6L6s
JAN-Philips 6L6GCs - the 'sweetest' tone
Sovtek's KT66 6L6 - killer tone
Tung Sol's 5881 6L6s - crystal clean with fat break up at volume
JJs are said to be slightly better than EHs, which are not quite as thick
JJ,s have great attack, warmer with higher bias but some detail loss
12AX7
TAD 7025-S looks like the best 12AX7 on the market for microphonics, noise/hiss, detail and dynamics.
JAN-Philips 5751 and Tung Sol 12AX7 are close seconds.
I think much of the sound that musician's like with valve amplifiers is due to the transformer inductance + the valve characteristic. The point is that different valves sound different in different amps but I bet that the transformer is the primary key to the great sounding amp.
ReplyDeleteThe output transformer is vital.
ReplyDeleteMy understanding is that the quality of an output transformer effects tonal range and distortion. The metals used and things like the thickness of the wire and how the primary and secondary windings are interleaved are key.
If they windings are not interleaved they'll sound harsh. If the wire is too thin you'll lose bass response. Too thick and you'll lose top. Get it right and you'll make your tubes sound fantastic.
NB: The bobbin material is irrelevant, a myth that paper is better than plastic, neither has any effect on the magnetic flux and that's what it's all about.
Tubes amplify the signal and, assuming they are doing a flawless job, effect compression and harmonics. You could say this is more important in that it is fixed once the tubes are set up. Whereas an output transformers effects can be compensated for with tone and gain controls.
But ideally you get a quality old school hifi transformer with good iron, properly weighted wire that is properly interleaved AND good tubes to feed them a nice warm, well compressed signal.
Probably all anyone needs to know on audio transformers is here:-
ReplyDeletehttp://www.jensen-transformers.com/an/Audio%20Transformers%20Chapter.pdf