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11-01-2023 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,658
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 2,658
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 454
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 2,658
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 2,658
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
11-15-2023 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,658
Joined on 10-12-2006

Post #: 26
Post ID: 27292
Reply to: 27291
Cargo Cult: Turning the Tables?

Which came first, the desire for “Good Sound” or the equipment to get Good Sound from our hi-fis? Actually, it’s a trick question, since most of us start out with “something”, and we move on from there. And taking it from wherever we first encounter it to where we need it to be is The Sonic Ballgame. All the while, there may be “absolutes” that determine Good Sound, but I’d be hard pressed (and not motivated) to lay out what “Good Sound” is in the first place, except, like we keep insisting around here, it’s personal. One thing I am sure of, that I will stick my neck out to say, is that there is potentially good gear “out there” that might or might not have been brought into existence for “The Right Reasons”, and, in any case, no gear will make Good Sound/Music by itself but it needs you to make it sound good. Back to the subject of this thread, the MA-9S2s, I went down a rabbit hole this morning and I got a laugh when I wound up listening (on YouTube:  https://www.youtube.com/watch?v=7vn5LWQQecw )  to (MA-9S2 project leader) Ken Ishiwata’s own hi-fi system. On the one hand, Ha!. On the other hand, what do you expect? I think it is not even boasting to say I get better Music from my MA-9S2s than Mr. Ishiwata gets from his system. But, does this really “matter”? For sure, we really want it to matter enough to save us time by “assuring success” with our chosen piece of equipment, that the specs and the direction taken by the original developer will somehow add up to Good Sound in OUR listening room. For better or for worse, per the basic tenets of GSC, the only way to truly make gear work is to work with the gear. Anything less remains random and/or accidental. We hear Potential and go on from there, and I believe it is possible to do/get More from equipment than the original developer did.>>

>

Paul S>>

11-18-2023 Post does not mapped to Knowledge Tree
Amir
Iran Tehran
Posts 347
Joined on 02-11-2009

Post #: 27
Post ID: 27294
Reply to: 27292
Minimum requirement
Paul 
I think the minimum requirement for good sound is not complex nor expensive.when minimum requirement is considered then I do not care about debates like paper vs metal, set vs pushpull , solidstate vs tubes , digital vs analog or horn vs dynamic driver or any other types of debates.
What I think is for minimum hardware the "good AC quality" and "perfect amplifier/speaker" matching is enough for me.
Just give me a good AC power then all things will go right.



www.amiraudio.com, www.hifi.ir
11-18-2023 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,658
Joined on 10-12-2006

Post #: 28
Post ID: 27295
Reply to: 27294
Leveraging Past The Minimum

Amir, where I am with my main system today is a ways from Minimum sound. I have shared that I got to where I am now by using experience to “leverage” the sound from my gear for targeted changes that I deem to be “improvements”, according to my (targeted) wishes at the time. I can still “hear through” my present system to the sound qualities I had in previous iterations of my system. This please me, particularly now, because I only wished for “More” this last round, in the first place. To be clear, I have NOT figured out a way to make the electricity a non-factor! I wish! But I have “taken steps”, and it has been less of a problem for me for the past few months; and I hope the improvements hold. Any remarks I make about “minimum” or “acceptable” should be understood in the context of my stated “goals” for my system, or they might also refer to considerations that some things I go on about probably do not really matter in the context of other’s systems, especially when understood in the light of their living situations. As it happens, I have taken the trouble to put together a Musical system that puts out a lot of power, and this is what I am recording and sharing now, partly or even mostly as a log for my own reference. I have made plenty of compromises along the way, and I mean to be both forthcoming and frank about them. I have certainly learned and benefitted from what others have shared on this Forum, and I hope to add something to this amazing Library with my own posts.>>

>

>Best regards,>

Paul S

11-22-2023 Post does not mapped to Knowledge Tree
Amir
Iran Tehran
Posts 347
Joined on 02-11-2009

Post #: 29
Post ID: 27296
Reply to: 27289
Amplifier Speaker matching
 rowuk wrote:
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.


