IF you can find them used, you may want to look at Manley Neo-Classic 300B SE/PP monoblocks. Unfortunatley, I thinkt he price went up to $9200 per pair today (might be tomorrow) from the previous $7400.
I just bought a pair about a month ago. First, the amps are selectable between SE at 11 wpc and PP at 24 wpc. They also have variable feedback setting and a switch to optimize speaker impedance.
I am using them to drive my Zu Essence speakers in a 12*16*8 room, and I can promise you that they are VERY dynamic and will play ridiculously loud in either SE or PP. The Essence are listed as 97 dB efficient, but Stereophile estimated their real efficiency to be around 94 dB.
Now that the amps are beginning to be fully broken in, I am literally startled at the dynamics and bass that they are capable of on material that I thought I was intimately familiar with when listening to it on my former solid state gear (Rega Elicit). Imaging and soundstage depth, width, and height are also in a different league.
I believe that Manley gear is supposed to be a synergistic match with Coincident speakers, and I think at one time, Israel had purchased a pair of EveAnna's 300B's.
If the Frankenstein is even better than the Manley as some tend to think-- then HOLY COW!
I, for one, have NO desire to switch out my amps. I may do some tube rolling to replace the stock Electro-Harmonix with something like Treasures or EAT's, but that will be it.
One caveat, I don't think the Manley's are as tonally neutral as some other gear, but I am personally fine with that. Rachel Yamagata was in my living room last night. The Manley/Zu combo is so dynamic that you can feel the pressure variations on the phrasing of the vocals on tracks on this disc.
Charles1dad, if the Frankensteins are even better, I am super-jealous.
PMB