Higher readings on OB and AB Big Board

[Jimb0]

Is it normal to have 118v at OA and OB on the big speedball board? I've tested terminals 1 through 10 and it read normal. I can try swapping a different tube set and see if it changes. 

Edit: On my second set of tubes my readings went down to 109v / 113v. I read somewhere before that stronger tubes will read higher? If so, why is this the case? If you don't mind explaining it to me.

 

[Paul Birkeland]

This voltage will depend on both the plate voltages of the 12AU7 and the health of the 6080.  The difference between the 12AU7 plate voltages and the 6080 cathode voltages will be higher with the Speedball for tubes with high emission, as the tube itself will draw 30mA DC with higher bias voltage.  When that voltage difference becomes really low, that's an indicator that the 6080 isn't as fresh.

Likewise a very potent 12AU7 will show plate voltages around 75V, while a really worn out one will be up at 100V (these are OA/OB on the small board up front).