High Sensitivity Speakers that work best with SS

I have 2 hi eff systems running on SS amplification there are many SS amps and hi eff loudspeakers that work well together.

"Mapman, do you have in mind any specific combination of very efficient speakers and a powerful amp?"

THe powerful SS amps are my current Bel Canto ref1000a mono- blocks. No specific speakers in mind, though I am more interested initially with smaller designs with bass extension that might compare favorably in terms of both price and performance to a decent pair of lower efficiency monitors.

Is this intrinsic to these specific designs, i.e. it is simple not possible to achieve similar signal-to-noise rations when building powerful amps? Or, is this because in these designs the designers pay special attention to this (unlike most designers of powerful amps)?

With the designs I listed 'intrinsic' is probably the best word. I don't think either the First Watt or an SET can be particularly powerful, but the OTLs can- the biggest so far is 500 watts.

NVP,

I'm biamping my Avantgarde Uno's with 2 tact S2150 amps with excellent results. Each amp puts out 150 watts/channel. 1 amp for the tweeter's and 1 amp for the midrange. They are extremely quiet with no hum or hiss even with the high sensitivity of the Uno's.

Hi guys,

Atmasphere, thanks for clarifying the situation. Before reading this post, I though it was common knowledge, but after seeing that nobody has pointed it out, I realize that maybe it was just my hunch. If you do not mind, I have another question about:

On higher efficiency speakers the distortion character in an amplifier that seems to be most successful is that where the distortion linearly decreases to unmeasurable as power is decreased. This is the realm of SETs, the Nelson First Watt designs and our own OTLs.

Is this intrinsic to these specific designs, i.e. it is simple not possible to achieve similar signal-to-noise rations when building powerful amps? Or, is this because in these designs the designers pay special attention to this (unlike most designers of powerful amps)?

Unsound, I do not thing either of us (or anybody else for that matter) has digressed. Understanding why a particular combination may not work is always beneficial. (Regarding the question mark it was not necessary as it was an indirect question, i.e. I am wondering ... )

Mapman, do you have in mind any specific combination of very efficient speakers and a powerful amp?

Mapman, I agree, which was part of why I wrote this article:
http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php

I used the word 'paradigm' in the article because the industry and designers that are taught a certain way don't always want to look at things that are outside of their box. But if they did, I think it would save a lot of audiophiles enough change to buy a new car...

I have seen apparently vendor neutral headphone websites that provide very detailed charts regarding headphone specifications at teh various frequencies. I found that very useful to help sort through the myriads of headphone/earphone products out there these days at all price points. Sure would be nice if something similar existed for speakers that would help one know better what should work best, at least on paper, prior to trying. I suppose magazines like Stereophile and others do provide such information, but it is not as complete nor centralized, which would maximize the value.

Maybe that's good fodder for a useful future Audiogon site enhancement to help people sort through the noise prior to spending the big bucks on high end audio?

...N...
W:-)E
...S...

Okay, where are we jumping to?

I've jumped off as well.

Unsound-most threads follow various paths, what's your issue here?

Well, it seems as though this thread has jumped the tracks.

Every now and then I consider moving my Sansui AU D-11 (upgraded) out of the bedroom system paired with EPI 100s and into my main rig to replace the Sophia Baby to drive my Cain & Cain Abbys. Maybe, one day...

I would also like to say that the smaller versions of all of these monster amps have sounded better to me as well, through my particular speakers.

Every high power solid state amp I haver tried with my Lascalas, including Mac, Levenson, Krell, Bryston, Threshold, and many others, have never sounded as smooth as my little pro Yammie. I am not suggesting everyone go out and buy one. It just does for me what I want it to, and that is the point of all of this. To find a combo, a match, that makes you enjoy your recorded music, and tap your feet. And yes, Nvp was looking for an explanation, but from one specific individual on this thread. Just saying....MrD.

NVP, I don't recall seeing a ? in any of your previous posts on this thread.

Larryi, in many cases you are correct, as I am guessing that Nvp also suspects.

Many high power amplifiers have a distortion characteristic that is actually higher at low power levels; depending on the amp the distortion might begin increasing at levels below 2-5 watts.

