If I wanted tubes AR would be my first choice but for SS I think there are better choices from other firms. I think my CJ 350 would fill your description better than anything AR has produced in SS and amps from Krell, Gamut, Musical Fidelity, McCormick etc would also be good choices. Tube sound with SS power is a hard thing to achieve; some feel it has never been done.
Audio Research makes some of the best solid state amplifiers out there. Unfortunately their solid state amplifiers do not receive the credit they deserve because Audio Research is primarily known for their tube electronics. That said , I can highly recommend an Audio Research D400 MKII. The D400 MKII will mate perfectly with your Reference 5 preamp and it will have plenty of grunt for your Sophias. The later version would be the D225 or the Reference 150 depending on your budget. I used a D400 MKII with my ESP Concert Grands and I can tell you from experience it is a terrific amplifier. I would put it in the same league as Levinson, Krell and Threshold and much better than the others mentioned here.
It would be nice if folks here could recommend something other than what they are currently using in their system.
The general thinking is that the D400MkII and the 100.2 are two of the best solid state amps from ARC. The 400II has more authority and maybe a tad more extension and it is clearly bigger and heavier in case that matters. The 100.2 is slightly more "rounded" sounding but it's probably mostly a matter of which will provide the best synergy with your system and room. I haven't heard a Ref 5 so I don't know it's characteristics (or which amp would best compliment it); if you might be power limited the 400II is probably the choice; if your system/room has any edginess the 100.2 might be the better choice. Both amps are likely to hold their value well in the used market; if you buy one and it doesn't trip your trigger you could probably resell it and try the other and be out not much more than the shipping cost on the amp you re-market.
"It would be nice if folks here could recommend something other than what they are currently using in their system. "
Why don't we all start recommending things we have never actually heard?
Okay rrog, here is one that will satisfy you.
My friend, with an ARC Ref. 5, uses the 220 wpc LAMM M2.2 (hybrid)
monoblocks. These amps are fantastic, and are among the best couple
of amps I've ever heard. (Fyi, they only have 1 6922 tube in each amp,
so they are almost solid state.) I should point out that he runs them
balanced, (i.e. with XLRs).
The sound is very refined, and incredibly transparent, and the bass
response is tight, fast and deep.
My two cents worth.
ARC 100.2 as recommended above ... if you can live with 100w (I believe) this is the ARC solid state amp to purchase
ARC SS amps stand on the same level as Classe, Mccormack.
McCormack has the best performance for the budget.
I'd recommend the ARC HD220. This is a hybrid and sounds simply wonderful. Plenty of power too.
forgot to mention ARC 100.2 runs HOT so it requires plenty of ventilation
I would recomend either the HD220 or M2.2 mono blocks if you have the extra coin.
ARC's preamps can be very, very good, but their amps are quite overrated in my opinion - they all use copious amounts of global feedback, whether tube or solid-state, and while generally transparent and resolving, feature the closed-in dead quality and two-dimensionality that amps using feedback suffer from. In addition, many of their pentode-based tube amps cut corners in ways that are inexcusable given their price, such as the lack of individual biasing for tube pairs. In any event, stay as far away as possible from ARC's digital amps with Wilsons - I know a fellow with a new ARC digital amp (I think it's the DS225) and Sophias and it is exactly as I would have expected - that Focal tweeter with a digital amp is just awful.
No-global-feedback amps, such as darTZeel or Ayre, tend to be very expensive. If they are beyond your budget, I would look at the Rowland Model 2/6/8/9 series, which can be had for very reasonable prices on the used market. Like ARC gear, they are fully differential balanced. I agree that the Lamm solid-state amps are very fine, but they are quite expensive, even used, and the Class A-biased model runs really hot. Both Lamm and Rowland work well with Wilson, especially Lamm (Wilson and Lamm have frequently shown together at CES's).
I have a friend with a Ref 5 - it's a really fine preamp once broken in.
Raquel, with all due respect, I cannot join with your opinion about ARC amps. I own an ARC VS 115 amp and I love it. Perhaps I think it sounds so good because I drive it with an ARC Ref 3 line stage and I am benefiting from synergy. I can't say.
Now . . . as far as negative feedback is concerned, I raised this question before on A'gon Forum. I also asked about other "specs" such as damping factor, rise time and skew rate and so forth. I mention this because the consensus opinion that was offered by the techies was that one should not rate the quality of an amp based upon any spec in a vacume. The techies explained that amp electronics designers have to weigh and balance many attributes when designing an optimal architecure. Thus, even though the VS-115 employs 12 db of negative feedback, one of the commentators said that it was not a lot in light of the amp's other attributes. I tried to find that post for you but couldn't find it in a pinch.
