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1974 Kustom 1-b bass amp [message #26982]

Thu, 20 September 2018 19:54

Hugh Andrews
Messages: 4
Registered: September 2018

Junior Member

Dug this amp out after many years of none use and it had 2 problems. 1) popping and crackling 2) and each note fades distorted (buzzing) at any volume. I replaced the electrolytic caps with 4700uf 50v caps instead of the 1900uf 40v caps as per suggestions from this forum and that solved problem #1. Notes are loud and strong, but as they decay it's distorted.I tried different guitars and cables. I disconnected the amp from the speaker and drove the speaker with another amp. It did not distort. So the problem is not in the speaker or cabinet. Does this sound like a a problem in the power section or the preamp? Or possibly the transformer? Also I cannot find a schematic. Any suggestions?

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