Which Solid State amplifier would you recommend for my budget?

suggest you consider van alstine or odyssey for superior $ value for sound quality and power delivered, the acoustats need both

60 watt monoblocks were plenty strong for my Acoustats. Currently very happy with an S300 after replacing the welded woofers with 4 ohm versions.

I have never got around to measuring the current sensitivity.

I think it will come down to what character you are looking for. I think you have identified some amps with “the right stuff” for speakers requiring high current. Given you have a Conrad Johnson preamp I would think the Krell would be a great match. Doing some reading I would pick the Rowland Model 5 second. 
 

While I was a Threshold fan 40 years ago, once Pass left, less so. 

+1 @ghdprentice What sound characteristics are most important to you and what specific improvements are you looking for over what you have now?

Also look at Belles. 

I have only used tube amps with Acoustats. I currently have their Servo amps that have been modded, but still put out 40 watts each and that’s more than enough!

All the best.

CODA Amplifier 11

Here’s a nice Bryston 4B SST2 available listed at $3250 but should be negotiable down to $3000…

https://www.usaudiomart.com/details/649918651-bryston-4b-sst2/

I'd easily take the Bryston listed above, compared to your list above... second choice would be the Krell.

Thank you for your suggestions. I am using a recapped ARC SP9 preamp and listen to orchestral and chamber music but I do love Rock.  I have a set of Quad 63s and although their midrange is beautiful I prefer the visceral effect I get from the Acoustats.  I have to admit that resale value is important only because there is always something to upgrade.  

I'm not familiar with the specific Threshold on your list but I'm a serious Threshold fan.  I have SA-200 monoblocks.  After 20 years of use one of my cats decided to pee on one of them.  I bundled both up and sent them to Threshold for them to look at and refresh.  They told me that one of the amps was slightly out of spec.  Not bad for 20 years of use.

I've seen SA-200s offered for sale but I have no idea if any are currently available, or at what price.  When I looked (just out of curiosity) a few years ago, purchasing a pair and sending them to Threshold for whatever needed to be done would fit in your budget. Outstanding amps.  And they were in the Pass era.

I also have FET-10 pre-amps.  If you stumble across someone who's selling both, consider it if you can fit it in your budget.

Good luck and have a great Thanksgiving.

Save some $ and go with a Purifi amp. Buckeye makes great ones.

Parasound 

+1 on the Belles @jerryg123 

Krell ksa100 if you can find one used and recapped. They sound sublime and are true class a to 100 watts. 

+1 for both Parasound and Purifi (from VTV).

Also look at Belles. ......A very good idea......

Modwright kwa 100 se.

Look at the Kinki Studio EX-M1 great amp 265 wpc i added a $300.00 sparkos op amp kit, and that made the amp sound even closer to Class A

Personel experience: Go with a Krell KSA-200S, KSA-300S FPB models. Its the benefit of the early Krell's without the Heat

Plan on sending them to the factory for a recap. Make sure they were not tweaked by an unauthorized service guy,

Any of the Parasound Halo's.

Good Luck

Stay away from these boutique amps,  nothing but trouble and headaches when you. Must ship em back for repair.

save your money,  for a while, and “have patience”, wait for the Sanders Magtech amp to be up for sale. Then jump on her as if you accidentally walked in on Elisha Cuthbert and Jamie Chung playing naked twister. 
 

best. Warranty in audio, gobs of power, high current, small and not too heavy. 
 

look up the review on the MBL Radiostrahler pair, even the pair of Sunfire 600s’ were lightly humiliated by the Magtech.  Last amp you will ever need. She looks unassuming and not much to look at, it’s the internals which matter, 

http://www.sanderssoundsystems.com/products/amplifiers/magtech-amp

call Roger, he loves to shoot the breeze, he is a engineer, you won’t regret the purchase.  

Hey Forte,

It would certainly have help if you'd specified which Acoustats you're using, & better yet if you had also included the dimension of your listening room in order to select the amp. But ....

IMHO, with the ARC SP9 the Krell  KSA-250 is your best match out of your selection, - - - except it's 15 yrs old & it's pure Class A. ("Sounds fab"), but because it runs so hot it cooks it's-self. A re-cap is necessary, so add another $1500 clams to your bill.

