I can only surmise that the 2c3d effect is indeed very minor or non existent when the switch is turned to "off", or that the music selection I took to audition the M3 was too limited to show this effect (remember I only listened to six cuts on 2 LPs of small scale acoustic music during a roughly 40 minute audition period), or that some other pleasing coloration of the system like the forgiving Benz cartridge may have obscured any minor remaining 2c3d effect, or that my ears are not sensitive enough to hear this effect when the switch is turned to "off", or that the dealer is just wrong when he says the 2c3d enhancement remains in effect when the switch is "off", or that it is any combination of these factors. I really don't know.
ack's system - end of round 1
- Thread starter ack
- Start date
I can only surmise that the 2c3d effect is indeed very minor or non existent when the switch is turned to "off", or that the music selection I took to audition the M3 was too limited to show this effect (remember I only listened to six cuts on 2 LPs of small scale acoustic music during a roughly 40 minute audition period), or that some other pleasing coloration of the system like the forgiving Benz cartridge may have obscured any minor remaining 2c3d effect, or that my ears are not sensitive enough to hear this effect when the switch is turned to "off", or that the dealer is just wrong when he says the 2c3d enhancement remains in effect when the switch is "off", or that it is any combination of these factors. I really don't know.
Last time I checked, no tube amp designer has teamed up with a cable maker to supply the output transformers at the end of the cable...
The point is that once the filtered cables are in place the bandwidth is not any wider than many other amps and square wave performance hampered. The raw amp then is not what matters but what comes out the end of the filter, which is no longer 2Mhz (or whatever bandwidth it has) but what the filter rolls it off at.
We know all of that; you are 25 years late to the discussion. In a Stereophile review of the MIT 850 speaker cables (part of a Spectral review) in the 1990s, for example, they measured the start of the rolloff at ~800kHz (I think they may have claimed the amp is restricted to 800kHz a the output terminals), with the -3dB around 1.2MHz or so. I don't know how the newer cables since then measure, but what's your point. We know there has to be rolloff to provide stability - what is incredible about these amps is that they actually go SO FAR OUT, like no other, to require stability. The same is true for FM Acoustics and their requirement to use their own speaker cables.
EDIT: If you read the 300RS write-up carefully, they briefly discuss their design decisions and how they use one output cable to stabilize the amp, regardless of that MIT is doing beyond that:
It should be obvious there is quite a bit more sophistication than what this mere mortal is writing...
EDIT 2: Here's the language from the Stereophile review:
Last edited:
Perhaps your point of view, but not the one of the manufacturer or happy owners. The question is not the bandwidth per se, but that an amplifier manufactured with this bandwidth and these features sounds better according to some people.
People find better for sonic reasons introducing controlled filters in the cables - perfect for me. As long as the frequencies are well outside the audio band, even objectivists should be pleased.
Perhaps your point of view, but not the one of the manufacturer or happy owners. The question is not the bandwidth per se, but that an amplifier manufactured with this bandwidth and these features sounds better according to some people.
People find better for sonic reasons introducing controlled filters in the cables - perfect for me. As long as the frequencies are well outside the audio band, even objectivists should be pleased.
Microtrip, I see from you signature that you use Transparent cables. Have you ever directly compared them to MIT in your system? If so, what differences did you hear?
Last time I tried MIT cables was perhaps around 15 years ago - the top 350's and 750's, I do not remember the codes. I had a good time with them, mainly with conrad johnson, but the 350's were RCA's and when I got balanced equipment I sold them. No experience with recent MIT cables as they are not distributed in my country.
The DMA-500 Anniversary Reference
INITIAL IMPRESSIONS
These amps arrived a while ago, but I have not had a chance to listen for too long, due to contractor work in the house and one of the ML panels going bad the other day, with heavy disortion at certain frequencies - these last 15-20 years, and mine are in that range. The unfortunate thing is that it won't be before August that I get the replacements, though the good news is that all other parts are still stocked at Martin Logan and the panels will be custom-made.
I also had the pleasure of re-evaluating the 4000SV CD player along with the 500s, and this time, its sonic superiority came shining right through. I would easily rate it above my DAC especially when it comes to control as the signal gets really complicated (Mahler 2nd's finale), and way above the Vivaldi 2.0 that I also had in here a couple of years ago. The most fascinating aspect of the 4000SV over my DAC is the low-end punch, control and pitch definition, which had me smiling at the quality of bass I have been able to build into these speakers, something that I was not aware of before.
Back to the amps... I am told these ARs are limited-edition, but I have to assume they will have to make more "regular" versions - that's my guess. To cut to the chase, the dealer brands these "super amps", "pure and natural" sounding. I would simply say that, with the advent of the SV technology, finally their solid state designs have been fully tamed. That in itself is a major breakthrough. On the downside, as I've written herein, the midrange sounded over many auditions with the M3s "weird", and we have since then traced it to the expensive MIT speaker cables, and that silly 2C3D thing - nothing to do with the amps or the M3s.
