Guild 66-J

Soul Tramp

Member
Joined
Jul 17, 2020
Messages
209
Reaction score
340
Location
Little Sebago Lake, Maine
While working on this amp I couldn't help but notice the sloppy lead dress. I didn't give it much thought as it's the norm for amps of this era.

Unfortunately it's the cause of my trem popping/ticking. The B+, and bias modulation wires are wrapped in the same bundle as the trem Speed wire that run to the pot. As well, the OT secondary (speaker) wire is rubbing up against it. There are some fundamental rules about layout and design, things like keep A/C away from D/C, keep low impedance away from high impedance, etc. This amp and all other "vintage" amps seriously violate ALL these rules. Over time the wire move around and create all sorts of noise and oscillation problems.

I'm going to move things around and probably end up isolating the trem speed wire from the rest of the bundle. You can see the bundle in the black tube at the bottom of the picture. The white wire is the OT secondary, two white striped wires are B+, the green and yellow wires are the trem bias modulation, and the blue wire is the speed control.


DSC08091.JPG
 
Top