I have a Marshall MG Series 50DFX amplifier, which isn't that great to be honest. It's ok for home/band practice but that's about it... Anyway, the master volume pot is very crackly and when turned the volume jumps up and down very rapidly. When left alone afterwards the volume is normally very quiet, which means I have to turn it some more to find a volume which is usable.
After searching around, I have managed to find out that this is probably due to some gunk in the pots. I have bought myself some contact cleaner but am unsure as to how I should go about this. At the risk of sounding very naive here... Do I literally just yank off the knobs and give what's underneath a spray..? Or am I going to have to take apart my amp to get round the back of the pots? I have never done this before and, although the amp is nothing special, I don't want to fuck it up unnecessarily. Has anyone got any ideas or advice?
Also, I am looking to get another amp, a valve if possible. I haven't got a great deal of cash available, £500 at a push. Has anyone got any suggestions/recommendations that I could look into? I play mainly alt-rock type stuff.