Question on Weber Bias Rite...

[Madison]

The tool worked great setting the bias in my DRRI, but when I got to my Dr Z 28 it was extremely difficult getting the octal set into the amp. I just about gave up, but finally it slipped into place.

1)Is there a spray on lubricant from Radio Shack I should be using?

2)While the matched Brimars on the DRRI read consistent 21mA each, the Groove Tubes in the Z read 28mA on one tube and 25mA on the other. Is this just a case of mis-matched tubes? There is no way to bias each tube separately, correct?

Thanks!

[Blue Strat]

Not sure why you're having so much trouble with the Z, tighter sockets maybe? Keep trying. Others have succeeded at this.

The GT's are just a little out of perfect match. 3mA is fine and NO ONE can hear a 3ma (or even higher) mismatch. It's the luck of the draw. Sometimes you'll get very close pairs like your Brimars, other times not quite as close.

[drgonzoguitar]

From what I understand about EL84 tubes (which is very little), EL84s tend to drift (after initial matching) faster than other octal tubes. I agree with bluestrat, I wouldn't freak out about 3mA difference.

[Madison]

Thanks!