Riviera Labs AFM-100 SE Class A Monoi amplifiers- something new and different

[Elliot G.]

Technical overview - Riviera

An audio amplifier must reproduce a signal with the highest fidelity for the human ear, not for instruments.

www.rivieralabs.com

I am not a scientist not did I ever play one on TV so I wont pretend to understand the scope of this project. I am a serious listener and the journey that I began a few months ago has brought me some confusion with a whole lot of amazement.
We used Riviera AFM-100SE at Capfest along with the APL-01Se Preamplifier and had a really wonderful result. We had many people and reviewers go nuts over the sound and there were many really great reviews and stories. I want to thank everyone for that.
I came back to Florida and wanted to try to understand what had happened. Was it the great set up? the understanding finally on how to work the room? or was it the gear and the combination of all of these items that finally translated into something I was truly happy and satisfied with?
Part two of the journey started yesterday.
I inserted the amps, just the amps into my system. THis required that I had to add some balanced cables and re-wire the system. I won't get into the nuts and bolts but rather just say that different gear offers different options and so my new set up required another long balanced set of cables so I can still use the incredible Divin Sovereigns.

I am now running a CH 10 series Preamp with the Riviera mono blocks, two Divin Sovereign subwoofers, The Divin Marquis speakers ( for now LOL Noblesse is next change in early 2024 but thats another project) Nordost Qbase Reference for the front end gear and of course a full Wadax Reference system.
I am an old guy and had some struggles getting this all done without hurting myself but I did manage to get her done! ( cable guy reference)
Finally got all the pieces connected and turned it all back on.
I was planning on letting it settle in so I put on a few familiar pieces of music and before I knew 2 plus hours disappeared never to be found again.

What is happening here?
What the heck has changed?
( i didnt yet move the speakers HAHAHA )
Why is this so involving?
Why do this little ( relative wise) amps sound like they have unlimited power and headroom?
Why am I smiling?

Time to go home let them run over night and try to think about what I have listened to and what I need to do tommorow to try to sort it out.

to be continued......

 

[heihei]

I think the Riviera stuff is incredible and one of my regrets is not having a full system for demo in my living room (I've only had the top pre-amp).

If you read their stuff, they focus on creating the right level of harmonics in the music rather than all-out accuracy, noting that the ear itself creates some harmonic distortions. I think we emotionally engage with harmonics very strongly (think for example about the goosebumps listening to a choir gives us), and is one of the reasons we find emotional engagement with the harmonic richness tube equipment brings. I think Riviera tap into this with their design.

 

[fxg]

Technical overview - Riviera

An audio amplifier must reproduce a signal with the highest fidelity for the human ear, not for instruments.

www.rivieralabs.com

I am not a scientist not did I ever play one on TV so I wont pretend to understand the scope of this project. I am a serious listener and the journey that I began a few months ago has brought me some confusion with a whole lot of amazement.
We used Riviera AFM-100SE at Capfest along with the APL-01Se Preamplifier and had a really wonderful result. We had many people and reviewers go nuts over the sound and there were many really great reviews and stories. I want to thank everyone for that.
I came back to Florida and wanted to try to understand what had happened. Was it the great set up? the understanding finally on how to work the room? or was it the gear and the combination of all of these items that finally translated into something I was truly happy and satisfied with?
Part two of the journey started yesterday.
I inserted the amps, just the amps into my system. THis required that I had to add some balanced cables and re-wire the system. I won't get into the nuts and bolts but rather just say that different gear offers different options and so my new set up required another long balanced set of cables so I can still use the incredible Divin Sovereigns.

I am now running a CH 10 series Preamp with the Riviera mono blocks, two Divin Sovereign subwoofers, The Divin Marquis speakers ( for now LOL Noblesse is next change in early 2024 but thats another project) Nordost Qbase Reference for the front end gear and of course a full Wadax Reference system.
I am an old guy and had some struggles getting this all done without hurting myself but I did manage to get her done! ( cable guy reference)
Finally got all the pieces connected and turned it all back on.
I was planning on letting it settle in so I put on a few familiar pieces of music and before I knew 2 plus hours disappeared never to be found again.

