Electrostatic speakers and low volume resolution

I am about 10 years behind you, and have heard many fine speakers. I currently own ML's and would not trade them for any comparably priced conventional speaker. sitting a bit closer might help.

Some large panel speakers do seem to play best at moderate volume levels and not quite so well at both extremes of volume. But, that certainly is not the case with all such speakers. The old Quad electrostatics (57s) sound very good at low volume levels. I liked the low level performance of the Martin Logan Quests I owned years ago as well.

If you are looking for the very best low level performance, look at high efficiency full-range drivers and compression driver (horn) systems. I suspect that the reason so many of the giant horn systems that reside in the tiny apartments in Japan have something to do with the ability of such systems to deliver great sound at low volume.

I've been reading some of your posts and am kind of familiar with your situation. What you're asking here may be too subjective of a question to get a good answer. Is it possible for you to audition some equipment first hand in order to gain some type of reference? Just something like Product A was a step in the right direction, but Product B was not. I fear without some type of confirmation as to what it will take to be successful, you'll be doing little more than guessing. Also keep in mind that low level resolution is something that all components contribute to, and not just the speakers.

This can be an amplifier problem as well. With many amplifiers, the distortion goes down as the output power is reduced- but only to a point. Below that point the distortion starts to go back up.

This occurs at different points with different amplifier designs and also with different power capabilities- the more power the amp can make, the higher the point where the distortion 'turns around' and goes back up.

For example with many amplifiers of about 120-150 watts this point might be at about 5-7 watts- just the point you are using at lower power levels.

With increased distortion comes less detail and a less musical presentation.

Yes, ZD, there are several places for me to do some auditioning and, to a limited extent, I've tried this and is how I ended up buying the Ethos pair several months ago. One of the things that I've been overlooking here is the equalizer, an oversite that might be hard to believe since I spent at least 3 threads extolling the magic of the Behringer DEQ2496. I'll be experimenting to see if I can use it in place of the loudness button of old.

Atmasphere, some of the most important information that I've received on these forums was yours when I was asking for advice regarding the use of tube amps with electrostats. Your description of the current / power relationship in this discussion of tubes versus SS was particularly useful in my understanding this comparison. It also reminds me that, based on these factors, tube amps may be less susceptible to low volume distortion. If my understanding is correct I would guess this to at least possibly be the case.

As was mentioned, high quality compression driver systems. More dynamics at low levels, very low distortion. As a very quiet listener (who once in a while does go to moderate levels) I know where you are at. This is the answer.

Would you be considering moving to more efficient speaker; as I would think it would produce the results you are seeking?

Broadstone, that is true to a certain extent but should not be held as gospel! Generally speaking though, Martin Logan speakers are tricky for any tube amp due to the low impedances of less than 1 ohm at high frequencies. Quite often though they can be solved with a set of ZEROs (http://www.zeroimpedance.com).

Ok, I'll try a combined response to these well considered suggestions. As far as trying more sensitive speakers like compression drivers, for example, that will be on my list. As I said earlier, the speakers that I liked best in almost all respects were the Canalis Animas which are not particularly efficient but in my audition of them I was seated no more than 6 feet away. In my home the best were the Jamo Concert 8's which ARE fairly sensitive at 94 dB. I was driving these with a Rogue Audio Sphinx, the same amp which I used with the ML Odysseys which combination seemed not to have the low volume problem that I'm having now.

Once again, Atmasphere, you've introduced another here-to-fore never considered issue. The possibility of increased distortion at volume levels below a certain point would never have crossed my mind. My current amp is the Peachtree Audio 220; I would really like to see what the difference would be if I were able to reinstall the Rogue Audio amp.

"The possibility of increased distortion at volume levels below a certain point would never have crossed my mind."

A very easy mistake for any of us. We tend to think of distortion as something unpleasant happening, usually at higher volumes. Distortion is anything that makes the signal stray in a direction further from what's on the recording. So, if your system has less resolution at lower volumes than normal, that's a distortion.

Atmasphere, if the Peachtree 220 amp is the cause of this low volume distortion and compromised detail, I'm wondering if using a more efficient speaker might actually exacerbate rather than improve the situation. On the other hand if using a lower wattage amp would also lower the point where this distortion begins maybe this could be another route I could take. In my setup, because I'm using the Peachtree Nova 80WPC integrated amp as the preamp, it would be a simple matter of removing the 220 from the system making the Nova a stand alone amplification source. In doing this, of course, I will lose the EQ setup as well as whatever attributes that the higher powered 220 provides.

