Anyone compared Sanders Magtech vs. McIntosh MC462/52 or MC611/01 with Magnepan 3.7/20.7?


I know a lot has been written about all of these amps with the 3.7 and 20.7 series Mangepan's, but I was wondering if anyone has done a direct comparison and can describe the differences in what they heard?

Yes, I know, the best way is to demo them myself, and I will be this coming October... but until then, I would be interested in getting other's opinions to prepare myself for certain things to listen for, think about, etc.

Contrary to all of the popular opinions out there on the net that you needs gobs and gobs of watts to make the Magnepan's sound good, that is not my total experience. I have a new pair of 3.7i's (one month old) and am running them off of the 8 ohm tap of a McIntosh 6700 integrated 200 wpc amp. It actually sounds fantastic with plenty of warm bass, and depending on recording, can be chest pounding - from either vinyl or digital. My audiophile jazz recordings with piano, guitar, vocal, drums, and upright bass are the most accurate (compared to a live jazz club) I've heard.

The issue is, I have to turn it up to a volume that would be similar to what you would hear live - which is fine when in the mood, but at times I would like to listen at a lesser volume. There seems to be a certain volume threshold that when crossed over, the speakers open up and do their magic / crossed under, they all of a sudden lose their good charms - dynamics and bass all but disappear. 

So, from what I've read, what I'm experiencing is from lack of proper wattage from the power amp, thus I'm on the upgrade path - I'm sure any of the above amps (in the title) would be an improvement as the least of them is more than doubling my current wattage - but I'm curious if anyone has compared any of these amps paired with the Magnepan's. If so, do they improve dynamics and bass? What did you like about one and not the other and vice versa, etc.? 

Thanks and looking forward to hearing your opinions --cheers!

Jimmy
7d04eaa2 2b5a 468a aea2 3e674548515ejimmy_jet
You are also describing loudness issues.


How about a pre or integrated with a loudness control, like a Luxman or Yammie?

The Luxman's loudness control is fixed, and subtle. The Yammie really pretty adjustable.


Best,
E

@jimmy_jet, your post brings up a few different matters:

1- The Fletcher Munson Curve Erik alluded to (Google it for info).

2- The power requirements of the MG3.7i. Highly dependent upon room size and acoustic properties (diffusion preferable to absorption, typical with planars), preferred SPL listening levels, etc. In case you don’t know, Roger Sanders created two different versions of his amplifier, one for magnetic-planars, the other for ESL’s.

3- The property of the Magneplanar loudspeakers with which you have recently become aware: the "Maggie mist". That phrase was coined in the 1970’s in the pages of The Absolute Sound, and refers to the tendencies of Magneplanars to sound veiled and lifeless until a "certain" SPL has been reached.

Some attribute the mist to the very low sensitivity of Maggies, but I myself am dubious. The Eminent Technology LFT-8b is of approximately the same sensitivity as the MG3.7i, yet does not exhibit veiling at low SPL. Others attribute it to the moving mass added to the Maggie m-p drivers by the conductive wires glued onto the Mylar (the ET LFT driver has it’s very low mass conductive traces vapor-deposited onto the Mylar), still others to their single-ended design (the 20.7i and 30.7 have push-pull m-p drivers, as does the ET LFT midrange driver. All three loudspeakers have true ribbon tweeters).

Whatever the cause, the Maggie mist is something you will need to learn to live with, as it is incurable (certainly not by an amplifier). All speakers have flaws, the trick is in finding one whose flaws you can live with. If you haven’t done so already, I suggest auditioning an ESL or two. They provide many of the virtues of Maggies, without some of it’s flaws. But then, they too have their imperfections. Pick yer poison!

Hello Jimmy,
     It seems like you're describing the well known acoustics principle of how loudness effects human perceptions of sound which was first scientifically studied and documented in the 1930's by Dr. Harvey Fletcher and Dr. Weldon Munson.  The resulting Fletcher-Munson Curves are a bunch of curves which show how sounds of different frequencies and at different sound pressure levels have to be boosted/subdued in order for the human ear to perceive an equal loudness level across all frequencies. Therefore they are also called Equal Loudness Contours.  Each individual varies somewhat on how they perceive loudness by frequency and these curves, contours and graphs are generally based on statistical averages.

    The Fletcher-Munson Curve is a graph that illustrates an interesting phenomenon of human hearing.  When listening to music through speakers or headphones, as the actual loudness changes, the perceived loudness our brains hear will change at a different rate, depending on the frequency.

     Here’s what this means:

  • At low listening volumes – mid range frequencies sound more prominent, while the low and high frequency ranges seem to fall into the background.
  • At high listening volumes – the lows and highs sound more prominent, while the mid range seems comparatively softer.

