Check the listing for details. Revv D20 20-/4-watt Tube Head - Black Tolex. Condition: New. Listed at 1149.00 USD. Killer Amp Head with Embedded Two Notes Tech Think you need a cabinet to achieve an awesome miked-cab tone? Not if you’re playing through a Revv D20 amp head. Make no mistake, the D20 is an all-tube amp head — with glowing-hot 6V6s and 12AX7s to prove it — but thanks to embedded reactive load and virtual cabinet tech from Two Notes, the cab is optional. You get all the usual character shaping, including a 3-band EQ, Volume and Gain controls, along with a push-pull gain pot for a crunchier voicing and a power-reduction circuit to attain cranked-amp sounds at lower volumes. A buffered series FX loop sweetens the pot. The Revv D20 is an amp with tons of modern features, but at the end of the day, it’s just a great-sounding amp — take it for a test drive, and you’ll agree.