Page 1 of 1

Sho booster problems

PostPosted: 21 Apr 2013, 21:19
by Mrdorbe
Hey guys I hope I'm in the right thread...
I built the sho booster used a pic I found in the Internet worked like a charm!! Clean boost perfect
But when I tried to build another one it worked but the pot made scratch noises and the sound coming out was overdriven.
I used the same parts and did everything the same can anyone think of what I could do wrong the second time that could cause this problam?

By the way I tried replacing the pot and stil the same also checked it with multimeter..
Thanks

Re: Sho booster problems

PostPosted: 21 Apr 2013, 23:15
by Lucifer
When pots scratch, it suggests DC where it shouldn't be.
Make sure one of the cap feeding the pot isn't shorted out by a sliver of solder or stray bit of copper track.

Re: Sho booster problems

PostPosted: 21 Apr 2013, 23:53
by Nocentelli
Isn't the control labelled "crackle OK"? I'd be more curious about why your first build didn't crackle, and also why this second one is distorted: I think the circuit probably overdrives at really very high levels, but before then you will probably also be distorting whatever stage comes next in the chain. It is a fairly clean, glassy boost most of the way up.

Re: Sho booster problems

PostPosted: 22 Apr 2013, 00:07
by davent
Sounds like something may have been wrong with the first one. Low settings a clean boost, high settings, kick the snot out of the first tube preamp stage, crunch. Crackle?- all's fine.

http://media.zvex.com/FLASH/SHO/

dave