Twilight Saga: Nagra VPA and Magnepan
.jpg "Nagra VPA monoblock amp")
For years, I’ve bought into the conventional wisdom about Magnepans: mating low powered tubes and planars is like trying to unite oil and water. But thanks to Nagra and Verity Audio’s distributor John Quick I had the chance to demo a pair of Nagra VPA amplifiers based on the legendary 845 tube, a worthy, perhaps the only true, rival of the 300B. Quick had sent me the Nagra VPA to use on Verity’s flagship Lohengrin loudspeaker, which I discuss at length in an upcoming issue of the Absolute Sound. On the Lohengrin, the VPA had the effect of making the loudspeaker disappear into the ether—in the best sense of the word. Instruments simply hovered in space, whizzed in and out, leaving me transfixed with admiration. But I suppose that’s not entirely unexpected given that the Verity runs at a commendably efficient 95dB.
The Magnepan 20.1 does not. Just look at the size of it in the accompanying pictures. It’s a behemoth. Plus those Gothams down low. So with high power, you can really peel it out with the Magnepans. But it’s hardly the only way to run the 20.1. As I quickly discovered, the Magnepans simply sound glorious when run with the diminutive, 50-watt Nagra. The tonal colors, low level noise floor, resolution of fine level detail, and purity of sound are stunning. Let me be clear: I did not use the VPA to run the bass panel of the Magnepan, a task that it could hardly perform. Instead, I used it to drive the midrange and tweeter in a biamped configuration using a four-chassis, custom tubed crossover designed by Tom Tutay of Transition Audio in Fort Walton Beach, Florida. This relieved the Nagra of having to reproduce any frequencies below 300Hz. The Magnepan also offers an essentially benign 4 ohm resistive load, but its efficiency is estimated at a lowly 86dB.
No, I’m not able to play the Nagra at ear-splitting levels on the Magnepan (I can already hear my colleague Jonathan Valin, who has a commendable distaste excessive sound pressure levels, crying out “Why would you want to!”). Well, I have to admit sometimes I like to crank it up. But overall, the sense of information conveyed by the Nagra means that you don’t really have much of a temptation to turn up the levels. On the contrary, it’s fascinating to hear how much detail appears when you listen softly. The VPA has that crepuscular feel, where reproduced music shades into the most delicate, blissful sound possible—a kind of twilight saga, if you will. As for potent dynamics: the blunt fact is that even when turned up, most music—at least the stuff I listen to—doesn’t seem to demand more than, at most, 30 watts, according to the snazzy needle on the VPA’s faceplate.
Suffice it to say that I’m beguiled, smitten by the Nagra VPA. It’s been around for a decade or so, and was radically upgraded years ago, but to my ears it sounds darned good, even if it’s not the newest kid on the block. And it’s forcing me to take another look at the issue of amplifier power and sonic prowess as well as reexamine some preconceptions about Magnepan loudspeakers. What more can you say than that?
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Comments
Do the VPA meters measure true peaks? Because with acoustical music typically having a peak-average ratio of 10-20 dB, an averaging or quasi-peak meter isn't going to tell you what the amplifier is doing on the transients.
In any case, the difference between a 50 and 500 watt amplifier is only only 10 dB, which corresponds to a subjective doubling of loudness. Depending on listening position and room gain, 50 watts should yield about 100 dB SPL at the listening seat; a bit more because the amp doesn't have to drive off the bass. I don't know that it will do the very largest works at Row A levels without clipping -- 110-115 dB is probably the minimum necessary for that, and in some peformances/halls/seats measured peak levels are substantially higher -- but for most material or for large works at moderate listening levels, it should be enough.
I have listened to the Nagra's play very nice music on my friend's Sonus Faber Strads.
I would think it would sound great with just about any non demanding load,never would have considered it for Maggies,thank you for the enlightenment.
Well, you didn't exactly bypass the "conventional wisdom about Magnepans: mating low powered tubes and planars is like trying to unite oil and water." since more of the current draw generally comes from the bass panels. In the past a lot of Maggie users including I had biamped with tubes to arrive at precisely what you report. I used to use ARC tubes with Class A solid state amps driving the bass panels with some success. However there was always a slight discontinuity I couldn't get past. (Listening to the new 1.7s, it is possible that the discontinuity had more to do with the panels themselves than the amps, and the amps just exacerbated the problem.) Now If the Nagra could drive the bass panels that would something special. What did you use for the bass?? Anyhow it appears that the Maggie mid/high panels and the VPAs are a match made in heaven.
