Dave is testing Sovtek 6B4G's and building push pull amps.... Dear god say it ain't so.
In his defense the DHT's are replacing triode wired EL-34's and the outputs are 49% nickel (soon to be 80%)
Quad QA12/P Amplifier - This is pretty close to Quads first amplifier. I got to put my hands on one of these once very cool early British amplifiers. http://www.itishifi.com