Competitive class D amp suggestions

with the possible exception of the sound at overload (but for that just make sure you have enough power).

Thanks Ralph, your point of view is clear. The last is a delicate question for me, at least: How one can know that it has "enough power"? Strange things happen. I have tried large Thiel speakers with a 200 watts class AB amp and i felt that, may be, the power was not enough since it sounded a bit "forced" at moderately high volumes (if this a correct way to judge if the power that an amp can give is enough for a speaker). But i don't observe similar things with a tube SET 5.5 watts amp connected to the same speakers. Perhaps, there is a more reliable way to check whether the power of an amp is indeed enough for a speaker?

Hi Ralph: Do you any plans for a Class D preamp in the future?

Technically that is possible but we've no plans currently.

How one can know that it has "enough power"? Strange things happen. I have tried large Thiel speakers with a 200 watts class AB amp and i felt that, may be, the power was not enough since it sounded a bit "forced" at moderately high volumes (if this a correct way to judge if the power that an amp can give is enough for a speaker). But i don't observe similar things with a tube SET 5.5 watts amp connected to the same speakers.

Clearly the amp has enough power, unless its actually damaged in some way.  The 'forced' sound may simply be distortion though. Keep in mind that not all class D amps sound the same- I imagine some can indeed sound 'forced' and other amps simply don't.

The OP asked Alberto Guerra (AGD) how his amplifiers sounds, well I own the Vivace and I can say they sound "wonderful". They bring a very live feel to the music. They are an "end game" amplifier in my opinion. I went from a pair of tube mono blocks (Consonance Cyber 800SE) that I loved, to trying a pair of Electrocompaniet AW 400 solid state mono block amplifiers in my search for a little more bottom end without loosing the tube magic. I did quickly go back to my tube mono blocks not being happy with the mid and upper frequency ranges that solid state brought. More bass was not worth loosing the "tube magic" of my mono blocks. For a short moment in time I had considered going with a Pass Labs Class A design but due to the heat, expense of running them and their weight I decided to explore Class D now that it was coming of age. After reading numerous reviews on the many quality Class D designs I came across a number of glowing reviews and testimonials on this new line of unique amplifiers designed and built by AGD. The two amplifiers I had my eye on certainly were unique looking so I reached out to Alberto and had a number of long conversations with him. Finally I decided to audition the Vivace and he shipped it out to my house on the east coast for an audition. This was the quickest audition I ever had in my life. Within the period of one song, before it ended, I knew I had a winner on my hands. I had my tube mono blocks off to the side because I felt I would be switching them back and forth listening for improvements. Well within one day I knew the switching back and forth was not necessary. I just carried each one up to the third floor and that is were they are now. Never once did I switch them out, it was so apparent these were game changers. The Vivace just blew both of my previous amplifiers out of the water along with any thoughts of a Class A amplifier.

The Vivace are quick, detailed, full sounding amplifiers that can awaken any speaker (mine being a pair of KEF Reference 3). I was in disbelief. Every aspect of my speakers sound improved radically. I auditioned them for a week straight listening for hours at a time trying to find fault. I invited my audio friends over to listen and they all were blown away at the improvement and the look of the glowing acrylic top and the tube. Yes it may appear a bit too much when you see them not lit up and the tube glowing a reddish orange, but once they are on and the room is darkened they are gorgeous and not over the top at all. Luckily they sound even better than they look.

The sound stage is expansive beating my tube mono blocks ability to through a wonderful sound stage. Not night and day but it is noticeably deeper and taller. The positioning of musicians within this sound stage creates a very real experience. The musicians hold their places and when two musicians share a mic or are standing close on the stage you can "see" and hear the smallest gap between them as they stand or sit there and perform for you. It can be a very intimate experience at times how real it sounds in terms of placement of the music in the room. Obviously this happens on the better recordings and as everyone knows it is very recording dependent. The low end to mid has much more authority and detail than even the Electrocompaniet provided with it's 400 watts per channel. The Vivace does not come anywhere near that power but I have never felt it lacking in power to drive my speakers and I doubt it would struggle with the most power hungry of speakers out there. The mid range is beautiful sounding, vocals stand out and are articulate. Instruments have so much more vibrant detail to them. Up right bass and violins have the sound of wood and you can almost feel the bow drawing across the strings. Eric Dolphy's "Hat and Beard" from Out to Lunch is an incredible song to listen to which highlights this amplifiers ability at detail retrieval and ability to create an incredible sound stage. Cyrus Chestnut's "Cornbread Pudding" showcases the amplifiers ability to reproduce piano and upright bass. If you are familiar with these two songs then you know that this amplifier is up to almost any task since it handles them effortlessly in terms of retrieval of the smallest detail that brings these pieces to such life that you feel the performers right there in the room and can hear the slightest and most delicate of details.