Amplifier/Speaker matching for Perfect Bass is neccesary but not enough so harmonis (perfect tone) are also essential for sound.A speaker has a sound signature and an amplifier also has a sound signature , the magical effect of perfect speaker/amplifier matching lets you hear most pure harmonics without having coloration/signature of amplifier and speaker in sound. 




www.amiraudio.com, www.hifi.ir
11-22-2023 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,658
Joined on 10-12-2006

Post #: 30
Post ID: 27297
Reply to: 27296
Simply Stated
Amir, what you say and the simple way you put it is indeed a very important consideration for speaker/amp matching, and it is something that one must actually hear and cultivate in the first place. Since there is no way to emperically quantify the "results" in this case, it becomes in fact a matter of "taste", a popular shuttlecock in Philosophy, widely misunderstood and underappreciated in Audio. Also in this catagory is the matter of "texture", a sub-set of "dynamics", and many other equally important matters better understood in Musical terms than in audio terms. All this is something we must all deal with at some point in our personal audio journey, along with the excruciating problems of "trade-offs", where something we want must give in order to get something else we want. basically, Either/Or. Simply stated, anyone who thinks they will get it all has not been at it very long.

Best regards
Paul S
11-26-2023 Post does not mapped to Knowledge Tree
Amir
Iran Tehran
Posts 347
Joined on 02-11-2009

Post #: 31
Post ID: 27301
Reply to: 27297
Both midrange and bass
 Paul S wrote:
Amir, what you say and the simple way you put it is indeed a very important consideration for speaker/amp matching, and it is something that one must actually hear and cultivate in the first place. Since there is no way to emperically quantify the "results" in this case, it becomes in fact a matter of "taste", a popular shuttlecock in Philosophy, widely misunderstood and underappreciated in Audio. Also in this catagory is the matter of "texture", a sub-set of "dynamics", and many other equally important matters better understood in Musical terms than in audio terms. All this is something we must all deal with at some point in our personal audio journey, along with the excruciating problems of "trade-offs", where something we want must give in order to get something else we want. basically, Either/Or. Simply stated, anyone who thinks they will get it all has not been at it very long.

Best regards
Paul S

Paul  
In my experience if power is enough then you will have macro dynamics but there is 2 important factor for matching, first is the bass and second is the midrange, both are important . midrange harmonics will un-lock when you have perfect matching. 
I think matching of amplifier/speaker is a big problem in this industry , for example Wilson Alexandria , I have listened to Alexandria with many amplifiers and finally convinced wilson Alexandria gives you best harmonics with tubes not SS amplifiers but finding a good tube amplifier for Alexandria is not easy. Wilson Alexandria needs power and most high power tube amplifiers are not as good as low power tube amplifiers. Dave wilson used high power VTL tube amplifier for main tower and high power SS parasound for bass tower (under 38hz) but I doubt if VTL (300W/CH) could shine as good as low power SETs.
I have no rule but It seems paper drivers do not like SS amplifiers and low feedback push-pull SS may like modern drivers more than paper drivers.
finally my knowledge about what happen between amplifier and speaker is zero. 




www.amiraudio.com, www.hifi.ir
11-28-2023 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,658
Joined on 10-12-2006

Post #: 32
Post ID: 27302
Reply to: 27301
Comfort and Composure

Only so much can be gained from thinking about speaker/amp matching in the abstract. At some point we have to decide what’s most important to us, personally. I think the idea of a “comfort zone” for given amps and speakers is objective to a point, and then it also becomes a personal decision. It seems to me that the “objective facts” of amplifier power requirements are that exponential increases in power are required for “linear” increases in speaker output, including so-called “nominal” increases in output power. Meanwhile, most amps and speakers are decidedly non-linear in terms of response, in terms of both power and frequency, as a given driver also responds one way with low amp power and another way as amp power increases. Multiple drivers and crossovers only complicate these issues; they certainly do not “solve” them, en totale. Factoring in to speaker/amp decisions are choice of Music, personal expectations, and limitations imposed by “outside” circumstances. Of all these things, I think the most overlooked “objective” issue is keeping speakers and amps “comfortable” at all times during listening sessions. It takes listening in a certain way to hear the “comfort factor”, but I am pretty sure most people who are at all interested to try it could pick it up easily enough. It is unusual to hear Big Music played forcefully without strain, not to mention that not everyone has any use for this capability, in the first place. I think it is even rarer to hear Music via a system that maintains Musical balance and composure from the softest to and through the most bombastic passages.>>

>

Paul S>>

12-03-2023 Post does not mapped to Knowledge Tree
Amir
Iran Tehran
Posts 347
Joined on 02-11-2009

Post #: 33
Post ID: 27303
Reply to: 27302
Eduardo de Lima

Delima was designer of Audiopax, I had Audiopax Model 88 .