I've been looking into speakers to possibly replace the only 6 month old Martin Logans and have thought about trying to buy back my 94dB Jamo Concert 8's. In my research I came across some very impressive reviews of the Grand Tetons and spoke to the owner (Alex Loon) who is apparently very proud of his design. I know almost nothing about Wavetouch and there is no way to audition them but he has a no-questions-asked return policy so I'm giving that some thought. If anyone knows more than what I've been able to find out, I'd appreciate hearing it.

Consider electrostatic headphones to accommodate your desire to hear the signal well, and to not disturb others.

Check out my review of the Kingsound M-20 tube headphone amp and KS-H3 ESL headphones. This will yield a premium sound on a par with whatever extreme dynamic speaker you wish to name.

Feel free to send me a personal message if you wish. BTW, the combo of Kingsound headphone amp/phones was so good I purchased them following the review.

I agree with Douglas, whether you are concerned with bothering others or you have some hearing problems, phones could be much better than speakers. Although people tend to listen at higher volumes with phones, they are actually quite good for getting clear, articulate sound at lower volume too. Because phones really don't deliver a normal soundstage (it all sounds like it is in your head), hearing issues associated with left-right imbalance become less bothersome--you don't care as much that more sound is on one side because soundstaging is somewhat irrelevant.

I own electrostatic phones, but, I think any kind of phone will work well.

Broadstone, from the sound of it all you have to do to confirm or deny my theory is to hook up your integrated amp. With less power, you will be pushing it harder and likely not using it in the lower power region. Try it and see if your low level detail is restored. If not then we need to look at other possibilities.

I appreciate the well considered advice regarding headphones and I do use them occasionally but only to shut out competing activities in our house and to limit my intrusion on others. Even though their sound reproduction is incredibly resolved, it just doesn't sound natural to me as if, like Larryi stated, the sound is originating in my head with no sense of a soundstage. Whatever the reason, even if only psychological, for everyday listening I'll not be using them.

On the other hand, because my stated goal is to acheive better detail at lower volume settings and, as I am very satisfied with my system at moderate to higher volumes, and because chasing it in other ways would be more involved and expensive, it probably makes better sense to develop a bit more flexibility and continue to use them for those described ocassional circumstances.

I've needed to upgrade my headphones anyway so will look into that. I have the Bose noise cancellers which work well for their designed purpose but are not well suited, IMO, for anything like audiophile listening. I also have a set of "fairly" decent on-ear phones that sound OK but don't do a great job of shutting out unwanted environmental sounds.

I have a question, though, regarding length of headphone wire. Although my seating position is only about 14 feet from my amp, the length of wire necessay to reach my location w/o running it across the living room would be about 28 feet. Will this be an issue?

Atmasphere, based on advice provided in my threads and many others of yours that I've read, I'm confident that this will have a good chance for success. I would already done as you suggest, but I'm waiting for help to gain access to the back of my entertainment center. It's large and has two heavy bridges between the 2 towers that I am unable to even assist with. When my 4 grandsons return from a camping trip, maybe I can talk them into doing this "one more time".

What other issues am I likely to run into going from 220 to 80 WPC? Thanks again.

Well, you may not have enough power at higher volume levels...

What a coincidence. I went outside right after I sent my last post to see what a police car was doing on our block and two of my neighbors were out also. I told them the situation and they offered their help to get the bridges down from the entertainment center and I went directly to the task of switching the speaker cables. It did make a difference using the 80W Nova as you suggested it might and I wasn't surprised that your advice worked. However, because I'm not very good at discerning subtle changes, I WAS surprised that I was able to hear it.

I also tried listening at higher volumes (even to the overture from tannhauser) and, possibly, because it wasn't at concert listening levels, it didn't seem substantially lacking in any important way. I know I have more listening to do before making a decision but we've substantiated at least one important issue regarding this power/distortion issue and I thank you once again.

Great Thread !!!

You are quite welcome.

Should I point out that tubes have a reputation of doing low level detail better than transistors? The more resolution you have (and ESLs have a lot) the easier it is to hear this.

However since you have Martin Logans, in order to get a tube amp to play them right, a set of ZEROs (www.zeroimpedance) is advised. This will allow a tube amp to deal with the near-short impedance that occurs at high frequencies in the Martin Logans.

