I have the Wavac, currently driving the Phy-HP KM30 coaxial driver in an open baffle. The virtues of the amp: Extremely quiet, supremely reliable, virtually no warmup time, all the virtues of 300b midrange with excellent extension at the frequency extremes. My only wish is that it had separate taps for 4, 8, 16 ohm output. The outputs are available internally, but require some soldering skills and courage.