Its a VOX Valvetronix VT30 and it seems not to matter what switch I turn, it all crackles unless we find a quiet spot, and its driving me around the bend. The input socket seems to be a bit tired as I have to wiggle the plug in it to get a connection. We tried it out in the shop a little over a week ago and it seemed fine but I am wondering if they had set the plug in 'just so' so it was OK. If I get the plug in a good position its fine for about 20 minutes and then seems to move a bit & it all goes quiet. I didn't try every permutation of all the switches in the shop though as there are 8 main switches with one or two of them having up to 11 settings (22 if you use the little button next to it - upper and lower case so to speak).
Its second hand but from a large music shop in Norwich city centre so I will go and have a polite word. They did say if I had any problems to bring it back, its probably just dusty and mucky inside but amps are a new thing for us. Umm, stupid question but is it supposed to buzz? I remember my brother had a lot of amps and I really do not remember a whole lot of buzzing going on with them.
Ok...
I havent used one of those but it looks like a Solid state amp with a small pre amp valve in the power amp stage...lot's of amp modelling options etc...hmm...let's start with the input socket. If it is loose then you need to tighten up the screw thread around the socket, it should not wiggle (do check that guitar cable though!) You will likely find that turning the nut on th einput screw thread works to a point, then you will need to 'grab' it from within while tightening the nut on th eoutside of the input socket. TURN OFF THE AMP AT THE MAINS BEFORE YOU DO THAT.
Get down to maplins and get some elecrical contact cleaner spray and spray in via the long tube into the input socket. Inside that socket is a metal clip which tensions like a spring and clips onto the guitar cable jack as you plug it in. This may have lost some of its tension and you may be able to bend it back out a touch to re tension it. If it is loose and not clipping tight on the jack plug it would give problems as you describe. I think you may need to take the amp back off to get into that socket, but before you do try tightening and cleaning externally as I said above first. I dont think your problem is to do with the other knobs/switches/buttons from what you describe.
Is it supposed to buzz? Most amps have a slight buzz. But if it is excessive you should first check your earths! Switch it all off at the wall. Open up the back of your guitar and look for anyloose wires especially a single black wire that should run from the internal gubbins to a metal surface like the tremelo block for example. If it is loose DO NOT USE THAT GUITAR. If it is loose re solder it to where it came off from. If in doubt get thee to the shop or your guitar teacher, a loose earth is life threatening and will cause a lot of buzzing.
If you are using hi gain settings (distortions etc) these will generate higher hum/buzz than clean tones. This is annoying but normal. You may have a noise gate patch on that amp somewhere (??) if so learn how to set it so it cuts out th enoise when you arnt playing.
One other thing which may be causing noise is the single small galss valve in there if its old and needs replacing. I suspect this isnt the case and the issue is with a loose input socket so try all that first.
Not by a long way but having a blast! I work quite hard and practice in 30 minute sessions. Sometimes I can get 3 sessions in during a day, sometimes only 1 and a bit. My guitar teacher is young and pushy and gives a lot of homework but doesn't expect note perfect by the following lesson.
