UL, cl.A /Ia=51 mA for each 6P3S-E tube. Schematic follows the idea of the KT88 push-pull Oddwatt design. /thanks Bruce/. Audio Output transformers are Hammond 1650, with triode and UL modes and output for 8 and 4 ohms, rated "HiFi" bandwith 20-20000Hz +/ - 0 dB!!