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07-29-2012 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,576
Joined on 10-12-2006

Post #: 1
Post ID: 18460
Reply to: 18460
Marantz MA-9S2 Monoblock Amplifiers
fiogf49gjkf0d
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 2,576
Joined on 10-12-2006

Post #: 2
Post ID: 18530
Reply to: 18460
Power to the People
fiogf49gjkf0d
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 2,576
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 247
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 2,576
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 2,576
Joined on 10-12-2006

Post #: 6
Post ID: 18547
Reply to: 18545
The Power of the "P"
fiogf49gjkf0d
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 2,576
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 2,576
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 2,576
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 2,576
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
05-30-2019 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,576
Joined on 10-12-2006

Post #: 12
Post ID: 25444
Reply to: 20655
Selling My Center Channel Amp
OK, I am letting go of the idea that I will ever build a working center channel, and I am selling the MA-9 S2 I bought for that purpose. As I mentioned in my initial posts in this thread, I got it from a Hollywood sound producer who kept perfect care of it, and I have had very little use for it over the ensuing years. Specs are available online. It weighs about 85 pounds, built to the highest standards in Japan.  It looks and performs as new, and I have the original, factory box.  PM me if interested.


Paul S
01-26-2021 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,576
Joined on 10-12-2006

Post #: 13
Post ID: 26055
Reply to: 25444
Update: Center Channel Amp Is Sold
Looking around for something else, just noticed I had not updated the MA-9S2 thread to say the single amp has been sold. Still have the pair, still plan to keep them.
10-13-2023 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,576
Joined on 10-12-2006

Post #: 14
Post ID: 27280
Reply to: 26055
Driving The Loudspeakers

I guess it’s time to talk about these amps in terms of The Loudspeakers. In truth, I thought of these amps from the first time I thought about The Loudspeakers, to the point where I “built and tested” The Loudspeakers with these amps in my head before I so much as ordered any speaker parts. I already admitted that I was grateful (rather than surprised) when the MA 9S2s proved such a good match for The Loudspeakers, because, although I was not certain of a good match, I would not have gone forward with the project at all unless I +/-  expected acceptable results. I never expected ULF from The Loudspeakers, so I still cannot speak to this in terms of the amps’ capabilities. Fair to say, I think, not many amps can get serious Music from an 18” woofer. And I suspect the MA 9S2s could do “good ULF” with the right subs. I can say that The Loudspeakers driven by these amps are at least as Musical as any “4 box” speaker system I have ever heard, meaning 2 speakers and 2 amps. “Full Range Speakers” might be a pipe dream, but these amps have allowed me to get pretty close, and it is hard for me to talk about my version of The Loudspeakers without including these amps in the discussion.>>

>

Paul S>>

10-22-2023 Post does not mapped to Knowledge Tree
rowuk


Germany
Posts 440
Joined on 07-05-2012

Post #: 15
Post ID: 27281
Reply to: 27280
Synergy my dear Watson
 Paul S wrote:

I guess it’s time to talk about these amps in terms of The Loudspeakers. In truth, I thought of these amps from the first time I thought about The Loudspeakers, to the point where I “built and tested” The Loudspeakers with these amps in my head before I so much as ordered any speaker parts. I already admitted that I was grateful (rather than surprised) when the MA 9S2s proved such a good match for The Loudspeakers, because, although I was not certain of a good match, I would not have gone forward with the project at all unless I +/-  expected acceptable results. I never expected ULF from The Loudspeakers, so I still cannot speak to this in terms of the amps’ capabilities. Fair to say, I think, not many amps can get serious Music from an 18” woofer. And I suspect the MA 9S2s could do “good ULF” with the right subs. I can say that The Loudspeakers driven by these amps are at least as Musical as any “4 box” speaker system I have ever heard, meaning 2 speakers and 2 amps. “Full Range Speakers” might be a pipe dream, but these amps have allowed me to get pretty close, and it is hard for me to talk about my version of The Loudspeakers without including these amps in the discussion.Stick out tongue>gt;

Stick out tonguegt;

Paul SStick out tongue>gt;


Paul, I find your reporting fascinating. I believe a lot of the success is due to the speakers being very "source tolerant". That means through efficiency, little dependency on amplifier damping factor. Through intelligent crossover design, little demand on the amplifier to compensate for phase anomalies or large impedance swings.

