The stunning DMA-500 Anniversary Reference monos take center stage

ack

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#1
Strange, but as it turned out, the 4-member WBF Boston Group met, for the first time in full body at any one of our homes, at my place yesterday, for an in-depth audition of the DMA-500ARs, new electrostatic panels and electronics, and some other tweaks, like my custom turntable platter interface described here and further undisclosed tweaks on the already-modified Alpha DAC.

From the left: Madfloyd, Al M, PeterA, and the host (having gained a bit of weight lately)



While patiently waiting for 6 months to get new panels from Martin Logan, I had been silently working on the bass drivers' crossovers again, subwoofer integration, and reduction in distortion. The DMA-500s mandated these changes to try to get the best out of them, at least in this system.

None of the guests knew what to expect, because no one had heard my system since before the arrival of the 500s and subsequent tweaks, and a couple of the guys had not heard the system for probably a couple of years, if not longer.

DIGITAL: Let me start there first. The 500s are so revealing that I had to do something more to the DAC; so I've made more modifications to the analog section, and at the same time, I experimented with the digital volume control again, plus running it through the 30SV's balanced-in module, which Keith Johnson says it was designed for digital (whatever that means). Whatever it does, it works.

ANALOG: Ever since I shielded the power umbilical cord of the Pass XP-25 in recent months, the noise floor dropped dramatically in that unit. And that aforementioned platter interface (a sandwich of Sorbothane/SPEC+ AP-UD1/Isodamp C-1002) has been responsible for a significant drop in rumble and increase in midrange clarity and resolution. It is so effective that tapping hard on the LP while playing produces very little feedback - probably my most significant invention so far.

MARTIN LOGAN PANELS and ELECTRONICS: The replacement panels are definitely more rigid than the originals; the new power supplies I also installed clearly dropped the noise floor a bit, reduced distortion quite a bit, and the new step-up transformers added more clarity and body - yes, I A/B'd freaking transformers at least three times, and the new ones are just better than the original... what a pain.

The DMA-500AR + 30SV: This Super Veloce technology from Spectral, embodied as custom transistors and everything around them, works and works wonders. The amplifiers have slew rates surpassing the preamp's.

SPEED KILLS? Yes, it does. When not handled correctly, it can be audibly fatal. Only after all the other system changes described herein did I get the Spectrals to really sing - they are ruthless, and jaw dropping at the same time.

HOW FAST CAN YOU GO? As fast as possible. When it works, it can be thrilling. I continue to be fascinated by the A90's speed and accuracy, but more importantly, just how fast the Alpha DAC can be, and to what levels one can take it. At the same time, I have come to love this modified XP-25 phono, which is as fast as everything else.

THE SOUND: We played a variety of recordings, starting with direct-to-disc. Perhaps the guests will offer their own opinions, but I believe we all felt that the dynamic headroom from these amplifiers came shining through; really impressive dynamics. The clarity of attack and decay, and of the entire presentation, was off the charts - both analog and digital. The level of articulation and timbral accuracy also very high. Comments like "very impressed", "so clear" and "so articulate" were not infrequent.

I personally thought analog had more body than digital, but digital was not far behind in anything. I also think HDCD in here sounds as great as analog, and that's a major achievement for both.

I'll just post a quote and picture that Madfloyd sent us:

I've never heard digital sound so good!!!???
boston-group-2.png


JAW DROPPING? I'll let others speak to that, but I'll just say that these DMA-500 Anniversary Reference monos have LIFE. The noise floor is so extremely low that I can't detect any grain or other artifact. The sound is so coherent top to bottom; the bass is extremely well controlled. Timbre and Articulation - my main goals - are in full swing. There is tremendous ease and control of the music up and down the entire spectrum. At the same time, I am certain this system doesn't do them full justice either, and would love to hear them in a mega system. One thing's for sure, at the dealer's using the Magico M3s, they sound nothing like what we heard in here yesterday.

KUDOS TO SPECTRAL: Yeah, IMO Keith Johnson's creations are masterpieces; but so are other products. I believe these amplifiers will stand the test of time quite well. But as everything else in audio, there will always be something better 5-10 years from now. Meantime, impressive and inspirational work! I had to end the audition with a 99-point wine, worthy of these electronics.

