#Signal path in 6sn7 series#

The 12A? series actually give a warm, laid back sound. Discovered the 6SN7 and 6SL7, and found them to sound far superior. I started with the 12AU7 and 12AX7 in preamps. My experience spans the use of these valves in a relatively short span of time. 'The really superior tubes of the mid-to-late Fifties and early Sixties, the 5687, 7044, and 7119, were only used in commercial and aerospace applications, never in high-fidelity electronics sold to consumers.' Audiophile vacuum-tube amps from the Seventies through today continued with the late-Fifties favorites of the 12AX7 and 12AU7, which are actually considerably worse than the octal predecessors, the 6SL7 and 6SN7, which in turn aren't as good as the early-Thirties tubes. 'The universal adoption of feedback in the late Forties allowed electron-tube designers to relax their concerns about distortion and focus on cost, heat emission, and package size instead. If you want a traditional mellow 'vintage' sound, you're thinking of a 12AU7, the tube used almost universally in late 1950's amplifiers and many guitar amps - and has distortion many times higher than the early Thirties tubes. Tubes in this family (27, 37, 56, 76, and 6P5) actually sound fast, quick, and incisive, and have very low distortion, along with a favorable distribution of harmonics. 'You might think that really old tubes - designs dating from the early Thirties - sound 'vintage' and 'tubey.' Actually, they don't.

Nothing like a little bit of history to put things in perspective - something that Lynn Olson does best:

Signal path in 6sn7