According to the schematics on this thread, each filament has its own self bias resistor (but are actually in parallel, so not individually self biased).
But those bias resistors are not capacitor bypassed, and the filaments are in parallel across the battery, so . . .
There will be crosstalk between the L and R channels. Channel Separation will be reduced.
But those bias resistors are not capacitor bypassed, and the filaments are in parallel across the battery, so . . .
There will be crosstalk between the L and R channels. Channel Separation will be reduced.