The voltage at 10 is very distressing, and the amplifier shouldn't be plugged in unless that is remedied. Can you double check that terminal? Is there any debris or component leads from 9 to 10 that might create a short circuit?
Are both the 2.49K resistors on the headphone jack still properly installed? Do they both look to be about the same color?
I found a problem: the wire from headphone jack to terminal 10 fell out from terminal 10 after bending caps near octal socket. So, I resoldered it and now terminal 10 shows 0. But all other terminals have the same voltages as before. Still have 0 at terminals 20 and B6, for example.
You really didn't need to measure the voltages at A1-A9. The voltages at terminals 1 and 5 tell enough of the story to not need that.
For instance, seeing 80V at 1 and 80V at 5 tells me that your voltage measurements at A1 and A6 aren't possible, and that you have 1.5V at A3 and A8. This is why we don't have these voltage checks in the Speedball manual.
What if some wires were broken during the installation of speedball boards? Actually, my manual from 2013 have these voltages and they are very different from mine.
Some observations during the voltage check:
1. LED from center A to A8 glows but the LED from center to A3 does not. I checked the contact from A3 to center A - it is OK, my meter shows some resistance.
2. All other LEDs on speedball boards doesn't glow. But during the previous voltage check I saw them glowing. Do I have glitches in my eyes?
3. Both tubes glows normally.