These Class D amplifiers pair up beautifully with my tube preamplifier (Backert Labs Rhumba Extreme) which I am sure is helping with the sound stage and detail retrieval, but previous amplifiers could not bring so much life to my music so yes they pair well with tubes but I am sure will work with any quality preamplifier. As much as I love my preamplifier, based on the quality of this amplifier I would to hear how it pairs with the AGD Andante preamplifier/steaming DAC that I have read about. Again another costly piece of equipment and well above my price point so I am very happy with what I have but it would be interesting to hear how the pairing would sound.

Concerning the glass piece that extends out of the acrylic top, well at first I was a little taken back by it, but it truly is a piece of art and nothing can compare to how beautiful this amplifier looks at night in a room where the light level is low. In addition, as previously mentioned, it is extremely easy to pull the glass tube out and switch it with another module or if I were to transport the amplifier pull the tube and box it. The packaging the amplifier came in is another story and I am sure helped to raise the price but that is the point, everything about this amplifier is high end from the packaging to the design to the sound and especially to the care and support Alberto himself gives you. What you are not getting is a card board box sent to your house with the corners bashed in and lots of Styrofoam and peanuts all over the floor and if an issue arises you are not put on holding waiting for someone to answer and resolve your problem.

Yes this is a very expensive amplifier but far from the most expensive. I have been in this hobby for years slowly growing my system and the one thing I am sure everyone knows as you spend more money on each piece within your system the better your system sounds (sure some mistakes are made on the way). You cannot expect a $300 dollar amplifier to sound as good as a $3000 dollar one and so on as you go up. Yes diminishing returns but from my experience going from a $4000 dollar amplifier, which was approximately the list cost on my tube mono blocks to the Vivace was far from a small upgrade. It was actually one of the most noticeable upgrades I have made. The other was going from a Conrad Johnson Preamplifier to the Backert Labs. After years and years of upgrading and trying to reach the the best system that I could afford I am very glad I discovered this amplifier and in my opinion it is worth every penny I scrapped together to afford it. I love its look and everyone should at sometime get a chance to see this amplifier in a darkened room, it is magnificent sight to behold, but more importantly everyone should get a chance to listen to it. That is really its selling point even if it is expensive and it has a faux tube in the sense that it is not a vacuum tube. I am just glad I took the chance and reached out to Alberto and had the amplifier sent to my house for that audition.

@axo0oxa,

Thanks for the excellent post. Thoughtful and detailed. I am not in the market for a new amp, but have always wondered / been suspicious of Class D. Having been in this pursuit for over 50 years… new ideas frequently fail instantly to give the advertised benefits (like the CD).

Glad you addressed the look. I was really put off by the single tube look. While I am normally drawn mostly to sound quality… sometimes a look is just too off-putting, the Vivace is certainly that for me. But good to hear that in person they are better lookin.

ghdprentice:

i probably have said that im not in the market for a new amp - about 100 times - until i hear an amp that i really like a lot - its amazing how sound quality - if its good - changes my mind about not being in the market for something - if enough people really like it - im all ears and my wallet is more than open - within reason

@axo0oxa thanks for a detailed overview on your Vivace.  I think your points of view with be taken into the consideration, certainly it does not sound like a joke. Why you decided to go with Vivace and not with less expensive Audion ? Anyway, apparently you realized your dream, which is the most important thing.

 

IMO/IME the breakthrough has already occurred- you can now finally buy a solid state amp that sounds better than the best tubes can offer (with the same liquidity, no harshness but with greater detail including depth)

@atmasphere this is what I always wanted to hear!  It only remains to experience it unless it is taken as faith (unfortunately, none of us saw the God, even ones with the strongest faith, so less probably that i will be able to see him ever on this land).

My Salon 2's are very happy with the Storm PA8. 4x1000w in bridged mode. All the others on 3rd floor. :-)

@niodari being retired and having just closed my business I had a little extra money just sitting there in the account I needed to close out. I was totally satisfied with all my components but my amplifier, which had served me well for years. I decided the amplifier was the last piece in my long journey and the last piece to my puzzle. I went for the Vivace over the Audion because I just happened to have the money at that moment in time and I did not want to feel I should have gone for more power, since my biggest reason for this last upgrade was controlling the bass drivers with more authority. All the additional benefits that came with the amplifier were a huge pleasant surprise. What I learned in upgrading my preamplifier in terms of going for the gusto held true with the amplifier as well. Sometimes in this journey you reach the point that you need to leap big to really hear major improvements. Luckily everything aligned for this last jump. I hope this answers your question.

this is what I always wanted to hear!  It only remains to experience it unless it is taken as faith

@niodari Its easy enough to hear. You don't have to take it on faith.

