First, I'm sorry if this has been discussed before. I tried searching through the past posts, but there is a lot of discussion about SVTs! I'm looking to buy either a new SVT Classic or used (76-79) SVT head. Does anyone have an opinion one way or the other? Basically, I'd like the classic tone that only an SVT can provide. Reliability is also an issue. Is there a way to test an old model to make sure it's in good shape (other than just playing it full on, trying pots, etc.)? Thanks for the info!