[Myles B. Astor]

Originally Posted by Joe Appierto

Naturally, that’s going to some degree depend on the amplifier you’re using and the associated system. Your unmodified Premier 12s, I’m guessing, fall somewhere between bi-amped 11As and the Premier 140, maybe.

There are two main schools of thought here in this forum. And please guys, if I’m misstating anyone’s feelings, please jump in because I don’t want to put words in anyone’s mouth.

The majority view is that the KT120s combine the best characteristics of the 6550 with the KT88. They may not be more powerful when used in a circuit not designed for them, but they seem to be a little more dynamic and have better headroom. They present a strong bass line without bloat and are articulate in that presentation. Mids and treble are smooth without being rich or warm.

The minority view (caveat: I’m one of this group’s members) is that the KT120 is an excellent sounding output tube. However, when compared to a good 6550 (e.g., SED =C= 6550C or a Tung-Sol reissue 6550), the KT120s lack a little top-to-bottom coherence, may be a little bit on the rich side of neutral and don’t have the same degree of clarity in the upper midrange and lower treble.

I’ve listened to the KT120 in both an unmodified 11A and a 140. I’ve yet to listen to them in the 140 now that it’s had the Teflon caps put in.

That's not what I find with the ART; perhaps the tubes are revealing issues elsewhere in the system? (One thing is that you don't realize the ultimate in transparency with the cj gear unless everything in the chain uses teflon caps.) These tubes, when you really get your AC power line issues together, are stunningly transparent and neutral. The SEDs are way more colored and muddy.