Jason is right. I too have the peavey 6505+ 112 modified into a head, running through a valveking 4x12. A tube screamer or overdrive pedal will make your amp sound better. I currently use the new maxon st9 pro, which is based on the old ibanez ts808.
My ltd came with the 81/60 combo But after playing an ibanez with dimarzios I scored on CL I was blown away by the tone I got.
If you don't use an overdrive pedal I suggest you to try one with your 6505+.
Hey thanks for the idea, I remember looking back at a maxon OD808 once upon a time but never got around to actually picking an overdrive up.
I will probably pick one up once im out of college (moneys tight lol) as i was also intended on getting a mesa dual rectifier and know that they go hand in hand with overdrive. Also dealing with the effects loop on the 6505 112 is a hassle haha