One VX-5 is a great choice. Two is even better. A Theta Dreadnaught is another excellent choice. But if you really want your system to open up, get rid of the ML326 first and replace it with something like an Ayre or Aesthetix. Its a great preamp, but it won't allow you to fully hear what a new amp(s) can do. As long as you are not underpowered, a preamp upgrade should make a much bigger improvement in SQ than a new amp.
Replace your preamp with a Shindo tube preamp. It will totally transform your system. Even there entry level Auriges preamp at about $6000 is a game breaker. I use this preamp and drive a pair of David Berning ZH270 power amps to my 3.6's. If you only want to do power amp change and stay SS then I would recommend the Pass amps in your price range.
While I have not heard the DS225 I did own a series of ARC solid state amps (100.2, 150.2, SD135) before moving to a Modwright KWA150SE. In my system it was far superior to the ARC amps. In my system it does all the things on your wish list. Whether it would be a good match for the Maggies and play well with the ML preamp I cannot say. May be worth a look since it comes in within your price range.
For solid state- Pass Labs.
Did you consider a ML power amp?
There are so much great gear out there. Bryston comes to mind as well. Keep us posted & Happy Listening!
If your preamp have balanced output you can try these out as a set of mono blocks. And yes i do make them.Liberty Audio B2B-100
And there even a couple of reviews out.Soundstage Access Positive Feedback Online
Have you considered the Spread Spectrum Technology Ampzilla 2000 2nd edition.Check out the review at 10 Audio, also rated highly in the pages of The Absolute Sound.I absolutely love my pair and as a bonus they run extremely cool for an amp rated at 300 watts! 8500.00 new but here on AudiogoN there is a dealer who sometimes has demo pairs at a discount.They also make a stereo version.
Sunfire 300 or 600. You will stop looking.
Gryphon Diablo (integrated, but serious SOTA quality and I am told very much in the lineage and sound qualities of their larger amps). I am biased as an owner of the Colosseum amp...but it is sensational to have all-out assault pure Class A power, filigreed highs and a purity of tone whose equal I rarely if ever come across. 11K in EU I believe...but not sure about US pricing if its even available.
CJ Premier 350SA (I know you asked for list but they're only avail 2nd hand)
Classe CA2300 is powerful, very refined, neutral with good tonal balance and does a great job revealing layers of musical information. A couple of caveats: it doesn't quite have the inner glow that is unique to a pure Class A amplifier, and the internal fan can be sometimes be heard from close with no music playing (never noticed it with music playing).
At the under 10 grand price point the Pass XA-100.5 should certainly be on the consideration set. With the new XA 100.8 series out the used pricing on these amps have dropped. Still very expensive but if I was going to allocate up to 10K for amplification these would be on my short list to audition.
Do me a favor and call Mr. Klaus Bunge from Odyssey and get yourself a Symphonic Line amplifier. Your search ends here. These german amps are absolutely the finest SS amps extant; sounding neither tubey or transistory, but just like music! Smooth as silk in the highs and mids, testicular and rock-solid in the nether regions. They are also priced right. Sure there's Gryphon or Voila or Dartzeel or Soulution or Balabo, but you need to pawn your soul to Beelzebul to afford one. I've heard these other amps at shows and other venues, let me assure you that SL's sound is absolutely in the same company. Call Klaus and tell him Jojo says hi!
Check out the CODA Technologies 15.0 Stereo amplifier.
From the article: Remember the old Threshold power amps? Well, Threshold is gone, and while Nelson Pass, founder of Threshold, has been producing amplifiers under his own name for some years now, other former Threshold employees are also designing and manufacturing power amps. Their company is CODA Technologies, and their amplifiers are completely up to date in terms of parts quality and circuit design, while capturing some of the all-out-assault of the hardware of years gone by.
For reasons too lengthy to describe, I cannot do monos, so I'm looking for a stereo amp. I've always read that Spectral amps require proprietary cables, odd input impedance matching such and they don't play well others so to speak.
You might consider checking out the Emotiva XPR-2 amp. It is very powerful, has gotten great reviews, and comes with a 30 day in-home trial and a 5 year warranty...
For reasons too lengthy to describe, I cannot do monos, so I'm looking for a stereo amp. I've always read that Spectral amps require proprietary cables, odd input impedance matching such and they don't play well others so to speak."
If you can't use mono amps due to space issues, the Theta amp I mentioned in my first post is multichannel. As long as your speakers have 2 sets of binding posts, you can use 4 channels on it. I mentioned it because you brought up the Ayre V-5. The Theta Deradnaught and the Ayre are designed by the same person. I think the V-5 sounds a little better, but the Theta is a bit more powerful. I use the Ayre myself, so I'm pretty familiar with it. That said, looking at your system, I still feel a new preamp would make for a better upgrade. But that's just my personal opinion.
What is it about your ARC that makes you want to upgrade that component, as opposed to another? You'll probably get better recommendations if you provide more details about it.
You can find a nice Mark Levinson 331 or 332 that sound amazing
I replaced my DS225 with the Ayre VX-5 and have been very satisfied. You may lose some of that perceived hyper transparency but you gain musicality with the Ayre.
Several others I would appreciate a perspective comparison on are the Mark Levinson 532H, the Ayre VX-5 and Plinius SA-103 which are my top three contenders to replace my ARC DS225. I've heard the VX-5 compared to my DS225 and it's clearly better but these other two are nagging at me as unheard possible strong candidates. I live in an audio waste land and a 12 hour round trip to an audiostore doesn't really work for me. I'm pulling the trigger on one of these but, buying a third amp for comparison is painful. So, anyone out there compared any of these three amps?
Herron M1A Solid-State Mono blocks!
You need to get a Mye Stand for your 3.7i and 4 Stillpoint Ultra 5's. Then see if you want to change amps.