new tung sol kt 120


so there is now a new tube on the market , the new sensor tung sol kt 120, its got more power than even a kt 90, has any one heard it ? thanks, chris
chrissain
Casouza,

Help me better understand "self-bias/cathode bias".

My Sonic Frontiers monoblocks use four KT-88s per amp. I have a knob on the amp that allows me to select one of these four tubes. Using a screw driver, I can turn a shaft with a slot in it to adjust the bias using a meter.

Is this a fixed bias amp?

Thank you.
Flyfish, yes, your amp has fixed bias, because it has bias trimpots. Actually this is a misnomer, because it is adjustable!!

The non-adjustable bias method is called self-bias or cathode bias, usually performed by a resistor in series with the power tube cathode.
So far, Jadis is the only company (that I've seen) that's announced they'll be incorporating the new KT120 tube into their amplifier.
has any one tried this tube in rogue m150s/180s? I wish there was more info on these tubes.
I have recently installed a set of the 120s in 2 of my amps... First in a McShane modded Citation 2 with a level 2 plus kit and a complete rebuild...and secondly in a pair of Heathkit W6M mono blocks. I can hear a marginal difference in the Citation although I expected a little more out of them, but there is a marked improvement in the W6s which actually outperform the Citation now. I must add that the W6s have also had a McShane type upgrade to the power supplies and have more than 5 times the capacitance of originals. I'm sure this helped. I bumped the bias up a bit, but am still running them at a very conservative figure for the bias. I'm looking for longevity rather than the absolute max the tubes will do, but they do kick butt!
The only thign you need to be concerned with is 1. The height of the tube is considerably more than KT88s and 2. The filament draw is quite a bit more than 6550s or KT88s. Check your schematic and make sure you have the extra current to handle them....otherwise you might make a boat anchor out of your power transformer. An easy way to check if you don't have specs is to measure the filament voltage with the stock tubes installed. Then try it with the KT120s. If you notice a drop in the voltage your transformer won't handle them....don't risk it. Otherwise, have fun... they have excellent bottom end and are very clean sounding tubes. My favorites have always been winged C 6550s, but I might have found a new favorite....and the prices on them are dropping considerably.
Hope this helps someone.