New KT150 tubes?

I've been using tube amps since about 1962 (albeit that was my cousin's white Bandmaster guitar amp), and anytime my Nutz get into a thread, well, it's a good thing...note that with all of those tube guitar amps nobody cared one bit about warm up or bias...we silly kids had no idea what bias was (I assume the repair dudes did). In any case, I've swapped the tubes out of my Jolida plenty and always turn the bias WAY down...after dialing the bias back and sticking new tubes in (and looking out for explosions or large flames) I wait a while and reset it, then check it again hours later...most tubes seem to stay in bias fairly well after the first warmup tweak, but I'm a serial tube finger burning bias freak anyway so I'll be poking it with my meter probes willy nilly.

Happy to report that the 150s are great...not unlike the 120s initial impression of effortless expansion of the whole frequency spectrum, and it seems the amp is a little louder, although that could be my imagination...little more heat but no biggie, bias is even and holding fine (after initially biasing them to the 500mv amp specs, all of the tubes were up 50mv when I re-set them later, no clue why but at least they were even!). My only criticism is that there's less filament glow like my newly installed "hidden filament" GL 12AX7s...I want more glow damnit, but will learn to live with it somehow...at least my Mullard 12AT7s look alive...

@ David12, I'm curious as to whether you attended the GS series soirée at KJW1 this weekend past?

No, I did'nt know it was on and I don't get to the wicked city very often, it's to expensive and time consuming. Did you go? I wonder if they had ARC's new GS amp series there, not that I would be tempted to buy them, I am very happy with my amp.

I do go to Guilford Audios get togethers just south of Reading , when Trevor puts them on and excellent they are.

Hey guys, with your KT150's installed in your REF75 and 150 respectively, was clearance with the cage an issue? Do you have to leave it off. You would not want to "encaged" those beautiful glowing 150's would you??

Me, i have been operating my Classic 120 monos with cage off for years. Not that i have a clearance issue as i use 16 6550 SED Winged C.

I am considering replacing the Classic's with a REF75 or 150. Will likely audition both in my system to see which one can drive my Verity Parsifal Encore most efficiently. My room is fairly large (15.5' x 25' x 7.5'). Would love to audition a REF75 with KT150's but my dealer's demo has the 120's in it. He tells me that the REF75 is sonically superior to the 150 but in my room and with my speakers, the 75 may run out gas at high listening level, hence a 150 being a better fit. Will have to see for myself. He's got 2 used REF150 for sale (customer trade in) that i could get a great price on.