What is happening here?
What the heck has changed?
( i didnt yet move the speakers HAHAHA )
Why is this so involving?
Why do this little ( relative wise) amps sound like they have unlimited power and headroom?
Why am I smiling?

Time to go home let them run over night and try to think about what I have listened to and what I need to do tommorow to try to sort it out.

to be continued......

Hello Elliott , i have an L10/M10m's/Wadax/Stenheim system and would be intrigued to know if you plan to try the Riviera APL-01Se with your M10'S? If you do/did, how did they sound, did the preamp sweeten the sound nicely? or too sweet? and would you say there is a good synergy between the CH and Riviera?

 

[Elliot G.]

I spent a lot of my day yesterday listening to my system. The system that I have lived with exclusively for a while and a system that I have truly enjoyed. I am a huge fan of the Divin Marquis and the Divin Marquis with the Divin Sovereign Subwoofers.
OK so let me try to explain what I am hearing and try my best to describe in words my reaction. I have said many times here that the audio vocabulary has been perverted and bastardized to where IMO one size fits all. I have no idea anymore what words like soundstage, definition, transparancy, organic, imaging and last but not least musical even mean in the context of the audio world today. These words have become the way to paint with a very broad brush for anyone who wants to talk the talk. Its easy but it gets me nowhere.
These words IMO are useless.
So I have said that so let me try to express my experience with the amps in question.

I ask you to indulge me for a moment.
Sit down, relax, and close your eyes ( after you finish reading of course) that you have entered your favorite concert facility. You sit down and the houselights are on. That you are now listening to a performance of lets say a 5 piece jazz group.
OK so you have that image in your mind.
Now lets pretend that you sit down in your seat and the house lights go out and the stage lighting comes on. The entire stage is illuminated, its all there, its all clear , its all there to "see".That is what I am trying to describe that is what I am hearing/seeing with these amplifiers. One word doesn't explain this and I certainly don't have a "term" that otherwise might make one understand the experience.
Illumination?
Purity?

maybe but that in itself is kind of meaningless as well. I am using a visual image since that is how I learned, that is where all the audio terms originated. HP may not be as appreciated as much I think he should but he was truly great with his words and he had a photographic background that shaped his descriptions of audio reproduction. My education came from that way of thought and so I am trying to describe in my words how and what I am listening to. I think HP would appreciate it or I hope at least he would.

I know there wil be blow back and the usual defense , I expect that but I can only report on my experiences.I have listened to many of the "best of today" and I believe this is something different and so I am writing about it.

 

[Elliot G.]

DHL is still threatening to deliver my preamp today however I have only hopes and prayers HAHA that this will occur as it is already afternoon.
If it does come all I plan to do today is de flightcase it and put it on a shelf and let it sit till Tuesday after the holiday weekend.
My curiousity however is bubbling over and I do want to give it a spin. Its a good day to do such as its cold here and raining.
Happy New Year to all!

 

[Elliot G.]

 

[gleeds]

Elliot, as you know I experienced the Goebel Marquis, Wadax and Riviera combo at CAF and it made me fall hard for the Marquis! It's great to hear the Riviera pieces are allowing the Gobel magic to shine through in the same at your place. It's especially nice to see your passion shining through by a new discovery. I'm really looking forward to my visit to Bending Wave in February to hear these components again (especially with the Noblesse).

 

[Elliot G.]

Elliot, as you know I experienced the Goebel Marquis, Wadax and Riviera combo at CAF and it made me fall hard for the Marquis! It's great to hear the Riviera pieces are allowing the Gobel magic to shine through in the same at your place. It's especially nice to see your passion shining through by a new discovery. I'm really looking forward to my visit to Bending Wave in February to hear these components again (especially with the Noblesse).