Rana N. Kabir
CEO, ENDS Technologies
I very much doubt whether the Nagra could drive the bass panel. I've used Classe on the bass panel. The problem of continuity always rears its head when using different amps to biamp.
Are audiophiles really masochists or just conditioned to be submissive idiots by the uber reviewers of the past? Looking at the scene pictured here I can't help but shake my head and laugh.
Not unlike the Frankenstein Monster assembled from a bunch of mismatched parts that could never, walk, talk or behave like the real thing similarly the Heilbrunn Monster above will never be right! I'm wondering what, besides complete ignorance and/or inexperience, would get one into a system such as this? If you knew what you were doing, COMMONSENSE would have led you to a pair of high quality full range speakers that could be easily driven by all kinds of amplifiers, specially if you're going to review this type of electronics. You're entitled to embarrass yourself by using this concocted monstrosity for reviewing whatever you want for yourself but please don't insult my intelligence pretending that you're qualified to dish out any kind of advice or opinion to others. Having read your articles in Huffington Post I can see that your lack of commonsense isn't limited to audio!
Could you tell us what you really think?
No problem, just let me know which part of my post needs further clarification and I'll be happy to oblige.
That would be all of it, inasmuch as your post seems nothing more than a series of ad hominem attacks. You present no evidence and you present no arguments: you merely insult the critic and his choices. Perhaps, if I may hazard an ad hominem of my own, you should consider a career as a talk radio host, a spin doctor, or a trial lawyer.
"your post seems nothing more than a series of ad hominem attacks"
You're right in as much as my post is about the author's qualifications to dish out opinions and advice, but its not ad hominem.
"You present no evidence and you present no arguments"
The evidence is presented by him in the blog and in his images if you care to look, and if that incoherent, finicky, pieced together monstrosity used as a tool for reviewing and valuation isn't an argument by itself, then I don't know what is.
"...you merely insult the critic and his choices"
I'm not insulting just stating the obvious based on his choices!
"I may hazard an ad hominem of my own, you should consider a career as a talk radio host, a spin doctor, or a trial lawyer."
I can only point to the obvious, I can't help it if you don't care to see that there's something inherently wrong advising people on the finer qualities of expensive equipment when all you can hear at best is a Mixture of incoherent sounds coming out of a dipole panel which is only partially driven by that 20k amplifier. As they say, you can bring a horse to the water, but... I'm sure you know how the rest goes.
I don't know whether that "monstrosity" is incoherent or not, having never heard it. I've never liked the cone/planar hybrids that I've heard, because I can always hear the discontinuity. But since the 20.1's are good down to 25 Hz or so, it seems to me possible that you can meld them with careful crossover setup and get lower extension and higher output by taking the bottom octave load off the planar woofer. So I'd characterize my attitude as one of curiosity.
I can't really comment on his choice of amplifiers, either. Again, I've never heard the combination. But it seems to me plausible that it's as sweet as he reports at moderate listening levels. At more realistic levels, I'd expect it to clip with anything less than several hundred watts going to the midrange. I remember the day when it was common to pair a pair of Tympanis -- the whole thing, including the woofer -- and it worked quite well, albeit it's not the sort of thing I'd think of doing now that good high current amplifiers are commonplace. And I don't have any bias against mixing amps in a bi-amp situation, in fact, it can be a great thing to do, you can use a high powered, high damping factor heavy hitter on the bass, and something that images nicely on the mids, and something sweet on the highs. I know one guy who uses a 2500 Watt pro amp on the bass panels of his Tympani IVA's, you wouldn't want to put something like that on the mids and highs but they're fine on the bass and he's found that anything smaller clips at the realistic levels at which he likes to listen.
Anyway, you make a lot of assumptions about what the reader knows or believes. Maybe someone savvier than I, but aside from the 20.1's, I haven't heard this stuff. Hell, I don't even read the Huffington Post. From my perspective, evidence is more convincing than conclusions, whether discussing a setup or a critic -- even if the evidence is nothing more than "I've heard that particular combination, and it sucks." Not to mention that while food fights are admittedly fun, I find reason more convincing. Which is why I still read the paper, rather than listening to the ranters on TV . . .
