Is it just a simple to swap out, the coupling cap for the transformer
No, the 5K load of that interstage transformer is not a good match or the driver in the Parabee. By the way, the RIT-5 is a parallel feed interstage transformer, so you'll need to feed them with a coupling cap if you do use them. You'll need a very different driver tube or a three stage amp to use these appropriately.
, the bias in below 85 seems like it'll fit right in?
I would need some more clarification to determine what you might mean by this.
The original 6N1P's are running in a srpp an early mod to the stock parabee which i like but maybe its time for a change. I have some nice other tubes that i have gathered including 417a and 801a which i think might make good simple driver circuits that could run off a CCS like the original Parabee schematic. I am in real need of sound advice, thanks for your help. David
As a driver tube, you need a lot of gain (mu), which the 417A has. You'll have to figure out how to deal with the enormous voltage drop required (417A doesn't want more than 200V on the plate), then I would listen to the whole thing without the interstage transformers before temporarily installing them to have another listen.