Thanks Gary,
I am working my way through the systematic listening of the components and after I have tried a few combinations I plan on removing the Marquis and I have a new pair Of Noblesse that I want to bring into the room and set up. I am sure this will have taken place in the month of January so the timing should be perfect to experience the Noblesse at that time. Next week I am going to put the Riviera Preamp in the system and see what happens next....stay tuned...same bat time...same bat channel!

 

[fbhifi]

“Holy Riviera Monoblocks Batman”

 

[WELquest]

Hello Elliott , i have an L10/M10m's/Wadax/Stenheim system and would be intrigued to know if you plan to try the Riviera APL-01Se with your M10'S? If you do/did, how did they sound, did the preamp sweeten the sound nicely? or too sweet? and would you say there is a good synergy between the CH and Riviera?

I can't resist -- I/AudioQuest, used a CH C1.2 into the Riviera Labs APL01SE and Riviera Labs AFM100 amps to drive Rockport Orions in my Munich 2023 exhibit. The CH source and Riviera amplification was superb! Of course AQ Niagara and Dragon might have helped too.

Those particular Riviera pieces normally drive Wilson Sasha DAWs at my Netherlands headquarters. At home in CA I have a dCS Vivaldi One Apex feeding an APL01SE and a pair of AFM50s driving Rockport Cygnus speakers -- With glorious results -- the no-pain version of extreme resolution and dynamics.

Two other personal systems, in CA and NYC, have a variable output (real preamp amp output stage) Aesthetix Romulus driving Riviera Labs AFM25 amps into Rockport Atria II and Rockport Avior II speakers. Yes, 25 watts truly can pass for infinite power, until it can't. All AFMs have the most exuberantly playful bass I've ever had the pleasure of living with. "Exuberantly playful" might sound like a coloration to some. I believe it's an appropriate way to describe less-compromised, less-distorted.

Silvio and Luca know what they are doing. Beyond the particulars of harmonic distortion, the Riviera gear is extraordinary in addressing what I have called-out for the last 50 years as the most important imperative in good audio: the challenge towards becoming one with the music as presented by an audio system is not the need for more information, it's the mandate to suffer less misinformation.

Hearing is an active process that absolutely requires our brains to cheat during the 50 or so milliseconds it takes before an aural image is presented to our consciousness. The composition we think the ear/mic is picking up is actually a combination of data from our speakers, our evolutionarily advantageous genetically programmed predictive algorithms, learned from "nurture" predictive algorithms, memories -- and crucially, imagination.

Thank heavens we are sometimes dead wrong with what we think we hear as a result -- without our brains making-sh*t-up, we would not have a stereo image, the immersive sound field so many of us crave.

The primary limitation to our brain's ability to construct a maximally engaging emotionally provocative aural image is not a lack of information so much as it's the interference to that process caused by noise and distortion (misinformation).

By noise, I don't mean tape hiss or a tick or pop on an LP -- those are properly reproduced information that we insult by calling them noise. I mean real noise, energy that shouldn't be there and which can't be "demodulated" into anything meaningful enough for the brain to then present as a discrete sound. This noise, whether energy coming out of a dielectric (caps, cable insulation) at the wrong time, or skin-effect caused inductance smearing a signal across time, TIM, or all sorts of energy challenges in the digital domain -- is what creates the not-black background that causes most of us to refer to the benefit of reducing the misinformation as "the music emerging from a blacker background" -- when there was no discernible white or gray background to begin with.

I believe everything Luca writes about in explaining his Riviera Labs design priorities -- and I believe that the extraordinarily open and deep soundstage that the Riviera gear enables is foremost the result of less unseen and unheard garbage/obstacles in the way of our algorithms and imagination doing their absolutely necessary jobs.

