Author Topic: Wah Wah Voltages troubleshooting  (Read 2071 times)

The Rocket From The Tombs

Wah Wah Voltages troubleshooting
« on: January 20, 2013, 01:54:45 PM »
I figured I'd make a new post considering the change in circumstances with the circuit. Anyway, I built the tonepad wahwah http://www.tonepad.com/getFile.asp?id=114. Used the 2nd wiring diagram http://www.tonepad.com/getFile.asp?id=76.

Made no substitutions and used the 33k resistor instead of the trimpot.

The circuit buzzes in bypass or with the effect on, just not as loudly with one, I'm assuming that's bypass. So, it's got no connection to ground? Cuz I'm sure I've got the battery in right.

*Tested with a full battery

Q1
C = 8.72
B = 8.23
E = 9.12

Q2
C= 8.80
B= 6.25
E= 9.31

Z1 (zener)
A = 8.72
K = 9.32

The help is appreciated! Thanks.



Johan

Re: Wah Wah Voltages troubleshooting
« Reply #1 on: January 20, 2013, 02:04:37 PM »
those voltages are crazy. did you forget to connect the ground on your board to the ground on the inputjack/chassis/battery?
J
DON'T PANIC

The Rocket From The Tombs

Re: Wah Wah Voltages troubleshooting
« Reply #2 on: January 20, 2013, 02:21:05 PM »
The only thing I've got goin to ground is that junction of the input/output shields and the DC jack.

ch1naski

Re: Re: Re: Wah Wah Voltages troubleshooting
« Reply #3 on: January 20, 2013, 03:05:22 PM »
The only thing I've got goin to ground is that junction of the input/output shields and the DC jack.
the board is connected to ground? Along with the rest?
Stupid question, but gotta ask.:D
Mockingbird wish me luck.

The Rocket From The Tombs

Re: Wah Wah Voltages troubleshooting
« Reply #4 on: January 20, 2013, 03:17:49 PM »
Yeah, I'm pretty sure. My wiring is identical to the diagram I posted.

The Rocket From The Tombs

Re: Wah Wah Voltages troubleshooting
« Reply #5 on: January 21, 2013, 09:34:46 PM »
So, I connected a wire from the negative battery wire, where it's soldered to the Jack, to the ground on my pcb. Now, I just get silence when I turn the pedal on, a little humming (probably normal) and when I press the DPDT I get the loud buzzing. Also, the voltages changed. To me they look screwier than the previous ones, hopefully someone else can make sense of them. Thanks.

Battery= 9.31 volts

Q1

C= 0.10
B= 0.65
E= 4.66

Q2

C= 3.82
B= 3.07
E= 8.46

Z1

A= 0
K= 8.75

ch1naski

Re: Re: Wah Wah Voltages troubleshooting
« Reply #6 on: January 22, 2013, 08:01:38 AM »
Hey, maybe you could post a picture of the guts, wiring and all. It might help someone see something wrong.
Mockingbird wish me luck.

The Rocket From The Tombs

Re: Wah Wah Voltages troubleshooting
« Reply #7 on: January 22, 2013, 05:03:05 PM »
Okay, sorry about the fuzzy quality, I made a few notes to try n make it easier to follow. I surface mounted everything, to save myself the trouble of the thin, flimsy drill bits breaking. In a few areas it might seem like there's a solder bridge but, they don't touch. The only bridge there is, is to fix a broken trace.

http://i1124.photobucket.com/albums/l566/FenderNGibson/Wah1_zpsdff7d389.png

http://i1124.photobucket.com/albums/l566/FenderNGibson/wah2_zps543d7a94.png


EDIT: So I was thinking, the transistors could be in backwards. If I looked at the layout from left to right, C on both trannies would go into the 470ohm and the 10k resistors, right?
« Last Edit: January 22, 2013, 05:13:27 PM by The Rocket From The Tombs »

killerkev

Re: Wah Wah Voltages troubleshooting
« Reply #8 on: January 22, 2013, 10:41:49 PM »
First of all, you should consider drilling holes for the components and placing them on the other side of the board. You're likely to have less problems....

The latest voltages you posted are backwards, maybe you posted wrong? The values you posted should be reversed for the C-B-E. Below are voltages from my wah:
Battery= 8.94volts

Q1

C= 4.42
B= 0.59
E= 0.04
Q2

C= 7.9
B= 3.85
E= 3.43
The link to the diagram does not show the wah. Repost. You would not get the voltages from the trannies if the transistors were in backwards.

The Rocket From The Tombs

Re: Wah Wah Voltages troubleshooting
« Reply #9 on: January 23, 2013, 08:19:35 PM »
http://www.tonepad.com/downloadWarning.asp?id=114

http://www.tonepad.com/downloadWarning.asp?id=76 (2nd one down)

Ah thank you, I thought I might've had it backwards. My voltages look pretty similar to yours, so I'll assume the trannies are fine. Is it possible the physical size of the resistors could cause any problems? cuz my resistors very in size, some are very small n some are bigger.

killerkev

Re: Wah Wah Voltages troubleshooting
« Reply #10 on: January 23, 2013, 11:11:28 PM »
Na, resistor rating should not effect the pedal working. Your voltages look good. If the effect does not work as expected in this case you HAVE TO FOCUS on the WIRING. It is the problem absolutely....oh, your inductor needs to be placed prperly. Buy a dremel for $30 bucks and put it together PROPER! I think I just sounded like a rapper!

The Rocket From The Tombs

Re: Wah Wah Voltages troubleshooting
« Reply #11 on: January 23, 2013, 11:33:48 PM »
Haha, wait how did I  place the inductor poorly?