-ack
 

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awsmone

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Apr 7, 2014
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Canberra Australia
#2
What no pictures of the bad boys?

Also some pics of your MLs since you modified and the mods be interesting? as an ML owner myself

I recently put my CLX back in action after I got the ASR beast! and because I blew a midrange on the Fat ladies, that I have now replaced but haven't listened to because ethe MLs are so good

The sound I am getting is pretty wonderful the ASR seem made for electrostatics

Fascinated by your experience but agree power really makes the panels soar

Do the 500 get hot running the MLs?

Enjoy..................
 

ack

VIP/Donor & WBF Founding Member
May 6, 2010
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#3
Well, you did see a picture of the bad boys :cool:

But here are some more, and yes they run hot, I run two computer fans in the back

dma-500ar-1.jpg

dma-500ar-2.jpg
 
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Al M.

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Sep 10, 2013
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Greater Boston
#4
Thanks Ack for having had us over for a terrific, entertaining and enjoyable listening session. The wine was excellent indeed, too.

The first piece you played, the Sheffield drum track, was impressive in immediacy and speed of dynamic impact, the exquisite timbre of cymbals and the high resolution of the skin sounds of the diverse drums. Also, rhythm and timing on this and other music were excellent, to a degree I had not heard before from your system. The Spectral DMA-500 clearly have an iron grip on the speakers which apparently dip down to 1 Ohm. Bass control on these difficult speakers clearly exceeded that of the DMA-400.

Last time I was somewhat critical of the resolution of timbral micro-detail by the digital which did not quite measure up to the standards that I expect. Your further modifications have worked: resolution was very high. So was resolution from vinyl. Among others, I was smitten by the fine detail of trumpet tone on For Duke, and the sound of massed violins on the Reference Recordings Berlioz Symphonie Fantastique. The experiment that you described of forcefully tapping on the LP while playing was impressive indeed.

The extremely low noise floor is stunning: not only was the Stockhausen piano CD (a reference recording) extraordinarily clean sounding, the decay seemed to go on forever.

Dynamics seemed excellent throughout, as did articulation, also on voices.

As far as the ongoing question goes if it would be worthwhile for you to buy Magico speakers to replace the ML: given what I hear from your heavily modified speakers (way past stock sound), as they are driven by these reference Spectral amps, and given what your personal priorities are of sound reproduction, I would say no, there is no point. Investing the money in sources instead would probably be best.
 
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ack

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May 6, 2010
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#5
Thanks Al!
 

awsmone

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Apr 7, 2014
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#6
That's great feedback Al, I will be interested to hear from PeterA whose musical priorities are similar to my own, and actually has Magicos

ML panels working well and driven well, are amazing transducers, but its hard to achieve those two, only taken me 8 years lol, and I had Prodigy before the CLX, so well done!

Getting the noise floor down on vinyl is critical, I am interested in your mod you and Al describe?
 

Al M.

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Sep 10, 2013
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#7
That's great feedback Al, I will be interested to hear from PeterA whose musical priorities are similar to my own, and actually has Magicos.
Yes, it will be interesting. Everybody has their own musical priorities, and mine are different to a certain extent both from Ack's and Peter's, even though there is very significant overlap in both directions.
 

awsmone

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Apr 7, 2014
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#8
Dear Ack

I don’t know if that record rack is bolted to the wall
But I had a very near fatal accident where the records were all edging towards the front lip of the record racks and toppled over luckily no one was in the room at the time
 

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bonzo75

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Feb 26, 2014
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#9
Hi in the second pic in the first post, where have all the others gone? Looks like only Peter in that frame with a "I can't believe how much better panels sound than cones look"
 

bonzo75

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Feb 26, 2014
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#10
From the left: Madfloyd, Al M, PeterA, and the host (having gained a bit of weight lately)

Are you guys in front of a hifi system or watching something at Starbucks?
 