In this system so far, the 500s sound like a refined pair of 400s, less shouty, with more treble control but higher resolution as well, exceptional bass control, very clear sound, and truly render what I have been chasing for decades: Timbre and Articulation. The completeness of notes, when the recording is up to it, is arresting; that elusive perfect leading edge is there - the bells in the Reference Recordings Fantastique LP are very believable. String tone as well. Timpani rise, sustain and decay, so clear. And voices, oh so natural... But let me take a step back: the slew rate of these amps is claimed to be 1200V/usec, above the 30SV preamp's 1000V/usec, and double the 400's. Settling time is claimed to be <300 nano seconds, slightly higher than the 400's. The dealer claims distortion levels are also lower than the preamp's.
If I were to pick one word to describe the 500s, it would be "Scary". Scary realistic, and scary in power and impact. I was literally frightened to play my friend Al's Rihm Tutuguri CD, and I think that may have dealt the panels the coup de grace. I have gone from "Gosh, these amps shut down on me" during my in-store auditions with the M3s, to "Thank God, these amps will shut down" and protect your speakers.
Over the years, and having seen other owners' trials and tribulations when veering off Spectral's guidance on how their amps need to be driven, I have learned to take their claims in the manual quite seriously. Some key points on the 500s:
And a quite-strong a statement from a well-established and humble engineer:
Well, from the little that I've heard in here, I would describe things from a different angle: a) I hear slightly more detail and realism than from the M3s, which has me ordering new panels, but I will go back and re-audition the M3s and focus on the things that I think I hear in here only; b) I still feel a properly crossed-over electrostatic transducer is hard to beat; c) there is very high timbral accuracy and articulation from my analog; d) the superiority of analog over redbook is now more pronounced; e) my wife started dancing with the first Chesky track, and she is completely unaware of the amplifier swap - thank you Spectral for making all your amps look the same!
Years ago I said the 400s are one for the history books; the 500s, instead, are museum pieces.
Fascinating achievement by the Spectral engineering team, and an inspiration for me to excel in my line of work.
INITIAL IMPRESSIONS
These amps arrived a while ago, but I have not had a chance to listen for too long, due to contractor work in the house and one of the ML panels going bad the other day, with heavy disortion at certain frequencies - these last 15-20 years, and mine are in that range. The unfortunate thing is that it won't be before August that I get the replacements, though the good news is that all other parts are still stocked at Martin Logan and the panels will be custom-made.
I also had the pleasure of re-evaluating the 4000SV CD player along with the 500s, and this time, its sonic superiority came shining right through. I would easily rate it above my DAC especially when it comes to control as the signal gets really complicated (Mahler 2nd's finale), and way above the Vivaldi 2.0 that I also had in here a couple of years ago. The most fascinating aspect of the 4000SV over my DAC is the low-end punch, control and pitch definition, which had me smiling at the quality of bass I have been able to build into these speakers, something that I was not aware of before.
Back to the amps... I am told these ARs are limited-edition, but I have to assume they will have to make more "regular" versions - that's my guess. To cut to the chase, the dealer brands these "super amps", "pure and natural" sounding. I would simply say that, with the advent of the SV technology, finally their solid state designs have been fully tamed. That in itself is a major breakthrough. On the downside, as I've written herein, the midrange sounded over many auditions with the M3s "weird", and we have since then traced it to the expensive MIT speaker cables, and that silly 2C3D thing - nothing to do with the amps or the M3s.
In this system so far, the 500s sound like a refined pair of 400s, less shouty, with more treble control but higher resolution as well, exceptional bass control, very clear sound, and truly render what I have been chasing for decades: Timbre and Articulation. The completeness of notes, when the recording is up to it, is arresting; that elusive perfect leading edge is there - the bells in the Reference Recordings Fantastique LP are very believable. String tone as well. Timpani rise, sustain and decay, so clear. And voices, oh so natural... But let me take a step back: the slew rate of these amps is claimed to be 1200V/usec, above the 30SV preamp's 1000V/usec, and double the 400's. Settling time is claimed to be <300 nano seconds, slightly higher than the 400's. The dealer claims distortion levels are also lower than the preamp's.
If I were to pick one word to describe the 500s, it would be "Scary". Scary realistic, and scary in power and impact. I was literally frightened to play my friend Al's Rihm Tutuguri CD, and I think that may have dealt the panels the coup de grace. I have gone from "Gosh, these amps shut down on me" during my in-store auditions with the M3s, to "Thank God, these amps will shut down" and protect your speakers.
Over the years, and having seen other owners' trials and tribulations when veering off Spectral's guidance on how their amps need to be driven, I have learned to take their claims in the manual quite seriously. Some key points on the 500s:
And a quite-strong a statement from a well-established and humble engineer:
Well, from the little that I've heard in here, I would describe things from a different angle: a) I hear slightly more detail and realism than from the M3s, which has me ordering new panels, but I will go back and re-audition the M3s and focus on the things that I think I hear in here only; b) I still feel a properly crossed-over electrostatic transducer is hard to beat; c) there is very high timbral accuracy and articulation from my analog; d) the superiority of analog over redbook is now more pronounced; e) my wife started dancing with the first Chesky track, and she is completely unaware of the amplifier swap - thank you Spectral for making all your amps look the same!
