Author Topic: Whammy II noise problem  (Read 2334 times)

jack_stereo

Whammy II noise problem
« on: May 23, 2016, 12:07:35 PM »
Hello,

I have a Whammy II from 94. I bought it when it was released and enjoyed it for quite a few years until it started having some noise issue that makes it no longer usable.

The thing is that at any slight touch of the metal housing, or when moving the gain trim pot, there's some big crackling noise and the incoming signal peaks and clips like hell. I've been testing it again today, and I'm tending to think that it might be some grounding problem, or something wrong at the gain stage.

I opened it up and saw some small "fixes" in the pcb, and i'm not sure if they were made at the factory, or if they were made years later, when i took the pedal to some service center, where they told me it was some DSP fail (wich i doubt). IF somebody has a Whammy II and could post some pics of the guts and the pcb, i'd greatly appreciate it.

Thank you all for your help

Govmnt_Lacky

Re: Whammy II noise problem
« Reply #1 on: May 23, 2016, 02:25:14 PM »
The thing is that at any slight touch of the metal housing, or when moving the gain trim pot, there's some big crackling noise...

This sounds like you have AC or DC on the Ground plane to me. I would suggest powering up your Whammy and check for voltage on the chassis. If you do find voltage, then you will want to look for areas where contact is being made to the chassis.

Pics might help as well...  ;)

Good Luck!
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jack_stereo

Re: Whammy II noise problem
« Reply #2 on: May 26, 2016, 02:33:57 PM »
Thanks fdor your reply Govmnt_Lacky

I opened it up and removed the pcb from the metal chassis. At first i thought the problem was the gain pot, since it made big noise when touched, so i decided to remove the small pcb with the gain pot (btw, two of the lugs are soldered together and there's a trace cut in the pcb, as well as another trace cut in the main pcb...i'll attach some pics later)

After doing so, i plugged the guitar and the signal is completely overload, sounds like straight fuzz (which is kinda cool in a way!). Just plain fuzz on both the dry and wet outputs, and the input completely overload....BUT, not crackling like before. So, after doing this, may the problem be just the gain pot?? Or could the problem be caused by any, or some of the opamps??

Mine is a Whammy Pedal II Rev C. The Eprom version is 1.10....I think it's one of the first runs of Whammy II

I'll attach some pics later

Thank yuo

jack_stereo

Re: Whammy II noise problem
« Reply #3 on: May 26, 2016, 06:23:37 PM »
Here are some pics of the pcb.
Notice the trace cut in the main PCB and in the gain pot PCB as well; and also the two lugs of the pot soldered together.
Notice also a capacitor and a resistor in series just above the trimpot ; and also those two resistors in parallel above Q3 and Q2

I'm trying to post the pics, but i just don't know how to do it. Any help would be appreciated. Thank yo

duck_arse

Re: Whammy II noise problem
« Reply #4 on: May 27, 2016, 11:59:30 AM »
jack, as we like to say around here, you need to post the pictures somewhere on the interwebs, like a hosting site, maybe like imgur. they will give you an address for your pics, and you come back here and paste the URL into your reply, between the tags provided by mona.



resized for sensible scrolling/viewing, please.
"Facts are on our side."

unthreaded, left-handed ants. and plenty of them.

jack_stereo

Re: Whammy II noise problem
« Reply #5 on: May 27, 2016, 12:22:42 PM »
Thanx a lot duck_arse!

So, here are the pics of my Whammy's guts. Hope it helps









jack_stereo

Re: Whammy II noise problem
« Reply #6 on: May 27, 2016, 04:13:30 PM »
 ;D ;D ;D Yes! I finally fixed it. The problem was the gain pot! All that noise was coming from the gain pot. It was as easy as that! Nothing to do with any ground issue or any bad op amp


I soldered a 100k pot to the pcb, tested it, and works like charm, no noise at all, and the old whammy II is back to life, and it sounds as good as i remembere. Wow, that was a trip, i hadn't used it for years, all because of a bad pot....i feel so silly, dammit! I should have never trusted the guy that said it was some DSP fail. Guess i was too young back then, I'm glad i didn't finally sell it for parts!

Thanks to all the ones that helped me