PS Audio BHK 300 mono VS Modwright KWA 150SE mono VS D'agostino Classic stereo

No experience here.

For your Thiel 3.7's, FWIW, going purely on the specs, in order:

(1) D'Agostino Classic Stereo
(2) PS Audio BHK 300 Mono
(3) Modwright KWA 150 SE

Thanks unsound, do you think the D'agostino classic amp could drive a pair of CS 7.2's just fine ?

No experience with PS Audio amps only power products. IME if you need anything their customer support is outstanding! 

No experience with PS Audio amps, but do have their P10 Power Plant, DirectStream DAC and PerfectWave transport and like gshepardbuster have found their support to be really excellent!

I believe PS Audio has a 30 day money back guarantee, if you purchase their products new, thru them or one of their authorized dealers.

Surely PS Audio is a very serious company, i've read good things about the BHK 300.
How about the BAT VK-655SE anyone ?

Yes, I think the D'Agostino's could drive theThiel 7.2's. Have you considered the Thiel CS 5i's?

No the 5i's are even more difficult load to drive, i'd prefer the more easier and recent 7.2s.
The problem is that 7.2s are extremely difficult to find now days on the used market but this is no hurry for me as my main speaker is the CS 3.7 anyway.

The good thing about the D'agostino Classic is that it doubles down all the way to 2 ohms, it's not the case of the other brands.

The D'Agostino shouldn't be troubled by any of those 3.
Is Gryphon an option? Or, perhaps D'agostino era Krells?

Well i did audition the Gryphon Antileon Evo but at 35K€ for a stereo amp that's very steep!
I'd prefer staying within the 25k€ range for monos or 16k€ for stereo amp.
I don't want to go the Krell route as i don't find them refined for Thiel speakers.
The Aesthetix Atlas (already auditioned) are in my short list until i demo the Ypsilon Aelius ll in 2 weeks.

Gryphon hasn't had a US presence in some time, I knew they were pricey, but just not how pricey. I can certainly understand your position. I've always like those Krells with Thiels. But, hey, it's your money. 

I'm familiar with D'Agostino Momentum stereo and it should drive  Thiel 3.7 based on specifications.

You should add Hegel H30 to your list.  I have one and is superb.  Again, base on spec it should the Thiel 3.7.   There are many professional reviews available online that describes the SQ accurately.

Thiel is terrific,
You have assembled a very worthy list of amplifiers.  I've heard the D' Agostino and the Ypsilon amplifiers on 4 occasions between the RMAF and CES. Show conditions no doubt but in good rooms that were very well setup on each occasion. Sometimes you can get a feel for the brand's "house sound" generally speaking. 

The Ypsilon is the more impressive in my opinion.  It comes across as more natural, musically involving and ultimately more interesting and captivating compared with what I heard from the D' Agostino demonstrations.  Ypsilon products consistently sound exceptionally well when ever I've heard them. 

You're planing to audition these various amplifiers which is near mandatory at this elevated level.  Obviously hearing them driving your Thiele is the ideal scenario.  I look forward to your listening impressions. 
Charles 

Well yes since the Ypsilon Aelius ll is in first position in my short list, the distributor has arranged me a home demo on my system with a Nagra Jazz preamp since he still didn't receive his PST-100 MKll linestage yet.
I assume Ypsilon gear being way above Aesthetix gear.
I already auditioned the Hegel H30 which gave very goog results on the CS 3.7
knghifi how did you like the D'agostino classic amp ? does it have a very refined sound presentation ?

