OK so I'm thinking of buying a peavey classic 30. The only down side of it is that it doesn't have a cover at the back (the valves are exposed). Are there any after market covers I could buy to protect it from any knocks that could smash the tubes?
The new models come with Valve guards
And for older model, guards are all over eBay.
ebay has tons of stuff for the classic 30. you can get valve guards and these things that stop the tubes from rattling. if you lug the amp around a lot and play it at high volumes, both are probably a good investment.