The techies also said that what's most important is how does the amp in question sound. Based on that standard, IMHO, the VS-115 sounds great. A number of knowledgeable members, including one who is an ARC dealer, said the VS--15 sounded about 85% as good as the recently discontinued Ref 110.
Now, I wax so much about the VS-115 NOT because I am looking for anyone's buy in or approval. Instead, I have owned the amp for about 2 years and am thoroughly familiar with it. Oh, BTW, ARC just released the new Ref 150 which is supposed to be phenominal. Per ARC's web site, the Ref 150 employs 14 db of NF, so I guess that means my VS 115 is better than the Ref 150. NOT!
Rapogee, I don't recall seeing that you mentioned how much you want to spend for your SS amp. As I recall from the "buzz," I have a faint recollection that ARC amps mate very well with Wilson speakers. In fact, if you check the ARC and ARCDB web sites, I believe ARC uses Wilson speakers in their sound rooms. Check it for yourself, but I think you would be happy with an ARC amp, be it tube or SS.
One last comment if I may, I believe that system synergy is very real and very important. My bias (pun not intended) is that if I owned a Ref 5, I would try to mate it with an ARC amp. Right now, used Ref 110s are finding their way into the used equipment market, especially as ARC continues to roll out the Ref 150. As I said, I don't recall you mentioning how much you want to spend, but if you already own the Ref 5, IMHO, I would really think about an ARC amp, especially tube.
Raquel, That's your opinion and I also disagree. I have owned many amplifiers over the years and Audio Research amplifiers are one of my favorites. I have owned all types including all tube, hybrid and solid state and Audio Research never fails to impress.
If you have the opportunity, try to get a darTZeel, Ayre, Rowland 625, or no-feedback triode tube amp into your system to compare to your ARC. There are indeed a lot of different factors that affect amplifier performance, but some are more important than others and global feedback is now known to be genuinely harmful to natural sound. The vast majority of designers still use it, however, because it's quite difficult to make a circuit stable, particularly a high-powered amp circuit, without global feedback, and most people buying amps don't know the difference.
Last month, I spent four nights in a row with a good friend and his all-Audio Research system, including VTM 200 monoblocks, plus big Wilsons in his large, purpose-built two-channel room. He recently demo'd a darTZeel and a new darTZeel is now on the way to him. 12 db. of global feedback is a lot, but even 2 db. changes the presentation - the difference is not subtle.
Just what we need. Another $18,000 solid state amplifier that's supposed to sound like a tube amp.
Rrog, I promised that I was not going to add anything else to this thread . . . but your comment set me off, not in a bad way but a good way. I looked over the thread yesterday and saw, as usual, everybody chiming in with their favorite amps. To me, it's like asking what is the best speaker . . . and there is a thread running asking that very question with over 1300 hits. My point, if it's not clear already, is that there is a lot of fine equipment out there. I happened to wind up with Audio Research, but that's me. I freely acknowledge that many other makes are just as good or better. I also want to reiterate what I said about system synergy. Some amps will will work better than others when driving a particular speaker, e.g., electrostats, horns, dynamic cones with unusual impedance curves and phase angles, and so forth. That's why, IMHO, I don't make equipment recommendations. Of course, if someone makes an unfair comment about a particular piece of equipment that I familiar with, I will respond, as I did above.
Bifwynne, I agree there are many other brands of amplifiers that are very good. I currently own amplifiers from several different manufacturers, but the OP specifically asked for recommendations from Audio Research. I also agree with you regarding system synergy, but there is more to it than just matching speakers and amplifiers. I believe matching preamp and amplifier is just as important and Audio Research is one of those brands that seems to work best together.
Rrog, I couldn't have said it better!! That is why I tried to respond to the OP with the same thoughts you just expressed, namely offer some ARC amp recommendations and observations, particularly mentioning the possibility of ARC tube amps. Further, I also agree that system synergy is an important consideration.
Finally, I couldn't help myself with respect to responding to the post which discussed interpreting and making purchase decisions based on electronic specs. I freely admit that I am NOT an electronics techie, but I have learned alot from A'gon members who are. And one thing I learned is that amp designers take a lot of factors into consideration, like the use of negative feedback, distortion, slew rate, rise time and so forth, when designing equipment. So . . . IMHO, if one is looking to buy electronics gear, I DO recommend that he/she should stick with good to excellent quality stuff from companies with good reputations (like ARC, among many many others), audition it if possible, and most importantly, make sure it will do a good job driving the speakers.
Sorry to wax philosphical again, but as I said above, when I read the various threads here and elsewhere, I find it difficult to apply advice and recommendations about gear that seems to be someone's favorite stuff when it may be impossible to even audition it, least of all understand the specs. JUST MY HUMBLE OPINION.