Here's my story...I'm stickin' to it.
I built the kit with C4s and impendence kit going in as the build progressed. Resistance checks all good.
When I ran up for the voltage test one tube went purple - the other did not (no glow at all). Amp shut down - tubes reversed - glow follows the tube. In a bit that purple tube snaped and cracked so amp went off and tubes removed. Replacement tubes put in and no purple but also but no glow at all from either tube. Voltages off from normal - missing heater volts. (I'm assuming Mr. snap crackle pop was a bad tube.)
All off and I stepped through the build one item at a time. I missed putting in the C1 to C4 jumper. Jumper installed - power up. Both tubes have glow.
Back set of LED's on the C4s are NOT on - front set are. 1A Q2 seems cold.
A5=0
B5=75
A6=0.33
B6=2.5
all others are good.
What'd I blow up?