Due to the dynamic nature of music this 'first watt' is quite audible even on speakers of only moderate efficiency. For this reason to get that 'inner detail' that is often the 'magic' of a good system, it may well not be a great idea to put a high power amplifier on a high efficiency loudspeaker as the distortion might be higher rather than lower. The human hear translates many forms of distortion to tonality (odd orders are brightness and harshness, even orders contribute to warmth and lushness) and due to the ear's masking characteristic, distortion can obscure low level detail.

On higher efficiency speakers the distortion character in an amplifier that seems to be most successful is that where the distortion linearly decreases to unmeasurable as power is decreased. This is the realm of SETs, the Nelson First Watt designs and our own OTLs.

If the amp has this characteristic then it will likely work fine with a high efficiency speaker even if it has high power. Sorry if I am being a bit verbose.

Is it possible that high powered amps delivering 1 watt will sound worse than a lower powered amp delivering that watt? I would hazard to guess that the answer is yes. I've heard a few demonstrations of high powered amps vs. low powered amps from the same manufacturer, and often, the lower powered version sounded better where high power was not needed. Sure, a whole lot of other factors are not controlled and the design and components, etc. could be radically different between the two amps, so I am not drawing any hard conclusions. I know some solid state designers have gone to almost heroic extremes to minimize the number of output devices in their design because they claim that paralleling multiple devices degrade the sound. I have no idea if this is true, but, at least this is a plausible explanation of why some don't like the sound of high powered amps on high efficiency speakers.

As for the issue of high efficiency speakers that are difficult loads, I have found that compatibility with tube gear IS very much related to the difficulty of the load. A speaker, like some of the Wilson speakers, are surprisingly efficient (mid 90s), but none sound very good with most tube gear because they are difficult to drive. Other much less efficient speakers, e.g., Spendors, are MUCH more compatible with low-powered tube amps. I recently heard an old BBC monitor speaker (mid 80s efficiency rating, a 15 ohm nominal impedance) used with some quite low-powered pushpull amps (5 watts or so) and the combination sounded fantastic.

If we take the words "high sensitivity" to mean "high voltage sensitivity", then here is my suggestion: Look for "high sensitivity" combined with a low rated impedance, like 4 ohms or less, and preferably with a nasty-looking impedance curve (a deep dip, perhaps a peak in the midrange, maybe a severe phase angle). Chances are pretty good that such a speaker would work better on solid state amps than on tube amps.

Note that what I've really described here is a "high-sensitivity" speaker that is poorly-suited for tubes, which doesn't necessarily make it superior to a high-sensitivity speaker that works well with either tubes or solid state. Imo, ime, ymmv, etc.

Duke
dealer/manufacturer

NVP,
Your thought process is on the right track.The motivation for Nelson Pass`s First Watt line of amplifiers was high quality sound at low power levels.He recognizes that higher efficiency speakers require 'quality' more so than power quantity.These speakers at normal listening levels may use well under i watt(often only fractions of a watt) of power.Some behemoth amplifiers don`t sound their best at these lower levels(nut some do pretty well).
Regards,

I currently use a Bryston 4BSST amp which is 300wpc into 8 Ohms, 500wpc in 4 Ohms. My JBL S4700s have sensitivity of 94db. It's a good combo to my ears. I'm guessing that JBL being under the ownership of Harman, were voiced using Levinson amps. Levinson amps are high powered too. I prefer Bryston soundwise. But that another discussion there. Anyway, the combo works well, and I'd like to try lower powered Class A solid state and perhaps even tube amps. But I'm not really in any hurry to do so...haste makes waste especially in audio!

Unsound, with all due respect, please leave it at that. Let others with first hand experience in building and measuring tube and ss amplifiers answer my question. It is a perfectly logical question.

Most often perhaps, but even if peak power is only required say 10% of the time, that power requirement could be 10's if not 100's or even 1000's of X the typical amount of power used. Without such power, the system would be in distortion mode say 10% of the time.

Unsound, of course "overdriving" an amp is also not good. But I have never suggested that. With normal speakers one most often uses a few watts (e.g 5 watts) for typical listening levels, whereas with very efficient speakers one most often uses between a hundredth and a tenth of a watt.

NVP, I would suspect that an amp working close to it's maximum capabilities might not necessarily perform optimally. Many high powered amps are biased at the low end towards Class A shifting towards Class AB as the power needs increase, avoiding the onset of clipping.