What it also means that in the sense that Romy actually uses the amplifiers to "voice" the system, this is not happening. The voicing of the speaker does not give you clues of what could be "if". Not needing to change is a wonderful state - especially for someone that followed that path. Perhaps you are now successful in regard to the Remedios "Low Maintenance" UseCase?


Whenever I feel blue, I start breathing again.
10-22-2023 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,576
Joined on 10-12-2006

Post #: 16
Post ID: 27282
Reply to: 27281
Taking Advantage of Others' Discoveries
Robin, I'm not at all certain that my new speakers are "source tolerant", because I have "taken steps" all along to "ensure" part-to-part compatibility. I have tried to "sync" my phono and CD/DAC as much as possible, and the main thing I wanted from the amp/speakers was/is to let the Music through (stay out of the way) by not causing problems. I've heard lots of amps, even big amps, brought down by "efficient" speakers, and one of my specific aims was to avoid this. Since I prefer the sound of SET amps, SS was a compromise. But I just could not figure out a viable way to get the frequency range and the dynamics I was (am) after with SET, since I decided not to even start with massive horns and DSET. From reading extensively Troels Gravesen's thoughts about speakers, crossovers, etc., incliuding drivers and topologies I am familiar with, I came to believe I could get what I was/am after by implementing a close variant of his design and plans for The Loudspeakers, including using my big amps bi-wired. Although I am still moving my speakers around some, I basically just turn the electrical equipment on and off; there is no ongoing adjustment or maintenance, apart from my insistance on setting VTA per record, which takes all of 15 seconds per pecord since I developed an easily repeatable system for that. Back to "efficiency", I am skeptical about this, to the point of cynicism, not with respect to "responsiveness", which I insist on, but in terms of what it takes to get loud FR music from speakers. After all these years, it seems to me that that "efficiency" alone may not be "enough", since a driver that starts out efficient might choke up if driven hard, and I do drive my system hard at times, and most speakers (and amps, for that matter) do not do what I want if they are pushed. I can say and I have shared that I can use my amps to push my speakers. I am near certain that the 18" driver would not "work" without an amp that can "handle" it without making its presence obvious. But even the UHF tweeter here can "take" 250W, and I am thinking that in this case the "headroom" afforded by the modern drives is part of what makes this speaker system "work" for me. The only way I could say more about "amp tolerance" would be to try other amps, and at this point I have no incentive to do it. I "think" someone could use these speakers as Troels did, at least in small-ish rooms. Pretty sure Bruckner in a large room is another story, and this is where I am now. To close, I am pretty sure my amps have a high "damping factor", and it does not seem to get in the way of my Music. And, again, I would be very amused - even delighted - to learn someone had LF/FR success with The Loudspeakers using an SET FR. I remember many years back when I noticed that the more power I fed my A7s, the better they worked for me.

Best regards,
Paul S
10-26-2023 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,576
Joined on 10-12-2006

