The 6L6 heaters are wired in series, to allow operating with 12V. So, check that the tube socket solder / wiring connections are good,
and that both 6L6s have good filaments. Simple ohm meter continuity test.
I'd be careful using 100 Volt line matching transformers as OPTs with 308VDC B+, and the plate current that the 6L6s will consume,
as line matchers aren't normally made for handling High Voltage DC on their primary windings, They are designed (and have internal insulation)
for a maximum 100 VAC audio signal (plus some safety margin) Also, if these specified OPTs are rated for 15W, the primary winding will be seriously unbalanced,
though the 10W tap, rather than the 15W tap, work well, and be properly balanced. .
With this transformer, 1.25W would be equivalent to 8K; 2.5W would correspond to 4K; 5W would be 2K; which is correct for the center tap,
10W would be 1K, which would be correct value; 15W would be
666 ohms
; and COM ( 0K) would be the "lower" plate connection. 666 is the "odd man out"
http://www.altronics.com.au/p/m1115-8-o ... ansformer/I just noticed that the V2 / V6 phase splitter plate resistors are of widely different values (120K and 220K),
normally these would have the same value, or at most, have no more than 10% different resistance values. . And the common connected emitters, err, cathodes tail resistor is of rather low resistance, but then, since on the left side of the PI tube, the plate current is 0.275 mA, and the right side, 0.15 mA, presuming that the indicated voltages are indeed correct. Take the square tire, and buff the corners down, for smoother operation
Maybe they did this intentionally to "fudge" the phase splitter into working into an unbalanced OPT primary?
Other than those items, it looks like a fairly conventional 6L6 UL PP design. One that was designed by a committee of soiled state circuit experts
/ed B in NC