Retubing an ARC VT100 mkll

From what I can see, there should be oodles of room to physical fit KT-120's. Not sure if the bias range or power supply can support this tube though. Anyone know for sure as I have also heard good things about this tube, but have not investigated it as I did not think it was compatible. Anyone know for sure?

Thanks to all. Guess the 6922EH's stay, and an octect of GL KT-88's are on the upgrade menu.

Hmmmm.....so now I'm torn between the KT88 Gold Lions or, for similar money, the Tung-sol KT120. Hifigeek1, if you were going this route, which would you likely go with? Thanks!

Thanks to all for your assistance on this. I plan on keeping the EH 6922 signal tubes, I just got through re-biasing them at about their midlife (using the A. Collins method). And my current output tubes seem to fit very snug, so I think a couple of quads of KT120's are on now on the menu. Will let everyone know how it goes. Cheers!

Ok, so, just finished installing and biasing (adjusted to the same 130 mV the amp recommends)a matched octect of Tung-Sol KT120's. Less than an hour playing time skipping through a bunch of artists I am familiar with(now Keith Jarrett playing J.S. Bach) and the verdict is positive so far. Can't speak to whether it can play louder than the EH6550's but they sound very good-perhaps a touch more effortless and glassy than the Electro Harmonix tubes but that could be just fresher tubes, hard to say. Mind you, the 6550 were only put in last Fall, so they were probably just at their "half life" based on my listening habits. Will keep the group informed as they break in, but good news is nothing went bang and they are dead quiet as well.

So the verdict after decent breakin time- they're pretty good. Not what I would call a flat out night and day difference but a bit more "drive" and a little less glare in the upper ranges especially when the volume is turned up. All in all I'm pleased for the $450 spent, but I will give full props to the EH6550 tubes - they were a good value. Assuming I can get 2 years out of the KT120 set, I am happy with the change over. BTW, one big physical difference is the heft and weight of the 120 vs the 6550. These things feel like they're built to last. Cheers!