@smargo  “i probably have said that im not in the market for a new amp - about 100 times”.

😊😀, yep, that can happen.

Its easy enough to hear. You don't have to take it on faith.

@atmasphere, this would be true if i were living in the US (it is too complicated to import equipment to Mexico for trial test, each time you receive a gear, you have to pay quite a lot of $$$ due to the duties/taxes). 

Meanwhile, as a "temporary solution", i got a Nuprime ST 10 amp from a local dealer, a reasonably priced used one  (i was left with no class D amp - the right channel in my Cherry Megaschino is almost silent, i  tried to contact  Tommy O'Brien lately without any success so far. the site is there but the emails come back, the telephone is out of service. He was personally dealing with most things, i suggest there is nobody else that can reply or take care of support. Hopefully Tommy is fine (a nice guy), but have no idea on what is happening with his company). 

After 3 days of auditioning, i decided to keep the amp. In fact, it has surpassed my expectations. It is quite fast, dynamic, airy with a considerable sound stage,  frequency extension is good, details are fine. The sound is extremely very clean but still the distortion is tolerable. It is a non-standard class D design, it does get quite hot. The sound is slightly colored, the base is a bit exaggerated, heights are clear, but a bit colored. The overall sound characteristic resembles Pass amps, if you like them, you may like ST 10 (much cheaper, much less power consumption...). This amp can be better than all (more expensive) class D amps i had except the Megaschino (which is broken now). 

After a few days of auditioning,  I suggest that this amp deserves  consideration,  it is a serious piece of gear. In fact, the reviews i read more or less objectively describe  performance of this amp. I wonder how much better could the overall sound be with other available options including more or less reasonably priced Voyager 350 and Orchard amps.  

"The sound is extremely very clean" ---> "The sound is *NOT*  extremely clean"

@axo0oxa thanks for this complement. You may still have more successful jumps, you never know. I made similar jumps also replacing amplifiers, and am not sure if more jumps are required. Compared to your tube SET amplifier, what exited you the most in your Vivace amp (except its cool look, i understand that these "tubes" looking as candles at night, may give an intimate peace-like feeling)?

https://forum.audiogon.com/discussions/rip-tom-o-brian-of-the-cherry-amp-co

@niodari Sorry, Tom passed away last December.

Must be living under a rock not to know that Tommy died.

Ralph, thank you very much for this, very, very, sad information. I didn't know him personally but we communicated a lot by email. One can say how a person is based on a letter exchange. He was always positive making good things and was doing that practically alone. He was, really, a very nice guy. Just to tell you that i am writing this message with tears in my eyes, a person whom I never knew personally. He had two daughters  i think. I will miss him...

P.S. He was relatively young, do you know what happened with him?

Lately he had some problems with  suppliers, and he was intensively working on a new MK3 Megaschino...

COVID is what happened

I ordered LSA GaN Voyager 350, should be here by Thursday. I will try it first in my second system. If I would like it then I may try it also in my main system. I will post what I will see. 

WOW ! To him not knowing.....or caring.....

We will see. 

In my second system recently i was using Cherry Megaschino (which now needs a repair of one channel), Mankey Stingray tube integrated, PS Audio Stellar S300 and most recently, since about one week or so, Nuprime ST-10. The latter is better than S300 in almost all aspects except that it does get hot. If the Voyager will be notably better than ST-10 then I may try it in the main system with my tube SET integrated. So far, the latter amp could not have been bitten, unlikely Voyager will surpass it.

I have the Voyager GaN 350 in my main two-channel system and the Wyred4Sound 1000r monos in my home theater room. Love 'em. Never going back to Class A. 

Which version of the ST-10 ? New, it would be version 4, which in reading, is the best of the 4.....I believe there were 4 versions.

Only class D I ever liked was a Lyngdorf 2170 but that was totally due to the room correction and only with some speakers. 
 

Not heard the new Gan stuff or any “high end” stuff but of the  medium priced class D vs medium priced AB or tubes I’ll take the latters all day. Haven’t heard a class D that gets the highs right or really the upper mids either. 

The Voyager just arrived today, i hope will connect it tomorrow and will post my first impressions. 