 

[morricab]

Technical overview - Riviera

An audio amplifier must reproduce a signal with the highest fidelity for the human ear, not for instruments.

www.rivieralabs.com

I am not a scientist not did I ever play one on TV so I wont pretend to understand the scope of this project. I am a serious listener and the journey that I began a few months ago has brought me some confusion with a whole lot of amazement.
We used Riviera AFM-100SE at Capfest along with the APL-01Se Preamplifier and had a really wonderful result. We had many people and reviewers go nuts over the sound and there were many really great reviews and stories. I want to thank everyone for that.
I came back to Florida and wanted to try to understand what had happened. Was it the great set up? the understanding finally on how to work the room? or was it the gear and the combination of all of these items that finally translated into something I was truly happy and satisfied with?
Part two of the journey started yesterday.
I inserted the amps, just the amps into my system. THis required that I had to add some balanced cables and re-wire the system. I won't get into the nuts and bolts but rather just say that different gear offers different options and so my new set up required another long balanced set of cables so I can still use the incredible Divin Sovereigns.

I am now running a CH 10 series Preamp with the Riviera mono blocks, two Divin Sovereign subwoofers, The Divin Marquis speakers ( for now LOL Noblesse is next change in early 2024 but thats another project) Nordost Qbase Reference for the front end gear and of course a full Wadax Reference system.
I am an old guy and had some struggles getting this all done without hurting myself but I did manage to get her done! ( cable guy reference)
Finally got all the pieces connected and turned it all back on.
I was planning on letting it settle in so I put on a few familiar pieces of music and before I knew 2 plus hours disappeared never to be found again.

What is happening here?
What the heck has changed?
( i didnt yet move the speakers HAHAHA )
Why is this so involving?
Why do this little ( relative wise) amps sound like they have unlimited power and headroom?
Why am I smiling?

Time to go home let them run over night and try to think about what I have listened to and what I need to do tommorow to try to sort it out.

to be continued......

I agree with Riviera’s technical reasoning and stated goals. Well done on them that they pursue this path and hopefully achieve a good measure of success in getting distortion that “hides” in gaps of our auditory system. Hiraga noted this pattern and it was further expanded upon by Cheever. It turns out that the good old SET circuit, when we’ll designed, also follows these principles and I think is largely responsible for the resurgence of that “obsolete “ technology. Would like to hear what Riviera have achieved in a controlled setting someday.

 

[Elliot G.]

So Happy New Year everyone.I hope you enjoyed yourselves and my best wishes for a prosporous 2024.

I installed the Riviera Preamplifier this afternoon ( barely) and its playing. The APL-01 SE is a heavy item, in fact quite heavy for a preamplifier and is nicely laid out. I have run my Gobel Balanced cables from the Wadax to it and from the preamp via the same cables to the subs and the amps.
Its all up and playing with no issues and I just briefly played a few cuts to check that its all playing well and will do some more serious listening later today after it plays for a while. My initital response is this is good maybe very good. It is NOT however a tubey sound and does not have that golden coloration. This to me is good as I dont want syrup on my music, only on my pancakes.
It seems to have a wonderful open sound maybe and I do mean maybe since this early on, maybe a little more than before and thatI like.
Stay tuned and look for the BAT signal

 

[Opabin]

I can't resist -- I/AudioQuest, used a CH C1.2 into the Riviera Labs APL01SE and Riviera Labs AFM100 amps to drive Rockport Orions in my Munich 2023 exhibit. The CH source and Riviera amplification was superb! Of course AQ Niagara and Dragon might have helped too.

Those particular Riviera pieces normally drive Wilson Sasha DAWs at my Netherlands headquarters. At home in CA I have a dCS Vivaldi One Apex feeding an APL01SE and a pair of AFM50s driving Rockport Cygnus speakers -- With glorious results -- the no-pain version of extreme resolution and dynamics.

Two other personal systems, in CA and NYC, have a variable output (real preamp amp output stage) Aesthetix Romulus driving Riviera Labs AFM25 amps into Rockport Atria II and Rockport Avior II speakers. Yes, 25 watts truly can pass for infinite power, until it can't. All AFMs have the most exuberantly playful bass I've ever had the pleasure of living with. "Exuberantly playful" might sound like a coloration to some. I believe it's an appropriate way to describe less-compromised, less-distorted. […]

Enjoyed hearing about your experience with the three Riviera amps. I’ve read somewhere that AFM100 produces a significant amount of heat (100 Class A Watts). How does AFM50 compare regarding heat generation? And otherwise, how would you characterize the capabilities of AFM50 vs. AFM100?

