Amplifier Repair

[Clay Campbell]

Anybody good with electronics. I have a 5yr old memphis amp im trying to repair. Its old school and still enough to not just junk it. I am trying to find replacements for the gain and LPF pots. and wondering what criteria i need to look for in a replacement.

 

[Travis Munday]

Well, for one, you'll have to find out what size they are, ie. 25K or 250K, etc. You can ohm-test the old ones and get their resistance values, but if they are faulty, that may not work. You'll also have to find out the type, Memphis might use an "off the shelf" type that is easily replaceable, or a proprietary style that can only be found in other Memphis amps, or even that same model line of the faulty amp.

 

[David Ponder]

Clay,



May I ask what makes you think they are defective? I worked on car stereos and amps for several years for a living, and rarely would a pot be bad. (Normally they would only be dirty and you can clean them with some contact cleaner)



Just asking..

 

[Clay Campbell]

Tiger, They are a KIE product but i cant find any too much like them on the internet, i can get a picture up tomorrow. I can't figure out there resistance values. Possibly could do the ohm test sometime soon. I cant find any specs on them on the internet either. There are numbers on the side of them two say 15C503X4GD and one says B203X2ED



Dave. My brother bought this amp new and he had it in his trooper on two autotek twelves for about a year. I talked to him about it and he said for as long as he can remember the gain has been messed up so that it didnt function properly and you had to mess with it until you go it to a sweet spot where it was good for output. The know that spins also is supposed to stop i thought when it is at full gain but it doesnt anymore. well when i got it and put it in my car it worked good for a couple of months but still had the sweet spot problem. Then it started not working in the mornings but working in the afternoons. then it got so touchy i could spin the gain all day long and would not get any output. except maybe once in a while it would hit a spot but it wouldnt stay there no matter what. Also after doing some research and posting this same question on a car audio forum i took the amp apart and inspected the pcb and connections. All connections look sturdy and clean and there appears to be not problems on the board anywhere, no black or discoloration of any kind. These amps are still going for $100 to $200 even at their age and broken ones for parts are like $70 so im trying to repair this economically