I have only two preamps, Nuprime, HPA 9 and Wyred4Sound STP 2, will try first HPA 9 with the Voyager (class A, quite a good preamp). I am not sure if ST 10 is of the last generation, perhaps not, it is produced about 2 years ago, i will ask. 

@mofojo , given two amps, one class AB and the other class D of about the same price, most likely, the  class D amp will be better.

@blkwrxwgn , unfortunately, Tommy O'Brien has passed away...

In fact, i also like the Cherry Amos faceplates, at least the dark red one if my Megaschino. Does anybody  know if there is someone who is able to deal with Cherry amps now (my Megaschino needs a repair of its right channel)?

I was able to audition my new Voyager LSA  GaN 350 for a couple of 

hours this morning. I let it warm up for just 30 minutes or so (this is a completely new unit with no burn-in). I hooked it up with Nuprime HPA 9 preamp using its RCA outputs (it has no balanced outputs), bookshelf  Thiel MCS1 speakers (sensitive 91db) with a Thiel subwoofer and passive crossover, Krell Kav 300 CD player used as a transport with a Cherry DAC.  

During these two hours, I compared it with the Nuprime ST-10 amp that I was recently using in the same setup. These are my first impressions. 

I didn't find the Voyager  bright, still a little harsh and slightly dry perhaps. Although it is 500 watts in 4 ohms, it gives notably less power than 150 watts ST-10 amp, at least with HPA 9 preamp (perhaps, impedance issues). I found its sound clear, natural, unaltered, in some sense, a bit fuller than with ST-10 since it goes a bit deeper into orchestral passages. The middle range is a bit more defined than in ST-10. The soundstage, so far, is a bit flatter than that of ST-10, but Voyager has a bit more details. The heights are clean (despite that some measurements claim that there could have been distortions in high frequencies).  The base extension is less than in ST-10, still it sounds natural. The sound of this amp somehow resembles to me  a class A amp sound, still not as rich and complete (yet? - this may change with break-in hours). 

The amp has no standby mode. I left it on without using it, and it  got quite warm. I would not leave it on all the time (Cherry Megaschino has also no manual standby switch, but it goes standby automatically after 8 minutes of idle time, and stay completely cool). 

I think I need to use the amp for more time to understand how much i like it. I may stay with it and use it in my third system with Thiel CS 3.6 speakers.  Meanwhile I will leave it in my second system for break-in (i use that system  for 1-2 hours in the mornings so it may take some time). I may also try its balanced inputs with Wyred4Sound  STP 2 preamp. Now, i see no point in trying the amp in my main system (where i use my 5 watts SET tube amp). I may try it in the main system after the break-in of 200 hours or earlier if an essential improvement will occur. 

I will post my further impressions in case my thoughts and feelings will be changed compared to what i think right now (first impressions might not be very objective). 

@niodari

Congrats. Do not worry as it will definitely break in. Now, that said, I did not like the the supplied footers, replaced them with inexpensive Nobsound + added ~ 5#s of weight to the top. The W4S (XLR>XLR) makes a lot sense, but quality XLRs and PC will matter. Replacing a Marantz HD CD-1 (used as a transport) with a Audiolab CDT 6000, was another excellent upgrade, as was improving the coax and PC cables to it. Feed it HQ ancillaries and it WILL reward you

hth

+ @tweak1

— A good power cord on the Voyager is a is a must.

—spring pods are such a deal (mine are autocrast. Same as nobsound.

Inexpensive and so effective).

Autocrast spring pods under my speakers are by far the best of the 4 vibration-management products i’ve tried.

I am utterly thrilled with the Voyager and the sound of my system now. But I Look forward to hearing better things still, when I improve my Dac, Pre and USB in the near future and also continue to build on the significant improvements in room acoustics I’ve realized lately.

@niodari 
I leave all my SS electronics on 24/7. Have not found the Voyager to get more than mildly warm.

I decided to swap PCs between my transport and my Voyager. The Voyager had a boutique PC from Tek Line Cables (15 yo, then $500, no longer in business), I also have one on my preamp/dac outboard PS. 

The new PC was better top to bottom with more defined bass umph. Looks like I need 3 more PCs; transport, dac/pre and CorePower PLC

@ghdprentice 

Your AR 160 Ref stereo is not just the best AR I have heard, it may be the best amp I have heard. The monos must be threw the roof.

So cool of your dealer to let you hold on to them.

