Traynor YGL3 MkIII screen resistor question

[sgelectric]

I'm working on a Traynor YGL3 MkIII 100 watt combo.In addition the the 470 ohm 10watt resistor located at the screen power supply node, there are 47 ohm 2 watt resistors on the screens of the outer pair of EL34s but none on the inside pair.What is the reasoning behind this?

For some reason I was unable to link directly to the schematic.The schematic is located under the traynor heading at the link below.

Bargain Bin Heaven Amp Schematics - Airline Garnet Gretsch Hagstrom Kalamazoo Kay Magnatone Selmer Silvertone Supro

Thanks, Steven

[Enzo]

Provides some isolation between the tubes, it prevents the screens from interacting.

http://www.webphix.com/schematic%20h...gl3_manual.pdf

[TransLucid]

Regardless of what Traynor did, it would be a good idea to add individual screen resistors to each screen, and a considerably higher value than 47 ohms (say 470 to 1k). This will protect the output tubes from excessive screen current, which is a common cause of failure.

[trem]

I have one of these amps, a head....... guess I should take a look at the screens.
Thanks