Best Class A amp with SLAM

I'm looking for a couple of great class A bias amps (monoblocks) with the best "slam" as well as a sweet sound.

I recently sold 2 Krell KMA 160 mono blocks and I really miss them. What's out there that has the same attributes? I want 100-160 WATTS RMS that I can weld with if I want.
Pass Labs XA100.5 or XA160.5
I actually have the XA100.5's. They're really good, but seem to not have that slam the Krells had. Perhaps I'm remembering them better than they were.
Maybe more powerful than what you are looking for, but I'm extremely happy with my Symphonic Line Kraft 250 monos. Big transformer plus big capacitance means big current available to fuel big dynamics, even on inefficient speakers like my Salon 2s. Fast as hell too!
Why did you sell the Krells then? Those were amongst my all time favorite amps.
Clayton M300 monos. 300wpc into 8 ohms, 600 wpc into 4 ohms, all in class A. With latest power supply upgrade, these seemingly never run out of steam. Can't say how they compare to Krell, and if slam only is your goal you should probably go back to Krell, but for the texture, naturalness and dimensionality that good class A can provide, as well as tons of power to drive a pair of Aerials, I have found these suit me well.
Same thought as Unsound, why did you sell them if you were pleased with them?
Sounds like you would be happier with new speakers, not new amps. Smaller woofers = quicker bass = slam……

Have been to a lot of live venues and never heard much slam.
The ability to weld and sound sweet are not necessarily mutual qualities!

If the Krells were working for you how about find another set??
"why did you sell them if you were pleased with them"

Isn't that what audiophiles do? IE get rid of stuff that already sounds good in hope of getting something better? :-)

OR sometimes of course things just break or need service to perform well again and people just decide to move on. Audiophiles are picky listeners and when the sound seems to change for the worse, even slightly, it can be very hard to figure out why and easier to just move on. It's an in-exact science in many ways.
...ditto what Map said.
Maybe I should have kept them and had them recapped. They were almost 25 years old and it was time for a change. As far as speakers go, I have Wilson Maxx II's and am amazed each and everytime I listen to them. As far as amps go, the Pass Labs are smoother and I'm not in to only slam, but I do miss that attribute of the Krells. My X100.5's will suffice for now. They're great amps. As I said, perhaps I'm remembering the Krell's through rose textured ears.
You should add to your audition list the Electrocompaniet AW series monoblocks: AW180, AW400 and AW600 (Nemo)

Smooth sound and can handle loads down to .5 ohms.
I also own the Pass XA.5 series, and although I love mine, it seems that these amps are a bit reticent in the bass/slam department. I've read that enough times from enough different people that I'm pretty comfortable attributing the issue to the amps.
Most slam?

Probably the biggest, heaviest, highest wattage, power gulping, least green, most expensive one out there, whatever that is?

I could have used a pair like that with my large OHM 5 speakers.

But not practical for me (or most) so I tried Class D and have not looked back.
Another vote to Symphonic Line Kraft 300. Fast, sweet and big sound with unlimited dynamics.
I owned many Pass Labs poweramps. If you choose for the XA or X series ( Always .5 ofcourse)you both cannot go wrong. The XA are a little more musical and the stage is maybe more 3D. But the drive and speed of the X series is better. Also the high's sound more open at higher volumes. My next will be X600.5 or maybe the XA160.5. Pass Labs gives a deep and wide stage. And is one of the best in focussing on the real sound of instruments. But you need the right cables to get the very small and direct individual focus instruments and voices give in real. Many make the same fault in this part. Do not use MIT or Shunyata cables with Pass. because you will not get the intimate sound you need. When you compare Audioquest with these two brands on Pass Labs you understand why the other two make the proportion of instruments and voice too big. You Always need to understand the properties of an amp before you choose the cables. Because they have there own properties as well.
Bet you a buck Bo sells Pass.
Pass Labs class A amps are not for slam. They are more of soundstage champs
He already has a pair of Pass XA-100.5 monos and is looking to return to the kind of slam he got previously with Krell that is missing from his Pass amps.

It makes no sense to steer him to what he already has when he wants something else.
Should listen to the X600.5 and X1000.5. Most of the time you will drive in pure Class A. But you will have more weight also when you play less loud. The thing I love is the focus it gives on the sound of instruments. You can hear the timbre of instruments. Stage is very wide and deep. People need to learn that instruments and voices are very small in dimension. This part in individual focus puts you so much closer to the music. The intimate sound it creates is an essential part for the absolute sound. I hate the demos when voices and instruments are played too big. I Always ask those people; how big you think the singer his head is?
Hey Bo, what do you think of the X350.5? I have my eyes on that one. I can't really afford the X600.5 or X1000.5.
Handymann, I was in your position after selling my last Krell FPB600 years ago. I've had 3 Krell amps and Krell was the only stable component in my system. They worked great with everything including 100db horns. Krell cd players are also excellent but all had tranport issues which was unfortunate. I decided to sell just to try something different.

