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.
handymann
@ Handymann, very good choice you made sticking to Krell, yes, The cx line of amps is very good, If you want a highly resolving set of amps with shocking base slam, look no further than the 750 mcx mono blocks!, I believe the 750 mcx amps are better than my 700cx stereo amp, thou the performance gap is alot closer than the other model lines Krell makes mono blocks compaired to the stereo amps in the cx line of amps past or present, cheers.
Well, it's not a bad idea to stick with what you know. If you're more comfortable with the Krells, so be it.
I will agree-the Pass Labs are more musical, but I don't think they're as quick as the Krells. I may seek out another set of the KMA series and have them re-built. When you open up the KMA amps, they're built like a tank. I think you could literally throw them off a cliff, brush 'em off and they wouldn't miss a beat. For all you Krell experts, is there any other model you think is as good as the KMA series?
I have to say that with Audyssey pro I can play so much louder than without would be possible. It is a way of freedom what is priceless.
Probably true.

Amp + speakers both matter. Biggest baddest amp + biggest baddest most efficient full range speakers with slam to match probably wins in the end. COuld be a commercial system geared towards a large venue or arena most likely and overkill for most any home.

In most peoples homes, even with larger rooms and higher volumes, it might be impossible to determine the best amp or combo in that many could test one's slam tolerance in practice. It's just a much smaller scale problem there.
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.

This cannot be held as a universal truth. The problem is that certain speakers will not have the right impedance curve in the bass to allow a solid state amp to do its thing, yet that same amp might be find on other speakers. Matching plays a big role.
Thanks Bo for the clarification and interesting comments. I don't want to hijack this thread into a cable discussion. Er, well maybe too late...
I think you understand it as I meant it. I can create an extreme touchable image these days. Every single part of a recording is very easy to locate. But not only in one line, but also in depth. With MIT I never heard a very direct voice or instrument. Wenn I play a big orchestra, the stage is wide and deep but within this big stage instruments are very sharp focussed. When I go back to MIT, you do not know where it is exactly. The exitement you feel when the image becomes touchabele is stunning. It it the big smile on your face when you hear it. When I hear it with MIT we Always look at eachother and we all say; nooooo ( we use our heads) it is not good. But also in speed, control resolution the MIT cables loose too much in quality. That is why I love comparing with cables so much. It is a very easy way to let people hear how to get a much higher level in sound quality.
Bo, what you just said makes sense to me now. I listen mostly to Jazz and Rock. I listen to some classical, like chamber music; but rarely full orchestral pieces. When I had my son stand and count and sing, he was 14' away from my listening position. When I play music, most singers are about that same perceived distance- just inside the back wall. So I get an intimate, nearly front row seat. Records have a sound stage from left to right, wall to wall and front to back going from in front of the speakers back into the rear wall. (Imaging is best in the dark when the back wall is invisible).

What I am getting at is full orchestral music on my system is too big, like you are saying. It is like being in the front rows, not in the middle or back. I wouldn't say the instruments are too big, just that they feel close. Is that what you are talking about?
Not got the Atma yet, taking very long :-)

I have tried a dozen Class A Amplifiers which I settled for the Clayton M300. It had everything I was looking for. At the moment they are running my Legacy Whisper XD with DSP in the chain and the transparency with the liquid midrange is as best as I have heard in any SS Amplifiers.

I am in the process of modifying my Bob Carver 305 Amplifiers with Caps upgrade.
I sold and owned powercables of MIT for over 6 years of time. In the last months I had a few clients with MIT and I did comparison with AQ cables. Next weekend I will have a client with MIT as well. We will compare his MIT interconnects and powercables with AQ interconnects and Purist Audio powercables. I will inform you about the outcome. A few months ago I was at a presentation with AQ cables. The shop also sells MIT most expensive Oracle cables. All the demos I heard overhere in the last 15 years I never liked the individual focus of instruments and voices. This time with AQ for the first time I could hear the intimate sound like in real. There words; Audioquest is a big step further now compared to MIT.

My experience are different. At my friends home I learned how small instruments and voices are in real during classical concerts played in front of 60 people with a small group of musicians. Voices and instruments are very small in proportion. The difference between MIT and AQ is also in the level of blacks. Instruments stand a lot more loose from eachother compared to MIT.

I had discussions about imaging a few times with the people from Pass Labs. They understand what I meant. Since I do this way of testing and comparing I did not have any person who prefered the bigger proportion of instruments. There is also a big difference in drive and control. The AQ give more weight and control. There is more air and detail in the high freq. as well. The best silver cables give superior detail and air compared to all full copper cables. MIT only uses copper in there cables. In the past I owned the most expensive powercables from MIT. When the Valhalla came out I sold them. These days I use Purist Audio powercables. Because they are more complete and defeat MIT cables also quite easily.
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?
@ 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.
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

Peter
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! :^)
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.
" 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?
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!
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.
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.
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."
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.
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.
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.
Of course, the class A amp with the most slam is this one:

http://www.atma-sphere.com/Products/#MA-3

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

Why do I have this feeling we will be hearing about Monitor Audio speakers yet again...
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.
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..
Handymann --

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

http://www.powermodules.com/sa-30.html

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).
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.
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.
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.
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.
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.
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?
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.
Pass Labs class A amps are not for slam. They are more of soundstage champs
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.
Another vote to Symphonic Line Kraft 300. Fast, sweet and big sound with unlimited dynamics.
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.
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.
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.