 

[Opabin]

So Happy New Year everyone.I hope you enjoyed yourselves and my best wishes for a prosporous 2024.

I installed the Riviera Preamplifier this afternoon ( barely) and its playing. The APL-01 SE is a heavy item, in fact quite heavy for a preamplifier and is nicely laid out. I have run my Gobel Balanced cables from the Wadax to it and from the preamp via the same cables to the subs and the amps.
Its all up and playing with no issues and I just briefly played a few cuts to check that its all playing well and will do some more serious listening later today after it plays for a while. My initital response is this is good maybe very good. It is NOT however a tubey sound and does not have that golden coloration. This to me is good as I dont want syrup on my music, only on my pancakes.
It seems to have a wonderful open sound maybe and I do mean maybe since this early on, maybe a little more than before and thatI like.
Stay tuned and look for the BAT signal

Eagerly awaiting the next report of your full Riviera setup experience as listener reports are still rather scarce (*more in Italian or French perhaps?). Thanks for sharing!

 

[Elliot G.]

Ive spent the afternoon listening that the pre-amp is ready to go. Ill go into it tommorow I ran out of time tonight.
I will say that I am very happy and BTW the 100 does run warm but not crazy hot.
Stay tuned it may get a little crazy not sure how to express my feelings yet.

 

[WELquest]

Enjoyed hearing about your experience with the three Riviera amps. I’ve read somewhere that AFM100 produces a significant amount of heat (100 Class A Watts). How does AFM50 compare regarding heat generation? And otherwise, how would you characterize the capabilities of AFM50 vs. AFM100?

Idling, not playing music, is when Class A amps are the warmest -- and yes, that is an environmental, financial, and temperature/climate consideration.

To me, the AFM100SE amps are not as hot to touch as the 100 watt Pass Aleph amps I loved for many years (which turned brown from the heat), but that's about the mass and airflow around the heat sinks. Comparing the AFM50 and AFM100 amps, I don't have them on same continent, much less in the same room, but I'm comfortable noting that twice as powerful a Class A amp simply has twice as much heat to dissipate.

My AFM50s are not nearly as hot to touch as were my D'Agostino M400 amps, and I suspect that might also be true for the AFM100s. Both M400s and AFMs have near infinite authority and power relative to how loud I play the Rockport Cygnus speakers in my living room -- but only one of those amps honors why I listen to music.

The AFM amps all have the same power sections (except for the amount of power), but, if I understood Silvio correctly, the input circuits are better finessed as one goes up, the "SE" of the AFM100s designating no-holes-barred. There isn't room for the SE goodies in the AFM50s -- but I still didn't hesitate to have the smaller amps, and if and when I wonder what I'm missing with my 2 pair of AFM25, I know it doesn't matter because after a year with them I live in constant delight. I'm not going to take the AFM25s into the living room to compare them. Heaven is heaven and comparing heavens is pointless, even if discernible and repeatable.

The sonic nature of the APL01SE preamp has been questioned in this thread. My evaluation experience is limited to adding it in-between a dCS Vivaldi One Apex and the AFM50s. The system was a bit dry and had a bit too much "tension" when using the Vivaldi directly (regardless of the many options for controlling the Vivaldi's output) into the AFM50, though much less tension than with my dCS Rossini Apex Player.

A D'Agostino Momentum HD preamp slightly reduced those qualities with essentially no other change, no change in character. All totally positive, but not enough.

The APL01SE was very similar in the no change in character department -- but the dry and too much tension of using the Vivaldi without a preamp are fully eliminated, and the system just plain breathes-bigger. The dry and the tension is not covered up, no honey or maple syrup, just the kind of relief one gets when an AC unit you weren't aware of turns off.