Delima believed there is some parameters that affect on amplifier/speaker matching. It's name is timbrelock if you check audiopax website.

I have worked with timbrelock, The Timbre Lock has two bias settings to provide a way of fine-tuning the bass and midrange . I worked with timbre lock and it works , one tune the bass and another tune the midrange. I did not check if audiopax could be match to all speakers but with some speakers timbrelock worked perfectly. 

I think some speakers will not match to audiopax but what I learned from audiopax was about how some parameters can affect on sound when the amplifier is match to speaker.


When there is  perfect matching (amplifier/speaker) the sound characteristic of both amplifier and speaker will be less obvoius/evident and I will get purer sound.




www.amiraudio.com, www.hifi.ir
12-03-2023 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,658
Joined on 10-12-2006

Post #: 34
Post ID: 27304
Reply to: 27303
Not Forgetting the Speakers, and Listening...
Amir, I have shared that I quite liked the (original) Audiopax amps I have heard. Whatever they claim, they do sound right to me. Although I have never played much with a de Lima amp I have played quite a bit with most of my own phono stages, pre-amps, and amps in terms of bias, including both tube and SS stages, and I agree that the sound can be "shaped" this way, obviously within the limits of what the system topography affords. Again, I very much prefer to start with (fairly) efficient, "lively" drivers/speakers, and (again) at this time I am using 95 dB speakers with very powerfull SS amps that I have used stock, to date. The MA-9S2s do have a provision to throttle back gain. I am not sure exactly how this works, but I had planned to use this feature for dimming my (once planned) center channel, which I wound up scrapping, along with my reason/excuse for using the attenuation feature. As far as the Soapbox Idea I am pushing in this thread, it is about using powerful amps with so-called "efficient" drivers/speakers, to get the "last word" in terms of FR transient response in the Musical Sound from the SYSTEM, including the speaker/amp combination discussed in this thread. I will say plainly that I still prefer the sound from relaxed SET and old paper drivers; but this preference is obviated/swamped by "real world listening" to big, complex Music, where, IMO, SETs and old radio drivers loose their sonic advantages, as they simply can't do Big Music to my satisfaction. We at GSC know about DSET, which is +/- an end run on the question of driver/amp "net efficiency" vs Total System Sound. This takes us back to knowing in advance what one wants to hear. I can't imaging being happy with 89 dB speakers driven by Audiopax, certainly not in the house I'm in now. However, it's possible that someone else might find it serves him well. Again, I agree that de Lima was "on to something", whatever it was, and I think there is already at least one thread (and certainly several posts) on the Audiopax amps posted here at GSC.

Best regards,
Paul S
12-04-2023 Post does not mapped to Knowledge Tree
Amir
Iran Tehran
Posts 347
Joined on 02-11-2009

Post #: 35
Post ID: 27305
Reply to: 27304
Two Audio Systems
 Paul S wrote:
I will say plainly that I still prefer the sound from relaxed SET and old paper drivers; but this preference is obviated/swamped by "real world listening" to big, complex Music, where, IMO, SETs and old radio drivers loose their sonic advantages, as they simply can't do Big Music to my satisfaction.
Paul S


I think this is very important thing in audio, I have convinced an audio system (even ultra advanced playback of Romy) can not play perfectly both complex music dynamics/accuracy/punch/scale/energy and simple vocals emotion. I think an audio system like two way AN UK/SET or Living Voice/Kondo will be better than Romy's audio system in simple vocals. we can not have all things perfectly in one audio system and I have convinced I should have two Audio system not one.


