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DIY Stompboxes => Building your own stompbox => Topic started by: vince37 on February 25, 2012, 05:03:30 PM

Title: Meathead Help?!
Post by: vince37 on February 25, 2012, 05:03:30 PM
I've built a standard meathead clone, The volume pot (500k linear) acts like a tone pot? anti/rolls of highs and fully clockwise is normal? Also there is no volume increase just a huge boost when engaged.. I have changed pots,no change. I have even built it twice, same results??

I'm out of ideas :(
Title: Re: Re: Meathead Help?!
Post by: slacker on February 25, 2012, 05:22:47 PM
Sounds like the pot is connected incorrectly. Have you got a link to layout you used, that would help figure out the problem ;)
Title: Re: Meathead Help?!
Post by: vince37 on February 25, 2012, 05:28:18 PM
Thats what I was thinking... maybe a log instead of linear?

Heres the diagram I followed,

http://tagboardeffects.blogspot.com/2010/10/dam-meathead.html
Title: Re: Meathead Help?!
Post by: IvIark on February 25, 2012, 06:41:03 PM
Vince, if the volume pot is acting like a tone pot then you almost certainly don't have pin 1 properly connected to ground. The point of that connection is to connect the output to ground in the fully ccw position, and if that isn't happening then the ground connection mustn't be true or the pot must be damaged.  Reflow the solder and check all your ground connections for continuity with a multimeter.

All the resistor values seem to be correct as well as your track cuts. What transistors did you use?
Title: Re: Meathead Help?!
Post by: vince37 on February 26, 2012, 03:07:13 AM
Hi Mark,

I've replied to you on your blog... Thanks for taking the time out :)
Title: Re: Meathead Help?!
Post by: vince37 on February 26, 2012, 03:23:37 AM
Mark, you were right... I didn't ground pin one on the pot... works now..

Huge thanks for people taking time out to help
much appreciated ;)