[HAM] DC filtering to the heater filament voltage of the AO28 preamp in order to reduce hum..

[Kon Zissis]

Hi everyone.
Yesterday I replaced the power supply filter capacitors and the power
supply section resistors , the plate resistors, the screen grid
resistors and the cathode resistors and the cathode bypass capacitors of
my recently acquired 1965 C3.
 
I have read that some techs add DC filtering to the 6.3 volt  heater
filament voltage of the AO28 preamp in order to lessen hum  and with
this in mind I decided to try this out.
To do this, I disconnected  the  centre tap of the filament voltage
winding of the power  transformer from the chassis ground and then I
connected the two outer wires of  the filament voltage winding to the AC
inputs of a PBPC 1004 bridge rectifier . 
Then I connected  the + voltage output and the - voltage outputs of the
bridge rectifier to valve heater filament  voltage wires that are on the
wiring panel on the left side of the AO28. 
I connected a 2200 uf 25 volts rated electrolytic capacitor between the
+ voltage and the - voltage outputs of the bridge rectifier  in order to
smooth out any ripple in the DC voltage and I also grounded the -
voltage wire so therefore the heater filament voltage   is now a basic
full wave rectified DV voltage.
 
Before doing this modification I had measured the AC heater filament
voltage  and it was 6 .5 volts AC. Now that I have added the DC
filtering , the voltage reading is 5.35 volts DC so this means that the
DC filtering has cut the filament voltage down by 1.2 volts.
 
The AO28 seems to sound better now that I have replaced the capacitors
and resistors that I mentioned earlier above,  and as far as I can see
there is no adverse effect with the DC filtering that I added to the
heater filament voltage and I would expect that the slightly lowered
filament voltage would allow the valve heater filaments to last longer
because they are not being stressed as much.
 
Is the way that I have wired up the DC filtering as described above the
correct way to do this or is there a better way to do this ?
 
Is there any problem with the fact that the DC filtered heater filament
voltage is now 5.35 volts instead of the previous 6.5 volts ? 
 
Will this slightly lowered heater filament voltage cause  any problems
such as cathode stripping or cause the valves  to not operate properly
or to distort earlier because the heater filaments  are now receiving
5.35 volts instead of the previous 6.5  filament volts ?
 
Thank you in advance for a reply.
All the best.
Kon