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previous: Mark Lavelle [QUOTE]Is the additional heat anyth... -- 8/30/2003 3:58 PM View Thread

Re: BF Princeton Reverb. Add 100 Ohm Heater/Lamp Resistors?

8/30/2003 4:37 PM
Bruce /Mission Amps
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Re: BF Princeton Reverb. Add 100 Ohm Heater/Lamp Resistors?
The filament suppy is all AC and isolated from chassis ground by the way it's used.  
The center tap of the filament supply has zero volts, hence there no current to ground even if the center tap is grounded.  
The additional current drawn by the grounded 100 ohm resistors across the outside of the 6vct windings is very very low current.  
At about 3.0vac to 3.5vac each and 100ohms,  
3.5v/100ohms = 35ma.  
It adds around 70ma of current drain to the 2a - 2.5a filament supply.  
The resistors aren't really needed if the PT has a decent filament winding center tap and it's grounded but it willl not hurt anything either.  
 
I suspect as others, you've shorted something else to ground or you just never noticed the heat.  
 
Bruce