Mapman, acoustic bass has very good bass definition, being long scale instrument, in comparison to bass guitar (unless slapped). If feel sorry for the guy who had to carry this instrument if my system cannot do it justice. |
KIjanki,
I really appreciate the highly damped/articulate/powerful bass with well recorded electronic instrumentation/recordings in particular, though I would agree with the benefits for acoustic bass as well. I cannot listen to many such recordings any other way in that they seem to totally fall apart into a muddy mess if the bass drivers are not optimally controlled. |
Mapman, yes they are related since negative feedback lowers output impedance but class D has pretty low output impedance to start with since speaker is always connected to low impedance source (GND or V+) with Mosfets and only direction changes. What benefits our speakers might be not the best with other already over-damped speakers. With class D they often complain about loosing bass. It is also matter of personal taste. I like well defined bass, meaning short when it supposed to be short and long if it is recorded that way, but many people like round, loud bass all the time. One cannot argue with taste. I also noticed improvement in quality of the bass with more natural attack and decay - very pleasant with well recorded acoustic bass. It is possible that my amp and speakers just like each other. Negative feedback improves everything but increases Transient Intermodulation responsible for odd order harmonics and bright sound (overshoot in time domain). Here is example showing how feedback improves DF that I posted a while ago:
Lets take amplifier that has gain of 30 (31.6dB). When input voltage is 1V output voltage is 30V. Output voltage drops (for whatever reason) 1V under 1A load to 29V. That's 1ohm output impedance (DF=8).
Now, let's build this amp with gain of 300 but feed 3% of the output voltage back to the input in opposite phase. As a result amplifiers output is the same 30V as before but input is the difference between 1V and 3% of 30V = 0.1V Lets verify (1V-0.03*30V)*300=30V
Lets load this amplifier with 1A. Our voltage drop inside is still 1V under 1A load, but output voltage will be higher than 29V because we subtract less from the input. Output voltage will be 29.9V and output impedance will be 0.1V/1A=0.1ohm (DF=80). Lets verify. (1V-0.03*29.9V)*300-1Vdrop=29.9V.
Output impedance dropped 10 times. Expression 1+B*Aol is known as Improvement Factor. In our case B (Feedback Factor) = 0.03 (3%), Aol (Open Loop Gain) = 300 thus Improvement Factor = 1+0.03*300=10. |
KIjanki, what about the question of unusually high damping factor as an insurance policy?
Benefits might be nill or little, but can there be any harm in general in very high DF in interest of assuring control of drivers?
I believe damping factor of amps and application of negative feedback are typically related, but that is a very different and quite complex topic as well. |
Mapman, that would be the best, since speaker designer knows more about DF effects than anybody else. |
"Unless woofer has separate amplifier it most likely has inductor in series to attenuate high frequencies. You might find out what is resistance of this inductor to have general idea"
Hmm, thanks KIjanki.
I hate to bug him because I know he is a busy guy, but maybe I will send this question to John Strohbeen at OHM and see what he says. I would be interested to know.
I think the wide range OHM CLS Walsh driver may run full range unattenuated but I do not know for sure. The crossover to the tweet (soft dome I believe) is quite high at 7K or so as I recall.
Or maybe John will see this and post to this thread. He does make himself known here on Agon on occasion though he is generally quite mum about how he accomplishes what he does in his speakers. |
Mapman, I'm also a happy owner of Icepowered amp (Rowland 102). I think that bass control is phenomenal but at the end it might be only difference with effective DF=100 to DF=50 (with DF=100 amp) and that is change of 100%.
Unless woofer has separate amplifier it most likely has inductor in series to attenuate high frequencies. You might find out what is resistance of this inductor to have general idea. In any case, if you have this inductor it will limit your DF more than amp. I wouldn't go lower than DF=200 amp, since my speakers, similar to yours, seem to benefit from tighter control. New Rowland 625, that looks very promising, has DF=200.
Damping factor in your Icepower amp drops with frequency getting to about DF=10 at 10kHz. It is the nature of the beast (class D amp) but it might be not important since tweeter's impedance increases with frequency. |
"take into consideration that DF is already limited to about 100 by XO inductor (approx. 0.08ohm) in series with the woofer."
Dunno how this works with the large OHM 5 Walsh/wave bending wide range driver so cannot say. If you do please explain. I would be most interested to learn!
I would agree that most likley little if any practical difference likely between damping of 850 and 1000 and perhaps even quite a bit lower, maybe down to 50 in many cases from what I read.
