6V6 pins 7 & 8 tied (heater & cathode)

[Tonewood]

I have a Masco C-6 amp, 12ax7, 6v6 & 6X5, one of each. I want to understand the ckt & get it working, then if I don't like it, change it into a tweed champ ckt. Had Hum. I have removed several bad caps so I can't check any voltages at this point.

I think I understand ckt other than:

The heater and the cathode of the 6V6 are tied together & connected to ground via the 270 Ohm cathode resistor & the 10mf bypass cap. There is no ctr tap on the heater winding.
Is the 10mf/270 combo enough to bypass the heater AC hum?
Does this elevate the heater to the cathode DC level?
What the heck are they tied for?

Thanks

[Wilder Amplification]

It elevates the heater to the DC cathode voltage as well as eliminates the heater-cathode voltage differential on the power tubes.