I'm using a Denon PRA-QS10 preamplifier right now. The LK150 is idle at this moment, I'm using a LK290 that just had the can caps replaced. The LK150 just got a new set of Tung Sol 6550's and put the vintage RCA's up.
I have other tube gear, Fisher 500c R200 X-101B HH Scott besides the mentioned amplifiers 299C LK272 233 a pair of Eico EL84 mono amplifiers and a Magnavox 6V6 console pull amplifier.
The two best sounding speakers I have found so far with tube gear, to my liking are the JBL L-100 and the EAW MS-30B.
Barney