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07-29-2012 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,056
Joined on 10-12-2006

Post #: 1
Post ID: 18460
Reply to: 18460
Marantz MA-9S2 Monoblock Amplifiers
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This report is on a new pair of Marantz MA-9S2s, following up on the relevant post in the "Powerful Amplifiers" thread.  I installed the amps in my usual stereo set-up, to make it easier to draw a bead on them.  I still have less than 100 hours on the amps as this is written.  I have written about my DEBZ speakers and ancillaries before (eg., the K&K phono stage thread).

The amp's design seems "modern": 2-stage, fully-balanced A/B; op amps followed by deluxe Sanken transistors; current feedback; lots of discrete and sealed, proprietary components; fairly cool running; effective, sophistocated protection circuitry. Output is 300/600W into 8/4 Ohms; gain seems high (more on this later).  They are Big, very well-built and HEAVY.

Initially, it seems like the amp has some sort of HF filter, and the overall character seems somewhat "polite".  However, neither of these traits seems to stick out or interfere with any music in any way, at any time.  Further, and most importantly, the amps consistently excel at presenting all kinds of Musical performances, from simple to complex, small to large, quiet to LOUD.  Something I find interesting is that even when the quietest sounds are quieter than in the past, yet the loudest sounds will still be louder than that volume setting would suggest from past expereience.  Likewise, details and contrasts are always available, across the board, whether Tone or dynamics, sums or differences, in quiet as well as louder passages.  It is uncanny at first, and then it is simply wonderful.

Last night I started out, very engaged, listening to great violin pieces at lower (for me...) volume settings.  Then I put on Cosi fan tutti, and I cranked it up.  I suppose the electricity was good, and all the Music was wonderful.  In fact, the Cft was the best rendition of a "large scale performance" I have ever heard from hi-fi.

Just to be clear, these amps do all the parts well enough, and they do the whole - the Music - as well as any amps I have tried.  They easily "handle" my DEBZs, including the 15" drivers.  Overall, quite a contrast to the sodden shit I endured until I found these.  Although I expected to go with Class A something, results are what I'm after, and these A/B SS amps simply deliver The Goods.  And I suspect they would work even in cases where the power was more than enough.

Paul S
08-19-2012 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,056
Joined on 10-12-2006

Post #: 2
Post ID: 18530
Reply to: 18460
Power to the People
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The amps must be broken in now; either that or someone may find me starved to death listening to Music.  I never imagined I could get Sound like this from my DEBZs, but the MA-9S2s are doing wonderful Sound via the DEBZs, with all sorts of music.  Obviously, the extra power helps, and it helps in ways that count, musically.  Also, the feedback scheme has been utterly transparent for some time now, apart from making amazing, noise-free sound in my room.  Pitch, timbre, weight, scale, ambience, tactile dynamics at all frequencies, apropos.  I could not be happier.  I am all the more pleased because the results far exceed my earlier expectations.  An amazing achievement, actually.

It has been hot and muggy for weeks now. I have no way to measure, and no idea about the quality of the electricity itself.  Even if it has been great all along, this has been quite a run, so far, and very relaxing to just switch on the amps and forget about them, week in and week out.

Paul S
08-26-2012 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,056
Joined on 10-12-2006

Post #: 3
Post ID: 18543
Reply to: 18530
PEGGED!!!
fiogf49gjkf0d
Today I listened for the first time to an interesting CD that's been sitting there unopened for some time, namely Mahler 3 by the Koln Phiharmonie, on the new-to-me WDR "label" (Westdeutscher Rundfunk), conducted by Semyon Bychkov.  I will get into the performance and recording, etc. another time. In this thread, the subject is musical dynamics, and what it takes to get them from hi-fi, as this relates to the MA-9S2s.

Sure - of course - this CD is "compressed"; but it is also pretty "dynamic" as recordings go.  Based on my volume setting of "20", the music was not as "loud" as I sometimes play it.  However, noticing the "dynamics", I switched on the VU meters, only to watch them "peg" repeatedly.  Folks, this might mean 600W or more into each DEBZ! FYI, there was no noise or anything from the amps or the speakers that would call "technical" attention to the event, apart from the meter pegging to the right.

