Fender Bandmaster Resistor Question

[LI150]

Been poking at some Fender Blackface amps.
Can anyone explain what these two 220K resistors do?
They are btwx pin 1&4 of the 12AT7 inverter tube to pin 3 of the 6L6 tubes.

 

[rayma]

Shunt feedback around the output tubes, called Schade feedback.
http://www.mcmlv.org/Archive/TubeTheory/Schade 1938 Beam Power Tubes.pdf

 

[LI150]

Thanks

That is quite the read!

 

[JMFahey]

Nice way to kill "guitar sound"🙄

 

[LI150]

Nice way to kill "guitar sound"🙄

That may explain why someone removed it....