greetings to all from Melbourne!
trust everyone is enjoying their music and keeping fine.

Just got hold of the KT120 output tubes last Wednesday, replaced the 6550c tubes on my conrad johnson power amp; "WOW!"
1. Tremendous expansion on the soundstage
2. Remarkable overall sonics, very well balanced.
3. Awesome bottom end, far more bass information I have ever heard so far from systems that I have owned and heard...
4. Highs are smooth, very easy to listen to, mids are just glorious, coming from Quad ESL's the midrange is even more special, and the bass is phenomenal!
5. The overal presentation is a true live performance, live scale easily achieved, no strain whatsoever! Obviously it is driving my ESL's quite easily, and the power amp is well matched with the ACT2 preamp.

weaknesses: nothing major that I could possibly think of other than, the tubes are fairly larger than the 6550's or KT90's, therefore make sure if you are changing tubes your amp can fit them well with plenty of headroom and space around the tubes. some amps will not be able to take the extra size of these beauties. The MV60se seems to have been made for KT120's because they fit just perfecty even with the tube cage on.

For those of you who are using either 6550, KT88, KT90 or similar, try out these new KT120's you will NOT be disappointed. To me they are like a combination of the best midrange an EL34 can give, the power and finesse of a KT90+6550 put together and the robust full presence of the KT88. They are simply Awesome!

The other fantastic thing is that my MV60se is not even wired to get the best out of these gems, therefore they are pretty much half asleep and still perform wonders. I was told that this lengthens tube life and they can certainly out last 6550's to nearly double the usage hours. I have yet to try an amplifier that is actually designed for KT120's, then we are talking. For now, I'm just heading home to invite Diana Krall and some friends over, Esparanza Spalding for some late tea... enjoy your music, this is truly an amazing tube.
check it out!

associated system:
preamp: conrad johnson ACT2
poweramp: MV60se
speakers: Quad ESL 2905
source: vacuum tube CD player from Cayin
cables/interconnects: DHLabs Q-10 & Silver Sonic Air Matrix
power conditioner: Thor PS10 by Nordost
magnetic field stabilizer: Quantum Qx4 by Nordost
audio rack: Apollo Designs, pure glass.

cheers, Raj J