Post #: 17
Post ID: 27283
Reply to: 27282
Developing Tolerable Sources

Rowuk got me re-thinking about how I arrived at the sound I now get from my system. The short answer (shorter than the Long Answer…) is that I started out trying to stay close to the sound of master tape from a nice reel-to-reel machine. Rightly or wrongly, I have always thought the best iteration of this sound was audibly less problematic than vinyl or CD sources, given ample consideration for the source sound in the first place. My approach with vinyl and CD was first to limit problems and keep CD “on par” with vinyl (and tape), then, later, I’ve tried to push for “more” Music without wrecking what I had before trying to increase the system’s range. Every component over the years was chosen to complement the other components, even if a component – such as the MA 9S2s or The Loudspeakers -  was chosen primarily to “push the envelope”. Since I did not develop The Loudspeakers myself, and I did not listen to them before I built them, I guess you could say I got lucky. Again, I did read what Troels Gravesen and others said about sound and the sound of his speakers, and I was more or less familiar with the sound of the big JBL monitors. (Again), I would not have gone forward unless I thought I had better than even odds of success. Back to the amps, I surely did consider “specs”, and I plugged the specs into my “experiential data base”, but it was use and listening that sold me. Generally speaking, the idea (of course) was to amplify the Good via The Loudspeakers without exacerbating the Bad. More Dumb Luck, I suppose, as it seems to have worked. Do the components complement each other? Sounds like it to me. I would say that problems are more subtractive than additive, and they do not swamp the Music I hear. Like I said in The Loudspeakers thread, recording techniques are clearly audible, and I consider this a result of “accurately” amplifying recordings. Fortunately, the “recording information” usually “allows ample room for” the “Musical Information”, as they are usually not the same thing in the playback I am listening to. I have turned up a few LPs where the mix and the sound I get was different enough from earlier systems that it surprised me, and not always in a good way. I am currently thinking this has to do with the way these LPs were made, vs. some fault with my playback, and I think I might “solve the problems” with cartridge SRA, once I set my mind to it. Back to Rowuk’s remarks about “tolerant” speakers, I think he is quite right, in the sense that Troels has gone way out of his way to make fairly complex crossovers as “easy” as possible for a real-world amplifier to drive through. However, I don’t think this means any amp could drive The Loudspeakers the way I want, and that’s why I chose the MA 9S2s, which I had already used to drive many complex “stacks” of vintage drivers I tested as potential center channels, and then I used them FR with my BassZillas. I can also say that with a lot of Music my BassZillas and The Loudspeakers driven by MA 9S2s are more similar than different, believe it or not, not because their differences are homogenized but because I only aimed for “more” in the first place, and I ended up close to where I hoped would. Actually, I got more than I expected, but I hate to crow.>>


Paul S

10-30-2023 Post does not mapped to Knowledge Tree
Amir
Iran Tehran
Posts 299
Joined on 02-11-2009

Post #: 18
Post ID: 27284
Reply to: 27283
Amplifier Speaker Matching
Paul I do not know what happen between amplifier and speaker but I think matching of amplifier and speaker is one of the most important things is audio. matching is not just about dynamics/driving or having enough power , it is about perfect bass and Perfect tone/harmonics and perfect coherency. In my opinion DPOLS (room speaker interaction), AC Power Quality and Amplifier/Speaker matching all are the most important factors for having magical result.


in this market very few amplifier/speakers are good match together.
to consider about matching in other area like Transport/DAC I have compared over 6 different expensive DACs with CEC TL0 3.0 and I think CEC is not perfect match for all of them.
I am not sure but it seems CEC TL0 likes DACs with richer midbass. one of the things that make me wonder about Romy's complex System is how Romy find perfect match in all area (Transport/DAC/Pre/Power/Speaker). as you know Romy uses different brands (CEC-Bidat-Lavry- Guy Hammel’s Placette-DIY Pre/phono/amp-Vitavox-RAAL) in each section. increasing complexity of system makes it so hard to have perfect sound. Peter Qvortrup told me matching of midrange driver to tweeter is not easy task and imagine how it will be hard to match 5 or 6 different drivers. minimalist approach does not give us perfect performance in all area but it gives us easy way to have reasonable good sound.
10-30-2023 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,576
Joined on 10-12-2006