As much access as I have, it's impossible to really, really fairly evaluate all the worthy, and not worthy, gear out there. I have never compared a CH preamp to the Riviera, but I am certain based on multiple amp comparisons, that a CH 1 or 10 preamp would also make me very happy, as would a CH A1.5 amp (only the A1.5 meets my physical requirements) -- but there is enough difference in the presentation for me to have chosen Riviera Labs.

If I didn't have the APL01SE or equivalent preamp, I probably would choose a CH amp if a dCS was the direct source. Whether the CH's input is more compatible or the amp is more forgiving, the tension problem that the APL01 eliminated is less of an overt problem with the dCS into a CH M1.1. That's why from when I first did a bunch of evaluations with the M1.1 several years ago, I referred to its wonderful sound as the beautiful-truth -- whereas to me, the Riviera gear is the truth, enabling beauty.

Another brand I own and deeply respect, but is in my company's development-tool "A" system as compared to in my home, is Constellation. Depending on your water preferences, it's somewhere between the purity of distilled and Evian, a fantasy of a pure mountain spring.

 

[Opabin]

Idling, not playing music, is when Class A amps are the warmest -- and yes, that is an environmental, financial, and temperature/climate consideration.

To me, the AFM100SE amps are not as hot to touch as the 100 watt Pass Aleph amps I loved for many years (which turned brown from the heat), but that's about the mass and airflow around the heat sinks. Comparing the AFM50 and AFM100 amps, I don't have them on same continent, much less in the same room, but I'm comfortable noting that twice as powerful a Class A amp simply has twice as much heat to dissipate.

My AFM50s are not nearly as hot to touch as were my D'Agostino M400 amps, and I suspect that might also be true for the AFM100s. Both M400s and AFMs have near infinite authority and power relative to how loud I play the Rockport Cygnus speakers in my living room -- but only one of those amps honors why I listen to music.

The AFM amps all have the same power sections (except for the amount of power), but, if I understood Silvio correctly, the input circuits are better finessed as one goes up, the "SE" of the AFM100s designating no-holes-barred. There isn't room for the SE goodies in the AFM50s -- but I still didn't hesitate to have the smaller amps, and if and when I wonder what I'm missing with my 2 pair of AFM25, I know it doesn't matter because after a year with them I live in constant delight. I'm not going to take the AFM25s into the living room to compare them. Heaven is heaven and comparing heavens is pointless, even if discernible and repeatable.

The sonic nature of the APL01SE preamp has been questioned in this thread. My evaluation experience is limited to adding it in-between a dCS Vivaldi One Apex and the AFM50s. The system was a bit dry and had a bit too much "tension" when using the Vivaldi directly (regardless of the many options for controlling the Vivaldi's output) into the AFM50, though much less tension than with my dCS Rossini Apex Player.

A D'Agostino Momentum HD preamp slightly reduced those qualities with essentially no other change, no change in character. All totally positive, but not enough.

The APL01SE was very similar in the no change in character department -- but the dry and too much tension of using the Vivaldi without a preamp are fully eliminated, and the system just plain breathes-bigger. The dry and the tension is not covered up, no honey or maple syrup, just the kind of relief one gets when an AC unit you weren't aware of turns off.

As much access as I have, it's impossible to really, really fairly evaluate all the worthy, and not worthy, gear out there. I have never compared a CH preamp to the Riviera, but I am certain based on multiple amp comparisons, that a CH 1 or 10 preamp would also make me very happy, as would a CH A1.5 amp (only the A1.5 meets my physical requirements) -- but there is enough difference in the presentation for me to have chosen Riviera Labs.

If I didn't have the APL01SE or equivalent preamp, I probably would choose a CH amp if a dCS was the direct source. Whether the CH's input is more compatible or the amp is more forgiving, the tension problem that the APL01 eliminated is less of an overt problem with the dCS into a CH M1.1. That's why from when I first did a bunch of evaluations with the M1.1 several years ago, I referred to its wonderful sound as the beautiful-truth -- whereas to me, the Riviera gear is the truth, enabling beauty.