I sought relatively high damping factor for the OHM 5s as an insurance policy more than anything else given what I know about them. The BCs met my DF criteria (50-100 or above) but I chose them mainly for the size/weight/sound/cost value proposition for use with a tube pre-amp specifically. I viewed the very high damping as a good opportunity to test out damping specs well beyond what otherwise might be considered acceptable on paper. After all, the proof in the end is always in the actual listening! What's on paper can only serve to help steer you in the right direction.
The sound I hear is very much in line with what I would expect in a properly damped scenario. THe bass is near perfect almost I would venture to say. Powerful, balanced, extended and most articulate, to an extent way beyond prior amps I have used. I'd describe the sound as relatively lean yet powerful and articulate..which is a good thing to me. Like a well conditioned heavyweight MMA fighter! Those used to or who prefer a fatter and perhaps more typical bass sound might be taken aback, especially at first.
But I can clearly hear differences among recordings and tweaks in ICs, sources, etc to the greatest extent I have ever been able to. I would hate to lose the BCs and have to attempt to reproduce this again. They are just a perfect fit for my application with the big OHM 5s but of course as always, others mileage will vary.
In fact, I could easily go in another direction for any of my other smaller speakers, including my smaller OHM Walshes. THe BCs work well for all these, but they are less of a challenge in general to push to the max. |
Mapman, take into consideration that DF is already limited to about 100 by XO inductor (approx. 0.08ohm) in series with the woofer. You don't want to limit it any further but it might be hard to hear difference between DF=90.1 (with DF=1000 amp) and DF=83 (with DF=500 amp). It might be different with your speaker but it is worth checking IMHO. |
Dhartwick, Good instincts, if you feel your room is off more than likely you're right. Having the same speakers as you I can tell you they have the potential to be FANTASTIC. OTOH because of their revealing nature, they can shine a spotlight on any shortcomings anywhere in the chain and sound mediocre. I have had to adjust speaker placement and further dampen the room with each upgrade. No doubt your room is important. |
Just FYI, the Nemo has a damping factor of 850. Not as much as the Bel Cantos but it is pretty high vs most amps.
I got a good deal on the Nemos used so it was a no brainer.
And I get to put my REF1000Ms now for a full 11 channel power amplification for my home theatre ;)
As for preamp, my friend moved from the 2 box McIntosh 500? preamp to the ARC 40th Anniversary. We all thought it was quite a good upgrade over the original and very close to the CJ GAT |
Hi Doggiehowser,
Based on our correspondence and other opinions out there and my own experiences, I'm leaning towards the McIntosh MEN220 Room Perfect solution. My goal is to get the speed and lack of coloration one hears from live unamplified music. I've heard super systems that come so much closer to this ideal, that they make my current system sound positively entry level--same for 99% of the other high-end rigs I've ever heard. I love my C2300 pre--it's put many others to shame, I love my SME10/IV.Vi/Dynavector XV1s, the 800Ds are the best overall speakers that I've heard short of a couple of megabuck rigs. The amp could be standing in my way, but given your experience I think I better go after the room acoustics first. My in-room frequency response isn't flat, and sound is not in phase in the sweet spot. I'm thinking I better get that sorted out and see where things stand. It's a cheaper experiment than amps or speakers, by a lot. (And, I've heard the 22k Lyngdorf system--Room Perfect is it's claim to fame--and it's got a good deal of the sound quality I'm after.)
Your help has also reinforced my suspicion that adding two Bel Canto Ref1000mIIs would result in increased bass heft--and better clarity at high volumes, I'm sure. Not areas I feel are so wanting, but I'm curious. I am an audiophile, after all. ;) |
Doggie,
THe BC ref1000m has very high damping factor, 1000, perhaps the highest of any amp I know of. That was a selling point for me in my application with my large OHM 5 speakers that are known to benefit from high damping.
Do you know damping factor of the NEmos? I am guessing it is significantly lower.
That would account for the perceived leanness in the bass with the BCs. It is a godsend with the right speakers that benefit from high damping, like the larger OHMs I use, but may result in perceived leanness with some others that do not require high damping. I suspect the Thiels might fall into the latter category but not sure, the B&Ws less so.
WHen I first heard my BC ref1000ms on my Dynaudio monitors, my first reaction was what happened to the bass? What happened is it was more highly damped yet correspondingly more articulate than ever before.
ANd yes, I agree that use of a tube pre-amp works very well to help balance things out.
I use the ref1000ms with both large OHMs and small Dynaudio and Triangle monitors. The Dynaudios draw me in every time, though some might still consider the bass to be towards the lean side. Even more so with the Triangles. With the large OHM 5s, pretty much close to perfection I would say.
