Tube-amp for Magnepan?

I have tried many, SS and Tubed...

Use a pair of Carver Black Beauty 305's mono blocks - Six KT-120's per side or his updated BB 350's - six KT-150's per mono block.

I use the 305's on my 20.7's; best sound that I have had in my 35 years in this crazy hobby. They will drive anything and sound great!

Highly recommended.

I've driven my few months old M3.7i with also a few months old CAD 120S MkII with many different power tubes such as Psvane TII KT88, Tungsol KT120, W.C (Svet/SED) 6550/EL34, Ruby EL34 (one bad tube) with excellent results. The front end 6SN7 has been either Tungsol GTB or Sylvania JAN WGTA or CHS GTB. The driver has been either TJFM or EH GP. The CAD 120S MkII is upgraded to the Vcap CuFT reference caps and Solemn bypass caps with Cardas solder.

The CAD 120S MkII is driven by the SLP-98P that have Sylvania 6SN7 JAN WGTA or CHS GTB like the ones in the CAD 120S MkII. And the TJFM 6SN7 are the driver. The Phono tubes are Telefunken or Psvane. The SLP-98P is upgraded to the Mundorf S-G-O and mil spec resistors.

All NIB or NOS tubes have been fully broken in with close to 150 hours.

Phono input is from the VPI Scout 1.1 with upgraded tonearm and Dynavector 20x.

Digital source is from the Oppo 105D with AQ Columbia interconnects.

The result is simply breathtaking with a lot of audible improvement in deeper black background with more sound clarity, instrument separation in terms of more accurate image, wider soundstage, deep tight bass, sweet midrange and extended strong clean crisp treble. The entire audio response is very flat and dynamic with balanced tones.

The volume is about midway at the SLP-98P for most phono records to fill the 25' tall ceiling 21x20 living room open to staircase and kitchen. For digital music sources the volume is only at 11 o'clock to have the same SPL.

Overall I'm extremely happy with the synergy from this awesome setup. The Parasound A21 Halo sounds really harsh for the already clean fast crisp sound reproduction from the M3.7i. The CAD 120S MkII has plenty of reserve power (60WRMS in triode and 120WRMS in UL switchable on the fly) to handle the M3.7is beautifully as they sound better than my SF dynamic speakers by miles.

The low power but beautifully sound Yaqin MC-13S with W.C EL34 and Mundorf S-O cap (6 total) upgrade cannot drive the M3.7i properly. It is hooked up to the SF in the second listening room but definitely cannot be in the same league with the M3.7i setup.

I am considering connecting a pair of MMGi's to the 4 Ohm outputs of a pair of Hammond 1642SE output transformers wired up with the 833-A radio station triode running on only 1000 Volts. Using older speakers this draws 120 ma plate current. Steve Gutenberg on youtube said he likes the .7's using only a 300B SET. But I think I will need something stronger.
Most people don't build DIY 833-A SETs and only a television evangelist could afford the WVIAC 833-A SET, but I have successfully built the 1000 Volt power supply with choke filtering and I have gotten the 10 Amp 10 Volt DC to work with, among other things a 4.5 Farad capacitor and pre-charger so the bridge rectifier doesn't go off like a cherry bomb when I power it up. But I love this amplifier and I use a transformer coupled 245 triode, the Stradivari of vacuum tubes, to drive the 833-A.
Since SET power seems to go further in sounding good, has anybody else tried this? I am going to visit a dealer next week and request trying MMGi's connected to this.