Again, the DEBZs are "96-97 dB efficient".  So much for "throwing away" "extra" power!

Again: Hmmm...

Paul S
08-27-2012 Post does not mapped to Knowledge Tree
decoud
United Kingdom
Posts 235
Joined on 03-01-2008

Post #: 4
Post ID: 18544
Reply to: 18543
Subsonic
fiogf49gjkf0d
The MA-9s2s are supposedly flat in response to 3Hz, so is it that all that power is going subsonically?
08-27-2012 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,056
Joined on 10-12-2006

Post #: 5
Post ID: 18545
Reply to: 18544
Near Death Experience With No Sense of Mortality
fiogf49gjkf0d
Good question, as usual, Decoud. No doubt it has something to do with the very unusual recording, plus my own penchant for "getting involved" in the music according to what the recording and the system will allow. It was not an LP, after all,  but a CD, and I doubt the CD in question goes down anywhere near 3 Hz, and I use a passive pre-amp.  However, it is a full "Mahler" orchestra, and you know the "dynamics" of the piece, so potential for plenty of LF energy in the "augmented" audible range.  I need to look again, but I think the right channel was more stretched than the left, despite (I think...) this Mahler orchestra has basses and big horns on both sides.  If you believe the "steady state" numbers, that much power input could be close to 120 dB.  I would be very amazed if it was, because there was no stress at all from the system during the loudest, most "gigantic" parts, not to mention my hearing is still intact!  Full "ambience" through everything.  For perspective, the opening drum rolls sounded to me to be a good 50 feet away.  I could still "feel" the impacts and the "ripples" very strongly, in addition to hearing them plainly.  I don't know what frequency it would be, but plenty of "tactile" sensations throughout the performance.

Maybe I should dig out my sound level meter and try it again.  Of course, this will have to until I have the house to myself again!

Best regards,
Paul S
08-28-2012 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,056
Joined on 10-12-2006

Post #: 6
Post ID: 18547
Reply to: 18545
The Power of the "P"
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Today I listened to a CD dub of early Etta James. Not to speak of the quality of the recording, but it is good enough to hear that Etta sings right up on the mic, and the mic feed is treated to some reverb.  I had the volume set at "15", not very loud, but the right VU meter was shooting up 3/4 of the way at times. When Etta hit certain consonants, such as a "P", the sound was so punchy up and DOWN the frequency range that I could feel my fucking pant legs flapping!  This never happened with the ML2s, but I'm not so sure it's all on the amps here.

I am in the process of checking out my iDAT, which is fully balanced Class A (2 Class A "channels" per channel), and it's 100% DC coupled.  Maybe I'm getting a ULF "bonus"?

Paul S
08-29-2012 Post does not mapped to Knowledge Tree
haralanov


Bulgaria
Posts 130
Joined on 05-20-2008

Post #: 7
Post ID: 18548
Reply to: 18547
Upper bass / lower midrange absence?
fiogf49gjkf0d
 Paul S wrote:
When Etta hit certain consonants, such as a "P", the sound was so punchy up and DOWN the frequency range that I could feel my fucking pant legs flapping!

Paul, this is always the case when one has too little upper bass and too much lower bass relative to the midrange  level :-))
The voices begin to sound too bass-weighty and at the same time thin and non-materialistic (jacket without a human inside it)...



"If you can't explain it simply, you don't understand it well enough." -A.E.
08-29-2012 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,056
Joined on 10-12-2006

Post #: 8
Post ID: 18549
Reply to: 18548
Sources and Fast, Powerful Amps that Won't Quit
fiogf49gjkf0d
Petar, you know my set-up well, and your remarks are correct within the context of that knowledge. However, despite the obvious technical problems, Etta's voice - per se - is actually - remarkably -  accurate, with plenty of body and soul.  While I still aim to address the issues you've raised here, I think what I'm hearing "overblown" in this case are very sudden, sharp bursts of air pressure that over-stimulate the microphone diaphragm, and then the reverb boosts the already-overblown ULF, followed by a DAC that passes DC, followed by amps that are willing and very able to boost those  signals with the same sharp rise times as the original events!

