Classification of some top SS amps (brands)

[Rocco I.]

Fine, but what about

- Soundstage (width, depth, height)
- Spatial representation of the music
- organic representation of the instruments
- physical presence
- blackness of the background
- calmness and airiness between the sounds or instruments?

All at reference level assuming that loudspeakers system, source, preamp, cables, treatment of power grid and whole acoustic concern are in order.

 

[Amir]

I have heard Soulution 5 series, Boulder (2060 generation so much older), Gryphon (owned Mephisto) and Robert Koda (own K160s today). All of these were either in our system or in a system very very similar at the store which I have known for nearly 20 years (same speakers as at home, same cables, different source (DCS Vivaldi vs Zanden 4-box at home). *BTW, I have also heard Constellation (excellent) and Ypsilon SET Reference Monos...but since you did not ask, will not take up any more air time on those.)

My observations:

- Soulution was very evenly balanced, powerful and you knew it had detail. It was subtle, but I think the 'messaging' in the signal was that the musical detail was just a touch (I mean a touch) highlighted so you knew it was there. By touch I mean, when you heard it, the detail retrieval occurred to you. You noticed it. In the end, I really respected it just did not feel passionately about it.

- Boulder was clean, effortlessly powerful and ultra q-u-i-e-t. I admired the fact that it came across as utterly unflappable in the sound room...but it even appeared to be the kind of amp you could drop down the stairs (so heavy!) and it would still work perfectly. Built like a tank and well built. And that kind of solidity, confidence also came thru in its presentation...again utterly unflappable by any signal, no matter how powerful, how percussive, deep, high, loud...or sometimes equally...insanely soft (almost missable without a super low noise floor). You felt someone was giving you the unvarnished truth...I will come back to this point later...and so it would seem that is entirely Boulder's goal.

- Gryphon. I have owned the original Antileon, Colosseum and then the Mephisto. So know them well...10 consecutive years, and between nearly getting the Boulder and then 3 Gryphons...super-powerful, pure Class A has been a theme for me. Right or wrong. The Gryphon's emphasis is on creating such a remarkable lifelike presence in music that it breathes a powerful sense of life into performances. Part of that comes from what I have now come to believe is a shade of extra power in the mid-bass (not much mind you, but 'just enough') that when you play recordings through them...piano, vocals, guitars have a power to them which is unmistakable, addictive and something you can easily sit back and soak in forever. It is super addictive, satisfying and whether you are at volume 1 or 100...you never lack for body in your music. I really really got a thrill out of that from Gryphon. Additionally, as time went on, the much much earlier (original Antileon) sense of darkness fell away, and generally speaking, while Gryphon's propsulsive bass tends to add weight to sound (and arguably a darker tone)...it really has a very very filigreed set of highs that are also very extended.

- Robert Koda. Now this is a tough one. First, I come back to the 'unvarnished truth' of Boulder. It was what I think of when I hear it, and that includes the term unvarnished. Some have found that some fundamentals or harmonics in the notes are ever so slightly stripped. On the one hand, I think I do see that in the older 2060...on the other hand, I can see that your upstream equipment could probably very easily counterbalance that. So it is a signature but not an insurmountable one.

Now we come to Robert Koda. This is a designer whose background is Kondo (ultra extreme, ultra custom, ultra music-as-a-pure-form-of-art) but who after 20 years has evolved to entirely solid state (again, pure Class A) and entirely his own designs. But he applies his intensity and extreme Kondo-homage purity ethic to his own solid state designs so that rather than deliver unvarnished...he literally seems to be design the purest and simplest circuit with the lowest noise floor (and does things like pure solid copper chassis tp block EMI, RFI, etc), design an insane 238-part hand soldered attenuator, where only 2 parts actually touch the circuit at any given volume or something crazy like that)...and his K15EX emerges as something that truly is the closest to pure music I have ever encountered.

Meanwhile, he takes this same ethos recently to develop the K160s...much, much tougher to figure out for me, coming from a Gryphon background. I drop them in...and they are so pure, so low-noise-floor and so effortless, they make the Gryphon feel like it has mechanical things going to reproduce sound. BUT...here is the BUT...it takes me a YEAR to finally get the bass right. Why? Because the entire system had been meticulously set up around the Gryphon whose propulsively powerful bass is renowned.