Years ago I said the 400s are one for the history books; the 500s, instead, are museum pieces.
Fascinating achievement by the Spectral engineering team, and an inspiration for me to excel in my line of work.
Last edited:
Tasos,
Congrats again. I look forward to reading more impressions of the 500s as time goes on.
It still blows my mind that people will use Spectral amps without a Spectral pre-amp and or MIT cables. Tuning to their subjective preference ; rather than trusting KOJ and the design team at Spectral. It's a whole system approach and as someone once told me ; if you have a problem with using a Spectral pre and Or MIT cables than Spectral isn't for you. Luckily, I didn't disagree with them The proof is in the listening.
Btw, is an SDR-4000SV in your future? I never heard it with the 500s so I can only imagine.
Congrats again. I look forward to reading more impressions of the 500s as time goes on.
It still blows my mind that people will use Spectral amps without a Spectral pre-amp and or MIT cables. Tuning to their subjective preference ; rather than trusting KOJ and the design team at Spectral. It's a whole system approach and as someone once told me ; if you have a problem with using a Spectral pre and Or MIT cables than Spectral isn't for you. Luckily, I didn't disagree with them
The proof is in the listening.Btw, is an SDR-4000SV in your future? I never heard it with the 500s so I can only imagine.
Congratulations, Tasos! I had already been mightily impressed with the DMA-400 monoblocks, more and more each time I visited to hear your system, so I very much look forward to hear what the 500s can do. As I have said many times, Spectral would be my first choice for SS amplification.
Sorry to hear about your panel. As we discussed last time I heard your system, you had already planned to buy replacement panels given the life expectancy of these transducers, so this came not entirely out of the blue. But being without music is no fun.
As for the bass performance of the Berkeley DAC being exceeded by the Spectral 4000 SV, I am not surprised. As you reported, you had raised the bass performance of the DAC by the modifications you made, so I cannot speak to the difference with the unmodified standard unit. Yet the bass of my standard Berkeley DAC was handily improved in quantity, quality and overall punch, in a not so subtle manner, by my Schiit Yggdrasil DAC. In direct comparison a stark difference was immediately obvious. However, for context, the Berkeley DAC is no slouch either when it comes to the bass; it was dramatically superior, also in plain blackness, to the bass of other DACs that I had heard at home, the NAD M51 and the Hegel DAC 25, not to speak of my own old Wadia 12 DAC.
Sorry to hear about your panel. As we discussed last time I heard your system, you had already planned to buy replacement panels given the life expectancy of these transducers, so this came not entirely out of the blue. But being without music is no fun.
As for the bass performance of the Berkeley DAC being exceeded by the Spectral 4000 SV, I am not surprised. As you reported, you had raised the bass performance of the DAC by the modifications you made, so I cannot speak to the difference with the unmodified standard unit. Yet the bass of my standard Berkeley DAC was handily improved in quantity, quality and overall punch, in a not so subtle manner, by my Schiit Yggdrasil DAC. In direct comparison a stark difference was immediately obvious. However, for context, the Berkeley DAC is no slouch either when it comes to the bass; it was dramatically superior, also in plain blackness, to the bass of other DACs that I had heard at home, the NAD M51 and the Hegel DAC 25, not to speak of my own old Wadia 12 DAC.
Thanks all. No I’d rather get a DAC with high res for $20k than a player. Digital is just not worth paying a lot of money for.
Congratulations, Ack! You remain at the cutting edge of Spectral electronics and I know you have been excited about this upgrade since these reference amps were announced. I am not surprised that the Spectral pieces seem to be your only components to which you don't want to add any of your modification magic.
Thanks Peter. There is one more missing piece here, that elusive phono, and from then on, I do not expect any further upgrades, considering that college and graduate school are upcoming expenses. Having said that, I am on the fence as to whether I am going to pursue a switch to Magico or not.
I've been listening all morning today, and I have to admit, even with digital and the distorting panel, the system sounds really good. If you prune that narrow distorting region in the panel out, the sound is more dynamic, accurate and articulate than ever before. These 500s are blunt instruments. It's a blessing that the panel is not entirely gone, and I can continue to listen to music while awaiting the replacements.
Hi Ack,
As a new member to this forum, I was wondering if you could share with me how you modified the Berkeley Alpha DAC 2? I own both a Berkeley alpha USB and DAC2? I was wondering if anyone on this forum has upgraded their Berkeley alpha DAC2 with the MQA renderer and if so, what is your overall impression of the upgrade from a sound improvement standpoint.
All the best,
Thomas Chiles
Norfolk, MA
As a new member to this forum, I was wondering if you could share with me how you modified the Berkeley Alpha DAC 2? I own both a Berkeley alpha USB and DAC2? I was wondering if anyone on this forum has upgraded their Berkeley alpha DAC2 with the MQA renderer and if so, what is your overall impression of the upgrade from a sound improvement standpoint.
All the best,
Thomas Chiles
Norfolk, MA
 | Steve Williams Site Founder | Site Owner | Administrator |  | Ron Resnick Site Owner | Administrator |  | Julian (The Fixer) Website Build | Marketing Managersing |