Has anyone bought Gold Aero PXB300 tubes from Upscale Audio?

You mean Gold Lion not Gold Aero.

Upscale is dependable, as are TubeDepot, TheTubeStore for these tubes

Upscale is about as good a tube supplier I've ever used. By the same token, though, when I lived in L.A. I'd have endless fun prowling the various, dusty pro electronics shops for the things.

Yes, I meant Gold Lion Soviet Tubes, PX300B’s. I need 4 matched pairs! So their tube matching is good too? Thanks guys!

In my experience yes

@facten   Thank you!