[R-390] R-390 filament voltage

[Jacques Fortin]

Thomas, the V505 filament is in series with the V506 and V511 ones.
The V511 is a 12AU7 double triode and the filaments (two in series) account for 12.6V, and both V505 and V506 should run with 6.3V each.
Maybe the following question is weird, but...
Have you replaced the V511 with a 5814A ??
The 5814A (used in the R-390A) needs a higher filament current than the standard 12AU7 (175mA instead of 150mA at 12.6V).
So if it is the case, no wonder that the filament voltages across V505 and V506 are higher than normal...

Let us know, anyways...

73, Jacques, VE2JFE in Montreal