Unsound, no need for "with all due respect", my comment was certainly not meant as a definitive explanation. (I am in no way qualified to do that, I'm a theoretical physicist/spectroscopiest.) However, I am not saying that subsequent watts compromise the first watt, but rather I am wondering whether the designers of powerful ss amps (e.g. 100 - 200 or more watts into 8 ohms) pay always attention to get the first watt right. It is common sense to expect that an apparatus may not necessarily performed optimally when operating at only 0.01 - 0.1 percent of its capacity. Even the smallest perturbation may be significant in that situation.

I hope Atmasphere (or somebody else) can clarify this question of mine.

Paul

Class A works well with an A class design :)

I wonder whether this is why Lou likes the Modwright KWA150Se with his speakers--it delivers the first few watts in Class A before switching over to Class A/B operation. Given the load presented I wonder if the KWA ever leaves Class A when paired with Lou's speakers. This may have something to do with the synergy between Lou and Dan's designs.

The 16 ohm load would be an easier load to drive for the OTL amplifier thus it's operating more efficiently would be my guess.
Regards,

NVP, with all due respect, subsequent Watts don't compromise the previous Watt. While one might argue that matching output devices require more effort, the benefits that extra power capabilities offer in an effort to avoid proximity to clipping is well worth the effort. SS amps don't have the bandwidth concerns that come with extra power output that tube amps have.
I believe Nelson Pass's First Watt amps are basically kitchen table experiments done on an appropriately small scale. His more serious efforts($) for Pass Labs typically provide larger power output.

Daedalus_audio, it was in Thom-mackis' room that I got to hear and see that. Duke had brought his speakers down the hall and we played them on Thom's M-60s. I pushed the system hard during that audition and found that I could play the system considerably louder, yet the meters on the amps showed that the amps were not working as hard.

Since Duke's speakers were nominally 16 ohms, the meters were more sensitive (should have read higher), yet they were reading lower.

I paired Pass Lab XA 30.5 with Zu Omen Defs (rated at 98dB) and the combination was fantastic. With the 30 Watts from this amp you could easily drive many medium or high efficiency speakers.

My feeling is that the less than ideal pairing between high efficient speakers
and ss amps is a consequence of the fact that many high power ss amps can't
do the first watt right. That is, high efficiency speakers require a very small
amount of power to sing (e.g. a tenth, a hundredth, etc. of a watt), whereas
most ss amp are simply not designed to do the first watt right, they are
comfortable when putting out more than 1 watt. I hope that Atmasphere can
shed some light on this. I thank you in advance Ralph.

Along the same lines, I always though that the 1st watt amps of Nelson Pass
were called like that because they were designed to do the first watt right.

Finally, as a few other have mentioned already, Avantgarde Acoustic speakers
are known to sing also with ss amps (not with all though).

Best wishes,
Paul

I`m not surprised the 1 watt SET amp sounded good(within limits). The Daedalus is a good speaker and will reveal the quality of that low power amplifier rather than mask it. I`ve heard them with the Modwright SS amp and the result was pretty good. However every time I`ve listened to them driven by a quality tube amplifier they just were better,more alive,engaging and natural.The tubes seem to bring out the music`s emotion in these speakers to a higher degree.
Regards,

Greetings all,

I was pointed to this thread and the reference to our room at the 2011 Audiofest.

One thing has become clear to me is that the Daedalus speakers will mirror what you throw at them.

Having had extensive experience with the Atma-sphere MA-60's and the 1 watt Serious Stereo amps driving them, I can honestly say that both amplifiers serve the speakers well, albeit slightly differently.

One watt 'll do ya, if you don't have a huge room and don't listen to death metal or Wagner at "proper" volumes.

At the other extreme, there's the absolute control you get from 200 watts of s-s, but depending on the amp, you may give up some of the harmonic envelope that we perceive as tone color.

Ya pays yer money and ya takes yer choice. Nothing new here.

I've always been a tube guy and so my leanings are toward the Serious and the Atma-spheres. Having said that, the ModWright designs convey the musical sensibility of a designer who knows what real music sounds like. They get the harmonic envelope right, and I can easily understand why they are Lou's amplifier of choice.

At the Newport show 2 years ago a friend dropped after hours, and brought with him a Who album. He wanted to see how close to concert volumes we could get with the ModWrights driving the Daedalus. Well, I put my 25dB musician's earplugs and we let 'er rip ...