That's an intriguing pairing of the Negra and Ypsilon, I bet it'll sound gorgeous.  Home auditions aren't always possible to arrange, it good that you have an accommodating distributor.  I am curious to read your listening impressions of the Ypsilon in your system and how it compares to the other candidates. I've heard the PST 100 and thought it was superb, natural the antithesis of electronic hifi sound character. An expensive brand but at least they sound quite good. 
Charles 

Yes my Ypsilon distributor is a very cool guys, he's driving down with the gear to make 2 home demos, one for a guy who wants to try out the Aelius on his Magnepan 20.7 and me on my Thiels CS 3.7
If at the end i decide to go the Ypsilon route i will purchase the full system : Aelius ll + PST-100 MKll.

ill be curious were youre finding are with the modwright 150 se...i know dan's gear is alot for your money

Dan's Momentum S250 stereo is outstanding but here in Europe for $12K less i can purchase the Ypsilon Aelius ll monos.
Concerning the Modwright 150 SE i could easily buy 2 of them within my budget.

Audionet Max monoblocks. Dans S250 stereo or BAT VK-655SE Stereo or monoblocks. I am a former owner of the CS7.2 speakers.

Hegel H30. 

It would appear as though the Yisilon Aelius II might not be as suitable below 4 Ohms, where these Thiels spend quite a bit of time.

Thieliste,
You have multiple good choices available as the suggestions you’re receiving confirm. However if you are able to have the Ypsilon pre and power amplifiers pairing , that is one very compelling direction to follow.
Good luck,
Charles

Unsound,
On paper you could be right, thus the beauty of a home audition in order to get the actual listening experience. Specifications are helpful but  aren't equal to a hands on contact scenario. We'll soon read his impressions. 
Charles 

Peter Breuninger has successfuly driven his YG Sonja and MBL 101 MKll with the first version of the Aelius monos.
The Aelius work in class A up to 60 watts wich is probably enough to drive the CS 3.7
The Aelius ll have had a substential revision with bigger tranformers.
Just to tell you guys, here in France many CS 3.7 owners have used the Sugden IA-4 integrated amp with big success and beautiful sound, only 33 watts in class A.

tom_hankins how did you drive your CS 7.2s ?
I might want to add a pair of 7.2s to my Thiel collection at some point but driving them properly is another thing.

Thieliste, 
Michael Fremer reviewed the Aelius for Stereophile and when JA did the customary post review measurements this amplifier was stable at 2 ohms and produced 445 watts into that load.  I don't believe that your Thiels will be a problem at all. I just believe that it will be likely the best sounding amplifier of those on your list. Just my opinion. 
Charles 

 Charles1dad, As Thiel recommends a minimum of 100 Watts at 2.83 V/m the Aelius would seem to qualify as a suitable candidate, depending of course on desired volume out put and room size.  
  I think it worth noting that instead of doubling power into 2 Ohms from 4 Ohms as a true high current design would, or even increasing power (as spec'd) the afore mentioned Stereophile measurements show the Aelius dropped power, which incidentally would mean that it would be dropping power where the sensitivity of the speaker decreases. To be fair, it might be possible that power from the wall might have been sagging, but I doubt that explains such a degree of disparity. 

Thieliste, Some amplifiers halve their Class A output as they double down in impedance. Under powering a speaker, never lets the speaker perform optimally, increases distortion, and can potentially damage speaker drivers. Working and working well are different things.

Hello unsound, I'd think that one determines "working well" by how it preforms in the music signal chain i.e. reproducing music in your system.  You'd listen and decide if you like or dislike what you hear,  this is why a home audition is so valuable.  What we want from an audio product is for it to sound good enough to the point where we'd willingly purchase it. 

Too much emphasis on the doubling the power  as the speaker impedance is halved.  The Aelius can handle a 2 ohms load, the relevant factor is does it  or any amplifier "sound" good while doing so.?  You'll only determine that via one method, listening. Thieliste will fortunately soon have this opprotunity. 
Charles 