     I believe you're trying to compensate for this universal and natural deficiencies in our perceptions of sound by utilizing a different amplifier.
     Logically, I would normally conclude that this is not possible.  Due to my personal and subjective experience, however, I'm not ready to eliminate a change in amps as a possible solution.  I'll just detail my experiences and let you determine their value to your situation.
     About 10 yrs ago, I decided to audition a class D amp in my system for the first time, mainly out of curiosity due to very good performance results I'd been reading from users on this audio forum and others.  
     My system was of decent quality and consisted of a Sony DVP-S7700 dvd/cd player,  VTL 2.5L tube preamp, Aragon 4004 MKII class AB amp and Magnepan 2,7QR speakers.  I ordered a Class D Audio SDS-440-CS stereo amp on a four week free in-home trial offer.
     I noticed immediately that the class D amp was a significant improvement over my previous mostly class AB amps I had used in my system such as Adcom, McCormack and Aragon.  Mainly its very low noise floor, overall well detailed but neutral presentation and its much better bass response, the best bass I'd ever heard my Magnepans produce.  I easily noticed these qualities right out of the box with no break-in time.
     In an effort to accelerate the break-in period,  I left the amp on playing cds almost continually, often turning the volume to low levels as background music as I was on the computer, reading or just doing other things.  So, it took me a little longer to realize that this amp sounded exceptionally good at low volumes, without the bass and treble being recessed in relation to the midrange as I was accustomed to always perceiving on music played at low volumes through my previous class AB amps.  
     It was almost as if this amp had an automatic loudness control that boosted the bass and treble proportionally as the volume was decreased.  What was equally unusual is that as the volume was increased , I perceived the natural balance of bass, midrange and treble contained in the music increasing in volume in unison from a low volume all the way to an extremely high volume. 
     I was so impressed with this class D amp, that I gradually replaced all the class AB amps in my combo music and HT system with class D amps.  I bought an Emerald Physics EP-100.2SE stereo amp, run in bridged mono mode, now drives my center ch speaker, a pair of D-Sonic M3-600-M mono-blocks drive my main speakers and my original Class D Audio amp now drives my rear surround speakers.  
     They all have similar sound quality characteristics and I perceive the same 'automatic loudness control' quality built into all of them.  I should caution you, however, that it could be I'm the only individual that perceives this quality in class D amps since I haven't read of other class D amp users perceiving this quality.  
     But I I recall an interview with a well respected pioneer in the development and designing of class D amp power modules, Bruno Putzeys, in which he stated that class D amp designers are able to make their amps sound virtually any way they want.  Would they want to incorporate circuits in their amp designs to compensate for the well known Fletcher-Munson curves?
     I prefer the theory that they would and have but I have absolutely no proof of this besides my highly subjective perceptions.
     I would just suggest you may want to audition a good class D stereo amp, or good pair of class D mono-block amps, in your system to determine what you perceive before spending more on other options.


Best wishes,
     
 
    
  
  


  
    
 
 
     
 
   

   

     



Jimmy,

Why are you driving the 4 ohm 3.7i Speakers on the 8 ohm taps?
In short, more umph and bottom end. For some of my audiophile recordings (using two step process or master from master tape), I’ll switch back to the 4 ohm tap because it is recorded with enough bass and gives it more air and soundstage. Also, you have to remember that with Mac amps using the autoformers, they increase in wattage and current  when you move up to a higher ohm output tap because the 2 ohm tap is guaranteed at least 200 watts without overheating or stressing the amp, etc. I read somewhere that someone worked it out that it was around 360 watts on the 8 ohm tap for this amp which Mac conservatively rates at 200 wpc.
"Mac amps using the autoformers, they increase in wattage and current  when you move up to a higher ohm output tap..."

I'd like to know where you read that since McIntosh indicates the same watts (and voltage) from 8, 4, or 2 ohm taps. The main difference between the different taps is the output impedance (damping factor) which can and does affect sonics depending on the length of the speaker cables and the way the speakers' impedance behaves as a function of the frequency. 
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I disagree about 'the Maggie mist' being unsolvable. If you work on the AC side.. the clarity can be astounding at low levels.(too).


@elizabeth So could you expand a little on "work on the AC side"? Do you mean just using a power conditioner for your amp? If so, what kind? Any particular brands/models? --thanks
I'd like to know where you read that..
@kalali Many threads out there on the www regarding that, e.g., one of many:
https://www.audioaficionado.org/archive/index.php/t-36171.html

FWIW here's my (limited) experience with one of Roger Sanders' amplifiers - my personal Innersound Electrostatic amplifier. This iteration dates from around 2000 or so, around the same time Harry Pearson wrote his brief but glowing writeup when he gave it his mid-year Editor's Choice award.

I have no experience with the Macintosh equipment you are asking about. Actually, the truth is I do not audition equipment very much. About 30 years ago I upgraded from a Luxman receiver to some Naim equipment. At that time I auditioned a lot of different equipment and chose Naim for the relaxing way it made me feel.

