RCA 6L6GC & GT 6L6GC - Blues Deluxe?

[Kinkless Tetrode 66]

Could you uses these probably unmatched tubes in the Blues Deluxe? I have a friend who constantly runs unmatched tubes in his Hot Rod Deluxe and never has any problems. I understand why you should match power tubes, but what happens if you don't? Why do some amps tolerate this (if they do in the long run, which I doubt) and other not. Seeing that I have a very similar amp, I am tempted to try this... What is your advice?

[xtian]

Generally, if you're after accurate reproduction the input, matched power tubes are important (think hi-fi).

Mismatched tubes can increase distortion, and some guitarists find this pleasing.

Others can chime in and point out what harm this might cause your OT or other components.

[martin manning]

How do you mean miss-matched? The subject line says different brands, but that doesn't necessarily mean that they are electrically miss-matched. You can measure the idle current (bias) on each side and see how close that is, then there is also matching for transconductance, which is the plate current per volt of grid signal. Without some detailed measurements you don't know if the signals going to the output tubes are equal, and that will change with volume, so I wouldn't worry about it. I don't believe there is any harm in running tubes with significantly miss-matched idle current (10mA or so, say), but it will probably cost you some low frequency bandwidth. See how it sounds and decide.