Whether the Robert Koda is absolutely dead even across the entire spectrum, I cannot say. All I can say is that after reworking the entire system, piece by piece particularly including repositioning the speakers by centimeters and Absolute Sounds adjusting the internals...the bass is extraordinary...breathtaking articulate and nuanced in a way the Mephisto was not in our system (despite being supremely articulate). And shockingly, much more extended...much deeper and more resolved at that depth. Even the famous midbass of the Gryphon is bested by now the Robert Koda...but it took a lot of minute adjustments across the entire system that had been living with Gryphon for 10 years consecutively. And by bested, I do not mean that the Robert Koda now has a protruding midbass, but rather that the finetuning of the system now provides a depth and power in the midbass that when amplified by the Robert Koda has pure power while at the same time having extraordinary nuance. And this gives a richness of detail and life to the midbass...without making it fulsome or weighty to do so. It just feels right. Finally, the Robert Koda bass is firmly best in sheer all-out power and now shows me that its bass always had the ability to match the absolute organic purity of its midrange and treble.

Relative to the Gryphons, the Robert Kodas are NOT drop-ins. The K15EX probably is for most systems to be fair. But you have to be ready to ensure your system is set up to produce exactly the sound you want BEFORE it gets to the Koda K160 monos...and then as soon as it does reach them, they will produce effortless, powerful, organic, nuanced music. But if there is something up in the chain just off (particularly in the bass), there is no extra fat in the K160 to smooth that over. It just wont play it until your system delivers it. it took me a year to get it right, and it has been another year of finetuning the upstream. However, this extra year of finetuning has resulted in extraordinary improvements where I realize that without the Robert Kodas, I would probably not have been able to achieve this because the earlier pre-Robert Koda amplification would not have been up to it. It takes time and effort...but the Robert Kodas make that so eminently worthwhile in a way that no other piece of equipment ever has for me with perhaps its equal being the Zanden 4-box which after 15 years remains in the system to this day. A note of advice if you will.

Hope that helps. One man's experience.

Thank you for describing the time/effort you spend for properly setup of new koda amplifier. I think good/trusted judgments come from right setup.
I Love Japan high end equipments.

 

[LL21]

Thank you for describing the time/effort you spend for properly setup of new koda amplifier. I think good/trusted judgments come from right setup.
I Love Japan high end equipments.

You are in the business...set up is so important. For us amateurs, we do end up with some trial and error sometimes...and the risk is we make poor decisions about equipment because they are actually uninformed decisions or hasty decisions. I have no doubt I have made some of those.

Nevertheless, through both the unsuccessful and the successful efforts, we can learn, and the rewards are special.

BTW, I have not heard TAD in a while, but when I did it was at Pioneer Plaza in Japan...hosted by the CEO who happened to be available and was very generous with his time. Very very memorable. Great designs.

 

[Amir]

You are in the business...set up is so important. For us amateurs, we do end up with some trial and error sometimes...and the risk is we make poor decisions about equipment because they are actually uninformed decisions or hasty decisions. I have no doubt I have made some of those.

Nevertheless, through both the unsuccessful and the successful efforts, we can learn, and the rewards are special.

BTW, I have not heard TAD in a while, but when I did it was at Pioneer Plaza in Japan...hosted by the CEO who happened to be available and was very generous with his time. Very very memorable. Great designs.

I 100% agree you that many decisions are uninformed decisions or hasty decisions.

before any hardware upgrade or any audio judgment I always recommend to check these items:
- Speaker/room matching
- Speaker optimal position
- Amplifier/speaker cable/speaker matching
- AC Power quality , AC polarity , Ground Quality

 

[LL21]

I 100% agree you that many decisions are uninformed decisions or hasty decisions.

before any hardware upgrade or any audio judgment I always recommend to check these items:
- Speaker/room matching
- Speaker optimal position
- Amplifier/speaker cable/speaker matching
- AC Power quality , AC polarity , Ground Quality

Yes! And then re-check setup as you say after inserting the new trial equipment as well. In the case of moving from Gryphon Mephisto to Robert Koda K160, it definitely required many adjustments to the system which over years had been finetuned to accommodate Gryphon amplification (in the system for 10 years).