I had withdraws like you, missing the bass control and dynamics. Nothing I had since can match Krell strengths but do have a more open, grain free and musical sound.

After reviewing AVM Ovation MA-8 Mono Amplifers, Peter Breuninger of AVShowrooms declared them the new Krell. He found them best Krell Evolution 900e mono in all traditional Krell strengths. I think Peter is a Krell fan. Google the review if interested.
It is a nice amp, even delivers a lot of Class A watts. Even when you play loud it still will be class A. You nedd to play at very high levels to get into the Class B mode.
Time to re-set this thread after getting derailed by the usual distractor.

The original poster already has Pass amps and wants to know if there's something that will provide the kind of slam he got from Krell while sounding "sweet," which I assume means warm and not harsh-sounding up top. He did not ask about soundstage or singer's head size or any of that.
I think I would go for the X.5 series. I also owned the XA100.5. I also prefer the extra slamm and weight of the X.5 series. The high's are also different compared to the XA.5 series. There are a few Krell amps I also like. But the focus on the timbre of instruments and voices Pass does a better job.
Ok, thanks Bo for your reply. Sounds good.
Handymann --

You should try out a pair of Belles SA-30 stereo poweramps in a (vertical) bi-amp configuration:

It may not look much on paper but, believe me, you'll be convinced of its merrits in-use. Simply put it's one of the best poweramps, if not the best, I've ever heard - price disregarded. Its sonic attributes are that of coherency, scale, ease, dynamic (both micro and macro) and transient prowess, naturalness, resolution, etc. In fact it hardly makes sense to point out specific areas it does well, it's just an overriding feeling of the music being unrestricted, indeed freed - there's really nothing it can't handle.

Perhaps it makes more sense pointing out what it does better than most amps I've heard; there's an inherent sense of power and vitality combined with an outspoken coherency, natural tone, and organic "vibrancy." Leading edges are sharp and clean, as they should be, yet in no way overpowers the flow of the music. To my ears this is a rare sonic combination.

For your information I have no affiliation with Power Modules(Belles).
Oh, pardon - it seems the Grand Slamm's can't be run in bi-amp mode. A single SA-30 mayn't suffice, but I'd try it out nonetheless..
Pardon again - Wilson Maxx II's...
The XA100.5 sounded great on the Wilson puppy 7. But for the Maxx I understand why you miss the slamm. I would try the X600.5. And yess you need the warm sound of an amp like the Pass. The Maxx can sound harsh. I heard them more often bad than good to be honnest.
Why do I have this feeling we will be hearing about Monitor Audio speakers yet again...
Where are you talking about P?
Of course, the class A amp with the most slam is this one:

-but I assume that cost is playing a role here too :)

Hahahahaha.....funny guy Atmashere!!
After hearing a few Class A Amplifiers I finally settled for the Clayton M300 for SS Duties. Pass Labs and few others are at first have a wow factor but eventually you tend to grow out of them. With the Clayton it has that warmth and transparency which is I find pretty satisfying. Clayton now sell for 19000 Dollars a pair of M300 but you can get them cheaper.
Nice amps Atmasphere! I would be proud of these babies!
Atma MA2 are on the way to me, But I will always keep Clayton as My Secondary SS amp and soon as the Atma Arrive. The Clayton will power up my Theatre System.
Atmasphere, I bet those would drive my OHMs nicely!

Any deep Black Friday discounts coming up?

Seriously, how practically does one keep all the tubes on a device like that functioning properly? I imagine a relatively small investment in a good tube tester would help.
Mapman...from the website product page:

"We included a very easy to use built-in tube tester (which can be used at any time the amp is on), allowing one to test the output tubes 'on-the-fly' in a matter of seconds. Bias and DC offset functions are automated, using an Atma-Sphere-patented method, with meters to monitor the tubes, output power, line voltage and other features."
Tube tester included...nice!

Auto-bias...that should help a lot.

I recall VAC features that on some of their best amps and touts how hard it is to pull off properly.

Now I just need the black Friday sale.....

Since we're talking CLass A here, I won't worry about the power bills, that's probably a given for any Class A amp that can realistically lay claim to having the best slam.

The BEST anything never comes cheap.

