Looking for tips on operating points for tubes in anode follower ...

[Jolojl]

I'm putting together some simple anode followers just to get a taste of what different tubes can sound like. Maybe someone with more experience than I could give some input as to various operating points for the tubes below ...

I use one and the same power supply for all at about 320V B+. I don't use anything but simple resistors (i.e. no chokes or ccs) to adjust operating point.

Up til now I have tried e280f in triode mode and the 5687.

The best operating point (in my ears and set-up) for the e280f I found around 150V on anode with about 10mA current.

The 5687 I have tried in 150 and 250V on anode with about 14mA current. I still would like to get it a bit "tighter" ... Any suggestions on a good operating point for 5687?

I also have 12b4a, 1626 and 6SN7 to try out ... For 12b4a I think I have found good information in the 12b4a threads on this site, and it seems like 100V/20mA is the point mostly recommended. I have also seen 160V/15mA (or near that).

But what about 1626?

And 6SN7?

Best!
Johan