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Desperitly need help ! (this is a tough one)

9/11/2003 3:27 AM
dazco
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Desperitly need help ! (this is a tough one)
I just bought another classic 30 and very neatly and carefully did the same mods i did to my last one.....cathode bias, fenderized the input, presence control, tone stack caps, and changed a couple other values. All mods from steve alola's site. I did the same to my old one and it worked fine. However, this amp is brand new and a few days after the mods it began making a random noise. Sort of a popping sound like you'd hear tapping your finger on a speaker cone. The pops come singly her and there, and sometimes in rapid succession for up to 3 or 4 minutes straight. Once warmed up they decrease to a few here and there sometimes minutes apart.  
 
I've sprayed all pot and jacks with deoxit, pushed and tapped the boards and component with the chassis out and amp on to try and cause the noise and see where it may be coming from. I hit almost every solder joint on the thing !!! I used a eye loupe to closely inspect all solder joints. At first i suspected a broken board jumper....as any of you know who've worked on a C30, the 3 boards are held together with jumpers that often break. This happened to other C30's i've had and once it caused the exact same noise. But they all are fine.Tried all different tubes. The only thing left that i can see is a component that is working but has some sort of problem like a leaky cap or something. But i have no way of knowing which one w/o replacing everything, which of course is rediculous. The fact that it tends to get better the warmer it gets should be a clue. Sounds like a connection, but as i said i've hit every joint and cleaned every jack switch and pot.  
 
I'm at a total loss as to what it could be or how else to troubleshoot it other than all thre things i've done so far. New amp ready for the trash? Help please!!!

 
Replies:
Allen Try swapping out the tubes one at a... -- 9/11/2003 11:39 AM
Enzo The essence of troubleshooting is t... -- 9/12/2003 12:19 AM
Rick Erickson [QUOTE]The fact that it tends to ge... -- 9/17/2003 6:41 PM