Hi , I have just bougt a Marshall Jcm
2000 dsl 401 Combo problem is when it has been on a while (about 30min) i get this hissing coming from the amp which disappears when i hold the strings or play....what could this be?
i purchased it brand new and i use it with my fender lite ash strat.
this is my first valve amp if this is normal please dont laugh at me just its strange how its fine for the first 30min or so.
ps i am aware there is a design fault on the amp leading to overheating but i dont think this is a contributing fact as the amp feels relativley cool when it occurs.
cheers any help appreciated.