Best 80-100 w Amplifier Available Under $4k Used?

So, I have a somewhat complicated dilemma that I've fallen into. For the past year, and prior to this weekend, I was extremely happy with my current system, which is composed as follows:

Silverline 17.5 speakers
Atma-Sphere S30 MIII.5 amplifier
Meridian GO2 Preamplifier
Meridian G08 cd player
Olive D4 Music Server
Bryston BDA-1 DAC

A good friend and audiophile, is moving to a significantly downsized home. He has always been very impressed with my Silverlines and was considering them as possibly the best option for his smaller listening area in the new home. He wanted to hear what they would sound like with his electronics, and yesterday, brought over his Plinius SA-103 amplifer and inserted it into my system in place of the Atma-Sphere amplifier. Given that he also has a GO2, a G08, and we also share the same speaker cabling, this essentially recreated exactly what he would hear with them in his system, although his new room is just a bit larger than mine.

Hearing the 17.5's with the Plinius was a bit of a revelation. Not entirely, or even necessarily because it was purely better than my S30.5 in terms of overall sound, but the Plinius drove the speakers with so much more command, and opened them up in ways I had never before heard. The slam was immense, and I was shocked by the quality of midrange from a solid state amp. The highs were also extended and extremely impressive.

At that point, not being sure if it was just the quality and performance of the Plinius that made the difference, or the additional power reserves, I made a request of my friend. He then went over to his brothers nearby home, and borrowed his Monarchy SM70 Pro monoblocks. We placed them in my system, in place of the Plinius, and while they clearly did not compare to the Plinius, there was again, a sense of greater openness, more slam, and more control than with the S30 when we switched it back in. While we both preferred the Atma-Sphere to the Monarchy's, it became apparent that the significant additional power in both solid state amplifiers was able to drive the speakers to greater heights in some important ways. Oh, and before I forget,as a reference point, I was still quite impressed with the Monarchy amps. For the money, these offer absolutely remarkable performance. They simply are not in the class of the Atma-Sphere, or the Plinius, but at a quarter to an eighth of the price of those units, how could they be expected to be?

So now you have the beginings of an understanding of the quandary of where I find myself now. My previously happy world listening to the system with the S30 MKIII.5 has been disrupted and I do not think I can move forward without addressing it. An easy answer would be to move to an upper level Atma-Sphere, and I would not hesitate for a moment to do so, but two things absolutely prevent that. First, I could not possibly afford an MA-1,even used. Secondly, my system is in a small room, and the heat from a pair of those would literally provide sauna like temperatures. I even have to abstain from using the S30 on very warm days in June, July and August (when I necessarily move to my headphone system).

And so, I'm left wondering what the best options are. From the sale of the S30.5, and a couple previously completed transactions, I could fund an amplifier in the $3500-4000.00 range, with an absolute hard limit on $4000. max. I would also clearly plan to buy used to maximize what was available to me. And, having experienced the listening session I described above, I would need an amplifier in the 80-100 wpc channel class.

I've long been an avowed tube lover, although the Atma-Sphere's are amongst the least "tube like" tubed amplifiers I have experienced, they simply sould like music, to me. I am not aware of any tubed amps of the stated power which would fit into my price range, excepting possibly the Rogue M150-180's, and I've heard those and found them a bit dry in character.

That would seem to leave solid state as my only likely option? Obviously, a used Plinius SA-103 is more than I can afford. I could however, purchase an SA-102, and hope that model is close to the 103 in performance. Other possible options could be the Modwright KWA 100SE, an Aesthetix Atlas, or even a pair of Parasound JC-1's. But I'm honestly getting into waters here that I truly don't know, with too many possibilities that I've not heard and do not otherwise have access to experience.

Your thoughts, expertise, recommendations and advice as to my best options would be greatly appreciated.
From past experience I suggest your seriously look at the McCormack DNA-250, 500 or 750. All three are easily in your budget and exhibit, fast, transparent and neutral listening pleasure. Excel on all music types. Superb reputation and service is available if needed, as are upgrades. Check the forums and read the reviews.

Threshold and Coda and Edge would also be on my list.
You already like the Plinius sound, and supposedly the SA-102 is very similar internally to the SA-103, so that seems a sensible route for you to take.