Five years ago I began to move away from Naim, starting with my amps. 
I use this amp with Quad ESL63 speakers. It replaced Naim 135 monoblocks that I had owned (and enjoyed) for many years. In the spirit of full disclosure I must mention that I bought the amp used about 5 years ago, and last year I had to send it in to Coda Technologies for a service. It came back sounding better than ever.

IMHO Roger Sanders is a genius and his amplifiers are astonishingly good and are a superb value. I encourage you to read his white paper on "Tubes vs. Solid State". 

Roger himself states that the Magtech is a better amplifier than the old Electrostatic. If money were no object, I'd have his new amp in my system; I trust his judgement and am confident in the performance of his equipment. Regarding the sound of my amplifier, I will say that I thought it audibly superior to the Naim monoblocks. My term for the differences I perceive is "performance transparency". It simply allows me to hear what is going on in the recording. Compared to the Naim amps all aspects of the frequency range are clearer, more effortless, natural, coherent and beautiful sounding. 
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@markusthenaimnut Thanks for describing the sound profile of this amp - it seems to be the overwhelmingly most recommended amp for Maggies (outside of Magnepan Co. using two Pass Labs x250.8's in mono block mode at shows to demo the 3.7i's) --cheers!

@elizabeth Thanks for the info of how long these panels take to break in - I was told 200 hours... but I definitely won't be changing up any gear until at least six months from now. Even at six weeks old, I can see how much they've changed. --cheers!
SO PLEASED that you are a Maggie fan.  As I have posted many times on this forum, until I opened my shop in the early 1970's, I thought as a person who played in various bands--marching, rock, jazz, etc.  (NOT a real musician) that I knew everything there was to know about how music should sound.  HAH! 

After setting up 25 different brands of speakers in the showroom, I started listening to them one at a time after closing.  Everyone's fav back then, Advent (thank-you Henry Kloss), was pretty bad when compared to others, but still better than some.  Speaker after speaker tried and evaluated against my live bass, guitar, trumpet, and several woodwinds (not me, a buddy who played them), against every source in the shop (Nakamichi, Sequerra, Thornes, Transcriptor (remember that hot mess??), Linn-Sondek, etc., etc.  We used SME arms, Thornes arms, cartridges from Supex, Satin, Dennon, Decca, Audio Technica, the entire B&O line, the entire McIntosh line, Phase Linear, on and on and on.  As a "high-end" shop we were able to try pretty much everything on the market back then, including Audio Research and Magnepan.

It was only when we paired those items with a quality source that it all came together for me, and these were Tympani I through IV models mostly.  While setting these up in a customer's home was a real challenge for us in some rooms (this was when things like traps, room acoustic products, etc., were just coming out) but when they were right, nothing was even in the same universe, including the Levinson HQD system that we made stands for at some point.

This does not mean nothing else sounded wonderful. MANY speakers were just fine and some very good--Bose direct reflecting a major exception--and many sets of electronics were just fine.  BUT, like first time I put on a REAL suit, the differences were so obvious that there were no disagreements.

Obviously, life has changed a lot in the last 50 years, and MANY quality electronic and speaker products are available now that were never considered back then.  SO, buy what sounds best in YOUR ROOM and enjoy.  I think over time you will love your Maggies more than any other speaker you have owned.  I do suggest changing your amp.  Back then, Mc amps were built like tanks but sounded pretty bad.  I would assume all that has been corrected by now, but when you are ready, try out a bunch of new amps and see if you find one you like better.  You may, or you may not.  As long as YOU are pleased, your dealer will be too!

Cheers!
Jimmy

I’ve been scratching my head and just can’t get over the idea that the manuf. would put taps (4 & 2) on an amp where in reality you wouldn’t need them, in other words if the 8 ohm tap is not only sufficient but actually provides more current/power than the 4 ohm tap then why spend the money to put those in the amp?
And wouldn’t they state that somewhere in their literature? Something like :" hey you got 4 ohm speakers? No problem just use our 8ohm tap, it provides 80% more power than the 4 tap!"
This just doesn’t make sense...

in fact there is a chart in your amp’s manual which specifies different gauge and legnth requirements for speaker wires based on the speakers impedance, which I believe indicates manufacturers intentions plainly-> 4 ohm taps for 4 ohm speakers etc. ...

Also,
if you look at the measurements for the 3.6 in Stereophile, and the 20.7 in hifinews these drop respectively to 3.5 and 2.0 ohms at certain points...
my "uneducated guess" is that this is where you’re hitting problems, where the speakers dip low and the 8 ohm taps are not sufficient.

Lastly
I’m sure you know of the minimum 3-5 feet (some say 7-10) distance from the walls behind them...
and I was gonna tell you that they’d need 300-500 hours to settle down, now Elizabeth’s experience is apparently something like 1000-1500 hours...
good luck
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