 

[gleeds]

Verdier makes a good point; numerous aspects determine one's best SS amplifier, especially at this level of play. For Rocco I., neutrality and musicality were at the top of his list, and for him, sufficient attributes to call it the perfect amplifier.

In my view to comprehensively evaluate how each top line amplifier compares (besides regular exposure to live unamplified music), one should have a reference level loudspeaker and a well, sorted acoustically neutral listening room. From there the ability to compare each amplifier against a scorecard of attributes. One should also consider personal bias and the soft" characteristics we often use when making such a large investment.

- acquisition cost
- auditory preferences
- build quality
- Company history and pedigree
- Industrial design and resale value etc.

Undoubtedly, all the amplifiers mentioned in this thread have their strong points, with each manufacturer putting forth their vision of the most faithful reproduction of recorded music. I agree having a short list is helpful.

I do want to hear the Robert Koda K-160 monos as they sound like one of those seminal products anyone who is serious about pursuing the art of reproduced must hear. Does anyone know if anyone has them accessible for an audition in the US?
Naturally, my favorite SS amplifier choice is the bridged version of the WestminsterLab monos

 

[Verdier]

I have heard Soulution 5 series, Boulder (2060 generation so much older), Gryphon (owned Mephisto) and Robert Koda (own K160s today). All of these were either in our system or in a system very very similar at the store which I have known for nearly 20 years (same speakers as at home, same cables, different source (DCS Vivaldi vs Zanden 4-box at home). *BTW, I have also heard Constellation (excellent) and Ypsilon SET Reference Monos...but since you did not ask, will not take up any more air time on those.)

My observations:

- Soulution was very evenly balanced, powerful and you knew it had detail. It was subtle, but I think the 'messaging' in the signal was that the musical detail was just a touch (I mean a touch) highlighted so you knew it was there. By touch I mean, when you heard it, the detail retrieval occurred to you. You noticed it. In the end, I really respected it just did not feel passionately about it.

- Boulder was clean, effortlessly powerful and ultra q-u-i-e-t. I admired the fact that it came across as utterly unflappable in the sound room...but it even appeared to be the kind of amp you could drop down the stairs (so heavy!) and it would still work perfectly. Built like a tank and well built. And that kind of solidity, confidence also came thru in its presentation...again utterly unflappable by any signal, no matter how powerful, how percussive, deep, high, loud...or sometimes equally...insanely soft (almost missable without a super low noise floor). You felt someone was giving you the unvarnished truth...I will come back to this point later...and so it would seem that is entirely Boulder's goal.

- Gryphon. I have owned the original Antileon, Colosseum and then the Mephisto. So know them well...10 consecutive years, and between nearly getting the Boulder and then 3 Gryphons...super-powerful, pure Class A has been a theme for me. Right or wrong. The Gryphon's emphasis is on creating such a remarkable lifelike presence in music that it breathes a powerful sense of life into performances. Part of that comes from what I have now come to believe is a shade of extra power in the mid-bass (not much mind you, but 'just enough') that when you play recordings through them...piano, vocals, guitars have a power to them which is unmistakable, addictive and something you can easily sit back and soak in forever. It is super addictive, satisfying and whether you are at volume 1 or 100...you never lack for body in your music. I really really got a thrill out of that from Gryphon. Additionally, as time went on, the much much earlier (original Antileon) sense of darkness fell away, and generally speaking, while Gryphon's propsulsive bass tends to add weight to sound (and arguably a darker tone)...it really has a very very filigreed set of highs that are also very extended.

- Robert Koda. Now this is a tough one. First, I come back to the 'unvarnished truth' of Boulder. It was what I think of when I hear it, and that includes the term unvarnished. Some have found that some fundamentals or harmonics in the notes are ever so slightly stripped. On the one hand, I think I do see that in the older 2060...on the other hand, I can see that your upstream equipment could probably very easily counterbalance that. So it is a signature but not an insurmountable one.

