#1
got a vintage vox ac30 off ebay (circa 70s) and a friend decided to lift it while it was on, ever since when playing the signal from the guitar goes quiet then very over driven, I cannot tell whether its my dodgy cables or my amp is at fault, please help
#3
If it's not a dodgy cable, check that one of the tubes haven't got loose.
#4
Quote by WeZ-84
If it's not a dodgy cable, check that one of the tubes haven't got loose.


This would be my guess, check the cable still, but reseating all the tubes (and maybe spraying some contact cleaner on the pins and work them in and out) would be a good idea.
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#5
ok now its really messed up..... i play a note and then it goes really quiet and then really loud etc.... i've checked the cable so now ill check the tubes
#6
OP FYI, this belongs in the Guitar Gear and Accessories forum
"A well-wound coil is a well-wound coil regardless if it's wound with professional equipment, or if somebody's great-grandmother winds it to an old French recipe with Napoleon's modified coffee grinder and chops off the wire after a mile with an antique guillotine!"
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#7
Moved to GG&A

Given the age of the amp, I would suggest getting it serviced by a competent amp tech, as it's quite likely that some of the capacitors might need replacing.
Rig Winter 2017:

Fender Jazzmaster/Yamaha SG1000
Boss TU-3, DS-2, CS-3, EHX small stone, Danelectro delay
Laney VC30-112 with G12H30 speaker, or Session Rockette 30 for smaller gigs
Elixir Nanoweb 11-49 strings, Dunlop Jazz III XL picks
Shure SM57 mic in front of the amp
#8
Quote by Blompcube
Moved to GG&A

Given the age of the amp, I would suggest getting it serviced by a competent amp tech, as it's quite likely that some of the capacitors might need replacing.

Yeah.

Might just be a worn or loose tube, but after 40 years or so the electrolytics in that amp are likely done.
Then there's also bad/broken solder joints and such. Have a tech check it out, it's not that expensive usually (eventual repairs might be, though).