"What a thrill when that showed up in the mail! Usually, I use an Ampeg VT-22 or Vox Super Beatle head. The Vox is excellent for steel guitar because it has very little inter-modular distortion at low volumes. It's an old one and has a nice reverb and echo for the steel."
In an interview with Consequence of Sound, Carlson mentions: "I just bought an Ampeg BT22, a 2×12 that I use, but it’s so heavy I haven’t taken it out yet. I’m going to put wheels on mine [laughs]." The B in BT22 must be misspelled.