Chocolate maybe. Having tried many, Hersheys may still be the best.
Nice features on that amp.
Dragon, when you get your MA2s run in, I would be interested in hearing how they compare with the M300s (that I also own a pair of). Do your M300s have Wilson's latest power supply upgrade?
A year or so ago, I tried to like a more "energy friendly" pair of high powered class A/B monoblocks and it was pretty much game over before it got started. The A/B amps had good bass but the Claytons ran all over them with respect to depth, texture and connectivity to the music. I have yet to hear a class A/B amp capture the body, dimensionality, and relationship between attack, sustain and decay, as well as the Claytons, or the Lamm M1.2 hybrids for that matter (that also operate fully in Class A).
The Lamm M1.2 Ref amps indeed have slam in the form of a very powerful and full sounding bass, up to their rated power, compared to some amps that start to become hard as they approach their power limit. The Lamms just lay it all out there until there is no more to give. They deliver the most powerful 100wpc I have heard, sort of like a classic big block V8 where you can just feel the power reserves without having to hear it wound up.
Hi, I might not have the very best, however, I will attest, that the Krell 700cx has plenty of slam with an uncanny mid-range not found in the 600c or original, the new krell amps have a different sound flavor, some may prefer it, I do not, there is nothing like the old school slam of Krell!, To top it off , I had krell modify the amp I have to be better than the original 700cx amp that are out there, sure this costed alot of money, this is what krell said!, Lol!, In the process of getting another source so sadly as of now the amp is still new in the sealed box!, its a minor inconvinence!
" the new krell amps have a different sound flavor, some may prefer it, I do not, there is nothing like the old school slam of Krell!,"

What's exactly is different about newer Krell compared to old?
My audiovalve challenger 180 monoblocks are class A and have plenty of slam as do my jeff roland model 6 monoblocks;probally really depends more on the speaker/amp combination for the resulting slam.
probally really depends more on the speaker/amp combination for the resulting slam."

Absolutely it does. The BEST amp with slam is probably the one that can do it best with most any speaker that is up to the task in most any room.

Kinda like how Peyton Manning and Tom Brady can rack up the yards with almost no regard to who is catching the ball on the other end.

Of how the UFC MMA champion with the most slam is probably the biggest one, ie the heavyweight champion.

The best smaller guys may be more skilled, faster and more nimble though, so that's not to say they might not be able to take out the biggest, baddest slammer on any given day.

SET amps are the featherweights. Talented and nimble but ain't gonna outslam the bigger boys in most cases.

Class D amps may be the "light heavyweights". Talented, lean and mean, slam galore and pretty nimble, but in a smaller, more efficient package. The George St. Pierre of amps! :^)
A pair of these as mono blocks will give you more slam than you could ask for, combined with finesse too. Olympia AX by PBN Audio

Good Listening

@ mapman, Hi, whats good to me about krell, some sounded good and some did not win me over, what i am saying is, not only do the model lines of krell sound different from one to the other, in most cases, the model within the model line sounds different from one another, one example of this is that the krell fpb 200 sounds alot different than the fpb 600, one of the most apparent difference is that the fpb 200 has deeper, bigger bass than the 600, thats were the line is drawn, the 600 does every other audiophile attributes much better, now with the evolution E series amps, they are class A/B amps, to were the 700cx is class A, Krell revamped the amps when people complained about the excess heat that does not bother me!, so the heat sinks are now in the chassis, alot less parts, alot less power on stand-by, green friendly!, The E series is class A untill the signal gets to the out put, then it is class B, this was the only way they could achieve this was going to class A/B, some may prefer the sound of the class A/B amps, some may prefer pure class A, they do sound alot different, in some ways the evolution E amps do sound better, in some they do not!, This depends on like anything else, your preferance and what you are tring to achieve with your sound, cheers.
Bo, I read your post about the best cables to use and the size of images they generate with Pass amps. If I am understanding your post correctly, then you are talking about bloated images. I use MIT cables exclusively throughout my system, from power cords to speaker cables, and I do not perceive bloated images. In fact, I had AQ cables in the past and I don't recall any change in image size with the same amp, preamp, and speaker combination.

I had my son, who sang in the Chorale in college stand at my stereo center and count and sing. His voice image seemed comparable to voice images on my stereo. Further, I listen to live ensembles at times at the University and perceive the sound of the instruments and imaging to be quite similar to my stereo.

Years ago, I heard a full SS, very high end system that had pinpoint images. My buddy used MIT cables. His system was startling due to these sharp, pinpoint images in space; but to me a guitar has a body, a cello has a body, a voice has a body. I preferred the imaging of my system even back then. I think it is more about the preamp than cables. I have used ARC pre's since 1989 with various amps. I perceive the images have body in my system and they are not bloated. A triangle, for example, or a cymbal have more of a pinpoint image. So does a wood block. Piano notes have sharp images with the corresponding body in the reverb.

I will also add that tweaks to stabilize and isolate the sources, speakers and even preamp and amp add sharpness/focus to the images; but I don't recall them making the images smaller.

Does that make sense to you?