Dennis Had Inspire Amps

[pstrisik]

Originally Posted by Musica Amantem

A follow-up on my tube-rolling quest (20 W output trannies, Triode-strapped kT-88 Inspire amp with black glass CV-181 and SE 274B, coupled with LP-27a using 56's).

Valve Art 350B:

The good: Great bass and PRAT. Nice soundstage. Relatively higher SPL (OTBE)
The bad: Veiled mid-range. High frequency roll-off. Piano and wind instruments' timbre is off. Lacking immediacy.
Shame, because these look well-built, are large and nice-looking.

Valve Art 6550 (Westinghouse-labelled Amperex Holland 5AR4 instead of SE 274B):

Surprisingly good! Excellent bass, neat, airy mid-range, not detail-masking at all. Not harsh or too bold. This may be even better than the GL KT-88, although the latter may offer slightly more sound body at the expense of a slightly less managed bass, masking some details. The KT-88 may offer more immediacy, but I'm not sure yet. These 6550's are keepers, raising my output tube favorites cluster to 5 very nice alternatives.

Have you tried current production Mullard EL-34 reissue? I keep coming back to them - though our amps are different. Mine is SEP.

I will add that I previously favored vintage tubes, including the vintage Mullard EL34 Xf2, prior to Dennis' IIPS and cap upgrade. Now it seems the reverse is true. New production seems favorable. I will hypothesize that the upgrade smoothed things out. I used to favor vintage tubes as they were smoother and less harsh overall. Now my favorite new production tubes are livelier and not at all harsh while the vintage equivalents seem less 3D and slightly veiled or soft. True? Don't know for sure, but I like it! Found the same before and after differences comparing new production TS6550 and vintage gray plate TS6550.