[Hammarlund] nuvistaplug mod for sp600?

[Eugene Hertz]

Thanks to everyone who replied about this mod. Looks like Nuvistaplugs are pretty much unobtainium so it looks like I will have to build my own, two questions:

1. I see on ebay that the tested Gm's of 6DS4 nuvistors vary some between 8000 and 9000. What is the implication of GM to my application? Does a higher GM mean more gain? Does a lower GM mean more noise? (or vice versa) Does any of this matter?

2. Since it looks like I might have to build my own, does anyone know where I might locate a 9-pin base that I could wire the circuit onto and then plug into the V1 tube socket?  I wonder if there is some kind of base that one can buy to allow prototyping on top of.

Thanks
Eugene