Tweed Twin grid resistor question

[Randall]

Why grid resistors on just two of the power tubes?

https://www.thetubestore.com/lib/the...-Schematic.pdf

[nickb]

I think they found it worked like that plus it saved a few cents so why not? Practically speaking you wire the resistor from one tube to the other and then a single wire to the board. In other words it's easy to wire up.

But it's funny you should ask. I just did an old Marshall that had this arrangement. I had to add a resistor in the feed wire to stop it oscillating on peaks. That's to say I had in effect 1.5k to the first and another 1.5k from that to the second.