So I like the sound and power I get out of my Ashdown ABM 500 EVO II very, very much. But whenever I can scrape up the cash, I would really like to get an all-tube head, instead of a preamp tube/solidstate power hybrid. What are some of your favorite all-tube heads? I know the Ampeg SVT is really popular, but I know there is more out there. What is your experience with whatever all-tube head you have used? I'm open to everything, but I tend to lean toward a vintage, warm, smooth, growly sound as opposed to a hi-fi, active sound. But my impression is that all-tube usually gives more warmth and growl (when driven) naturally.