Question about voltage testing

[jckid649]

I have been doing some initial power up testing and find strange numbers on my voltage tests. With no power tubes installed and the amp out of stand-by I'm getting readings of 2.8 on the heaters of the pre amp tubes and readings of over 700 at B3 and B4 with the amp set at Max Negative Bias. Is this a problem and if so what could be wrong?

[xtian]

If you're measuring only one side of the heaters to ground, your 2.8 vac reading could be OK. If you measure heater-to-heater, you should get 6 volts ac.

With no tubes installed, your B+ dropping string doesn't actually drop voltage, so readings at B+, B+1, B+2, etc., will all be about the same.

What amp is this? Schematic?

[jckid649]

If you're measuring only one side of the heaters to ground, your 2.8 vac reading could be OK. If you measure heater-to-heater, you should get 6 volts ac.

With no tubes installed, your B+ dropping string doesn't actually drop voltage, so readings at B+, B+1, B+2, etc., will all be about the same.

What amp is this? Schematic?

The Ceriatone Expression.

So you're saying without the tubes installed the B+ readings are going to be higher?

[xtian]

Yup.