What Is Best Monoblocks For Around $10,000 Used?

I'm searching for an amplifier upgrade in my system. My system is presently made up of a Classe CA-401 amp, Krell HTS 7.1 pre-pro, Piega P10 loudspeakers and Mark Levinson No.39 CD player. (The P10's and ML 39 will eventually be upgraded.) I listen to 2-channel redbook CD's, but the system also does Home Theater with a Krell Theater Amp Standard handling the center channel, rear channel and Zone 2.

I'm searching for a pair of mono-blocks that sells in the used market for about $10,000 (plus or minus), to replace the Classe CA-401 stereo amp. I've considered the Krell 450Mcx, but heard it sounds dark. (I don't know what dark is.) I've considered the Musical Fidelity KW amps, but they only have single ended inputs. The Pass Labs X600 may not give me the bass I'd like to have.

Can anyone make any suggestions on a good, resolving pair of mono-blocks?

Thank you.
I highly recommend the Levinson 436 amps. See my ad on Audiogon.
I've used them for several years and compared them to Krell monos, Classe, and several others. In my system (all Levinson and Revel) they have been magnificent. I can provide pictures on request. I have given this advice to many even before I've decided to upgrade to 33s. These amps do some phenomanal things and in the right system can really bring it to the next level. How do they sound? Well they are chameleon like, in that they don't have a sound of their own, but reflect the surrounding cables, sources, and components. Highly nuetral and have let me know the right or wrongess of ever tweak or upgrade I've ever tried. Revealing but very musical, and unfatigueing.
I'd be happy to talk with you, and my phone number is included with my ad.
I think the Pass X600 is an excellent amplifier. I've never been less than impressed with its bass. It's even better sounding than their X1000. The X600 is virtually a Class A amplifier; the first 120 or so watts are Class A, so in normal use it only comes out of Class A for transient peaks. Balanced operation is recommended, I think. I don't sell 'em, but do like 'em.

Take a look at the Lamm pure class A monos. They are rated at a lower power than what you speaking about but may work anyway. They are in your price range used or demo. They are my personal wish list mono blocs, definitely the best I have heard. Very finely detailed, and very slightly warm. I really didn't get a chance to manipulate their bass qualities they seemed very well balanced not bassy vise grips. They certainly didn't seem like they would fail to produce prodigious power, my current amps are 400wpc monos. I know what power means.
Have you listened to the Krell Theater amp on the front channels? It may give you more of an idea what the bigger Krells may sound like.
I second the Lamms. I don't think they can be beat in this price range. You don't mention power restrictions, though the amps you've mentioned do have more power than the Lamms, but lack the Lamm's sonic refinement. If you can get by with a mere 200 wpc, check out a pair of Lamm 2.2's.

Dark sound usually suggests that the highs are slightly rolled off.
You need to hear the Pass Labs X600 mono blocks. The bass is exceptional and the amps pull in detail in the entire range. You can find them used for around $7500. I have absolutely no desire to trade, upgrade or sell mine. They're that good!
I didn't specify a power requirement, since as I mentioned, I will eventually be upgrading the speakers. If I can find a pair of outstanding amps in the lower power range (>200wpc), then I must search out more efficient speakers (Wilson, etc). That is why I'm seeking an amp upgrade first. Either way, the amp should have enough "beef" to satisfy the needs of my large 8000 cubic foot room.
I could be way off base here but me; I would be looking for a great 2ch pre amp,first.
As a new owner of the lamm 2.2, I can assure you that its got plenty of power to drive a big room.

Comparing the lamm to the pass is like comparing a ford mustang to a jaguar. They both have their fans and they are really different. My friend has the pass labs and if your room is well treated then its a very good amp but its not in the lamm's league ordinarily.
I've hear nice things about the Lamm 2.2 amp. What types of speakers would be suitable for this amp?
well lamm often showcases with the wilson speakers at show so that is another reason I got the lamm amp.....so the wilson watt puppy 7 is the best bet unless you got mad cash for the maxx 2
I am sure a lot of people will disagree with Karmapolice. Calling Pass a Ford is like calling M-B or BMW an econobox.

But maybe Karmapolice is referring to Lamm's reliability when he uses Jaguar as an example.