I’ve read numerous posts by Thiel owners who preferred tube rather than their SS amplifier due to superior sound quality in "their" opinion. These tube power amplifiers don’t increase power into diminishing loads, yet to many they managed to sound better. Lots of factors determine the ultimate sound quality we hear.
Charles

charles1dad, the importance of doubling down depends on how linear the impedance plot of the speakers are to begin with, and how much power can be delivered once there. The OP 3.7's have an admirably flat impedance plot, so it's less of an issue here. Thiel's recommended power output would suggests about a minimum of 400 Watts into 2 Ohms. So the Aelius's measured 440 Watts is within that margin. Keep in mind the 3.7's have a sensitivity of roughly 85 dB/Watt at that impedance. 
 Sure it's valuable  to know what others have found to work for them, to try and get a consensus, but I have no idea who most of these strangers are, what there biases are, if they have any real experience, or have any idea if they know what there talking about.
 Some reports mirror my own findings, other report things I've heard, but have found that we have different priorities, other reports contradict my own experiences, others appear to be pushing an agenda without any true experience with the particulars at hand. I try and find a pattern from Audiogon posters to affix a personal value to their inputs.  Many different people choose various things for a myriad of reasons, not all of which make a lick of sense. I try to include those things that are objective and have proven themselves to most likely to be repeatable. Lots of factors? Yes, including these. As for opinions, well everyone has one, and so do I.

 

 

I may have read a negative on this but can't find the post.  I am thinking of getting a pair of CS3.7s.  Would a high power class D ice or ncore amp with a tube pre fit the bill?  Or would it all end up too dry up top?
Thanks,
George

Answered this in the Thiel thread, but as it's more germane to this category, may I add a suggestion you pay special attention to the output impedance of the tube pre and the input impedance of the Class D amps your considering.

Unsound,
I understand your perspective. My essential point is that listening is the final arbiter and is of course guided by personal objectives and taste. This explains why one Thiel owner will insist that high power/current SS amplifiers are the only way to go.  Another owner will retort, "been there and done that,  tube amplifier was better for me".  It appears that Thiel owners have various routes to success. 
Charles 

If i was going to go the pure wattage route i would pick the D'agostino classic amp which doubles down all the way to 2 ohms and be done with any load problems.
But since this is not my vision of things i prefer to go quality watts and a lot of refinement.
I know most older Thiels are known to work best with big older Krells and so on but this is not my cup of thea.
The CS 3.7 are not as hard to drive as the 2.4s for exemple and i'm not even talking about the CS 6 and 7.2s.
I'll let you guys know my impressions with the Aelius ll.
I don't know anyone who has tried Ypsilon with Thiel speakers yet so that's going to be interesting.
All i can say for the moment is the best i've heard to date with the CS 3.7 are the Aesthetix Atlas mono Signature + Calypso Eclipse linestage.

Thieliste,
I like your approach and priority placed on the actual listening quality, isn’t this the whole point of having home audio, to "enjoy" music reproduction?
I get the big powerful high current bipolar transistor concept to manhandle any and all speaker loads. This doesn’t mean or ensure necessarily good quality of sounnd. I really appreciate the input coupled interstage transformer and only two stages of gain design of Ypsilon, very smart! Quality watts indeed. I wish you could directly compare this amplifier to the D'Agostino on your Thiels,  two very different design concepts. 
Charles

Dealer alert but here goes: I have the BHK 300’s on my TAD CR1’S and couldn’t be happier. Ps audio planned on offering a solid state input option but the tube input just trounced it for sound quality. To me that’s a big deal since I have found hybrid seems to sound best on my system. And of course the ability to tube roll gives another level of tweak ability vs. a pure solid state design. If you ever travel to NYC and want to hear ours give me a shout out at Triodepicturesound.
Since PS audio repurposed the casework from their power products and makes things on a larger production scale, the amps are half the price or less than probably anyone else could produce them for, so you’re likely getting a $30-40k amp for the bargain price of$15k.  Why spend more?  Use the extra cash for stellar cables like the Audioquest Wel signature and Niagara 7000 power conditioner which I can attest work extremely well with these amps - yes huge mono blocks benefitting greatly in dynamics and detail  from power conditioning!  
I believe Robert Harley bought his review pair of BHK 300's.  