Another brand I own and deeply respect, but is in my company's development-tool "A" system as compared to in my home, is Constellation. Depending on your water preferences, it's somewhere between the purity of distilled and Evian, a fantasy of a pure mountain spring.

Thank you, WELquest, for your generous and helpful reply. I admire your precision and tact, especially in the comparisons of Riviera with other makes. The love for your Riviera amps, so obvious in your description of their importance in your music listening, has only encouraged my interest in the brand. Now I will simply have to look for a chance for a proper audition.

 

[Tbzc]

I have been using Riviera APL 01se since approx. 2 years and has been the preamp of my choice ever since. I still vividly remember when I have compared it to my past reference preamp (dht, fully balanced, tube power supply) and it sounded almost broken compared to Riviera. APL 01se was much more musical, notes where connected (I have used “continuousness” to describe this), bass was much more natural (strong, full, controlled). The energy in music was almost lifelike. Voices sounded really as a human being was standing in my room. But IMHO Riviera is not for “analysts” among us because it drives you to listen to music holistically and just enjoy it. Riviera preamp became the heart of my system. It really injects life and enjoyment in it. But all these descriptions should not misslead you in thinking Riviera is colored and not transparent. No, it clearly differentiates among good and bad quality recordings. Only that the later are still quite enjoyable to listen to. And all the details (including stage) are there.

What is interesting for me is the theory how Riviera uses human perception as a basis to finetune the sound. I think Lamm also claimed something similar but the result is in my opinion quite different. Having owned M1.2 monoblocks and extensively tested LP 1, I think I have pretty good idea of Lamm’s sound. For me, Riviera is a clear winner and much closer to what I think what natural sound is.

 

[LL21]

Idling, not playing music, is when Class A amps are the warmest -- and yes, that is an environmental, financial, and temperature/climate consideration.

To me, the AFM100SE amps are not as hot to touch as the 100 watt Pass Aleph amps I loved for many years (which turned brown from the heat), but that's about the mass and airflow around the heat sinks. Comparing the AFM50 and AFM100 amps, I don't have them on same continent, much less in the same room, but I'm comfortable noting that twice as powerful a Class A amp simply has twice as much heat to dissipate.

My AFM50s are not nearly as hot to touch as were my D'Agostino M400 amps, and I suspect that might also be true for the AFM100s. Both M400s and AFMs have near infinite authority and power relative to how loud I play the Rockport Cygnus speakers in my living room -- but only one of those amps honors why I listen to music.

The AFM amps all have the same power sections (except for the amount of power), but, if I understood Silvio correctly, the input circuits are better finessed as one goes up, the "SE" of the AFM100s designating no-holes-barred. There isn't room for the SE goodies in the AFM50s -- but I still didn't hesitate to have the smaller amps, and if and when I wonder what I'm missing with my 2 pair of AFM25, I know it doesn't matter because after a year with them I live in constant delight. I'm not going to take the AFM25s into the living room to compare them. Heaven is heaven and comparing heavens is pointless, even if discernible and repeatable.

The sonic nature of the APL01SE preamp has been questioned in this thread. My evaluation experience is limited to adding it in-between a dCS Vivaldi One Apex and the AFM50s. The system was a bit dry and had a bit too much "tension" when using the Vivaldi directly (regardless of the many options for controlling the Vivaldi's output) into the AFM50, though much less tension than with my dCS Rossini Apex Player.

A D'Agostino Momentum HD preamp slightly reduced those qualities with essentially no other change, no change in character. All totally positive, but not enough.

The APL01SE was very similar in the no change in character department -- but the dry and too much tension of using the Vivaldi without a preamp are fully eliminated, and the system just plain breathes-bigger. The dry and the tension is not covered up, no honey or maple syrup, just the kind of relief one gets when an AC unit you weren't aware of turns off.

As much access as I have, it's impossible to really, really fairly evaluate all the worthy, and not worthy, gear out there. I have never compared a CH preamp to the Riviera, but I am certain based on multiple amp comparisons, that a CH 1 or 10 preamp would also make me very happy, as would a CH A1.5 amp (only the A1.5 meets my physical requirements) -- but there is enough difference in the presentation for me to have chosen Riviera Labs.