"I don't know whether that "monstrosity" is incoherent or not, having never heard it."
With experience one would know instinctively about this kind of thing, but don't take my word for it, the author isn't hiding it and mentions it in one his posts.
I should clarify a couple of things before things get out of hand here.
First, I apologize to everyone for the food fights, that wasn't my intention and I realize that I opened the door with the tone of my post. I apologize to Mr. Heilbrunn for that too, but I still state my position that I do not find him a credible reviewer of high end audio equipment.
2nd, I never criticized any component in this system or what he likes to listen to for himself, what I criticized was his choice of this speaker project as a tool for analyzing and reviewing electronics, for me, it shows a lack of experience and common sense.
"Anyway, you make a lot of assumptions about what the reader knows or believes."
I'm curious about my assumptions. Just for now lets put aside how bad a tool dipoles with their inherent dependence on their surrounding make. The author freely admits that the amps can't drive the maggies, he also mentions the discontinuity and incoherence of the system in this setup. We also know that what he's reporting on is a melange of different amps mixed together with some project xover; is concluding that one can't get a realistic measure of the Nagras, or any other amplifier for that matter under these circumstance such a stretch?
Wised Up:
you may have a similar opinion of me, too - and perhaps a whole host of people in this industry. But I will tell you something you do not know because you haven't had the experience:
Jacob's system is one of the best systems I've heard in the world, bar none.
Your argument depends on some theoretical knowledge, but not upon actual experience.
If you're lucky enough to be given the chance to hear this system for yourself, you might likely be inspired to go back and delete all of your posts here ... I suspect you will have been summarily stifled by what you hear.
This is not a hobby nor an industry that you can reliably paint-by-the-numbers. You make assumptions about things that - frankly - just aren't so, at least in the implementation of this system.
Jacob has assembled a system that deserves serious attention, but the only way you could ever actually know that would be to hear it for yourself. Until that time, your opinion is rather meaningless because it is baseless and weightless. I don't mean that as an insult, but rather as a simple metric by which anyone should consider the qualifications of anyone else's opinions on matters like these.
The Signal Collection, LLC
North American Distributors
of Connoisseur-Grade Hi-Fi
"With experience one would know instinctively about this kind of thing, but don't take my word for it, the author isn't hiding it and mentions it in one his posts."
I try not to rely on instinct in this sort of discussion, because while it may be accurate 95% of the time, there's another 5% in which it won't be. So my hard and fast rule is that if I haven't heard it, I won't judge it. Of course, I catch myself ignoring my rule all the time, but that doesn't mean I should.
"Is concluding that one can't get a realistic measure of the Nagras, or any other amplifier for that matter under these circumstance such a stretch?"
I didn't see this as a formal review of the Nagra, rather than a blog report of an unusual mating. Had it been a formal review of the amplifier, I would agree that it was a poor choice of speakers, though as a general rule I'd say that dipoles are more sensitive to placement but less sensitive to room acoustics than monopoles. Ribbons also present a more linear load to the amplifier and of course they're usually less efficient, and react differently to amplifier damping, meaning that they're fairly unrepresentative.
I think Josh is right to suggest that perhaps actually listening to the system might indicate what it actually sounds like.
In any case, Wise Guy might display a little more wisdom if he didn't make certain assumptions. Using the Nagra amps was simply an experiment, one I didn't think would work successfully but was curious to try. The results were much better than I had expected. That's it. I'm not recommending that anyone reconstruct such a system. The Nagras were sent to me to try and I was surprised by their performance--a great amplifier.
Furthermore, I have had the Wilson Maxx 3 over the past year and now the Verity Lohengrin. So I'm familiar with the differences between dipoles and cone driver systems. All loudspeakers are affected by their environment.
> "...in his images if you care to look, and if that incoherent, finicky, pieced together monstrosity used as a tool for reviewing and valuation..."
WOW, you are some sort of an audio genius to be able to infer that much info about system performance by simply gazing at an image. I would like to immediately hire you for my Audio Consulting firm since you will be able to save us lots of money by improving customer setups by simply looking at snapshots!
> "With experience one would know instinctively about this kind of thing,..."
LOL. Never mind. It is apparent (should I say, instinctively I know) you have a lot to learn about Audio since that’s one principle you can’t apply to audio systems with certainty.
Rana N. Kabir
CEO, ENDS Technologies