Thanks emailists, yes i found the BHK 300's to be very reasonably priced for such nice hybrid monos.
I am also a hybrid believer as i like very much Aesthetix design.
I have to see if i can find a dealer to audition the BHK 300's.
Anyway happy new year to all of you audiophile guys.

emailists i forgot to ask you what preamp are you using with the BHK 300's ?
Is it the BHK Signature preamp ? if so how good is it ?
Thanks.
tomcy6 thanks i did read the Stereophile reviews of the Ypsilon monos and preamp.

Seemingly no love for the Modwright KWA-150SE amps in bridged mono mode. FWIW, i’ve heard the original KWA-150 & thought it had was very well engineered and finished. It had "plenty" of power as a single stereo amp to drive even a moderately difficult load in let’s say a medium size listening room. And the KWA-150SE has even more control. Run in bridged mono mode, the Modwright amps should be able to drive all but the most amp-crushing loads.

Sonically, I found the Modwright warm and tube-like. It has excellent resolution & inner detail, and as a result is one of the few amps i’ve heard at that price point which sounds musical at low listening levels. I think these amps are underrated, perhaps because they’ve been around for a while.

A member of the audiocircle forum Phil A is driving his CS 3.7s with a Modwright KWA 150SE and is very happy with the results.
He was using Bryston 14BSST before and found the Modwright much more musical.

You have received lots of informative comments and interesting viewpoints to your question. Having recently gone through an amplifier search/trial I can attest to both the impact an amplifier can have on the sound of one’s system as well as the importance of personal listening preferences in choosing "just the right amp" for your system. Even between several very good and highly regarded amplifiers, minor sonic characteristics can easily affect your level of satisfaction in how your system sounds.

Regarding your three listed amplifiers, they all have their supporters and are all highly regarded amplifiers so the questions to answer are, first, are they all capable of delivering the level of dynamics you desire with the speakers you plan to use and, second, which of them sound best to you on the types of music you enjoy most.

The D’agostino and PS Audio amps should drive just about anything. As some have pointed out, the ability to double output when the impedance is halved is a desirable quality because it allows the amplifier to drive difficult loads with a minimum of frequency and output aberrations. Of the three, based on the posted measurements, the D’Agostino amp should drive about anything you would throw at it and should exhibit a tight fisted control of the bass.  I suspect the PS Audio amps will also work well with most speakers but I recommend reading JA's measurements section in the Stereophile review of the PS Audio amp because he concludes those amps may not work so well with speakers that have impedance dipping below 4 ohms.  I suspect the Modwright amp will not equal the other two in controlling a wide range of speakers because it has less power to begin with, and does not double power into even 4 ohms. For those reasons, unless I could confirm that it sounded excellent with a specific pair of speakers I was planning to keep, I would not consider the Modwright.

Some other differences to consider between the PS Audio amps and the D’Agostino, are,
1. The PS Audio BHK Sig. 300 amps are monoblocks, which I prefer both for separation of the power supplies and also because of the ability to use very short speaker cables,
2. The PS Audio amps have a tubed input stage, which means you may deal with minor tube noise and will have to replace tubes. This is not a big deal to me since you are only looking at two tubes per amp, but some may not like having that extra layer of maintenance and operational responsibility, particularly people who like to leave equipment powered up all the time,
3. The PS Audio amps use mosfet output transistors while the D’Agostino uses Sanken bi-polar output transistors (which I liked the sound of in a pair of Cary MB500 monos I once owned). In general, I like the sonic signature and control of bi-polar devices. In my personal amplifier evaluation, I was able to own and compare at the same time a pair of Lamm M1.2 Reference amps (that use an input tube and mosfets) against Clayton M300 amps that use Motorola bi-polar output transistors. I ended up selling the Lamms because I simply did not like the sound as well. Similar to a BAT amp I once owned that used mosfets, I found they made the Lamms sound comparably "soft" and particularly in the low frequencies (in fairness, the Lamms only output about a third of the power of the Claytons, which likely also had an effect). This possibly "softer" mosfet sound may be reflected in the Stereophile review of the BHK 300s where Michael Fremer says, "The BHK 300s’ bottom end is nimble, well textured, and rhythmically solid, though there’s still more weight, power, and physicality to be had in the very lowest octaves."

