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rock ola 418 amp questions

Posted: Fri May 08, 2015 5:27 am
by mb9513
Hi all: ran into odd problem with the amp in a rock ola 418. amp 39310. ran fine for a while I was running in. then lost right channel. it has 2 separate out put connectors. one for low and one for high frequency and they both are gone. When the balance is hard over there is some low sound. I tried to change it to monaural to see what part of the amp is goofed up and got no sound out of right at all. Have check all the usual suspects like all the pots with de-ox it. swapped all the right left tubes. have it pulled and setting on the bench now. thought I would check the forum for suggestions. it is designed so it is just about impossible to do voltage checks. any help would be great. Mark

Re: rock ola 418 amp questions

Posted: Fri May 08, 2015 8:00 am
by Rob-NYC
Check the cartridge and it's connections. If the common is broken at any point the cart is then across the channels and out of phase for both. The cart itself could be responsible for this as well.

Rob-NYC

Re: rock ola 418 amp questions

Posted: Sat May 09, 2015 6:01 pm
by ds100h
Replaced potentiometer and problem is resolved. Thanks for help.