6af11

The 2-watt Percolator is available as a $259 DIY kit or a pre-assembled head (tested here) that looks like a cross between a Heathkit project and an assignment for woodshop. The sturdy, solid poplar cabinet houses a 20-gauge, laser-cut steel chassis containing an all-tube circuit that runs off a single new-old-stock Compactron 6AF11 tube driving an 8 ohm output. Developed by GE in 1960 as transistors were encroaching on tube dominance, Compactrons aimed to modernize valve technology by combining the functionality of multiple tubes in one. The 6AF11, for example, contains two triodes and one pentode.

The Percolator offers a variety of dynamic, tactile tones via its single volume control. Up to its midpoint, the knob serves up burnished clean sounds at conversation volume. Past there, you get a little more volume but mostly more dirt. At two-thirds, you get a gritty, Fender-like overdrive with adequate definition for rootsy rock—though even a Tele’s bridge pickup struggled a bit to find its characteristic snap and twang. Cranked, the head gets gristly and less distinct in a way that psych-rockers would love.