Now we come to Robert Koda. This is a designer whose background is Kondo (ultra extreme, ultra custom, ultra music-as-a-pure-form-of-art) but who after 20 years has evolved to entirely solid state (again, pure Class A) and entirely his own designs. But he applies his intensity and extreme Kondo-homage purity ethic to his own solid state designs so that rather than deliver unvarnished...he literally seems to be design the purest and simplest circuit with the lowest noise floor (and does things like pure solid copper chassis tp block EMI, RFI, etc), design an insane 238-part hand soldered attenuator, where only 2 parts actually touch the circuit at any given volume or something crazy like that)...and his K15EX emerges as something that truly is the closest to pure music I have ever encountered.

Meanwhile, he takes this same ethos recently to develop the K160s...much, much tougher to figure out for me, coming from a Gryphon background. I drop them in...and they are so pure, so low-noise-floor and so effortless, they make the Gryphon feel like it has mechanical things going to reproduce sound. BUT...here is the BUT...it takes me a YEAR to finally get the bass right. Why? Because the entire system had been meticulously set up around the Gryphon whose propulsively powerful bass is renowned.

Whether the Robert Koda is absolutely dead even across the entire spectrum, I cannot say. All I can say is that after reworking the entire system, piece by piece particularly including repositioning the speakers by centimeters and Absolute Sounds adjusting the internals...the bass is extraordinary...breathtaking articulate and nuanced in a way the Mephisto was not in our system (despite being supremely articulate). And shockingly, much more extended...much deeper and more resolved at that depth. Even the famous midbass of the Gryphon is bested by now the Robert Koda...but it took a lot of minute adjustments across the entire system that had been living with Gryphon for 10 years consecutively. And by bested, I do not mean that the Robert Koda now has a protruding midbass, but rather that the finetuning of the system now provides a depth and power in the midbass that when amplified by the Robert Koda has pure power while at the same time having extraordinary nuance. And this gives a richness of detail and life to the midbass...without making it fulsome or weighty to do so. It just feels right. Finally, the Robert Koda bass is firmly best in sheer all-out power and now shows me that its bass always had the ability to match the absolute organic purity of its midrange and treble.

Relative to the Gryphons, the Robert Kodas are NOT drop-ins. The K15EX probably is for most systems to be fair. But you have to be ready to ensure your system is set up to produce exactly the sound you want BEFORE it gets to the Koda K160 monos...and then as soon as it does reach them, they will produce effortless, powerful, organic, nuanced music. But if there is something up in the chain just off (particularly in the bass), there is no extra fat in the K160 to smooth that over. It just wont play it until your system delivers it. it took me a year to get it right, and it has been another year of finetuning the upstream. However, this extra year of finetuning has resulted in extraordinary improvements where I realize that without the Robert Kodas, I would probably not have been able to achieve this because the earlier pre-Robert Koda amplification would not have been up to it. It takes time and effort...but the Robert Kodas make that so eminently worthwhile in a way that no other piece of equipment ever has for me with perhaps its equal being the Zanden 4-box which after 15 years remains in the system to this day. A note of advice if you will.

Hope that helps. One man's experience.

Many thanks for this really exemplary good and insightful experience report!

 

[LL21]

Verdier makes a good point; numerous aspects determine one's best SS amplifier, especially at this level of play. For Rocco I., neutrality and musicality were at the top of his list, and for him, sufficient attributes to call it the perfect amplifier.

In my view to comprehensively evaluate how each top line amplifier compares (besides regular exposure to live unamplified music), one should have a reference level loudspeaker and a well, sorted acoustically neutral listening room. From there the ability to compare each amplifier against a scorecard of attributes. One should also consider personal bias and the soft" characteristics we often use when making such a large investment.

- acquisition cost
- auditory preferences
- build quality
- Company history and pedigree
- Industrial design and resale value etc.

Undoubtedly, all the amplifiers mentioned in this thread have their strong points, with each manufacturer putting forth their vision of the most faithful reproduction of recorded music. I agree having a short list is helpful.

I do want to hear the Robert Koda K-160 monos as they sound like one of those seminal products anyone who is serious about pursuing the art of reproduced must hear. Does anyone know if anyone has them accessible for an audition in the US?
Naturally, my favorite SS amplifier choice is the bridged version of the WestminsterLab monos

Last time I spoke with Robert Koda a couple of months ago, there was not a dealer/distributor in the US unfortunately.

 

[Elliot G.]

