Tube Matching


I will shortly have a pair of monoblocks with the following tube complement:

5u4
6SL7
6SN7
2a3

My question is about matching:

1. How close must each tube match to the other in the other amp? Do the rectifiers have to match at all? Is it imperative that the power tubes match (manual bias)? How 'bout input(6SL7) and driver.
pawlowski6132
In my experience, you won't hear difference in different amps if the tubes themselves are all within spec. The key issue in matching tubes is relative to the other tubes in the circuit they're in. It's especially important in push-pull amps, where you want the output tubes to match. It's also important on the driver tubes where you want each half of the following circuits to be getting a balanced signal.

But across amps? In single-ended amps? Not likely to be audible as long as the tubes are operating correctly. In a single-ended design, like most 2A3's use, the tube matching is really just referenced to its own circuit. The character of the tube -- how it sounds through your speakers -- is not really a function of the gain of the tube, or its conductance. If your tubes are mis-matched right to left, you may have to boost or cut the volume slightly, but the sound itself won't change.

Don't sweat it!