I have heard both Lamm and Pass, I will not claim Lamm is in a different league.
I'll throw in my vote for Lamm... I do own the M2.1, and think any of their hybrid amps would be your best bet. I haven't heard the new X.5 pass amps, but I do feel the Lamms are a big step up from the older X series. With that said, if I hadn't heard the Lamms, I would probably own Pass. I certainly don't think they're bad amps.
In the already expensive world of audiophile equipement, pass labs is a relative bargain and thus is something like a Ford Mustang (which is a bargain for a sports car). The lamm is no bargain and is a prestige name so kind of like a jaguar. I think semi must think that the ford mustang is an insulting reference and you think that then you really don't get how most people really like the mustang.
The lamm is like the jaguar as well for being refined and elegant and best with well produced music. The pass is better known for great bass for those that really want to rock. Most would not compare the mid range and vocals of the lamm with the pass (especially the newer lamms). No one would say the lamm bass is on par with the pass. Apples and Oranges. Brute force versus refinement. Its a matter of taste.

Karmapolice - - Which speakers are you using with your M2.2's ? WP7's ?

I am using the wp7's and it works great for everything but poorly produced cds.


Before you have a chance to hear the new Pass X.5 series side by side with your Lamm, I don't think it's wise to claim what you claimed. From my reading, I don't think you have done so.
Why do you want to spend so much? I owned the Pass X600. The fellow who sold them to me found several solid state amps he likes better, and ended up with the biggest Boulders. I went another direction entirely, and ended up with MH2O Signature monos, and am thrilled. I just added an H2O Fire preamp, and am done. Period. New, they won't touch your $10,000 ceiling.

Maybe you should read George's post. He asked specifically about the pass x600. I gave him MY OPINION about the pass x600. No I have not tried their latest and greatest but then George asked about the x600 not the x600.5. The x600.5 are over 10k. So if he has has a 10k ceiling then he probably does not want the x600.5. If you think the x300.5 is better than the x600 than maybe YOU should SAY THAT.

I gave the man my opinion based upon what I know not based upon all posibilities. No one knows everything and I gave him my two cents. The fact I have not heard every pass amp does not mean I cannot give my opinion on what I have heard. Apparently, you are very sensitive about pass amps which means either you own it or you sell it.

I think every amp has pro's and cons and if you think the pass is a perfect amp that power to ya
This is easy you should get a pair of THETA CITADELS! If you can find them. Everyone who has ever heard them has fallen in love they are good as it gets. You buy these and your done!
Does any have any comments, pro -- or -- con, on Krell or Edge?
Innersound ESL KW, now that's power
I had the Krell 350c's and I liked them a lot. They are basically the same as the newer 450s. I went with the 600c because the sound was very close for less money. I thought the 600 was slightly better.
Worldcat - You are correct. CITADEL's are hard to find. However, with their modest power rating of 425>8 and 650>4 ohms, they don't seem to have the beef of amps with larger power supplies when used with speakers of lower impedance. My Classe CA-401's runs 400>8 and 800>4 ohms; and, I sometimes run out of steam when driving my Piega P10's rated at 4 ohms. I have not listened to the Citadel's, but heard nice things about them. Can you be more specific what it is about their sound that is alluring? Thanks
There is no solid state sound with them at all. They have incrediable power All that you would need. Very nice on top mids are very smooth and very detailed. Bottom-end is solid. I would put them up with any amp. But you can compare them with other amps and make ur decision.
Well since you are already familiar with the Classe sound why not consider Sim Audio another Canadian product. There mono's are very reasonably priced and are rated class A. The model W-10 mono's are highly rated they list for $10,000 new and used they run around $6,000 or $7,000. I have heard them with Dynaudio Temptations very clean extended top end lots of air with very deep powerful bass they are rated at 700 per mono. Good luck with your choice !
Boulder 1060 should be in that price range.
Can anyone comment on the Krell 450 Mcx monoblocks? Positive, or otherwise? Would love to hear some feedback on these highly regarded amps.
Bryston 7b-st or sst - will beat any other monoblock regardless of price.

I looked into buying this amp last year but found little to no reviews and was already wary about krell so did not put in on my short list.

So not sure what you mean by highly regarded? It does not appear to be highly regarded or otherwise

re: Krell 450 Mcx
By 'highly regarded' I should have explained better. That is not from reviews, but from general reaction. Many place these on a higher standard. If they are not exceptional amps, perhaps that may be why there are not many reviews on them? If they are exceptional amps, I'd love to hear that, too.
George, I just bought a pair of barely used Krell FPB 450Mcx monoblocks, upgrading from a Krell KSA-100 Mark II stereo amp. I'm using balanced interconnects to an Aragon Soundstage pre-amp, and I'm bi-wired to a pair of Krell Resolution 1 speakers.

