Soviet East German Radio

[pwdrive]

All valves manufactured with the same type number are all more or less the same electrically, that 33k you refer to just happens to be a value selected, it could be more, it could be less, all depends on circuit design and the HT available, no difference in audio tone for different makes of ECH81, the ECH81 will work with an HT as low as 12 volts.

Rohre, so far as I know is the German word for tube.

Lawrence.