Crackling and Popping

[Corey5150]

Hi guys!

I have a haze 15 head, I made a couple mods to it (Brought it to jcm specs) all was good (several weeks ago), this past week I added a cold clipper switch and presence knob it functioned for about two hours and then all of sudden it makes loud pops and a constant crackling sound. There is no guitar signal coming through. I have inspected the connections and gone back through and reverted the last two mods I did.

I thought perhaps the power tubes went bad so I changed them. I started pulling tubes to see if I could isolate the problem. Crackling remained with all pre amp tubes removed. I haven't modified anything in the power amp (I should mention when I removed the power tubes - the noise stopped).

Can anyone help point in the right direction? I'm thinking filter caps, but I'm unsure and don't want to waste my time ordering a bunch if there's a few things I can check.

Also worth mentioning I’ve checked continuity around the areas I worked and it seems fine.

Thanks!

[bobtec]

I would of stpped at the first mod Go back to where it was ok..Most old timers here are gone This was a great site Until people started Hacking Im just a dumbass I have not been here for a year Take the Mod out

[danman]

Your symptoms point to a bad solder joint somewhere in the amp. If you feel comfortable, power up the amp with a speaker attached and chopstick every wire and solder connection to see if you can find the bad one.

[glpg80]

I would check to see if your voltages all seem adequate - check your B+, heater filament voltage, and check to make sure all cathode resistors have a DC voltage across them. If all of that checks out, check the solder joints of all of the mods that you added by chopsticking them. If your voltages do NOT check out and seem low or off, then I would look for a recently added shorted capacitor - common with Mica capacitors that aren't 3M brand or made in Mexico. You can check to see if they are shorted by lifting one side and measuring resistance across them - they should be open (OL) or (Hi Z) on your meter. If it measures anything else, it's bad and the culprit.