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anyone know about electronics?
Posted: Jan 26th, '07, 09:54
by chris_1127
having trouble with a bass amplifier, the potentiometer that controls the master volume is a bit iffy - at first i thought it was the connections to the pcb as the foil on the board was broken, however I soldered a "bridge" over this and araldited over, but am still having problems. If I wiggle the pot, it cuts in. However having tested the board for continuity it all checks out ok.
Should potentiometers only have variable resistance between two of the poles? theres 3 poles on the pot and only 2 of them seem to have any connection between them.
Re: anyone know about electronics?
Posted: Jan 26th, '07, 10:37
by andrew
chris_1127 wrote:having trouble with a bass amplifier, the potentiometer that controls the master volume is a bit iffy - at first i thought it was the connections to the pcb as the foil on the board was broken, however I soldered a "bridge" over this and araldited over, but am still having problems. If I wiggle the pot, it cuts in. However having tested the board for continuity it all checks out ok.
Should potentiometers only have variable resistance between two of the poles? theres 3 poles on the pot and only 2 of them seem to have any connection between them.
checking for continuity is a very limited test especially as components often break down under load. you would be far better tracing an input signal using a oscilloscope.
Without seeing the pot (and knowing its type/spec) it would be impossible to tell you if it should have two or three connections you should be able to tell by looking at the circuit board on which its mounted. Do all of the legs have tracks going to them?? Does one leg look different to the others?
I would be tempted to replace the pot - if you remove it and take it to your local maplins they should be able to give you a replacement.
Posted: Jan 26th, '07, 10:43
by chris_1127
thanks andy, the 3 tracks all go off in different directions on the board so I would have expected connections to other legs but must admit I dont know a lot about electronics. its a 10k damped rotary pot if that helps - I am getting very limited high frequency sound out of the amp but theres no bottom end to it at all. Will try and get hold of a replacement today and see how i get on with it.
Posted: Jan 26th, '07, 11:04
by baskie
nope i dont, sorry

Posted: Jan 26th, '07, 11:55
by chris_1127
you've let me down Baskie, I had high hopes that you would be able to solve this one for me, in your own illegible way

Posted: Jan 26th, '07, 12:01
by Jonny
I'll have a word with my dad later. He should be able to help.
Posted: Jan 26th, '07, 12:06
by chris_1127
cheers, electronics place down the road has a load in stock apparently so going to try getting and fitting a new one when i get my lunch break.
its a 10k rotarty damped logB pcb mounted one of that makes any difference to which pins should be linked
Posted: Jan 26th, '07, 12:35
by baskie
rip it the fook out fnd go down resco and buy some shit cheapy harry one . job well done. and only cost u a fraction of da price and is alot easier to sort it out. lol. so stop being flashy and just get amongst it. ;)
Posted: Jan 26th, '07, 13:52
by chris_1127
swapped the pot over for a new one - seems to work fine now. Cheers chaps
funnily enough rescos didnt have them, thanks for the suggestion though baskie
