[HAM] Fuses for the AO28 preamp.

[Kon Zissis]

Scott Hawthorn asked:
>I have converted the AC  heater filament voltage to DC
 
Why?
 
Hi Scott.
Some techs do this to the preamps in Hammond organs as well as to other
valve amplifiers as a means of reducing background hum which comes from
the AC filament wiring and the hum can also be induced in an amplifier
when the audio signal wires are near the filament wires. 
 
Mike Phillips wrote on Hammond Zone  that he did the DC filament voltage
modification to Jon Lord's C3 in order to reduce hum. 
 
I do not know if I can hear any difference after adding the DC filtering
so therefore this might just be a ''splitting hairs '' thing but I hope
that other techs and hobbyists who have done this modification will
reply  and say whether this modification is worthwhile.
All the best.
Kon