12AU7, Goldpinröret har lite snävare toleranser samt guldplätterade ben som motverkar dålig kontakt.
Beskrivning från Eurotubes:
My observations: This is the newest 12AU7 variant from JJ which is a Long plate Gold Pin version of the ECC82 tube.
The difference again is that the Gold pin tubes are a little smoother and richer sounding and the long plates have a fat, thick tone.
Once again I don't use the long plates in combo amps where the tubes are located ground zero to the speakers.