So, I've bought a set of MK III kits, minus chassis, built my own spacious chassis, had them powdercoated, and I have just finished building the first amp.
So, it comes to Biasing time.
When I've first plugged it in and switched on, there's no bias voltage, whatsoever...
I soon realised this was simply because the 3-point post was glued to the chassis, which was powdercoated.
I Soldiered in a separate ground lead from the ground post to the closest ground point.
Now I have the complete opposite problem. The amp is switched on, and bias voltage slowly builds up, until 5 seconds in, it's to 2 volts.
I immediatley Googled the issue, finally finding a thread on this forum from a few years back.
One of the first posts said to pull all the tubes out and check that there's -40 to -65 volts on pins 5 & 6 on the power sockets.
As the thread goes on, the guy having the issue says he has that voltage at those pins.
Long story short, I have no current whatsoever at pins 5 & 6.
I have re-set every joint in and around the bias circuit.
Could one or more of the Bias supply components been damaged / blown when I had no ground?