Heater voltage Ceriatone DC30....

[playonit]

Just got all the major bugs worked out... now I notice a new one... heater reading 2.8v. .... I don't know if I am checking it right... Meter set AC volt ,black ground TO chassis, measure voltage at pins 4&5 (12ax7)?????

Also, when measuring voltage on the rectifiers pins tubes in or out.. I get neg volt reading??? but amp is working and sounding wonderful???

[paulster]

Your heater winding will either have a centre-tap connected to the chassis, or two 100R resistors to create a faux centre-tap connected to the chassis.

This means that your heater pins are effectively at +3.15Vac and -3.15Vac relative to chassis ground.

You need to measure between pins 4 (or 5) and 9 on the 12AX7s to get a true reading.

It sounds like yours is a little low though, assuming you're going to see about 5.6V.

[playonit]

"You need to measure between pins 4 (or 5) and 9 on the 12AX7s to get a true reading."

It sounds like yours is a little low though, assuming you're going to see about 5.6V.[/quote]

Does measuring between pins mean red probe to pins 4-5 and black on pin 9?????

Thanks

[Darkbluemurder]

"You need to measure between pins 4 (or 5) and 9 on the 12AX7s to get a true reading."

It sounds like yours is a little low though, assuming you're going to see about 5.6V.

Does measuring between pins mean red probe to pins 4-5 and black on pin 9?????

Thanks[/quote]

Yes, that is what it means. I would not bother though. To me it is safer to leave the black probe connected to the chassis so I can probe with one hand using the red probe. Just measure like you did from pins 4-5 to ground and from pin 9 to ground and add both values together. 5.6V is a bit low but still in the +/- 10% range.

Cheers Stephan