SO bottom line system synergy top to bottom is important and damping factor of amps should be a major consideration.
Also consider that the EC Nemos list for almost $30K a pair from what I read. THe BCs go for $6K. That's a big difference in cost. One would expect the Nemos to hold an edge, however slight that might be. If a tube pre is all that is needed to bring the two closer in performance, that is still quite a trick for the BCs. Not to mention the huge differences in size, weight, and power consumption. Those are really the things that would lead one to go Class D over a high performence monster amp. I know it was in my case. It's truly a David versus Goliath type scenario! Pretty amazing! |
Mcintosh 1201 monoblocks, BAT VK-600se. The two SS amps I have heard with the B&Ws that I liked best(Mac 2301s for tubes) |
Hi Dhartwick
I think prior to tweaks, there was a fair bit of difference between the Nemos and the Bel Canto REF1000Ms in the showroom. In my case, the BC and Nemos were carried by the same dealer who also carried my speakers (Thiel CS3.7s) so it was very easy to make a direct comparison. In the showroom, the Bel Cantos sounded very lean vs the Nemos. The bass control was similar but just felt more weighted in the Nemos.
In the time I had the Bel Cantos, I made a couple of significant changes:
a. Sound Application RLS240 conditioner
b. ASI Liveline power cords
c. ARC Ref 5SE
With these in place, I felt there was a significant improvement in the overall performance of the system.
When I swapped the Bel Cantos out for the Nemos, the major change I felt was in the bass. It was still as tight as with the Bel Cantos but there was more authority and more presence to it which I liked, similar to what I heard in the showroom. But the leanness I heard in the showroom was alleviated by the ARC tubes.
As for the Plinius SA-Reference, my friend feels it edged out the Nemos. It's rated lower in terms of power output (that's what I meant earlier) but in terms of performance, my friend preferred it a lot more than the Bel Cantos and based on the experience of the same dealer showroom, he thought it sounded just a bit better than the Nemos. |
Doggiehowser - Thanks for that answer. If I understand correctly, you're talking about a small difference between the Bel Canto Ref1000mII and the Nemo. Since you said the SA-Reference was a slight improvement in every regard except the bass, as compared with the Nemo, I'll conclude that the Bel Canto and the SA-Reference are also close. Does my conclusion jive with your experience? I realize that the magnitude of the difference you heard may become greater were you to compare amps in a more revealing system--if such a thing exists. |
One of the larger Blue Circle amps might be an interesting option to consider. |
@05-07-12: Dhartwick
How do you describe the improvement that the Electrocompaniet gave you over the Bel Canto Ref1000MkII. And, what magnitude of improvement?
Doggiehowser - is that the Bel Canto 1000MII that you replaced or the Bel Canto amp before it?
===========
I used the Bel Canto REF1000s first, and this was upgraded to MkII aka REF1000M specs subsequently.
I recently swapped out the REF1000Ms for Electrocompaniet Nemos while my SA-Reference was sent to my friend's place while I wait for my second set of speakers. He was also using REF1000Ms and the same speakers as mine (Thiel CS3.7s)
The REF1000Ms have tight control of the bass but was a bit lean in the midrange, but I did alleviate that with an ARC Reference 5 (then 5SE) tube preamp.
The Nemos maintain that same control of the bass, but there's just a bit more heft and authority to the bass and the midrange is a bit sweeter than on the Bel Cantos. |
I may have user bias as I'm on my 3rd set of Mcintosh amps and preamps, Mc300 Mc500 1.2kw. I keep hearing of the lack of speed with Mc, maybe its true, as I've not compared in house with anything but. I will say the 1.2s are way more transparent, quiet, liquid, controlling, dynamic, immediate, fast, etc. than my previous Mc amps. At a recent visit to my dealer he had the new Diamond 800s with Classe 600 monos and needless to say it sounded very good but did not have the "mojo" of my 800ds with the 1.2s. To be fair my amps are next to the speakers and his were 10+ feet away and rack mounted and my cabling is better than he was using. Although it sounded great, it was'nt even close, but for almost twice the price and twice the power it should be. |
Gshepardbuster, whichever Krells were about 18k a pair in '07 would most probably be a step forward, though I don't know how big a step. I listened to them extensively in what were then very familiar circumstances (i.e. I sold them and I sold McIntosh, among other stuff). The McIntosh amps I had to compare the Krell with were about 1/2 the price (500w monos I think) and were not as transparent or fast. The Bel Canto Evo 200.2 which I compared with the Mac and the Krell came out in the middle, closer to the Mac. Of course, the big Mac amps you speak about are another matter. I've not heard them. I love the company, love the resale value, and love to support a domestic manufacturer, so it would be great if Mac is what I wind up with. Sound quality is still, however, my ultimate criteria. I've just never heard a Mac amp that's as fast as music really sounds. I'm totally open to the possibility, however. |
