[quote author="CJ"]what tube is the ecc 88 output?[/quote]
while i can't speak for io, i think he's using a ... ECC88 :wink:
[quote author="CJ"]the cathode resistor looks low, i know you have two sections = 1/2 cathode r value, but it still looks a bit low.
how much current thru output plates?
you need the grid biased up for headroom due to strong hits on the ef 86.[/quote]
depends on the B+. if it's 250VDC, and he's dropping 100V across the 10k, 10mA is flowing through both tubes, which gives a bias point of roughly -3V and a a (single) cathode resistor of 300r
i'm not sure this is the best operating point. you need to push a lot of voltage through that ECC88 with a 10:1 output tx
not too fond of the EF86s (or pentodes in general) and i probably would have used a pair dual low MU triodes instead