 Paul S wrote:
  I can't imaging being happy with 89 dB speakers driven by Audiopax, certainly not in the house I'm in now. However, it's possible that someone else might find it serves him well. Again, I agree that de Lima was "on to something", whatever it was, and I think there is already at least one thread (and certainly several posts) on the Audiopax amps posted here at GSC.

Best regards,
Paul S

Audiopax is just an example to have an idea what could happen between speaker and amplifier and I do not recommend any body to buy Audiopax for all type of speakers.

 Paul S wrote:
We at GSC know about DSET, which is +/- an end run on the question of driver/amp "net efficiency" vs Total System Sound.
Paul S

I doubt complex DSET concept and complex SS DAC of Romy could present simple vocals as good as (or as emotional as) simple NOS/SET tube systems. every bit of complexity could change the sound.



www.amiraudio.com, www.hifi.ir
12-04-2023 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,658
Joined on 10-12-2006

Post #: 36
Post ID: 27306
Reply to: 27305
Specialization vs. Compromise
Amir. for me. regardless of what I've started out to do in audio, I have been forced to compromise along the way. I am sharing my speaker/amp compromises in this thread. My "second system" is a radio (or computer) and headphones (or "desk speakers"). This means all other listening, and all "serious" listening I do is on my "big system", from delicate, heart rending solos to Bruckner. I am very picky about Sound, but it is all personal, after all. I actually think my present system "scales" very well, from small to great works, and I have plenty of SET experience as a reference. While my system will not best NOS SET for some "specialty" renderings, it will get closer than you might think. Meanwhille, I have never heard NOS SET "do' Bruckner the way my system can do it; not close, IMO. These are the bases for my current compromises. I encourage others to share theirs.

Best regards,
Paul S
12-24-2023 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,658
Joined on 10-12-2006

Post #: 37
Post ID: 27316
Reply to: 27306
Fun Facts Link
Saw the following for the first time yesterday. I think this stuff is more fun if/as one takes it seriously. It's not like I don't care about specs; but for me it's more like it matters on reflection if the amp "works" in the first place, and even then specs are taken with salt. Anyway, "impresive specs", I think, and it may be the first I've heard about a "buffered output", and a number of other features that sound like good ideas when I think about them. I'm still not sure about the 1st gain stage, the significant difference between the op amps I thought they used and the "discreet amps" they say they used.

https://www.supersonido.es/productos/documentos/Documento294.pdf

Merry Christmas!
Paul S
11-17-2024 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,658
Joined on 10-12-2006

Post #: 38
Post ID: 27698
Reply to: 27316
The Current Situation
Just short of a year since my last post about these amps. Since then I have tried to take advantage of the amps' capabilities as I continuously explore Music of my choice, along with the presentation of that Music. At this time I have HUGE, powerful Sound when I want it, when the recording supports it. Though I rarely switch on the "power meters", I want to report here that I have not seen the meters' needles move more than 1/2 way during the loudest, most giantic orchestral passages (eg., Bruckner, Mahler, Wagner, etc.); I think this means about 30W. What does this mean? I think it means that the amps have "a very fast rise time" for both current and voltage, as LF is never slighted if the amps are getting the information from the sources. And this with fairly heavy 18" LF drivers. I also have beautiful, delicate, thoughtful Music when I want it, including most of what the ML2s did, in terms of pitch, tone, timbre, texture, body, on and on. and I need only change the recording to change the presentation. Again, these amps "support" proper scale. For people who wonder, the MA-9S2s are NOT "better" than the Lamm ML2s I wrote so glowingly about, years ago. Those amps are legendary for all the reasons I have cited. Rather, I have made the choice to go for more power and drive at extended frequencies and at high volume settings without going through the trouble of building and developing DSET amps, in defference to my age and health. Anyone striving for The Ultimate in home audio has a long road ahead of them, regardless of the topology they choose. I have to say, despite I continue to mess with my system, I do consider the MA-9S2s to be +/- a "shortcut". People might be surprised when I say that the sound and presentation I get from these SS amps are not so different from the ML2s, apart from the power. I wish, but the MA-9S2s cannot do "SET bass", but the bass they do is very close to SET quality, with much better extension and a great deal more power. Overall, I am happy I went the way I did, including in terms of Musical Satisfaction.

Paul S
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