Marshall 50w Making Crackle Noise at High Volumes

[stonecutter54]

SO, the common denominator is THEIR cabinet and THEIR cable resulting in no problems, And YOUR cabinet with YOUR cable(s) resulting in problems. I'd say you need to take a closer look at your CABINET.

Agreed.
On Sunday I pulled the cabinet apart and rewired it (with different wire) and soldered the connections. Prior to that it had been wired with clips and the wire/terminal connections had NOT been soldered. I thought maybe the clips were vibrating on the speaker terminals and therefore causing the crackle. Nope.

I put three different mics on three of the four speakers and even after rewiring everything, all three speakers produced the crackle when recording. You could even hear it when standing in the room with the cabinet.

Note: Sometimes the amp has to warm up a bit before the crackle kicks in....so maybe that's why I didn't hear the crackle at the shop....maybe.

Last Night:
I also tested the amp using both the 8 and 16 ohm speaker outputs - both crackled.

However......I replaced the power tubes again and I think the crackle went away - it sounds like the second section in the clip above. There is strong fret rattle, but not the same electrical sounding zippppt-zipppt-crackle noise that happens when running the original tubes.

Just to be safe, I dropped the amp off at the tech's today and explained everything. Hopefully, they'll go through it more thoroughly and validate its the tubes or find the root cause.

I'll keep ya posted. Thanks for all the replies and help!!

[Lefty Lou]

I would almost say it was one or more voice coil related problems experienced at higher volumes with your cabinet according to the previous evidence submitted, but having just mentioned a tube warmup period prior to the "staticy" noise issue expands the troubleshooting overview somewhat.