After 13 years of use the Marshall JMP-1 started to make crackle and popping sounds. It was time to replace the two ECC 83 tubes in the pre amp with new and fresh ones.
Kim:"I've been experiencing these popping sounds at rehearsals lately, and during recording. I hope that by replacing the tubes in the pre amp will fix the problem, I've installed two 12AX7 tubes and they are supposed to be the same as the original ECC83's.
I think they sound great...just like they should sound. My ears are ringing after testing out my new tubes. I love my rig at high volum, it's powerful".