Last time I spoke with Robert Koda a couple of months ago, there was not a dealer/distributor in the US unfortunately.

I spoke with Robert about a year ago and he told me that he could not produce enough product to open a dealer/distributor in the USA . He did explain that he makes everything by himself and if that is still the case his output is very small.
I was interested in representing the product here.

 

[LL21]

I spoke with Robert about a year ago and he told me that he could not produce enough product to open a dealer/distributor in the USA . He did explain that he makes everything by himself and if that is still the case his output is very small.
I was interested in representing the product here.

Given the caliber of brands you represent, I will take that as a very good sign. Interestingly, AE also represents Wadax and Goebel.

Yes, Robert does most everything himself. BTW, I noticed you represent a number of subwoofer manufacturers:

- Goebel (Baforce and Sovereign)
- REL (6-pack, 32 and 31)
- JL Audio (Gotham)

I will PM you separately.

 

[Elliot G.]

Given the caliber of brands you represent, I will take that as a very good sign. Interestingly, AE also represents Wadax and Goebel.

Yes, Robert does most everything himself. BTW, I noticed you represent a number of subwoofer manufacturers:

- Goebel (Baforce and Sovereign)
- REL (6-pack, 32 and 31)
- JL Audio (Gotham)

I will PM you separately.

Lloyd, I have very little RK experience but I contacted him because of his stellar reputation. I truly don't know how they stack up against some of the Worlds best electronics however I was confident that they wouldn't disappoint.
THe fact that they take a long time to get does mean something in my mind as well. The down side is if they take forever to get its not much of a business decision as it makes getting a ROI almost impossible.

 

[LL21]

Lloyd, I have very little RK experience but I contacted him because of his stellar reputation. I truly don't know how they stack up against some of the Worlds best electronics however I was confident that they wouldn't disappoint.
THe fact that they take a long time to get does mean something in my mind as well. The down side is if they take forever to get its not much of a business decision as it makes getting a ROI almost impossible.

All very fair. They are very special electronics, purist in the absolute form. But I could understand needing to meet global demand if you are in distribution.

 

[defride]

I do want to hear the Robert Koda K-160 monos as they sound like one of those seminal products anyone who is serious about pursuing the art of reproduced must hear. Does anyone know if anyone has them accessible for an audition in the US?
Naturally, my favorite SS amplifier choice is the bridged version of the WestminsterLab monos

I hope you do get to hear RK in a sympathetic system at some point, I've heard K-70 sound wonderful. On that basis top of my anticipation list for Munich in the spring was the Fono Acoustica room. I've a predilection for Kharma, Wadax has always intrigued and as for Robert Koda, a lot of love.



The room was truly awful, a tight, lean sound that was as far from high end music reproduction as I've heard (Friday of the show). A great disappointment and hard to understand. No doubt all the components on show should deliver something satisfying in the right setting. As is usually the case in the audiophile world, the parts and the sum of those parts rarely come together like a mathematical equation.

 

[Amir]

I hope you do get to hear RK in a sympathetic system at some point, I've heard K-70 sound wonderful. On that basis top of my anticipation list for Munich in the spring was the Fono Acoustica room. I've a predilection for Kharma, Wadax has always intrigued and as for Robert Koda, a lot of love.

View attachment 115798

The room was truly awful, a tight, lean sound that was as far from high end music reproduction as I've heard (Friday of the show). A great disappointment and hard to understand. No doubt all the components on show should deliver something satisfying in the right setting. As is usually the case in the audiophile world, the parts and the sum of those parts rarely come together like a mathematical equation.

This hopeless story is popular in most homes not because audio hardware is not good , most of the time the reason for awful sound is the setup condition .

Robert Koda is one of best audio manufactures.

 

[defride]

This hopeless story is popular in most homes not because audio hardware is not good , most of the time the reason for awful sound is the setup condition .

Robert Koda is one of best audio manufactures.

Exactly my point, apologies if you weren't able to follow

 

[PhP]

Hi!

Note beforehand: no, I'm not looking for new amps, especially SS amps - I'm just curious!

I read here and there in wbf about some solid state amps: Boulder, CH Precision and many more. Often people just report about how great the amp sounds in their own system. What I miss a bit is a general assessment in which cases which top-amps should be shortlisted and for what reason. I myself don't have much experience with them; I've barely heard SS amps in comparison so far.

