Moofoo,
I agree with Charles and wouldn't hesitate to suggest that you try them out for yourself and see if they work with your system. At the time I tried them I was using some capacitors in my speaker crossover that I had found to be very sensitive to the other components in the system. I had been surprised at how much they distinguished between the ribbed plate and smooth plate Telefunkens in my Rogue M180s. But there's other guys that come into the shop here with whom I've talked and they didn't like them either, and our systems are completely different. Then again, Chissain liked them in his M180 amps, and we can't discount Wolf's 15,000+ tally of KT120 success stories. I can only relate what I heard through my system, and it was the consensus of my three guests who were with me. What we heard was that the system went from being holographic to where the sound could be definitely identified as emanating from the speakers... I guess the proper term would be that the soundstage collapsed. Turning up the volume resulted in the bass overpowering the balance of my system. The tubes seemed more grainy than the GL KT88's, and with less high frequency extension.
This was their synergy with my system, or I should properly say, their lack thereof. But there's certainly too many people out there that really like them for you to not audition them based on my comments, they just didn't provide a sound through my system that I enjoyed. The issue with these tubes has since become moot for me as I have moved on to an amplifier that doesn't accept KT120s.