Jeff Rowlan Model 5, is 20+ yrs old, & will need a $1G - $1.5G recap job, + they're going $5G's as is.

Threshold s/5000e [not being a pure Class A amp, (Threshold's rep is for building Class A amps)], + it's 15yrs old, so a re-cap is just around the bend.

The 525 Rowland is a Class D amp, so no comment.

IMHO .... take SOIX's suggestion & get the Bryston 4B SST2 at $3250. A spot on match for your ARC SP9 & your Accoustats, + the 4B is good for another 10 yrs before a re-cap. 

I would look at the Benchmark AHB2 amp. Great amp $3299.

New. Parasound A21+.
Used. Too many to mention. I very much like my Pass X250 which would fall into your budget but rarely show up on the market.

Rogue Audion Dragon on here that you might get for around $3K.

Krell KSA owner here........ but look at the amps mentioned above by jjss49.

They are newer and won't require service anytime soon.

I still own a Rowland 5 but moved it to my AV system as it wasn't as smooth as the CJ Premier 11a I now use.

Agree with the Belles recco, and some of the older Classe that is actually Class A are really excellent

I have the Nelson Pass Nakamichi PA –7 for sale. Hard to beat. Built like a tank. Sounds fantastic at 200 wants per channel. Nashville $1350

I own a recapped vintage  Conrad Johnson preamp.  It matches in perfect synergy  with a Benchmark AHB2 amp. Remarkable sound with classical and rock.

I would recommend a PS Audio BHK 250.  Tube input stage, 500 watts into 4 ohms.  It’s a very satisfying amp.

Had the Krell KSA 200s and I would characterize it as “illuminating “.

I woukd suggest the Set 400 by Van Alstein. Alot of bang for your buck at $2K!. 200 wpch in 8 ohms as well. A lot of clean, dynamic sound.

+5 Belles, I would suggest the Aria monoblocks.  

Just a general observation here, as I have not heard any of your shortlist.  Please let us know your speakers.  The speaker / amplifier combination should always be considered together.

Parasound

One more to add….musical fidelity m6si.  It’s 2 mono blocks on the same chassis.  I use it drive Martin Logan’s ethos.  It’s has plenty of juice and smooth as butter. 

I agree with the Belles recommendations. If budget is an issue, the Belles Aria integrated is the most muscular 75 watts you can ask for and this model comes with a headphone jack. If you are more interested in a killer integrated with a huge, dual mono power supply,  the 85 wpc into 8 ohms and 130 wpc into 4 ohm Aria Dual Mono integrated is a fantastic speaker friendly amplifier and a great fit with the Spendor D7.2 loudspeaker. If you want more power, choose the Aria Signature integrated with a huge dual mono power supply outputting 125 wpc at 8 ohms and 225 wpc into 4 ohms. With Belles, you just can't go wrong. Two things I immediately noticed with the Belles Dual Mono integrated was it woke up my speakers and exhibits zero listening fatigue.

Should also look at Heed as they make some freaking awesome sounding Class A integrated for a very very reasonable price. Gene Ruben is a dealer in California. 

I have Heed Elixir that I just love in one of my systems. 

The Best Integrated Amplifiers | Buyers Guide 2022 - Part-Time Audiophile (parttimeaudiophile.com)

When I had 2 + 2s, I had both the interface (allows you use your own amps) and 4 of their servo-amps (semi moded); I highly recommend them. There's a guy in FL who does great upgrades for them

hth

I recommend one of the class D amps … Orchard audio or one with Purifi units inside. The Orchard Ultra has great sound for the $$.

I have Acoustat 2+2’s and Spectra 66’s. I am currently using a Mark Levinson ML-9 (which can be had pretty reasonably) and I’m extremely happy. I have a Rowland 5 I just purchased coming this week. I will see how it does compared to the ML9 and my Acoustat Trans Nova amps. 

I believe the Rega Elex R is all you need and can save a few dollars. These are lovely non harsh sounding amps.

Used FM Acoustics that I am selling for $3000.  AL the others above cannot compete.

Happy Listening.