Well, what can I say, after only a day or so of listening and comparing with rock & pop it's a big difference though I have to say the KSA-100 proved to be no slouch and is certainly a tremendous value. The FPB 450Mcx amps deliver more of everything: more and tighter bass, a more controlled and vibrant midrange, and a more extended and slightly airier top end, with the most prominent improvement being in the midrange. The music really bloomed in that area.

With rock music, the KSA-100 sounded somewhat anemic and thin with my speakers, and I surmised that the Resolution 1s needed more power to get that punch I was looking for. Now rock sounds much better, I was delighted by the added warmth and rawness in the guitars, right there in the lower midrange. Percussion took on substantially more impact and immediacy. The upper midrange also warmed up and opened considerably.

The improvement in the top end frequencies was *not* subtle, cymbal crashes had more authority and extension, the high notes on the keyboards came through better. I was pleased to note that harsh treble, a typical hallmark of poorly mastered CDs, did not hurt my ears despite the added extension. Those CDs still didn't sound good though...

Bass, well, this is kind of a strange one. With the KSA-100 much of my collection seemed to simply be lacking bass while other songs seemed to have plenty of it. With the FPB 450Mcx, the bass is significantly more amplified but the same overall characteristic remains: much of my music seems to need more bass while in other songs it's very powerful now. I've come to the conclusion that bass reproduction is largely room-dependent and my listening room, at around 10' x 14' and only 9' high and with one partially open wall, is simply not ideal for good bass reproduction. Some frequencies are "sucked out" while others are amplified. I have to live with it for now.

In addition, the soundstage opened up greatly. With some tracks the breadth and depth of the soundstage was dramatically better. When I'd upgraded to the KSA-100 from an Aragon 4004 Mark II, I'd noticed a similar improvement in the soundstage, though not as great as this time around.

I didn't notice a big difference in the imaging, but I guess that's more connected to the speakers and the physical characteristics of the room.

The system is now much more revealing and it's easy now to assess the quality of the digital mastering or re-mastering of CDs. I would now suggest that only around 10% of the CDs out there have truly been mastered properly. 50% are acceptable but could have been done better. 30% or so are poorly mastered / re-mastered. The remaining 10% is garbage and unfit to listen to. Some surprisingly big name mastering studios known for solid mastering slip up every once in a while and fall into these last two categories; I found a couple remasters by Bob Ludwig of Gateway Mastering and one by Rhino Sound that weren't up to scratch, though I have to say that most of what these guys do is really good.

Overall, "opening up" and "blooming" are the key descriptors I would use to characterize the upgrade from the KSA-100 to the FPB 450Mcx monos. The improvements in the midrange and soundstage are much more than incremental, but certainly not staggering. Like I said, the KSA-100 is no slouch and for ~$1100 used I can't think of a better value.

Now, let's compare the power consumption characteristics of the two amps. For weeks I had my KSA-100 plugged in to a Monster Power HTS 2000 MKII line conditioner, which is equipped with a current meter. Upon switching on the KSA-100 it would immediately pull about 5.5 amps (~650 watts!) and gradually taper over fifteen minutes down to about 4.2 amps (500 watts). This consumption would not change, regardless of whether or not I played music or how loud I played it. True Class A behavior I guess. Well, maybe there was a volume level where it would change but if so, it was well beyond what my poor ears can take.

Last week I had dedicated 30A outlets installed in preparation for the new amps. As an aside, I did not notice a difference in the sound when plugging the KSA-100 into the dedicated outlet vs. the Monster Power HTS 2000. Anyway, after I got the FPB 450Mcx amps, I plugged them both into the HTS 2000 just to see how much power they consume. Upon switching on the master power switches on the backs (which Krell recommend leaving on at all times), both amps together pulled about 0.6 amps (~70 watts). Then when I pushed the button on the front to turn them on, the consumption spiked to about 3.0 amps and came down within seconds to around 1.9 amps (230 watts). Then when I started playing music it would immediately increase with either volume or with more complexity or bass in the music. I took it pretty loud (but not deafening) and I saw the current usage go as high as 9.0 amps (> 1 kW). When I brought the volume down or the music became softer on its own, the amps would continue to draw high current for a few seconds before coming down. That's where the "Sustained Plateau Bias" name for the power conservation technology comes from, I suppose. Anyway, I later plugged the amps directly into the dedicated outlets, and again didn't notice an improvement in the sound. I guess the HTS 2000 would primarily manifest as a constraint during high volume playback.

