RM100 biasing tubes question

Hey everyone I'm new here and the RM100m is my first tube amp. Checking the bias on the tubes seemed pretty simple and straight forward, but when I plugged my voltmeter in it read that each tube was biased at around -15mA. The manual for my voltmeter said that if there was a hyphen (-) in front of the number it meant that the polarity was reversed. Anybody know what that means? The EL34's should be around 30-35 mA correct? Any reason why they would come biased at 15 mA?

Any help would be appreciated. Thanks

That just means you've got the red & black probes on the wrong test points... if you reverse the probes, it should read positive.

No harm done, tho, by mixing 'em up.

--B

Thanks...my voltmeter has a couple different places to plug the wires into it, so that's where I must have went wrong. I'll try switching em around and see what happens. Thanks again.

Some of those places are probably for measuring current (amps and milliamps).

Be careful.

*Updated*
Heres a link that may help

http://mechatronics.mech.northwestern.edu/design_ref/tools/multimeter.html

Thanks Drew...yep, I had the red lead in the "com" hole and the black lead in the "mA" hole which is backwards. Once I get home I'll give it another try.

Any idea what it's a good setting for playing heavy metal would be? I think the EL34's can be biased between 25mA and 35mA.

Just to throw another point in. Anyone know what the manual is on about when it says measure between tube one and two, and it should be between 5ma, higher than 8ma the tubes aren't matched. Im ok with this - but what about tube three and four. Sent Randall an E mail but alas no reply. Whats the best bias figure for 6l6's. Also check out the video clips at the address below.

http://www.randallamplifiers.com/products/amplifiers/mts/index.asp

Cheers