Post #: 19
Post ID: 27285
Reply to: 27284
Playback in the Real World

Amir, the Marantz MA 9S2s are the subject of this thread, and I chose to keep using this amp because it was consistently acceptable to me with different sources and driving vastly different speaker loads, including giant (Sound Lab A1) electrostatics. I think it saves time to know pretty well what you want in terms of sound as you “audition” gear, and one has to be careful about gear that is “impressive” on first hearing. You cite a number of component pairings, including amplifiers vs. speakers. Yes, it is hard to juggle the variables involved in a multi-driver, “FR” speaker, including the amp or amps to drive it. It seems funny to put it this way, but Romy’s pairing of DSET and massive horns is actually meant to be a sort of shortcut to optimal playback, just as my own solution is meant to be my version of a “good compromise”, in an effort to “balance” sound and system complexity. Clearly, there are simpler, cheaper solutions for anyone willing to put in the effort to think it through and work it out over time. I have mentioned several times that it is much easier to put together a system that puts out less range and power than mine does, and I think most people are well served to consider a “limited” approach, especially apartment dwellers and those with smaller listening rooms that are easier to charge. I do “get” Audio Note (and the like), and I actually “endorse” the notion, if not a particular product. In any case, it’s personal, after all. And even in cases where someone wants more power, I think it’s generally “easier” to split off LF.>>


Best regards,

Paul S

11-01-2023 Post does not mapped to Knowledge Tree
Amir
Iran Tehran
Posts 299
Joined on 02-11-2009

Post #: 20
Post ID: 27286
Reply to: 27285
High Power Amplifiers
Paul 
Excuse me for off-topic , I also have high power solidstate amplifier and I have some experience with high power solidstate amplifiers.
Actually very few high power solidstate/Hybrid amplifiers are good and most of them are not ok.
The problem is my high power solidstate amplifiers need high quality AC power and it is not easy to find good high power AC regenerators.
My loudspeakers are 90db (over 6ohm impedance) .
11-01-2023 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,576
Joined on 10-12-2006

Post #: 21
Post ID: 27287
Reply to: 27286
Big Amps. Mains Power, and Amp Loads
Amir, I told of my own approach to wall power in other threads. Basically, I tried to make my gear as tolerant of AC variations as I could without simply smoothing everything over. My DAC runs on battery power. I modified the power supply and changed the first gain stage of my phono stage. And I chose fairly efficient, very responsive speakers, despite my amps are very powerful. I will get to the latter in a minute. I think I also got lucky with the grid power, as initial problems with the Smart Grid have settled down, also a nearby school put in a giant bank of solar panels for their electrical needs. Anyway, as I have already shared, the average power I get now is better than ever, and it has seldom gotten really bad for a while, now. I very rarely get spectacular power these days, but I accept and work with the present trade-offs, and I am happy to be able to listen to Music most days I choose to.

Back to efficient, responsive speakers for big amps: I was very hopeful when I finally found the MA-9S2s, after a long (years...) search for powerful amps. I bought one used MA-9S2 to play with, and I used it and tested it for a while before I bought a new pair of MA-9S2s for my main, stereo speakers. One of the main things I tested for was real world performance; could I get the Music I wanted from the CDs and LPs I already own? The MA-9S2s were a good deal "less sesitive to my average wall power problems" than my Lamm ML2s were, meaning, fewer problems driving the same speakers under the same conditions. My BassZills were said to be 97dB. My new Loudspeakers are said to be 95dB. They are a harder load for my amps than the BassZillas were, but I still have few problems I can trace back to wall power problems. Of course, I don't know just how bad your wall power is, but I well understand the problem of powering big amps. And I also undersand the value of efficient, responsive speakers, and that even responsive, efficient speakers need real power to go hard FR. If someone uses a big horn to get down to, say, 400 Hz, he still has to deal with the driver underneath it. If that driver is a 15" direct driver, then he needs real power to do that, IMO, even if that driver is said to be "efficient".