The Deadalus' didn't flinch.

You see ... both Lou (Daedalus) and Ralph (Atma-sphere) come from a pro-sound background where two key parameters to be met are high sensitivity AND power handling (in speakers), and of course, reliability.

I find myself gravitating to guys with this philosophy - especially the sensitivity and reliability part. Same thing goes for Duke, for whom I have the utmost respect.

So, unlike many speakers, your amplifier choices for Deadalus are limited by your imagination. How often can you say that about a hi-fi component?

Disclaimer ... I know and like all the folks referenced above.

Cheers,
Thom @ Galibier

Atmasphere, I doubt you have ever had the opportunity to actually measure the Daedalus speakers or do a direct A/B measurement with Duke's 95 db speakers so your comment appears to be based on sonic memory.

these speakers have been tested in a sophisticated, professional lab and my specs are solid.

you may note that in 2011 Galibier showed in the large 11th floor room at RMAF using his pair of Ulysses and 1 watt SET amps!

check Scott Faller's 2011 RMAF show review: in
Enjoy the Music

http://www.enjoythemusic.com/rmaf_2011/faller/page2.htm

I have had a few tube amps paired with my Lascalas, but prefer the control and background silence of my modified 50 wpc Yamaha pro amp driving them. To me, it is a match in heaven (of course, there are other variables). I have never had a "mega" tube amp, simply because of funds, but I am sure a "great" tube amp would have me go back to tubes. Always,Mr.D

JBL L-300 is a high efficiency speaker that works well with all types of amplifiers. It works with low and high powered solid state and I also used the L-300 with a 14 watt SET amplifier (Mastersound) with excellent results. There are several efficient speakers from the 1970s that work well with solid state amplifiers also. One in particular is the Pioneer CS-99A. Another speaker for tubes or solid state is Electro Voice Wolverine 2 way with 12" woofer.

I think it worth repeating; that is easier to achieve a flatter impedance curve with less efficient speakers than with more efficient speakers.
I suspect the biggest concern for matching ss amps with speakers that are typically used with tubes, is appropriate damping for the speakers being considered.
With all that said, it's probably easier to match ss amplification than tube amplification to most speakers.
It's a hobby and if you want to play around with different things, I get it, but I still stand by the idea that it is wiser to choose speakers first, and then getting whatever amps work best with them, not the other way around.

Gopher, I wonder what it is about Tektons that would account for a better mating with a SS amp? Voicing perhaps in some way?

First Watt amps are a special case in my mind in that they are designed around being lower power. That means high efficiency speakers for best results no doubt. Most SS amps are not designed to care much about speaker efficiency. The better, more expensive ones tend to be higher power as well opening up more options for less efficient speakers. WIth tube amps, power tends to be lower and more expensive to own per watt I would say and high efficiency speakers are of course then their natural mates.

It does not make much sense to me to consider what well designed amp A sounds like compared to well designed amp B. There is no sound without adding speakers (and source as well). Only then can results be judged. That's like trying to judge two different chicken soup recipes without including all the other seasonings that go into it.

I would say though that a flat impedance curve is appealing on paper at least in order to start out with a level playing field. Of course, one will still not know what really works or sounds best to them until they try different things, so maybe not much practical advantage or difference there for most.

With speakers that require higher power solid state amps, the strategy that has been re-affirmed repeatedly for me over the years to work best is to not risk cutting corners in terms of power rating of amps used. In most cases like this for most owners of "audiophile" grade speakers in most rooms, I do not think anyone should regret using 200w/ch or more amps as an insurance policy against clipping or other distortion artifacts that might be introduced when an amp is not 100% + up to the task being asked. Newer higher efficiency solid state amp designs are the ticket here IMHO. In terms of overall efficiency, and ability to deliver better sound, higher efficiency amps help equal the playing field for less efficient speakers to be able to keep up with their more efficient cousins. Throwing a 250w/ch Class D amp at a pair of inefficient speakers that might benefit from it is not a big stretch these days for most "audiophiles". Its one way that advances in technology continue to change the playing field IMHO.

I think I've read the tekton speakers prefer high watt solid state, despite their high sensitivity ratings.

