Question about heater wiring in a Champ build

[Regis]

Hi Guys,

I am converting an old Voice of Music SE hifi amp into a Champ, and have some confusion about the heater wiring. This amp has a 6X4, a 6V6, and a 12AX7. It has a "Hum Balance" pot in the heater line.

At the end of the line at the 12AX7 should I attach one lead to pins 4 and 5, and the other to pin 9 or ground it? If so what should I do with pin 9? Ground it? Some of the Fender schems say to do that.

Thanks, stupid question I know.

Regis

[Rob Mercure]

Regis,

Assuming that you've got a 6.3 V heater circuit (you could have the 6X4 and 6V6 in series for some strange reason <grin>) then you tie the 12AX7's pins 4 & 5 together and connect one heater wire there - the other wire goes to pin 9. If you attach the leads to pins 4 & 5 you'll need 12.6 volts to light the bottle up all the way.

Rob

[Regis]

Regis,

Assuming that you've got a 6.3 V heater circuit (you could have the 6X4 and 6V6 in series for some strange reason <grin>) then you tie the 12AX7's pins 4 & 5 together and connect one heater wire there - the other wire goes to pin 9. If you attach the leads to pins 4 & 5 you'll need 12.6 volts to light the bottle up all the way.

Rob

Thanks Rob,

I kinda thought that was it. I had conflicting schems and wasn't sure. KOC has it the way you described in TUT3.

Thanks again,

Regis