The Greer Thunderchief has been described as sounding like the best AC30 ever, but with more girth and thump to it. Plenty of that great chime, but as a quad of 6V6s, it has that oomph to it that EL84's can sometimes lack. The amp's control panel sports Volume, Treble, Bass, Presence, and Master Volume knobs. The amplifer's back panel sports a 3-way rotary boost switch (early models feature 2-way toggle). The boost allows players to switch between no boost, a mid/high boost, or a full range boost. Runs all 12ax7s but sounds very open as if it did run a pentode preamp. Interesting design, and very versitile tone controls. Power Output: 32 Watts Output Tubes: 4 x 6V6 (Cathode Biased) Preamp Tubes: 3 x 12AX7 Rectifier: 1 x 5AR4 Controls: Volume, Bass, Treble, Presence, Master