01-18-13: Atmasphere
If you are using Voltage Paradigm design rules, it may well be that the speaker's crossover points will not work properly with all tube amps even though the speaker has a flat impedance curve. From what I've seen/heard of the Daedalus though I don't think that it is any concern in that regard.

Good point, Ralph. Agreed on all counts.

I suspect that the Daedalus efficiency is less than the 98 db figure stated.

That's a possibility, as far as I am aware, as the only numbers I have seen are the published specs. FWIW, I can say that my Ulysses and my 65 watt amp show no signs at all of approaching their limits while producing 105 db peaks at my 12 foot listening distance. Although that of course does not rule out the possibility that they might be a few db shy of the specified number.

Best regards,
-- Al

I think that most speakers, high efficiency or not, sound better with good tube amps than solid state, provided the amps are not pushed very hard. But, with many low efficiency speakers it really is hard to run them in a low-powered amps sweet spot if one listens at fairly high volume. I personally don't like most high-powered tetrode and pentode amps, the exception being OTL amps.

High efficiency speakers allow one to better exploit the advantages of tube gear, but, they can make the best of solid state gear as well.

I have heard my system with the First Watt J2 amp and I liked that amp a lot. The J2 delivers clarity, natural timbre and a grain-free sound. It does not quite deliver the enveloping soundstage of a good SET amp and notes don't quite give the impression of blooming into space and decaying naturally like a SET amp, but, the J2 is still good in this regard. The slightly hard edge to the initial attack of notes gives it away as a solid state amp. Still, I think it is a VERY good amp, particularly considering the price. I wish there was some way to hear their SIT amp in my system (the friend who bought the J2 and lent it to me for a week is not likely to buy another First Watt amp).

Almarg, I suspect that the Daedalus efficiency is less than the 98 db figure stated. Duke of Audiokinesis makes a speaker that he claims is about 95 db, yet it is more efficient. I do agree though that a nice flat impedance curve does allow you to audition the differences between tube and transistor without much editorial from the speaker. In most cases.

However, If you are using Voltage Paradigm design rules, it may well be that the speaker's crossover points will not work properly with all tube amps even though the speaker has a flat impedance curve. From what I've seen/heard of the Daedalus though I don't think that it is any concern in that regard.

I am surprised that Nelson Pass' FirstWatt amps haven't been mentioned yet. SS amps designed and often built by a master, and intended for sensitive speakers. 6moons has reviewed most of them if you want an idea of the different models' flavors and requirements. I loved the F2J and F3 in particular.

Rrog,

I won't put any limitations on it.

Thanks.

Mapman, Are you inquiring about current model speakers or are you interested in vintage speakers too?

Isnt it great to have Atmasphere here? Always clear and knowlegable.

On my journey so far I have heard quite a few SS amps on my AG Trios (110db/w)

The Audioprojekte CA10, The sugden master class SPA4, Halcro DM38, various ICE power amps from Bel canto & Jeff Rowland and some Tripath battery amps to name a few. In my system I have enjoyed most of them. There is something to be said for the kind of noise floor and crispness they can bring to the table.

If I were less demanding any of the above amps I could live with. But, and I say this as a tube hater, there is nothing like the sound of a great tube especially SET. The EML 45 mesh tube (capable of 2W) has a beauty that is just job done!

Atmasphere can most likely explain technically why, but I can only say with a good tube music is alive. There is an emotional connection. Texture and density is there in spades while being transparent. It seems that image density is hard to find with SS no matter what the sensitivity of the speaker. Having said that a tweak on the sub cut off freq, clean power and other audiophile silliness does help.

I must say I enjoyed some class D. I look forward to a SIT amp. I also look forward to some hypex soon. Do not underestimate where this class D technology is heading because the sonic cons are getting ever shorter even if overkill for high sensitivity.

I use Daedalus too, the DA-RMas. I get the point of using 200watt SS amps with them. They are dynamic speakers anyway and putting that many what's through, gives real slam, but good amps like Modwright, also bring finesse.

Having said all that I still prefer the delicacy of low powered tube amps, my 20 watt Ayon Spark particularly.

What is often forgotten, is efficient conventional cone and box speakers give you options. They really will be happy with a wide range of amps, but being transparent, high quality transducers, whether SS or tubes, it's the quality of the watts that count.

My Tekton Lores sound fantastic matched with my Heed Obelisk Si w/ X2 psu.