components. I can post a picture of the board tomorrow morning, just to make sure that I've not done something stupid like put my electrolytics in backwards. I did graze a box cap with the iron and melted part of the corner. Could that be the issue?

2) when i plug in power and actuate the footswitch, the led turns on. i have measured the voltages of ic's and recorded the following:

4558: 1) 4.57V, 2) 4.59V, 3) 4.49V, 4) 1.2mV, 5) 4.52V, 6)4.57V, 7) 4.5V, 9.1V. While there a few values that are a tiny bit off, I feel like these are close enough (correct me if I'm wrong).

LM471: 1) 4.9mV, 2) 4.96V, 3) 4.77V, 4) 1.3mV, 5) 5mV, 6) 4.98V, 7) 9.11V. These seem a bit wonky...

3) when i plug anything into the pedal, whether it is "on" or "off" i get a horrendous buzzing sound.

I'm at a bit of a loss as to how to proceed, other than clipping all my leads to the board and retrying wiring things with a new switch. I have to say, my pride is a bit hurt. This is not my first electronics rodeo, and didn't think I'd be felled by a "Cowboy" level pedal...

Thoughts? Please don't hesitate to ask any additional questions that may clarify things. Thanks in advance for your help

[Lubdar]

I ran into this as well, I think someone else posted something similar to this as well. Take anote alligator clips connected to ground and the other end touch it to one of the resistors in the tone bypass section. Should take care of theverything issue.  You only need to do it once, it's not like you have to make a permanent connection.  I'm not sure why it happens but it does...

[blackedition]

I ran into this as well, I think someone else posted something similar to this as well. Take anote alligator clips connected to ground and the other end touch it to one of the resistors in the tone bypass section. Should take care of theverything issue.  You only need to do it once, it's not like you have to make a permanent connection.  I'm not sure why it happens but it does...

hmmm... so connect ground to which resistor number? I tried connecting ground to resistors by the bypass switch, but it hasn't seemed to change anything...

Sent from my SM-G920V using Tapatalk

[blackedition]

Here's a look at the board...

[Ralfg]

Make sure you grou d your jacks when testing. From your picture it looks like one is not grounded. In grounded jacks will make a horrible noise.

[blackedition]

I have it wired up like the madbean build manual... the input jack is grounded, but the output jack isn't...

should i ground both?

one thing that i didn't do, that i should have, is test everything without the 3pdt switch. i am going to clip all the wires and test just the board that way when i can (either later tonight or tomorrow night). that way i can rule out the board having any issues...

if nothing else, this build is a great learning experience...

[reddesert]

I have it wired up like the madbean build manual... the input jack is grounded, but the output jack isn't...

should i ground both?

Absolutely.  The madbean offboard wiring picture only works because the jacks are grounded when they are screwed to the enclosure. For testing outside the box, you need to ground the jacks with a wire or clip lead.

[blackedition]

Yeah, I thought it was weird that the output jack wasn't grounded by wire!

So small update. Once properly grounded, I was getting a bypassed signal through the pedal. When I activated the effect, I got no signal whatsoever.

I then clipped the leads to board to remove the switch from the equation. I connected power (+9v and ground), and the input, output, and ground wires from the board. This left the "L" connection unconnected. When plugging in the power, the LED didn't light and I got no signal through the board. The LED should light, no?

Just a quick test before work. More testing later. Sigh...

[Jebus]

The L is the connection for the switching ground for the led. If its not connected the led wont light up.

I would suggest you to build audio probe: http://www.diystompboxes.com/pedals/debug.html

For me that is the easiest way to debug pedal that has no signal at all. In matter of minutes you will locate which is the amplifier stage that has signal at input but not in the output.

[blackedition]

@Jebus, thanks. i figured as much. i have one of the JMK test rig pcbs that I haven't gotten around to populating yet... this build is making me feel like a total idiot haha. i swear i have some electronics experience and a few brain cells!

i guess i'll need to get a mouser order going to get the stuff for the test rig and a couple more builds... i'll definitely need a confidence boost after this one...