"However since you have Martin Logans, in order to get a tube amp to play them right, a set of ZEROs (www.zeroimpedance) is advised. This will allow a tube amp to deal with the near-short impedance that occurs at high frequencies in the Martin Logans.
Atmasphere (Threads | Answers | This Thread)"

Don't the output transformers that most tube amps have, do that already?

^^ No. I don't know of an output transformer that is designed to handle a 0.5 ohm load!

Fortunately this impedance occurs at about 20KHz, so there is not a lot of energy involved. But if you are using a 4 ohm tap on the amp to drive the speaker, the feedback needed to cause the amp to give flat frequency response might be insufficient. The ZERO solves that.

Going back to an earlier discussion where I asked advice regarding the use of tubes with electrostatics, I kind of abandoned the idea because a number of issues arose that were a little involved for me to get comfortable with. One of the main ones of these was the prospect of finding a tube amp with a 2 ohm tap and whether using the ZEROS at the 4 or 8 ohm tap would accomplish the same thing. Based primarily on Atmasphere's explanation I assume that both approaches are viable and equal(?) in their ability to handle these extreme loads. I'm not claiming any kind of complete understanding of the relationship of feedback to distortion or its control, but my gut tells me that the ZERO approach using "normal" taps from the amp would be the better choice, if for no other reason than having greater latitude in choosing an amplifier.

Once again, I find myself in a discussion that exceeds my experience and level of expertise but realize that just because I can't hear anything above about 8000Hz doesn't mean that those frequencies above that level don't contribute to distortion. However, in regard to those "shunt approaching" frequencies described, there are no musical instruments, at least in the base harmonic, that come near 20KHz. If my understanding is correct, then, does this mean that using the 4 ohm tap with the electrostatics may be acceptable at low to moderate volumes?

^^It might be, but when you use the 4 ohm tap of most tube amplifiers, the output transformer often has a loss of bandwidth at both extremes and some are better than others. The ZEROs take care of that problem by allowing you to use a higher impedance tap where the transformer is more efficient and the amp makes less distortion.

While fundamentals of instruments don't go that high, harmonics of them certainly do.

Good, I guess my understanding wasn't THAT far off. Based on what I've learned in these discussions, then, I am interested again in trying a tube based power amp with the ZEROs. I will still keep the Peachtree Nova as a preamp for its latitude of source connections and keep the ML's partly because they're new and partly because, having used electrostats for 35+ years, I'm habituated to their sound. The next step will be to decide on an amp. Atmasphere, does it make a difference whether the ZERO unit is located at the amp or speaker end of the cable?...I'm considering using the naked ZERO but, based on cost considerations, it will be awhile before I make these purchases.

Atmasphere, I read your article on the development history but forgot to ask an important question. Would it make sense to try impedance matching with my SS amp first before buying the tube amp to see if that improves my low volume issue? Also, if I plan to use the ZERO might I just as well get an OTL amp?

We do have customers that have had Martin Logans and our amps for extended periods- one guy still has the same speakers (CLS2s) and a set of MA-1s built in 1990. So you can use OTLs.

Paul Speltz, who makes the ZEROs, has a letter from Steve McCormick that states that his solid state amps sound better driving 4 ohms through the ZEROs than they do direct, and Steve's amps drive 4 ohms without difficulty.

IOW even solid state amps make more distortion when driving lower impedance loads (this can be seen in the specs of any solid state amp), so the ZEROs can be used to reduce that distortion. Since the ear translates distortion into tonality, the result should be smoother sound.

I've pretty much decided to buy an autoformer whether or not I decide to switch to tube amplification but I have a question re choosing the best impedance tap to use. Because I use electrostatic hybrids, the amp sees a very wide range of impedance loading relative to the frequency of the signal. With this in mind, along with the term "matching" in my thoughts, and having awareness of the 4 ohm "nominal" impedance of the MLs, how do I choose the best tap?

In my limited research on the subject I assume that 16 ohms (if reachable) is at least a safe starting point. Also, when considering the starting point to calculate multiplier values, does one use as a starting point the 4 ohm nominal or the less than 2 ohm value of the estimated lowest impedance that may be expected?

Listening is the best means. The use of the ZEROs should not represent a compromise to the tonality of the system.