Best regards,
Paul S
11-01-2023 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,576
Joined on 10-12-2006

Post #: 22
Post ID: 27288
Reply to: 27287
Current; Amps vs. Arc Welders

It’s been some time since I seriously considered hi-fi gear in terms other than sound qualities. But I did think broadly and specifically in terms of “current” when shopping for big amps. I have heard some bad-sounding amps that were said to have “high current capabilities”. Does this mean they do not actually deliver “high current” to/through the speakers’ circuits, or does this mean there is more to consider than just “high current”? I think useable high current is very important for driving tough speaker loads acceptably, and I also know for certain there is more to a good amp than high current capability. Close listening to serious Music will out problems, and experience helps to pinpoint problems with amps. We know going in that speakers (and crossovers) are reactive loads, and big speakers present complex problems to an amplifier, especially if one insists on one amp per stereo channel, as I have done. In hi-fi, as in Life, there’s no Free Lunch. The less you ask from your system, the more likely you are to get it cheap. The more you ask, the bigger the hassle on all fronts.>>

>

Paul S>>

11-02-2023 Post does not mapped to Knowledge Tree
rowuk


Germany
Posts 440
Joined on 07-05-2012

Post #: 23
Post ID: 27289
Reply to: 27288
Synergy?
In my over 50 years of personal audio, I think that I can explain part of the speaker/amp compatibility. This opinion is everything but comprehensive.

Bad matches in amp/speakers manifest themselves very often in the bass. Please consider, these thoughts have been observed on speaker systems with the amplifiers connected directly to the voice coil without crossovers. Some combinations sound flabby and others seem to have the life and 3 dimensionality constricted out of them. In my own research, I find that there seems to be a necessary balance between the BL of the woofer and the damping factor of the amp. If the woofer has high BL, lower damping factor seems to be beneficial (until things get flabby again). The opposite can also be true: woofers with "low BL" seem to work better with high damping factor. Just maybe part of the magic is based on total Q of the entire woofer system.


This makes sense to me because every musical instrument works the same way - we promote resonance through high total Q or inhibit resonance with low Q.

Passive speaker level crossovers affect the BL/Q of the woofer and probably demand a respective consideration in amplifier damping factor.


Whenever I feel blue, I start breathing again.
11-02-2023 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,576
Joined on 10-12-2006

Post #: 24
Post ID: 27290
Reply to: 27289
Well, Sure...
No question that there are basic electrical issues to deal with in matching amps and speakers. After our best attempts to deal with these issues on paper or in our minds, we listen. Part of dealing with reactive loads is keeping amp output impedance low, and this can even be a deciding factor in some cases. We have shared thoughts about matching the output transformer to the task at hand as a way to use (D)SET for LF. The question always remains, how does a given amp "work" when it's wired to/through the chosen speaker. Of course, I would hate to be in a position where I had no thoughts about "electrical issues" while amp shopping, since that means one has to try everything, and I had plenty to try during my last shopping period, even after I limited myself to "powerful amps".

Paul S
11-05-2023 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,576
Joined on 10-12-2006

Post #: 25
Post ID: 27291
Reply to: 27290
Back EMF, Ohm's Law, Amps, and The Can
Robin, I have had recurring thoughts about speaker/crossover/amp "compatibility", and I wound up on the shoals of back EMF. You pointedly mentioned BL, and, on the one hand, you are "right". At the same time, an "easier" (high BL) circuit can very quickly become more difficult as the voltage/current relationship morphs, in any number of ways, for any of several reasons, except the fixed case of Ohm's Law. I have heard it said that if one stares too long at this equation, one turns to stone. I have read that the MA-9S2s were (re-)designed specifically to handle real world speaker/XO EMF without losig their composure. But, again, I am generally suspicious of claims of any sort, and particularly suspicious when doing the job as Marantz claims appears to mean at least temporary suspension of this basic electronics tenet. This means I actually listened to the MA-9S2s despite my suspicions, and I wound up putting them through their real-world paces, using my ears to integrate them into my changing systems as best I could. I kept them because they "worked", and now I have the luxury of speculating about why and/or how they work without really needing to know the answer(s) to those questions. Yes, I am kicking The Can down the road... again.

Paul S
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