Got some new RS55. Newer type from same production. Visual difference would be anode material, the type I has a nickel anode where this type II has a perforated (mesh?) grey (carbonised?) anode. Looks intriguing with some white light escaping throught the anode. Also this type II draws slightly more current on the filament. Luckily about the same for the pair, otherwise the one toroid transformer supplying the current will start humming.
See for some pics below.
How the type II influences sound compared to the type I? I will report on this later after a running in period.
Left the Type II with grey anode versus the nickel anode of the Type I
Construction of the grid and cathode is alike..
The topcap which is carrying the high voltage - dangerous!
Cleaned and operational with some light escaping through the anode. Serial numbers almost succesive!