Number9

Active Member
Oct 15, 2018
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#11
Hi ACK,
Would you mind posting a photo of your front wall (speaker/room setup)?
TY
 

ack

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May 6, 2010
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#12
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ack

VIP/Donor & WBF Founding Member
May 6, 2010
5,464
148
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Boston, MA
#13
Hi in the second pic in the first post, where have all the others gone? Looks like only Peter in that frame with a "I can't believe how much better panels sound than cones look"
The host is probably conveniently taking his sweet time making sandwiches because he can't stand the sound, and Al is probably caring for his ear bleeding in the bathroom. Peter has his ears covered, while Ian has nothing better to do than take pictures.
 

awsmone

Well-Known Member
Apr 7, 2014
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Canberra Australia
#14
Lol
Actually my interpretation of Peter A expression/photo was:-
Oh my this a great sound ..,,bugger I bought Magico or

Oh my god this is sh....t what do I say to Ack without a wrist slashing ?
 
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ack

VIP/Donor & WBF Founding Member
May 6, 2010
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Boston, MA
#15
Lol
Actually my interpretation of Peter A expression/photo was:-
Oh my this a great sound ..,,bugger I bought Magico or

Oh my god this is sh....t what do I say to Ack without a wrist slashing ?
I think it's the latter. He's gasping for air; he also took a ride with Al and thus has no other ride to get back home fast enough.
 

ack

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May 6, 2010
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#16
Hi ACK,
Would you mind posting a photo of your front wall (speaker/room setup)?
TY
Here's an older picture with the previous amps, from my system thread; the rack is unfortunately not secured to the wall; it should be

 

ack

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May 6, 2010
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Boston, MA
#17

Number9

Active Member
Oct 15, 2018
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#18
ACK, thanks for the photo. I bet the ML's sound great powered by the Spectral! It would seem to me though (and I am by no means an expert) that bracing your racks to the wall could be counterproductive from the standpoint of isolating your components from your room. I suppose you can come up with a way to stop the energy from the wall from getting to your rack. I am pretty sure the majority of turntable racks you see for sale that mount to walls are more geared for convenience than performance. Just thinking out loud and have no concrete evidence though.
 

PeterA

Well-Known Member
Dec 7, 2011
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#19
Part 1

Context:

First let me thank Tasos again for hosting this wonderful matinee gathering. It was not until midway through the session that we realized our group, informally known as the Boston Audio Group, had never actually met at one place at one time. We did all attend a debut of the Magico S7 at Goodwin’s High End together, but this was the first time at one of our houses to assess recent changes to one of our systems and to enjoy socializing together.

Tasos is a great host. He is known for offering Espresso, making delicious melted ham/cheese/tomato sandwiches, and for delivering a formal presentation explaining his latest modifications while standing in front of his system. He is also liberal with invitations to play the music his guests bring with them. This time, he also opened a delicious bottle of wine with which to celebrate our meeting.

The four of us have varying preferences and types of systems, but we share a common interest in hearing live music and debating audio topics with the intent of improving what we hear at home. We often disagree, but I think we respect each other's opinions and different points of view. I think Tasos’s system represents one extreme within our group, and perhaps Al’s represents the other. Ian’s and my system fall somewhere in the middle. This is based in part on the equipment used, but also in the ways we approach the hobby and our individual sonic goals. I’d like to share this as background to give context for my later comments. These summaries are only my impressions and perhaps slightly different from the way each of the four of us might describe them.

Ack: Electrostatic panels driven my Spectral/MIT with both analog and digital sources. Goals: Timbral accuracy and articulation. Transparency to the recording. Live music and reproduced music are two completely different activities. Live music is a reference for the timbre and dynamics of a system. Modifications are a means to optimize existing gear. Strong technical background and understanding of electronics. Willingness to experiment. Specifications matter but listening confirms improvements.

Madfloyd: Large sealed dynamic cone speakers, big tube amps, analog and digital. A musician. Goals: musical beauty and realism. Clarity and instrumental separation and an overall “clean sound”. The sweetness of a solo violin and the grandness, power and scale of a large orchestra. Perhaps our most frequent visitor to the BSO.

PeterA: Mid-sized cone speakers, SS Class A amps, vinyl-only system. Goals: taken from Jim Smith - Tone, Dynamics, and Presence, with an emphasis on natural and believable sound. Reproducing the energy of an instrument or voice in the listening room. Jazz and Classical, some classic rock.