Actually, Atmashere, I don't anticipate that tonality would be compromised; my goal and belief in trying the Zeros is to improve tonality through reduction of low volume distortion. Because most of the info I've been able to find address autoformers in general as relates to tube amps and none, as far as I've found, discuss the choice or calculation method to determine which impedance tap would have the best chance working with my system, that question still remains.

Since you have a solid state amp that does OK on the speaker right now my first inclination would be to simply go with the 2X multiplier tap, IOW 4 ohms.

Thanks. When I get it, that's where I'll start and I'm anxious to try it. Should I anticipate any changes beyond the low volume distortion issue being addressed here?

Not be heretic about it but our ears do not have flat frequency response to start with, hear differently at different volumes, and become less sensitive over time as noted. So digital signal processing or equalization may be all the doctor ordered to provide any needed corrections.

See the chart to the right in particular in this very informative Interactive Music Frequency Response Chart . Take not of what instruments produce sound at what frequencies and how that relates to teh sensitivity of our ears in the chart. It will help to get a handle on things better perhaps before taking any action, if needed.

Gear that sounded good when younger probably is still sounding equally if in good operating condition. So you can change gear or do some basic equalization/signal processing to correct the problem. Many ways to skin the cat.

Realize also that dynamics and frequency response are related, not two completely independent aspects of sound, althoughthat is how we tend to think about it often. An issue with dynamics might still be solved by adjusting frequency response.

An example that makes this clear is that there is NO dynamics when there is no frequency response that we are able to hear, say at 22Khz. But the same sound might well get our dog's attention.

I find it funny how some will change any of their hardware at the blink of an eye the instant something does not sound exactly right but will never consider the simple things that might be done to correct common simple problems like that fact that our hearing is neither perfect nor static over time.

Equipment makers gotta love it though.

Broadstone, according to what I have heard, it should also sound generally smoother without loosing any detail.

Mapman, I don't see your response in any way heretical. As a matter of fact, your response here as many of your others seems more in the down-to-earth, experience based approach to problem solving. I know I will never again hear music the same as when I was younger and I finally realize that, save for one component, chasing this issue through equipment changes may be fun but not likely to result in significant improvement.

The component that I refer to is the equalizer. To many self considered audiophiles the use of one falls into the category of heresy and is an affront to their sensibilities. As I've said before, though, if one has an unrestricted budget, a purpose built listening room with all well selected components and has perfect hearing, they will still likely be looking for improvements through addition of or changes to equipment; as an example, upgrading equipment is one of the most popular subjects on these forums.

Now that I'm using the equalizer (Behringer DEQ2496), between automatic room balancing and frequency adjustment to compensate for age related hearing loss, I'm able to get back much of what I've lost. If I had discovered the EQ approach years ago I could have saved significant time and money in this quest. I tried, as I said previously, to use the EQ as a sort of loudness control for low volume listening but it hasn't really worked that well so far. That being the case, I still want to try the autoformer approach and will as soon as my checkbook recovers from purchase the new speakers.

"04-02-15: Mapman
Not be heretic about it but our ears do not have flat frequency response to start with, hear differently at different volumes, and become less sensitive over time as noted. So digital signal processing or equalization may be all the doctor ordered to provide any needed corrections."

It may be a reasonable fix in some systems, but not all. Not taking account that its another component in the chain, an EQ alters phase on whatever frequencies you are adjusting. In my main system, for example, I was careful to select components that keep the signal unaltered, with regards to phase, from my source to my speakers. Using an EQ would undo all that.

Thanks, Zd. I'm not advocating use of an EQ as a solution for all problems and I do understand, or at least am aware of, phase issues associated with additional artifacts being introduced into the sound stream. However, if I had the know how and did what you described in the first place, I would still be faced with the issues of my hearing loss, the extent of which is not bilaterally equal. To further complicate the scenario, my listening room, unfortunately, is my living room and using the auto room equalization capability of the 2496 has resulted in a noticeable improvement that I've been unable to acheive by other means.

About 2 years ago I had a motorcycle accident which resulted in my having to use crutches for awhile. Using them wasn't as efficient as normal but it was a heck of a lot better than going w/o them. I look at the EQ a lot like that except that, unlike crutches, I'm walking better than before the injury.

I guess what I'm saying, then, is that for someone like me who has been in the hobby for over 50 years but have only recently delved into its more technical intricacies, the EQ provides adjustments that allow more direct, wide ranging and relatively simple control.