During moderately loud playback, the amp gets *very* hot. The fins (particularly towards the front of the amp) and the faceplate on the fin side become too hot to touch for more than a few seconds. My KSA-100 and my friend's KSA-200 get very warm but not hot enough to burn. I think the 450Mcx fins could burn sensitive skin quite easily, if grasped for more than say ten seconds.

Physically, the amps are relatively compact but dense. Each occupies significantly less volume than the KSA-100 but weighs at least as much. There's only one handle, on the back, which makes it a bit awkward to move around but by supporting from the bottom it's acceptable. The faceplate is glossy black and looks like it would scratch easily.

Finally, note that the amp doesn't take RCA inputs, only XLR or CAST. Also, the outputs are nominally spade only but I managed to just pinch the wire directly in there and will get the spades this week.
I'm using a Krell KSA-200S but for $10K my shortlist (besides ones already mentioned in this thread) would include a set of the big Krell Audio Standards (around $30K new). If you have some patience, they can be had used for about that money.

In fact, I think someone (not me) is selling a set right now here on Audiogon...
Brystons, Bel Cantos mono'd, VTL MB450 Sigs, M-F or BAT.....

Not a big Krell fan, but nice stuff. ex krell owner.

Bel Canto Evo2 mono'd owner, love em. So does my electric bill.!!!
Not having read any of the responses, I highly recommend Nuforce amps(I also recommend Oritek X-2 interconnects.).
Hi George,Right now there are apair of Tenor mono blocks up for sale at Alterativeaudio.com for $8000.U.S.D. or $10,000 Canadian...
Why spend $10,000? Bel Canto REF1000. This is a monoblock that kicks out 500W into 8 ohms and 1000W into 4 ohms with a damping factor over 1000 and THD under 0.007%. The REF1000 has extraordinarily clear midrange and top end, combined with bass control that makes it sound as if you added a servo-controlled subwoofer. All of this with a WAF second to none: They do not weigh 150 lbs. each; they weigh less than 15 lbs. each and are contained in half-chassis boxes.

This is part of the new wave of B&O's ICEpower amps and happens to be the most powerful consumer version.
No doubt - Atmasphere MA-2 monoblocks - OTL, Class A, 220 WPC.
Whatever you spend does not always equate to sonic narvana. Although support from ARONOV is not worth a fart, the LS9100s are a good starting point IMHO. My guess is that since they are no longer in the Manf. end of audio, getting a set for a reasonable amount would be an added positive.

THEN: Have them pass through the hands of "JenaLabs.com" Jena Crock, giving her "Carte Blance" to Correct/Uupgrade according to her design principles. (MultiCaps, Jena's silver wire, etc.) or give drop her an email and ask for her ideas.

What you end up with is a "PP" self bias(ing) 100 watt set of Monoblocks that may not be the top of the heap but whatever would be next would not be too far ahead of the Aronovs.

My interest in the R'Nov's was started with comments made by Mr. Risch and the upgrade path to Jena through her reputation within the audio community.

When I win the lottery, a nice pair "DeHav" 845's will be sitting in my room!

Lots of good tube gear out there, part of the deal is spending the time finding and listening to it.
I really like a small company formed by 2 ex-Chord engineers-Chapter Audio.They offer the Couplet mono's at approx. 800 watts per.But it is not just the power,as the amps are neutrel,dynamic and cast a 3-D halo that makes you feel the spit from the singer on the recording.
Used McIntosh MC1201 pair or new MC501 pair. Higly resolving, highly musical, huge power, deep dynamic bass, just plain beautiful sound.

The pure Class A Llamms blew me away in terms of bringing the detail out , fabulous tone as well those are my destination amps. The A/B powered ones are almost as good. Never did hear the tubed Llamms but from what I have read they are great but a different animal.
Since someone mentioned Krell cx series amps - I have had the Krell 700cx in my system for over two weeks. I was VERY happy with this amp. But then Lamm M1.2 Reference came and for me the search was over. They are so much better than the Krell (and other amps I have tried - BAT VK150SE, Nagra VPA, Classe CAM-400, Plinius SA102).