ack's system - end of round 1

stevebythebay

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Might arrive sooner than the phono stage, I’ve been told. And that one’s in pre-pro status. You didn’t hear it from me
 

ack

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So here are a number of reasons why I and many others only deal with reputable, well-established companies. I discussed my distortion problem with Martin Logan today and told them I suspect the step-up transformers, because: a) the onset of the distortion back in May was really abrupt, following a nasty CD track at unreasonably loud volume, which took out the panels plus something else - so likely typical high-impulse-current damage (and these 500AR amps are relentless); b) the crossover shows no signs of damage and I over-spec'd it anyway; c) the power supply is usually all-or-nothing, though not always.

They promised to discuss internally with engineering and get back to me by the end of the day. The response was that, based on my serial number, those transformers are prone to failure and will be sending me new ones to try, and return if they don't fix the problem. Moreover, they will charge me their cost, and if returned, I can then ship them my power supplies for measurements, evaluation and follow-up. Service...

I hope it doesn't come down to the crossover, because figuring out which part or parts may be faulty is going to be really tough. At that point, I'd say it's either Hello CLX or Hello Magico (unlikely to wait for a Keith Johnson speaker), and that would be bad, because I'd rather spend the money on an S-sub, which will address lack of very deep bass in here (<25Hz) and provide higher pitch definition.
 

ack

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The incredible Vishay 1839 10nF bypass capacitor

While I await for the new panel step-up transformers this week, I experimented with my crossover again. This time, I wanted to confirm the effect of the tiny VISHAY-RODERSTEIN MKP-1839 400VDC axial bypass capacitor I placed across all of my panels' Mundorf Supremes years ago when I built my own crossover, when the previous panels were still at the top of their performance.



As many DIYers have discovered before me - e.g. see https://www.audiocircle.com/index.php?topic=42809.0 - these tiny things are a god-send for capacitors like the Supremes. After taking them out, and with the new panels in place driven by the ultra-detailed DMA500AR amps, I confirmed once again after many years that the treble can be a little harsh, and interestingly enough, depth of stage collapsed, as small spatial nuances disappeared! Fascinating, really. Some treble harshness with the Supremes is also what many other people have reported on various forums.

So then I soldered them back in, this time two per, i.e. 20nF. Piece of mind again! The soundstage regained depth and nuance, with smoother treble again. Frankly, when I placed this same capacitors in the output of my DAC a couple of years ago, that's also part of what I heard back then.

I had always been a skeptic of bypass capacitors in the crossover back in the day, but I can't ignore the results. This is one of the easiest and most rewarding modifications one can make, either in a power supply (to increase its speed) or the crossover. I am really curious why speaker designers don't use them, as I have never seen them in commercial speaker products, other than the custom-made speakers this guy makes https://www.audiocircle.com/index.php?topic=42809.0 (BTW, as many already know, http://www.humblehomemadehifi.com/Cap.html is the capacitor-information mecca)
 
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ack

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Back in business, after 6 long months of distortion and reduced acoustic output - new panels and power supplies; step-up transformers are in perfect condition, really high quality too. The new power supplies are obviously quieter as well.

martin-logan-panel.jpeg

martin-logan-power-supply.jpeg
 

stevebythebay

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Nice. Your “new” speakers should sound great. Break them in, if that’s the right phrase, carefully. Watch out for bombastic 1812 cannons.
 

ack

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Thanks! So far, they do sound wonderful, but I think I am still going to take my sweet time to get a pair of Magicos, that are as transparent.

Regarding the power supplies, I haven't seen so many diodes in a PS before, there must be upwards of 25 in there, some even between the polypropelene capacitors.
 

stevebythebay

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I've listened to Magico speakers in the past at various dealers and venues. Seems they are rather challenging to position well. Most cases they were hard to tame on the lower bass area and with the electronics can be less than alive. But my tastes always go for both musical realism and sheer engagement; both I have found lacking in the Magoco speakers. I think what you own should deliver on all counts with the right front end.
 

ack

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Yes, what I have delivers on all counts, which is why I haven't made a move for anything else. But I am always thinking, there's gotta be something better. We'll see, not in a hurry.
 

Al M.

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Congratulations, Ack, that everything is working again! I am really glad that the repair worked, because you have been able to dial in your speakers so perfectly to the room with all your modifications, and as we discussed, soundwise I really don't see a reason for you to switch to Magico, even though I love some of the brand's speakers as well. Your sound is stellar as it is (actually, now with new panels and amps it must be even better, I am curious!).

I agree with Steve, Magicos can be really hard to place correctly, and if this turns out to be an issue -- also given that your room does not offer that much flexibility --, instead of great new sound you might have a very expensive problem on your hand. The chances of that happening are just too uncomfortably high, in my estimation.