ZD, one of the many things that I've had difficulty understanding, and I know to be important, is the relationship of signal phase and sound quality, especially how it comes into play in designing a system. I've read several papers on the subject and one of the common points is that phase alterations are generally not considered good and that EQ's have a phase altering effect. I fully understand that to be the case but understand also that every artifact in the system that has to do with signal processing will also.

In two articles it was at least alluded to that CD players alter signal phase but that the shift is linear across the spectrum so that this phase change would be audibly unrecognized. Even this I don't understand; if the signal across the board is delayed by the same amount, wouldn't the phase change in the upper frequencies be more dramatic because of their waves being closer together?

I'm in this way over my head and probably off base in some of what I think I understand but I've not been able to get how one would go about putting components together to minimize the effects of phase alteration and how one component (in this case, the EQ) would have a greater negative effect than any other. Is it just because any "unnecessary" additions exacerbate the cascading effects of phase alteration w/o providing an off setting improvement?

BTW, and somewhat off subject, some time ago I started a thread regarding phase testing using pink noise and how I noticed some migration of the sound as I progressed through increasing frequencies. I performed the same test after I did the automatic room equalization and, although this resulted in auto adjustment in only the lower bass frequencies, this migration of sound in the upper frequencies seems to have been reduced.

Phase is tricky! We can't hear phase on simple tones like a sine wave, but we can hear it in a spectrum of frequencies. Our ears use phase to construct the sound stage. If phase is altered, it can also be interpreted as tonality.

I had this demonstrated in spades years ago when I was trying to find why a phono section was sounding bright. It turned out that the manufacturer had abandoned the RIAA curve at frequencies above 50KHZ- well above human hearing- but the phase shift that resulted sounded like brightness. The fix was to restore the RIAA curve even though the preamp hardly had much bandwidth above that!

An EQ unit between me an the source would be one of the things I would look at eliminating if low level detail in the system seemed to be lacking. There are often other ways of dealing with hearing loss.

Tricky is an understatement from my standpoint. Phase relationships are so important to realistic sound reproduction one hand and potentially destructive on the other that understanding it sufficient to work with it in my system is making my brain tired. It's one of those things that, at this point in my development, I'll just have to count on the experts for guidance.

As far as dealing with individual hearing issues goes, I can only think of two things beyond the EQ that can work. Nearfield listening is one which I have in my garage setup (repurposed B&K AVR 307, iTunes lossless files and Celestion A speakers) which is not too special but sounds very good. The other is the use of hearing aids which I don't tolerate well because of ear canal problems. I've gone through 2 attempts using quite advanced aids and choose not to continue using them except as a last resort when or if the time comes for that.

All sources in my system (CD player, Apple TV, Sony Jukebox and DAC are routed through the preamp) and each, when in use, will contribute to phase alteration to some extent. BTW, how do autoformers fit into the scenario. As far as eliminating the EQ goes, I feel it has been too important an addition to consider removing it at this point.

Adding a super tweeter would be another method.

Low level resolution starts with source. What is your system reference for source?

Trying a "super tweeter" sounds worth considering but, as with everything else, there are a couple of things I need to better understand. First, I'm not sure what the term "super" denotes unless it simply describes a driver capable of reproducing frequencies beyond that of "normal" tweeters. Anyway, because the piezo is, in effect, a capacitor that would be connected across the speaker posts, I assume, would it not also try to act as a HF filter to the signal delivered to the panel? I'll study this approach a little more and keep it on my list.

Coincidentally, I initiated a thread a while back regarding the use of a piezoelectric transducer with a full range driver to avoid having to incorporate a crossover. I got some grief over that post but it was something I tried in the late fifties with a "sweet sixteen" speaker that I had built and it worked well for me. I mention this only because at least two of the listed so called super tweeters are piezoelectric.

Davide, if I understand your comments, I guess all issues in the chain potentially have their beginnings at the source. In my case I was able to acheive some relief in low volume resolution using a lower powered amplifier. As far as which component should be under looked at first for this issue, my first consideration would be the speaker. I say this because, although they were one of my favorite speakers in the past (still are) I've owned two pairs of Magnepans and found them not at all good resolving at lower volumes.