Doggiehowser - is that the Bel Canto 1000MII that you replaced or the Bel Canto amp before it? |
My 800ds are in love with their 1.2kw Mc monos. If I was to ever split them up I fear the ones left would run away from home to search for the other. All B.S. aside the amps tell the speakers when to jump and how high without appearing to be trying hard and act the same at low levels. Of course this is with dedicated 20amp lines and good PCs. With these or maybe big Krells I have no doubt you will find that immediacy and presence that you seek. |
If Nola and Nearfield speakers deliver the sound you like, consider those
maybe? The bc should be a good matcn there as well. B&W is a much
different design that may never sound like those. |
How do you describe the improvement that the Electrocompaniet gave you over the Bel Canto Ref1000MkII. And, what magnitude of improvement? |
Dhartwick -
Pardon, of course you need your preamp to your turntable setup :/
Still, I'd recommend you try out a combined DAC/preamp in bypassing your separate hardware preamp, and hear what comes of it. I think you'll be pleasantly surprised. |
Dhartwick -
Whether exchanging your Bel Canto poweramps will get you to your desired goals - i.e., more "speed and overall realism" - is debatable. Then again, maybe a pair of NuForce Ref. 18(soon to be 20) mono's could very well do better here. NuForce's Ref. amps in general are known for their great abilities (among other virtues) into speed and timing, which I can attest to owning one of their poweramps myself.
Moreover, I'd go the "less is more" route and get rid of your preamp, and invest in a new and combined DAC/preamp - maybe even the Bel Canto DAC3.5, which I've heard houses a splendid build-in digital volume control. I'm sure there are other very worthwhile DAC/preamps alternatives as well - that would also better your Bryston as a stand-alone DAC - as long as it gets the separate hardware preamp out of the way. To my ears separate preamps in general robs the sound of see-through(transparence), texture, and dynamics - where a good "substitute" DAC/preamp solution is found instead.
Why power filtration? Maybe I should ask which kind of power filtration you use? In general I find power filtration to flatten out the sound and rob dynamics, just my oppinion. A good star-grounding and dedicated outlets/power group should bring you a long way.
Cables: I'd avoid heavily shielded cables - be they IC's, speaker- or powercables. Heavily sheilded cables in my ears dulls the sound as if putting up a filter between me and the music. Also, I have an affinity for solid-core wires and finds it actually makes sense to speak of this aspect in a general fashion, in whichever combination they're used; an overall cleaner, tighter, and more physical sound.
Sorry if I'm coming off sounding "this way and none other" - that's not my intention. |
I have heard the Nemo amps running large B&Ws (not sure exact model). No doubt that is a very good pairing that would be hard to beat if the B&W sound is what floats your boat.
Larger Mac SS amps seem to be another popular pairing that might work well given the Mac pre-amp already in place. |
"I'm assuming these speakers can be taken to a whole different level--big assumption as I've not heard them better, but I've heard only my own pair."
What's the basis for that assumption?
There may be many reasons why your rig does not sound as good as others that are totally different. A lateral move cost wise to a different sounding system might prove to be as effective as a perceived upgrade.
ALways start with nailing the speakers first. Are they a good fit into your room? How are they similar or different from others you have heard that seem better? Are there better options out there for your application? How much of an investment is really needed?
Also just a caution that large B&Ws are not known to be tube friendly. If more tubelike sound is what you seek, then you might want to consider determining a budget and coming up with a good tube amp/speaker combo. Unless your room is very large, it might not end up costing as much as you expect. |
You have a lot to change, the Bryston DAC is a good dac but not in the league of setting up a super system.
Moving to a better amplifier will help, it comes down to price vs performance. The NEMO's are incredible amplifiers for the big B&W they were designed to power them.
Also Chord's amplifiers are also amazing with the B&W.
I would also look at power conditioning, are you using any? Power Cables? Vibration Isolation, room tuning?
All of these items play a crucial role of making a system come alive.
|
How much do you want to spend you seem happy with the sound of the KR amp. I am sure a used one will be much less. A big Austrian tube amp like an Ayon. |
Electrocompaniet Nemo?
Designed for the original B&W Nautilus in mind.
That's what replaced my Bel Canto REF1000Ms driving my Thiel CS3.7s
I also have a Plinius SA-Reference. It's not as powerful but it is a full Class A design but seems to have a slight edge over the Nemos in all but absolute heft. |