I'd suggest you order another pair of spare panels instead...
 

ack

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Thanks Al. Well, let's all take another listen over here, and see where the flaws are. You, Peter, Ian and everyone else, ping me with availability and let's sit down together for a few hours. Perhaps all I need is an S Sub...

I really don't exactly know what the 500ARs can do in here yet, because I only had them for 2 days before the onset of distortion, but I have a fairly good picture. Should be fun... glad this is over before Thanksgiving!
 

microstrip

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Regarding the power supplies, I haven't seen so many diodes in a PS before, there must be upwards of 25 in there, some even between the polypropelene capacitors.

It looks like a classical Cockcroft–Walton voltage multiplier, as used in most electrostatic speakers. See https://en.wikipedia.org/wiki/Cockcroft–Walton_generator . A lot of the diodes are Zener's - to give some kind of regulation to the HV.

For detailed analysis of this type of ML board see : http://www.martinloganowners.com/fo...37b756894de981&p=178127&viewfull=1#post178127
 

ack

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Great discovery micro! Thanks for this. Let me copy this circuit diagram over here then, it's from ML; I need to study it in more depth

 

Al M.

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Thanks Al. Well, let's all take another listen over here, and see where the flaws are. You, Peter, Ian and everyone else, ping me with availability and let's sit down together for a few hours. Perhaps all I need is an S Sub...

Sounds good, Ack, I look forward to hearing your system again, and it would be fun to do it that way. Yes, maybe an S Sub is all you need!
 

cannata

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I've listened to Magico speakers in the past at various dealers and venues. Seems they are rather challenging to position well...

LOL, Magico is difficult to position well? Coming form an Alexia owner??
Had both (Alexia 1), and many more Wilsons, and now on my 3rd Magico pair. All I can say is that at least with the Magico it is possible. The work will pay off. With many speakers its just a constant battle for a bearable compromise.
 
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cannata

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ack,
resistance is futile, no Ssubs will address your issues. I will strongly recommend an M3. A cure for all your problems ;)
 

ack

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ack,
resistance is futile, no Ssubs will address your issues. I will strongly recommend an M3. A cure for all your problems ;)

You may have seen my numerous thoughts on the M3 in this thread... others have also visited the dealer and have had the same negative reaction. There is something really seriously wrong with that speaker
 

cannata

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I did see your comments, they don’t make much sense to me.
Rest assured, many “others” don’t think like you and your “others”.
Go to a different dealer, or try to arrange an audition in your house.
 
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PeterA

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I did see your comments, they don’t make much sense to me.
Rest assured, many “others” don’t think like you and your “others”.
Go to a different dealer, or try to arrange an audition in your house.

I don't want to be too off topic for Ack's system thread, but I am one of the Boston audio friends who has heard the M3 up hear. I liked it very much the first time I heard it, but I recently went back with Ron Resnick to hear it again. The system sounded lifeless. No dynamics, poor tone, flat and dead. I don't know what it was, but I am not willing to conclude that it was the speakers, per se. The table and cartridge were brand new with perhaps one hour on them. I can't stand the large MIT speaker cable box, so who knows what the various settings were doing to the sound. Perhaps it was the tubed phono stage matching with the Spectral. It is a mystery which we have discussed many times amongst our Boston group in emails.

Given the quality of that demo, and the quality of Madfloyd's M project and my own Q3, I can't believe that Magico would release a speaker that sounds so bad, so I remain open minded until I hear it again in a different setting, perhaps with completely different gear and a more appropriate room. I agree with you cannata, I have only read outstanding reports about the M3 from others who own it and have heard it in different contexts.
 

PeterA

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This may be quite controversial, and I have not heard Ack's system in a very long time, but I wonder how different a sealed box/cone speaker system would sound compared to his panel design which relies in part on the back wave and room reinforcement. There is a lot of open space behind Ack's MLs, with an open stair case behind the right speaker and an open kitchen area behind the left speaker. Ack has achieved excellent sound though his extensive modifications and fine tuning. It is what I would describe as a "mature" system, but I have always wondered about the back wave of the speakers in such an open environment. A magico speaker would surely sound very different, though not necessarily better.

As some of discussion on this thread has turned to speakers, I wonder what others might think of this aspect of the room and a particular speaker typology. Thanks for the invitation, Ack. I think it might be time to visit again and hear your new amps and repaired speakers. No time like a New England Winter to stay indoors and listen to good music on a good system.
 

ack

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Given the quality of that demo, and the quality of Madfloyd's M project and my own Q3, I can't believe that Magico would release a speaker that sounds so bad

Don't forget that the original S5 had serious issues as well, as did the V2 (though I know you liked it), and last but not least, the new A3 which has been described internally among us as a piece of junk. It may well be that the M3 just does not have the low-end drive to pressurize that big room, and it ends up sounding thin; and perhaps the entire speaker cannot fill that room. The truth is that in over half a dozen times, that speaker has left me completely cold.
 

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