Right now, in broad terms, I'm thinking like Decoud.  Somehow, there is too much ULF getting to the amps via the CD chain.  Again, it has not happened with LPs, despite the potential there for rumble, and other ULF problems.  IF I get more, deeper (U)LF from CDs, I never noticed it with the ML2s.

Perhaps I have unwittingly biased my speaker LF to compensate for previous speaker/amp issues, and I will certainly follow up on this possibility.  However, the more I think about it, I think something is going on with the iDAT's right channel.  I'm thinking perhaps the ML2s simply crapped out on this "inappropriate" ULF, while the MA-9S2s just amp it up, and they make the drivers do what they want them to do.

Best regards,
Paul S
08-29-2012 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,056
Joined on 10-12-2006

Post #: 9
Post ID: 18550
Reply to: 18549
It Might Only Be the Right Side Amp's Meter
fiogf49gjkf0d
OK...  First, I tried an LP, and the right amp meter pegged on the big, loud stuff, just like it's doing with CDs.  Then I swapped the R and L inputs...  and only the right amp meter pegged on the big, loud stuff.  Repeating the Etta James CD to re-try the "P experiment", only the right ampl meter pegged, with the channel input.  Through all this, the left amp's meter never came close to pegging.  Same sound as yesterday, mind you, no matter which feed went to which amp.

Anyway, this seems like a "solution" that includes all the evidence I've bothered to assemble so far, including the lack of audible stress when the meter pegged.

Oh, well, the amp has a 5-year warranty...  I supose it'll have to go  back to Japan...

And no, Petar, I did not "forget" to put what you just said in the context of what I just said, and, again, you are right about that.  ;>Wink))

Best regards,
Paul S
02-27-2014 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,056
Joined on 10-12-2006

Post #: 10
Post ID: 20636
Reply to: 18550
Usual Mysteries; Long wait; No BS
fiogf49gjkf0d
OK, I took both amps to the "local" authorized repair station, only 1 hour and 45 minutes away, and after a long wait they told me Marantz had some sort patent fix for whatever it was, and they'd do it to both amps, but they had to wait for parts from Japan. To make a long story short, they fixed one amp to their satisfaction, and I picked it up. It worked fine here. They could not fix the other amp, so they sent it to the Marantz USA OEM, United Radio, in upstate NY. UR did their work and returned my amp. When I tried it, I could not get sound from it, so I phoned UR, got an RA label, and I packed the amp up again and sent it back to UR. Naturally, they could not replicate the fault; the amp worked fine for them from the get go. Just to be sure, they ran tests under load for a week, then they sent the amp back to me again. Now it works fine. There were no charges for any of the repairs, and Marantz paid for all shipping, . I paid for my gasoline.

The meters read the same now. The amps sounded great until 1 PM today, when the sound suddenly got a bone caught in its throat; the effing electricity!

Paul S
03-18-2014 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,056
Joined on 10-12-2006

Post #: 11
Post ID: 20655
Reply to: 20636
Character/Consistency
fiogf49gjkf0d
Over the weekend I had and took a chance to hook the amps up to a giant and "difficult" pair of speakers. I was pleased with the results, when the meters were running much farther to the right than I ever see them do when they are driving my own speakers, and the listening room is also much larger than my own. We did not really push the system, but we clocked 101+ dB peaks from about 5 meters away. Another thing, the "guest" speakers present an entirely different load than my own speakers do. Throughout, giant sound and ambience from the giant speakers, and no signs of stress from the Marantz MA 9S2s that I can remember, except perhaps some undiagnosed muffling in the biggest tuttis (LP source), and the character (for better or for worse...) of the sound/these amps did not change over frequency range or volume/load. I think these things idle at 500W; but if I ever saw specs about where they kick into Class B, I don't remember. Anyway, no audible sense of this transition.

Sure, the best idea is to design the speakers and the amps together to suit a given room. Absent that, I like having amps that can handle what comes their way with aplomb.

Paul S
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