Al M: Monitor/sub speakers, tube amps, digital only system with physical CDs. Goals: Liveliness, Dynamics, big and up front listening perspective. Immediate sound. Capturing the live gestalt of direct sound as heard close to the musicians. Jazz, Classical, avant guard compositions. Deep into composition and music theory and understanding the intent of the music maker.

It is an interesting dynamic. The four of us tinker away with our own systems and then regularly share our audio experiences with each other via email chains. We are often quite candid and critical, but I think we welcome these exchanges because they lead to greater understanding and appreciation of what we are trying to do. Although there is often some frustration and disagreement, discussions usually lead to learning. We then on occasion get together, in twos or threes, to hear the results, discuss further, and to learn about new music. This particular visit at Tasos’s was fun because all four of us were together.

Amongst the four of us, Tasos is unique in that he makes the clearest distinction between listening to live music and music reproduction in the home. For him, they are completely different experiences and pursuits. Tasos prefers a further listening perspective when at the BSO, usually first row center, first balcony. My usual seats are in the center of the orchestra section, row G or K. Ian and Al have lately been listening above and off to the side of the stage, first balcony, looking down at the players. I think they also enjoy being up close in front of the stage. These different perspectives are fascinating.

Tasos listens for accuracy of timbre and articulation at the BSO and of course just to the beauty of the music and the overall experience, but not so much to imaging, sound staging or Presence. This is reflected in the sound of his system which is all about dynamics and clean articulation and accurate timbre. Al likes a very immediate up front sound, and usually selects seats which give him that experience live. He then tries to get that at home. I think Ian and I are a bit more in between. For the three of us, listening live does seem to influence how we want our systems to sound at home. However, for Tasos, I think the live reference is primarily about understanding and recognizing instrumental timbre.

I find it fascinating to then compare the sound of these systems with the stated goals of their owners. Al likes an immediate and lively sound and an up front listening perspective. We hear it in his system. Tasos does not prioritize imaging, sounstaging or a sense of Presence. Perhaps this is because of the constraints of his room and his chosen speaker typology, but one does hear a very dynamic, clean, articulate sound from his system. Interestingly, the sound is extremely immediate and close to the listener, the exact opposite of how the music must sound further back in the hall with its more distant listening perspective. This makes sense once you understand his view that listening live and to recorded music are completely different activities. Tasos also prioritizes transparency to the recording which is consistent with hearing live music from different musician, playing different instruments, performing in different venues. Perhaps all four of us appreciate transparency in this sense and recognize that live sound is so variable.

All of this is context for the following impressions I now have of the sound of Tasos’s system.
 

PeterA

Well-Known Member
Dec 7, 2011
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North Shore of Boston
#20
Part 2

The System Sound:

Ultra clean
Accurate timbre
Very fast and dynamic with a large dynamic range
Clear and articulate
Immediate sound with an up front listening perspective
Transparent to the source within the limits of the room

I suppose this is the kind of sound one would expect from ML electrostatic panel speakers, Spectral electronics/MIT cables, and highly modified source components. However, it is not what I heard the first time I visited, or the most previous time about a year and a half ago. At those times, I found the sound to be somewhat bright and lacking transparency and dynamics. The system is now completely transformed.

I do not know exactly what equipment modification or replacement is responsible for the dramatic change in the sound that I heard. Tasos will know more about cause and effect, but I will try to describe what I heard. The system I heard before had what I would call a lot of “detail”. Sounds were clean, fast, clear. But with that came a brightness, a sterility, a limited tonal pallet, an overall coolness. For me, it lacked emotion. The music seemed distant and did not draw me in. I appreciated what I thought was a high degree of resolution, but it was not involving and did not sound convincing.

I would visit, listen to some LPs, and lose interest. I blamed the MIT cable settings, the unipivot tone arm, the replicant stylus, the sterile SS electronics, or the panel to woofer integration. I do not want to presume that Tasos paid attention to my rather candid reactions over time, but he continued to tinker, to modify, to research the new Spectral gear and to experiment. This forum has threads describing his considerable efforts.