You might also consider the even earlier Plinius SA-100 mk III; there's one listed here for less than half your max budget. I have the SB-301 myself and, like you, find the Plinius bass performance exceptional.
I am right on with Tom6897, I was going to suggest McCormack or Coda.
If you want to try cheap?? If you can come across an Old Sumo Nine or Nine Plus and willing to wait for modifications, after modifications, they are truly wonderful... I have laid my hands on a Nine, had it Modded to the hilt and am shocked at what it does for the price point. It is clearly in the league of the above mentioned products, after mod about half the money.
I agree with all the suggestions. If we are talking about plinus and coda I would suggetest rowland model 5 or 7 well with in price and might hook you.
Having owned the Silverlines I would strongly consider the VTL ST150. I've had the VTL driving a set of Dynaudio Special 25's with plenty of authority and power to spare. (Sorry I never have bot the VTL and Silverlines at the same time...)
Why did you skip over the M-60s when you dismissed the MA-1s?
What a difference a day makes.You thought you were hearing it all and then you heard the Plinius.
This has happened to all of us that enjoy this hobby and can still to keep an open mind.
There is always something better and most times it is just out of our reach.
Others here can tell you of their experience with different amps and some will make suggestions but until YOU hear the amp these posts should be just what they are(suggestions.)
You might want to contact Silverline and ask what amps they use with your speaker.Or visit audio dealers that would allow you to borrow an amp for home audition.This of course would mean buying NEW but that would prevent you making the costly mistake of buying something used on the blind and find it not to your liking.
Best of luck in your quest.
There is a Plinius SA-250 mkiv here on sale for $4888 obo. It is only eight years old. You might want it, I would guess. It is a little more than what you want to spend though.
That guy had the same SA-250 for sale in the fall, for $4250. I offered him $4K and was told not only would he not accept that offer, but that he'd only accept $250 more than his listing price.

He then told me he was thinking of keeping it, but would let me know his plans within a week. Never heard back from him. I found the whole thing very weird.

I ended up buying Elite AV's SB-301 demo unit from Scot Markwell and am very happy with both the amp and the transaction, so I guess things happen for a reason.
I of course didn't know that. And it was only a suggestion, there will be other listings. The OP very much liked his speakers with Plinius; it is very possible that in some ways Rowlands or others will sound better. Is he prepared to try a dozen of expensive and very heavy amps? I don't know.
01-23-12: Swampwalker
"Why did you skip over the M-60s when you dismissed the MA-1s?"

Unfortunately, in my small listening room the M60's (which essentially double the heat output of the S-30) would literally create a sauna. I've even had this discussion with Ralph from Atma-Sphere previously, and he agreed.

Also, based on the Plinius experiment, I don't think 60wpc is going to deliver to these speakers what 100 or more will.
I think it is interesting you have (presumably) not heard the Atmasphere amp with an Atmosphere pre amp to get the full benefit of the tubes when comparing to the Plinius.

I do understand you want to get away from tubes and wonder if Merdian makes a suitable amp in your price range to match the (beautiful) GO2 Preamplifier.

Otherwise I would recommend the SA100MKIII (which I have owned in the past) it is very liquid with beautiful tone.

This post may be redundant but is my two cents...
The improvement in sound you seem to be describing is most likely to do as much with the increased damping factor as it does with the increase in power. That's a function of the output impedance of any tube amp, which is to say high, and solid state which is going to be much lower. The lower the output impedance, the higher the damping factor, the better "grip", especially on low frequencies. At your budget, you may want to look at the Wyred4sound mono blocks. Ultra low output impedance and amazing slam to duplicate what you hear with a Plinius with a decidedly tube sounding upper range. You can get them brand new with a warranty and still stay in your budget. The "surprise" factor with these amplifiers are the increase you'll hear in dynamics and may change your opinion about how much power you need. See reviews in editor's choice Absolute Sound, 6 Moons, and a few others. Probably find reviews on Wyred4sound's site.
consider the Music Reference RM 200-T available here on a'gon right now. Great sounding, reliable, dead quiet, long tube life & doesn't draw much power. Review available in Stereophile Dec. '11 issue. No affiliation w/the seller of this unit - just a happy MR user.
I surprised that no one has mentioned Bryston. They would be in your budget used and have a 20 year warranty to boot. I got off the upgrade carousel once I got my 14bsst2. Way more power than you looking for by I think this amp is perfect, you don't need to use it all, it's nice to know it's there. These bigger amps in solid state just sound better in my opinion, bigger caps etc etc, just my 2 cents

Oh and Bryston/Thiel is always voted as one of the best sounding rooms at CES so they must be doing something right
I think Rep4ever's comments on damping factor versus watts is probably right. I can see the excitment that comes from switching to an amp that provides damping your speakers may need (mine don't). I think the recommendation of the Music Reference RM200 is a very solid recommendation if you like what tubes can do versus SS, and not quite the heater that the Atma-sphere amps can be.

Did you have a fairly long-term to listening to the Plinius? Did you get to live with it for a while? I ask because sometimes we like something because it is different, and we focus on that difference and there is a big difference between what a 30 watt OTL does and a high powered SS amp - did you have enough time to hear what you might have lost in addition to what you gained?
or get another S30 and bridge them
Sorry. I love my Atmas so much I forgot to read the thread.