Would like your tube amp recommendation


I've got Magnepan 20.1s, PrimaLuna Dialogue Premium preamp, Accuphase P1000 SS amplifier, with digital source (Byrston BDP1/BDA1).  It's a pretty sweet sound, but looking for something a little more musical with a larger sound stage.

I like the PrimaLuna preamp, and was wondering what to expect if I replace the Accuphase with PrimaLuna Prologue or Dialogue monoblocks.  Would they drive the Maggies?

Thanks,
Richard
rvnye
Agree that the VTA M-125s are very good value, if you build them yourself.

As built by VTA, the M-125's were very noisy, but can be quietened quite a bit. In my case, almost 40db.

Complete instructions:
http://ielogical.com/Audio/VTA_M-125.php
I suggest you give serious consideration to the Octave MRE 220 monos.  I have them paired with my ARC Ref. 10.  I wrote a review on AudioShark that can be easily Googled.  In short, it is the best "of both-worlds" amp I have ever encountered: speed and precision of SS and the true-real of tubes.  Output: 220W/4ohms.  It can drive any speaker out of the box.  However, you can get an external power supply (Black Box or Super Black Box) to remove any doubt and to enhance soundstage effects.
I've been looking at a pair of PrimaLuna Prologue Premium monoblocks on AG for $2,800.  With KT120's they are 80W/ch.  Maybe bi-amping the Maggies is in order.  Keep the Accuphase for the bass, and PrimaLuna tube amps for midrange/treble.  Or maybe the PrimaLuna's alone will power the speakers.

Your best value and bet will be the 125 watt M-125 monobloc amps from tubes4hifi.  You can buy them assembled and ready to play for about $2800 plus shipping.  If you like to get your hands dirty, they'll also sell them to you as a kit for about $1800, minus tubes.

http://www.tubes4hifi.com/bob.htm#M125
I don't know if they would drive your speakers, but you will not find a better tube amp than the Thrax Spartacus monoblocks.
If you have 20.1, the no-brainer answer for tubes is ARC.

I use auto-formers with Maggies so it makes them easier to drive, but the big ARC amps will have no problem.

Frankly, to get what you want, I would go full ARC with the preamp and DAC too.  Go fully balanced to gain extra db and other advantages that will mate well with most ARC tube amps (some of which are strictly balanced).

Maggies and ARC electronics are ideal combo...but one other thing that expands the soundstage is...believe it or not...a great sub with Maggies.  A properly mated sub adds much more than just subterranean bass.  REL did a great demo at CES...Even with reference Rockport speakers, the subs added a level of ambiance and scale that recreated more of the recording space.
I’ve got the original MG20s bi-amped with a VTL compact 100 tube mono blocks fed into a Phil Marchand XM44 cross-over which then feeds the midrange/tweeters. A pair of Emotiva XPA-1 mono blocks handles the bass panels. My room is 20x21 but my entertainment system takes up a whole wall and steals 3 feet. I’m here to tell you my 100 watt tube amp(s) will drive the mids/tweeter quite well into the 77db range without any signs of strain. Separation is on par with tube amps in this price range ($2400 pair). I’m not claiming my system is the pinnacle of all sound systems, it’s not. The one I heard at Stereo Design on Clairmont Mesa blvd in San Diego is. THAT was the system that made a believer out of me. It had the MG20.1s and a host of Levinson amps which sounded like you could walk around each performer on the stage...Ok, back to my system: vocals (esp female) sound very open and airy (trade mark of Maggies). Fiona Apple’s "slow like honey" is worth the price of admission alone. But alas just as others have said the big cat Maggies really need large, open spaces to truly shine. I have a 30x40 garage I’m dying to empty out and set up my system in, perhaps this Summer; we’ll see. https://audiostuff.shutterfly.com/
My Accuphase P1000 is 125W @ 8ohm, 250W @ 4ohm, 500W @ 2ohm, and 1000W @ 1ohm!! It has a beast of a power supply, and the current flows out unimpeded. But I was wondering how they would sound with PrimaLuna tube amps. Maybe I can borrow a couple from "Uncle Kevvy" for a home trial.

My Maggies are in a relatively small 12’ X 17’ room. With really well produced music, they sound great. But I wish they had a wider sound stage (I have the ribbon tweeters on the outside of the speakers), and more defined instrument placement.
Most think Maggies are just fine with whatever power they are using.
I did until I lived next door to an EE professor who demonstrated to me
the difference between my 200 watts a side at 4 ohms and his 600 a side .
IMO 300 @ 4 is a bare minimum .
A lot will depend on your room size and listening preferences, but the 20.1 was/is an excellent speaker, although I do agree it seems to need some power. But you can drive it quite successfully with less than 300 watts. Jim Winey used to make a point of telling me every time he saw me that the MG-20s he heard at Johnathon Valin's house sounded the best he had ever heard, driven by our MA-2s. I've also heard the MG20.7s driven by a pair of ARC  Ref 150s which worked great as well.

Whatever sensitivity/efficiency number the speaker has, add 6db to deal with the fact that its a line source and you will get a better idea of how easy it is to drive.
Have you seen this review of your speaker?

http://www.theabsolutesound.com/articles/magnepan-mg-201-loudspeaker/

The reviewer thinks they need 300w into 4 ohms to "come to life", and with a sensitivity of 85db/2.83v, which is 82db/1w because of the 4 ohm, I would agree. Some simple acoustic music would probably sound ok, but anything with dynamics would suffer.

Premium speakers require high octane power,suggest you check out Coincident Technology Dragon MK 2 mono blocks.The only thing between you and the music is air.
In short, the answer is yes. I was at a dealer hoping to audition the dialogue HP integrated. They didn't have it. But he didn't know much about Primaluna. So, he brought in the prologue premium and hooked it up to the Maggies. We listened for about an hour and frankly we were both quite impressed. It really sounded great, and did not seem like it was working hard at all.  

If if you step up the amplification to mono blocks, it would be even better. If you can afford it, consider the dialogue HP mono blocks. I listened to them recently and came away very impressed with those as well.  Even so, the prologue or dialogue monos will definitely drive those Maggies very well. 

 In the end I walked out after placing an order for the Dialogue Premium HP integrated. I think it will be a great step up from my current Dialogue One I'm using to run my B&W 803s.  I've been happy with the Dialogue for almost five years, so it's time to move up the chain. 

Good luck with your search!