Years ago, I played the Sheffield Drum Track, and I was shocked at how slow, soft and unexciting it sounded. I was surprised because even with my Magico Mini 2s and Pass XA.5 amps, it sounded much more dynamic and explosive. Well, rather than dwell on what once was, I can now write that that Drum Track sounds incredible. There is an immediacy and explosive quality that was only imagined before. The articulation and difference between the various drum skins and cymbals is remarkable. It was the first recording that Tasos played for us because it so clearly demonstrated the improvements in his system.

We played a few more direct to disk LPs, Thelma Houston, For Duke, Charlie Byrd, Beethoven’s Appassionata. These all sounded excellent. Very immediate and alive. The brass horns and cymbals were very realistic sounding. Tasos plays his music loud, but this music lends itself to that. The sound remained clear, clean and very articulate. The speakers showed no strain. There was just explosive, effortless and immediate sound. Any hint of high frequency distortion and brightness which I heard before was completely absent.

Two other recordings really stood out for me: Kuijken playing Bach’s Partita No.2 on Harmonia Mundi, and the 45 rpm Reference Recording of Berlioz’ Symphonie Fantastique, “March to the Scaffold”. The former had all of the sweet string tone and beauty that this recording is known for, and the latter demonstrated just how much timbral accuracy and clarity a good recording of large scale music can have. The bells, the brass section, the massed strings, bass drum and tympani were extremely realistic sounding. This was a highlight of the afternoon, and a great recording to end the listening session with.

Of particular note was how well the modified Berkeley DAC compared to the VPI turntable. The presentations were slightly different in terms of spacial information and listening perspective, but the tone, and beauty were very similar.

There is one more aspect to the sound which did change quite a bit since the last time I was there, and I do not really understand the cause. The listening perspective had been pretty close with the music just behind the plane of the speakers. It is now even closer, extremely up front and immediate. There is not a lot of presence, dimensionality, or depth to the sound. Imaging exists but is not noteworthy. Tasos does not focus on this aspect of the sound, and I suspect it has much do to with the restrictions of his room. The room is wide but not deep, has no acoustic treatment, and many hard surfaces. Perhaps most problematic is the location and size of his equipment rack and gear stacked high, just behind and between his speakers. He is working around and accepting this condition.

Having mentioned our candor with each other, I would be remiss if I did not mention that a few recordings did not sound as good to me. Two in particular, a Holst choral recording and Cantata Domino on Proprius. I listen to these recordings often and usually bring them to assess other systems. One of my priorities is natural sound and believability. I want to be somewhat convinced that I am witnessing a performance, and that depends on my ability to get lost in the space of the sound. The soundstage, dimensionality and sense of Presence that I am used to hearing from these two particular LPs was missing. That prevented me from really enjoying them at Tasos’s house. I need to “see” the singers in the church or on the stage as well as feel their energy and hear their music. When the visual component in my mind’s eye is lessoned, the whole presentation becomes less involving for me. The realism breaks down. The up front perspective of Tasos's system prevented me from believing the singers were in front of me, or I was sitting in the cathedral. But, this aspect is less important for Tasos.

The immediacy and energy from the jazz and large scale classical, even the solo violin, were very convincing in his room, often, startlingly so. Those drums, that brass, the orchestral instruments, were often outrageously real sounding. So, what I attribute to the room limitations and rack location preventing a more realistic portrayal of soundstage, imaging, and Presence, is the one caveat I heard from his system. And that is not an issue for a guy who prioritizes other sonic attributes and views reproduced music completely differently from the live experience.

Most of us live with a set of compromises, especially with our rooms. Tasos has a lovely home but no dedicated room in which he can move his system. His listening room is lovely and has a clean, modern aesthetic. It is wonderful for entertaining, and I commend his wife for putting up with Tasos’s audio equipment in such a public space. I think they enjoy entertaining guests and sharing music with others, so this is part of their lifestyle, much as it is in Madfloyd’s household.

Tasos’s system is completely transformed from what I remember from a couple of years ago. It basically looks the same, but there are many changes, both big and small. What was for me a rather cool, hifi sound before, is now much more like real music: engaging, alive, ultra clean, dynamic and articulate. These are his goals, and he has achieved them.

Congratulations Tasos, and thank you for hosting a very memorable gathering.

To the Sun that Warmed the Vineyard,
To the Grapes that Made the Wine,
To the Host who cracked the Bottle,
And Made it Yours and Mine.
 
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