Hi there,
I may get flamed for saying this, but I think your tweaking dollars are likely spent much better elsewhere. I look at the gage of the wires connecting components and I can't see a lot of reason, from a conductivity perspective, for changing tube sockets, RCA sockets, or speaker terminals, for that matter - the difference between the light gage wire in the circuit and the relatively light gage metal in the sockets is not that great, and the total combination has been through a lot of optimization by the Bottlehead crew already.
That being said, I have used, in some cases, different tube socket inserts (ceramic bodies that fit in the same frames as the stock parts) when I could get them with gold plating, on the rationale they'd be less susceptible to corrosion - which is true about gold plating, but now I kind of think that was a rationalization because they looked cooler.
I also upgraded the speaker terminals to some similar to the "Big Stud" that Bottlehead used to sell as an upgrade - still five-way binding posts like the stock offering, but larger and gold plated (still easy to find at Parts Express). Those I did mainly because I thought they looked cool, but also because they accept a wide variety of wire configurations and gages, and they have a deep enough knurl and diameter to allow even my fat fingers to cinch them down when reaching back into the stereo cabinet. Plus they were a Bottlehead upgrade part so I figured they had the Good Housekeeping seal of approval.
I still would say, on a pure smiles per dollar basis, you'll notice way more with upgraded coupling capacitors and the like. I get that tube sockets are more of a pain to upgrade later, though, so certainly understand the question. I can also say I've never thought a stock BH build was in any way deficient, nor can I say that tweaks like these (sockets and studs) were audible to me.
Good luck,
david