If I didn't have the APL01SE or equivalent preamp, I probably would choose a CH amp if a dCS was the direct source. Whether the CH's input is more compatible or the amp is more forgiving, the tension problem that the APL01 eliminated is less of an overt problem with the dCS into a CH M1.1. That's why from when I first did a bunch of evaluations with the M1.1 several years ago, I referred to its wonderful sound as the beautiful-truth -- whereas to me, the Riviera gear is the truth, enabling beauty.

Another brand I own and deeply respect, but is in my company's development-tool "A" system as compared to in my home, is Constellation. Depending on your water preferences, it's somewhere between the purity of distilled and Evian, a fantasy of a pure mountain spring.

What a great write-up! Thank you for that. I have enjoyed reaching about the CH and Constellation and more recently Riviera having first read about it from Gian60 who often comments here. I believe Mark Coles of Sablon Audio also uses Riviera in his own system.

All definitely names that have consistently received comments about purity of signal.

 

[Elliot G.]

The APL01SE was very similar in the no change in character department -- but the dry and too much tension of using the Vivaldi without a preamp are fully eliminated, and the system just plain breathes-bigger. The dry and the tension is not covered up, no honey or maple syrup, just the kind of relief one gets when an AC unit you weren't aware of turns off.

I like how you described it. I used the same syrup less description to a friend yesterday. There is no "golden glow" one would not instantly say well that's a tube piece. I listened a lot yesterday and was trying to think about how to describe what is happening with my system and my room.
I first set the pre into the system and listened for a while and then I remembered that I still had the other preamp pluggerd into the primary earth spot of the Q Baae reference form Nordost. I am using this power distribution device on the front components of my system so I changed the power cord into the proper space and began listening again.
I have said many times the "audiophile terms" mean little to me , so I want to describe what I am hearing in the simplist and the clearest way that I can. I am no author or a linquist but I will do my best.
The combination of the AFM-100SE power amps and the APL01 SE special edition Preamp light my system up. Yes they light it up. I seem to be able to "see" into the music more. Thsi illumination of the instruments, voices and the spaces between is unique in my experience. One would think well it must be brighter? right? no that's not it. Well it must be changing something else right? no I don't think so.There is a sense of purity that the system can do now that it never did before. I can say I loved the result we got at CAPFEST and lot's of people heard that system and enjoyed it as well butI really wanted to hear it at home. Can I live with it in my room, my system and with my ability to go through the music that I enjoy to really undersatnd what I heard at the show.
There is something unique to the gear. It is different and plays that way. The amps are relatively compact yet they sound like they have unlimited power. I can play my system louder now than ever before, such that it scares me a little. LOL
It produces this level of purity accross the whole musical spectrum and I can hear things in recordings I thought I knew with much great clarity and ease.
Few examples: I use a flamenco piece by Pepe Romero called Zapateado which featues acoustic guitar and flamenco dancers and it can be thunderous, explosive and a real wow track. It has never sounded this way it just is scary real, the dancers speed and floor pounding is in my room. I love the Movie "the last Samurai" and the Franz Zimmer soundtrack , especially the ending is haunting, beautiful and expansive and very powerful. It is just amazing to listen to this in my moderate sized room. When I played it late yesterday two of the guys here burst into the room and said it sound incredible through the door and they wanted to come in and listen. The third is a piece I just found from Willie Nelson's 90th Bday party which I saw a bit on TV and managed to find the album on Qobuz. There is a song, sung by his son Lukas called Angel flying to close to the ground" that is live, just Lukas and his guitar at the Hollywood bowl , this recording right on the edge of being too much yet it isn't . It is a treat for me to hear this young man who sounds and plays like his Dad do this tribute to the master. Its GOOSEBUMP Moment.

I am not a scientist and don't really understand the tech talk but I do know what I am listening to and I truly love it.
These components are something that should be heard I think they really are onto something special.