madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: mattc on December 22, 2013, 07:06:29 PM

Title: Weener White Noise
Post by: mattc on December 22, 2013, 07:06:29 PM
Well, I'm now two for two.   I needed help with the Fat Pants (thanks to all who helped!), and now I need help with my Weener.  I really don't know how to troubleshoot this any farther, so any help would be greatly appreciated!

(1) Project Name:
Weener Wah (the original)

(2) General description of the problem:
When the effect is on, I get a faint amount of the guitar signal and a LOT of white noise.  When I move the wah pot, the white noise gets "wahed".  It seems like there is noise getting into the signal path instead of the guitar signal, but I don't know how to track that down.

(3) Steps that you have taken to try to resolve the issue:
I wasn't sure about the orientation of Q1, but changing that didn't change anything.  I've tried re-flowing the solder to all the joints.  I checked to make sure the Whipple is oriented correctly (which I think it is)

(4) List any substitutions you used for parts/values:
I didn't have a 22k for R3, so I used something around 24k.  I have a 22k coming in the mail...

Here's some pictures:

Top:
(http://mattc.smugmug.com/Music/Weener/i-bXgnR6h/0/O/IMG_6219.jpg)
(http://mattc.smugmug.com/Music/Weener/i-6V7RnRs/0/O/IMG_6223.jpg)

Bottom:
(http://mattc.smugmug.com/Music/Weener/i-H39gtf7/0/O/IMG_6225.jpg)
(http://mattc.smugmug.com/Music/Weener/i-GhHmpNQ/0/O/IMG_6224.jpg)

Bypass Switch:
(http://mattc.smugmug.com/Music/Weener/i-f4CWJW2/0/O/IMG_6218.jpg)

Switch:
(http://mattc.smugmug.com/Music/Weener/i-W9KC3WN/0/O/IMG_6222.jpg)

Freq Control:
(http://mattc.smugmug.com/Music/Weener/i-mT7vvRd/0/O/IMG_6220.jpg)

Wah pot:
(http://mattc.smugmug.com/Music/Weener/i-Q6zWFN9/0/O/IMG_6221.jpg)
Title: Re: Weener White Noise
Post by: jimilee on December 22, 2013, 08:17:38 PM
Is everything grounded properly, how does the off board wiring look to the jacks and dc switch? The resistor value isn't going to change anything in this instance, I wouldn't bother with it. Do you have to turn your amp all the way up to hear the noise? Do you have bypass?
Title: Weener White Noise
Post by: rullywowr on December 22, 2013, 08:43:33 PM
Nevermind... You got it
Title: Re: Weener White Noise
Post by: mattc on December 23, 2013, 08:51:13 PM
Quote from: jimilee on December 22, 2013, 08:17:38 PM
Is everything grounded properly, how does the off board wiring look to the jacks and dc switch? The resistor value isn't going to change anything in this instance, I wouldn't bother with it. Do you have to turn your amp all the way up to hear the noise? Do you have bypass?

Bypass works fine.  I am getting power to the LED when I engage the effect, so I think that's all correct as well.

I am not sure what you mean about everything being grounded correctly?   
Title: Re: Weener White Noise
Post by: jimilee on December 23, 2013, 10:17:37 PM
Quote from: mattc on December 23, 2013, 08:51:13 PM
Quote from: jimilee on December 22, 2013, 08:17:38 PM
Is everything grounded properly, how does the off board wiring look to the jacks and dc switch? The resistor value isn't going to change anything in this instance, I wouldn't bother with it. Do you have to turn your amp all the way up to hear the noise? Do you have bypass?

Bypass works fine.  I am getting power to the LED when I engage the effect, so I think that's all correct as well.

I am not sure what you mean about everything being grounded correctly?

Bt grounded properly, I mean is there a ground coming from the dc jack to the input jack to the stomp?
Title: Re: Weener White Noise
Post by: rullywowr on December 23, 2013, 10:30:19 PM
Aside from everything being grounded properly, which is a good tip...have you used this inductor before? 

I racked my brain for so long one time on a wah project only to learn that the inductor was shea-doobied. 
Title: Re: Weener White Noise
Post by: mattc on December 26, 2013, 07:25:03 PM
I went back and reflowed the solder again.  I added grounds from the board to each jack.  I used the meter to verify that I have continuity from the power jack ground to the board and jacks.  Still no luck. 

When it is off I get signal.  When it is on I get hiss, that when I turn the wah pot, he hiss gets wah wahed.  The freq pot changes the frequency at which the the hiss is getting wah wahed.   The LED lights up when I turn on the effect.   Because the signal (hiss) is getting wah wahed, I think the inductor is working.   I have a red fasel here, but I ran out of de soldering braid, and (of course) RadioShack is sold out, so I haven't tried that.

Any other ideas?    Any other pictures I could take to help?

Thanks in advance!
Title: Re: Weener White Noise
Post by: jimilee on December 26, 2013, 07:48:39 PM
Audio probe to see where signal loss occurs would be next.
Title: Re: Weener White Noise
Post by: mattc on December 26, 2013, 08:21:55 PM
Can someone point me in the direction of a tutorial on how to use an audio probe to track down the issue?
Title: Re: Weener White Noise
Post by: mattc on December 26, 2013, 09:13:41 PM
Progress!!!!

When I put my finger on the following resistors I get a clean wah signal: 3, 6, 8, 11, 16.  When I take my finger off, no signal.

I reflowed all the joints on these resistors, but it only works when I put my finger across the joints on the left side (looking at the bottom of the board)

It also works when I put my finger across the bottom of the peak trimmer and Q1.

So I have a grounding issue?   I have no idea where to go from here, and my wife says she won't hold it the entire time I want to play....
Title: Re: Weener White Noise
Post by: midwayfair on December 27, 2013, 05:46:17 AM
Quote from: mattc on December 26, 2013, 09:13:41 PMmy wife says she won't hold it the entire time I want to play....

Dude, if your wife won't hold your weener....

*shakes head*