It may be that this does not interest someone or he thinks that you can not generally classify. Then I ask him very much not to write here. Thank you!

I would be interested in the differences of the following brands:

- Analog Domain
- Boulder
- CH Precision
- Gryphon
- Robert Koda
- Pilium
- Soulution
- Vitus

I realize that there can be different model lines that may sound different. Then you can simply write with which specific model you have made what experience. And no, I'm not concerned with which amp can drive the very worst speaker or any other special cases - it's simply about average speakers that could just as easily be driven by any other amp. I would find the following criteria interesting:

- Neutrality
- resolution
- stage imaging
- physical presentation ("body") and authenticity
- other strengths and weaknesses

It would be best if someone, when describing the sound of one of the above amps, could at least relate it to one or two other brands. In principle, however, it is also sufficient to address strengths and weaknesses in key words.

I am very curious to see your opinions.

Thanks!

Hi Verdier

The very best I know and I tested a lot, also shared with 1 other well known audio store in Europe and with 1 speaker manufacturer :

1. APURNA™ (France) monoblocs Apogée or Soprano Limited Apogée
2. Robert KODA K160

All the other you listed sound great but audio to more or less degree. I had some for my private use, then some as audio dealer. Since 2022, I stopped all and keep only APURNA™. The designer use disruptive technology from aerospace and military.

Apurna | PHPAUDIO

www.phpaudio.fr

Cheers
Philippe

 

[heihei]

I hope you do get to hear RK in a sympathetic system at some point, I've heard K-70 sound wonderful. On that basis top of my anticipation list for Munich in the spring was the Fono Acoustica room. I've a predilection for Kharma, Wadax has always intrigued and as for Robert Koda, a lot of love.

View attachment 115798

The room was truly awful, a tight, lean sound that was as far from high end music reproduction as I've heard (Friday of the show). A great disappointment and hard to understand. No doubt all the components on show should deliver something satisfying in the right setting. As is usually the case in the audiophile world, the parts and the sum of those parts rarely come together like a mathematical equation.

It got better - by the weekend it was acceptable rather than dreadful it started out at, but still disappointing given the quality of the components.

 

[heihei]

Of those on your list, I've spent time with the following in my own system:

CH Precision (L1 + X1, A1, M1 mono) - the L1+X1 is an exceptional pre-amp, probably the best I've heard in my system - transparent with a huge soundstage, but the power amps I found neutral to the point of boredom. When I listen to music, I want it to be an event and make me pay attention but the CH amps didn't do that and so I found them disappointing relative to the hype & cost.

Vitus (SA-25, SM101, SP102) - I love the A-class sound Vitus produces, but the cheaper end of class-A range of amps tend to lack a bit of power and drive, and detail is not their strong-point. I suspect you get more of this the higher up the range you go, but by that stage, you are getting very expensive.

Solution (5-series) - really like the speed and transparency of these amps, and if I'd had a dealer closer to me at the time, I might have explored them more.

Outside of the above 3, I spent quite a bit of time listening to D'Agostino, Burmester, Ayre, Constellation, but if I'm honest, none of them created a strong enough impression that I demo'd them in my system. It led me to conclude that it's quite hard to produce an SS amp that is "different" enough to stand out from the crowd.

This perhaps begs the question of what I ended up with.....

In the first instance, a pair of Berning Quadrature Z's, but as these are valves (albeit with 220W of power) they are outside of this thread, but they beat the above in my view in terms of speed, transparency, timbre, and emotional engagement.

What I currently have does fit this thread, and is a pair of Audionet Heisenbergs, which were the first SS amps I heard which beat the Bernings - fast, beautiful timbre, but perhaps most importantly, they make every listening session an event, primarily because they have incredible dynamics, particularly around the leading edge of notes.

If I were to start looking again, I would have Pilium at the top of my list to explore based on comments I've read here and limited exposure at Munich, as they appear to have similar properties to the Heisenbergs which I prize so highly.

 

[Verdier]

@heihei
What speakers do you have?

 

[audio.bill]

@heihei
What speakers do you have?

According to his signature, Wilson Benesch Resolution + Torus.