As of August 2012 the ZKIT1 board has been revised to reflect the Edcor transformer color codes for the recommended Edcor transformers.



Since the Edcor power transformer does not have a center tap, we have included a place for a pair of 100 ohm 1/2 watt resistors that go between each leg of the 6.3VAC and ground.

If you are using a different transformer, like the original Decware, or a Hammond 272FX, both have center tapped 6.3 volt windings in which case the 100 ohm resistors would have no effect.  NOTE: If you use one of these other transformers with a center tap, be sure it is connected to ground on the circuit board.  The spot marked "Chassis Ground" would be a good spot.  If the board goes into a metal chassis of some sort, then a this spot can also be used to ground the metal chassis to the board.  The earth ground on the IEC connector can then be connected to the metal chassis instead of the circuit board.

Steve

I have the older style board with the newer Edcor transformer without the center tap.  It seems to be working, what will the 100 ohm resistors do?  Will it lessen the hum I'm experiencing with the amp?

Thanks!  Will have a listen to the amp when done and then decide on the resistors.  Thanks again for the help!