Wooly Mammoth debug help

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Wooly Mammoth debug help

Postby DarkNDubby » 30 Mar 2012, 20:57

Hey everyone,

I am desperate for a little help here. I've done maybe a dozen successful builds so far, but my last 2 have really been tripping me up. Hopefully, someone here can help me with what i think is the easier of the two.http://www.sabrotone.com/wp-content/uploads/2011/06/WoolyMammoth.gif

I have built a Wooly Mammoth clone using Harald's layout on Sabrotone. Everything work perfectly except for the EQ control. The EQ control does not affect the tone at all when going from full clockwise to full counter clockwise. I have verified 5+ times that all the components and wires are correct, and I have reflowed all the connections several times and double checked all the cuts. I have been referencing this schematic http://imageshack.us/f/60/woollysd1.jpg/, and it looks like the issue is somewhere between Q2 and Output pot, but it's strange that there is absolute no perceptible change in the EQ. I tried swapping the 10n cap thinking that would make the difference, but no joy. I am at a complete loss here. I've spent a couple of weeks coming back to this with no success. Can anyone provide any insight? I would be so grateful!

Thanks in advance.

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Re: Wooly Mammoth debug help

Postby Duckman » 31 Mar 2012, 02:06

Look here, maybe (just maybe) your problem was discussed before :thumbsup

viewtopic.php?f=7&t=4&hilit=mammoth
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Re: Wooly Mammoth debug help

Postby DarkNDubby » 02 Apr 2012, 20:41

Thanks, Duckman. I read through the entire thread. I didn't say anything that was related to my issue, unfortunately.

Should I move my post in there? I spent some more time with the project this weekend, but at this point, other than reflowing and rechecking connections, I am not sure what to do.
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Re: Wooly Mammoth debug help

Postby bato001 » 04 Apr 2012, 04:45

I have had this same problem with other builds and it has always been caused by 1.) a bad pot 2.) improper wiring of the pot (ie: wire supposed to go to tone 3 goes to tone 2 and vice versa) or the biggest offender ---3.) Solder bridges between the vero strips.

I hate to sound like a broken record, but with Vero Builds always use a utility knife to clean between the traces. Removing crispy fried flux and microscopic solder bridges is always your first step in trouble shooting a vero build. It doesn't mean you are a bad or sloppy solderer, it means your human. I always keep my utility knife handy when I am soldering vero and clean between the traces as I go.
"Ever wondered how some of your favourite guitar players got their tone? Me too. Probably a good amp and lots of practice." Little Lord Electronics Homepage

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DarkNDubby (04 Apr 2012, 19:56)
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Re: Wooly Mammoth debug help

Postby DarkNDubby » 04 Apr 2012, 19:58

Thanks, Bato. I'll go and try to do some more cleaning. I have run a utility knife between the busses already, but I'll give it another go. I rechecked all wiring many times, but I'll give it another look tonight also. I swapped out the pot already and still had the same issue, so it probably isn't the pot.
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Re: Wooly Mammoth debug help

Postby Duckman » 04 Apr 2012, 22:37

Try to post some pictures of both sides to get more eyes on this.
Most of the times is a simple error, like emmiter of Q1 soldered to pinch pot because lines cross in the schematic, or something misplaced but we assume that's all alright. Don't give up :thumbsup
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Re: Wooly Mammoth debug help

Postby DarkNDubby » 13 Apr 2012, 17:29

Thanks for everyone's input on this. As an update, I finally got the tone controls working. I had 2 caps of different values switched. Doh!
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Re: Wooly Mammoth debug help

Postby Duckman » 13 Apr 2012, 20:24

:thumbsup
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Re: Wooly Mammoth debug help

Postby bato001 » 14 Apr 2012, 04:40

DarkNDubby wrote:Thanks for everyone's input on this. As an update, I finally got the tone controls working. I had 2 caps of different values switched. Doh!


Nice :thumbsup
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