You should search out the reviews of these amps, however, I would caution you to take them with a grain of salt since the reviewer’s systems and listening preferences are not necessarily your own. As an example, although both writers wrote positive reviews of the D’Agostino Classic, Jacob Heilbrunn said, " If this amp has a weak spot, it’s the treble where it can harden slightly on very complex and dynamic passages," while Ken Kessler’s review did not find any problems with the treble and said, "The Classic eschews sibilance unless the recording is poor." Both reviews are very positive and, in particular, Kessler’s review speaks very highly of the Classic.

My strong suggestion is to listen to the amplifiers you are interested in before purchasing, and preferably listen to them in your own system. I ended up auditioning four different amplifiers and had to purchase all of them to do so but, in the end, I was able to distinguish clear differences and to choose the amplifiers I liked best. Good luck and let us know how you make out.

mitch2 thanks very much, you gave me some very good technical information here.
The problem is that i'm not going to be able to home audition all of the brands i'm considering, the list is very long :

D'agostino.
Ypsilon.
Aesthetix.
Karan Acoustics.
PS Audio.
BAT.
Modwright.

For the moment i will have the Ypsilon home demo in 2 weeks time.
The distributor is nice enough to organise a home demo for me and another client.

There is one other brand that i forgot in my list : Audionet

I had Thiel 3.7s for a couple of years. From my firsthand experience, as I have posted here before, I would only recommend a high power high current amp for 3.7s.  I had the KW 150 and it simply ran out of steam and went into clipping even at medium volumes.  I would second the recommendation of BAT 600se and 655 Se as these amps really deliver a lot of current and give good dynamics.  I also had excellent results from Marantz MA9 monoblocks and a Krell Evo 402e. Jim Thiel used to demonstrate 3.7s with the 402e if that tells you anything. 

I have never seen such excellent feedback/advice from so many on any one thread. thieliste, I think that your audition of the Ypsilon will tell you a lot.

I am totally delighted with a Classe' Audio DR-9 (100W/ch@8 ohms rated high current SS amp that doubles down to 2 ohms) with my "older" Thiel CS5is using a MW5400ES tubed player for the front end. The lower-rated-power DR-9 simply does more things right than my Krell FPB-600c at all but insane volume. May be the same with the Ypsilon vs the D'agostino or Krell in your system, dunno. Only your ears will know for sure.

Recent experience has taught me that tubes somewhere in the chain are magical with the Thiels. Makes them relax just the right amount to bring out the musicality vs analytical over-achievement without.  

As always, the synergy of the equipment chain makes the difference.
emailists' advice to leave a good amount of your budget for cables, cords, and a top power conditioner is prudent, IME.

Best to you thieliste,
Dave

dlcockrum i'm surprised you're able to drive the most difficult Thiel ever with only 100 watts even if it's doubling.
I'm sure the D'agostino classic would be a perfect match for my CS 3.7 with let's say a VAC or VTL preamp.
But who knows perhaps the Ypsilon Aelius will have enough current and sound beautiful on the 3.7s.

"dlcockrum i’m surprised you’re able to drive the most difficult Thiel ever with only 100 watts even if it’s doubling."

Quote from ’Blazing Saddles’: "It’s twue! It’s twue!" lol

Over 25 years with several different amplifiers driving the 5i’s (including one of the highest-wattage monsters of all time), I find that it is much more about current delivery and superior amplifier design (minimizing anomalies at the frequency extremes, the ability to reproduce correct timbre and deliver micro and macro dynamics optimally) than rated power (to a limit).

Enjoy this golden time in your audio journey, thieliste.

Dave

Thiel recommended between 100-400 Watts for the CS5's. In my conversations with JIm Thiel he told me his all power recommendations were based upon quality ss amps that could double down, and that should one choose to use tubes, etc., they should increase the power  accordingly.