Broadstone- I realized how seemingly inefficient my beloved electrostats were, and how high the threshold was for system noise, only after I switched to horns. I started back in the early 70's with a pair of old Quads (a/k/a '57's) and used them standing alone, then with various subwoofers and super tweets, including Deccas and Sequerra ribbons, before switching to a Crosby-modded '63 back in 1990. They served me very well until the mid-2000's. (I still have both pairs of Quads, and the Deccas, sorely in need of resto). When I switched to horns, my system was noisy as hell! All kinds of squirrely stuff, from noise on the line, to tube rush, to low level grounding anomalies. This isn't to dump on electrostats- to the contrary, still think the original Quad is the best mid-range reproducer in the biz, but what it taught me was that all the low level nuance (like the noise) was probably below the threshold of hearing on these things (and my ears were much younger then). Not suggesting you run out and buy horns, but I offer this only as another way to look at the same experience.
There is also something else- it seems that for every system, and every record, there is a 'right' volume that sounds natural. I rarely listen at really loud levels, but to realize what's on the record, I find that there is a spot that is just naturally right for that recording, and it varies.

"04-03-15: Broadstone
Thanks, Zd. I'm not advocating use of an EQ as a solution for all problems and I do understand, or at least am aware of, phase issues associated with additional artifacts being introduced into the sound stream. However, if I had the know how and did what you described in the first place, I would still be faced with the issues of my hearing loss, the extent of which is not bilaterally equal. To further complicate the scenario, my listening room, unfortunately, is my living room and using the auto room equalization capability of the 2496 has resulted in a noticeable improvement that I've been unable to acheive by other means."

Sorry if there was any confusion. My response was to Mapman's comment. I know your situation is unique and you have reasons for using an EQ that are outside the norm. If you didn't have your hearing issue, then my post would be more relevant to you. But I was in no way suggesting that you should stop using your EQ. If you'll remember, I was one of the people that pushed you to try it. I have the same EQ myself that I use to try and fix bad recordings.

"BTW, and somewhat off subject, some time ago I started a thread regarding phase testing using pink noise and how I noticed some migration of the sound as I progressed through increasing frequencies. I performed the same test after I did the automatic room equalization and, although this resulted in auto adjustment in only the lower bass frequencies, this migration of sound in the upper frequencies seems to have been reduced.
Broadstone (Threads | Answers | This Thread)"

That's a good observation. I don't know if FIM distortion would be the proper technical term, but that's kind of what's happening. By having the lower frequencies not proportioned correctly, they were having an effect on other frequencies.

Something similar, that you can try with your EQ, is to do the same thing with sounds that are bothering you, and the EQ is not helping. Sometimes, if you try to lower specific frequencies with an EQ in an attempt to fix an annoyance, you'll find that sometimes the problem gets worse. What happens is that along with lowering the problem sounds, other elements that are in the same frequency range, that are not giving problems, get lowered as well. This may actually have an enhancing, or spotlight effect on the problem, because you're cleaning up everything around it. On occasion, if you're lucky, you can actually raise the EQ frequencies that you are working with, and the other sounds in the same range, over power the problem. I know that sounds counter intuitive, but it does sometimes work.

ZD, thanks for the clarification and I DO remember your advice/suggestions regarding the use of an equalizer as a potential solution so your response was a little confusing. On the same subject, I don't remember if I thanked you for that but I'm doing it now; addition of the equalizer has been one of the best single things I've done. I don't always have it on but when it's needed, I don't see another way that I could've had the same success addressing my personal issues.

I'll do as you suggest here and try some of these adjustments, as counter intuitive as they may seem

Whart, I've used Martin Logan electrostats for about 35 years now (SL3, Prodigy, CLS2, Odyssey, Ethos and a center channel which I don't remember the model of) with all kinds of decent ancillary gear so am no stranger to their unique demands. In so many ways I like, or have at least become habituated to, their sound so I'm not likely to give them up. I agree with several of your comments but, even though I recognize the possibility, I'm not convinced that their efficiency is the problem.

Hi Broadstone, There's a thread on the Marin Logan Owners website that has the title," i tried 34 amps in 12 months with the Montis, My review is here."

In this thread the OP makes the following statement:

"This brings me to the mark levinsons h series (532h and 533h to be specific). They are THE ONLY amplifier that i can listen to at low volumes and HEAR everything and each detail. It doesn't lose a thing even at low volume. I have never experienced this before."

You might want to check out the thread. The guy is still trying different amps so you might want to talk to him.