What I heard at your house was superb and definitely had the “organic” sound of tubes. Although I would not say that it was “tubey” at all. 
My Class D AGD Audions do not approach or attempt to recreate that tube organic sound. They produce a more “clear window” into the music. I would say a more neutral take rather than organic. However, I don’t necessarily miss what your tubes do. It is very satisfying.

@niodari 

I only just discovered this thread last night, and I see you've purchased an amp. Even so, I'd like to suggest a Class D amp no one has mentioned. Nuprime announced its Evolution STA dual-mono amp in January. I had already been researching the various new Class D and GANfet amps, and knew the only way I could hear this or that amp, was to go ahead and buy an amp in order to listen to it in my system. Because the Evo STA was the newest of the bunch, I decided to take a chance and buy one. 

The EVO STA needed a solid 250 hours of burn in before I was satisfied that there were no more obvious changes to its sound. This amp has a warm tube-like character to it yet simultaneously is very revealing and clear. I love how it sounds in my system.

I have no idea how it compares to the various other above mentioned amps, but I sure do love its sound. I think it's worth considering if you haven't finished your search. The MSRP is $4995. However, if you check with your dealer, he/she may have 'confidential' pricing. 

Michael

@mresseguie, thanks for sharing your experience with Nuprime Evo monoblocks. My earlier idea on these amps was that they are more accurate than ST-10 amp but also more analytical. Based on your comments, apparently, this might not quite be the case. The ST-10 gives a tube flavor, nice sound stage but the distortion is a bit notable. If the Evo amp inherited the former features but eliminated the distortion without being analytical, they should be very good amps (I think this was a key consideration in the design of new @atmasphere class D amps).  It could be interesting a direct comparison of these two Nuprime amps.  

@tweak1, @rc22 Thanks for the suggestions. In fact, I also read in the manual that a better power cable is recommended. I replaced the supplied PC of the Voyager GaN 350  with Audience Forte f3 PC. perhaps, there is some improvement in power and in base (I have to return the other cable and audition the amp again to be completely sure).  But the most important thing that needs improvement remains a little dryness and lifeless in sound. Hopefully, this can be improved with break-in.

So far, my analytical thinking tells me that this is a very good amp. Pre-consciously, i am not still too attracted to the amp, all is good, but something (the soul) is still missing. May be i need to spend more time with the amp and this might be changed. For the final verdict, I will wait until it is fully broken in and then will try it in my main system (with better cables, transport, dac, acoustics, etc). This weekend I used it more than i usually do, it should already have close to 15 hours (in some amps, i was observing an improvement already after 10 hours). As to the other interconnect cables, honestly, i don't understand how a transport  interconnect cable may influence on the performance of the amp (it may improve how the transport sounds of course). I have never tried spring pods but will bear this possibility in mind.

Later this week i may try the amp's balanced inputs with W4S STP 2 preamp. 

@mglik 

Thank you for your very kind words.

I'm kind of surprised there hasn't been more discussion of the Nuprime Evolution STA.  Anyone heard it?

It would be interesting if there are some comparisons, in particular, between Nuprime ST-10 stereo, ST-10 mono blocks  and Evo STA amps. I suggest ST-10 stereo may have the highest value performance/cost. 

As to the Voyager, it made the first "improvement jump" after about 20 hours of use. If following 10 jumps will be equally significant, then this amp is a great amp,  a perhaps, with a best value performance/cost. So far, i use the same setup with RCA cables and Nuprime HPA-9 preamp (if i mentioned it earlier,  the HPA-9 was better than the W4S STP 2 preamp hooked up with the Nuprime ST-10 amp). 

I gather Jason Lim shut down production of the Evolution monoblocks because the Evolution STA offered 90-95% of the performance at just over half the price, so it is now their flagship product.  I can't seem to find out whether the STA uses proprietary modules or ones purchased from an OEM.

I took a chance on a used pair of Audions because they don't come up that often and I wanted to hear them.   Count me highly impressed.  Totally black background, very fast, neutral tonal balance, good spatial representation - I do think they are revolutionary.  From my perspective, the current top contenders are the AGD and Atmasphere Class D amps (Ralph, I may be giving you a call).  I would love to hear Ralph's Class D amps and the Vivaces as well. The AGD Audions sound great with my VAC Signature IIse preamp and my Tekton Encore speakers.  Have yet to feed them into my Avalon Eidelon Diamonds.

Would love to hear people's experience of the Atmasphere Class D.  From what I've heard, people who have heard them very often end up buying them, and they are flying off the shelves...

Think there may be one or two who were not blown away with AGD.

But the comments of AGD owners are unanimously raves.

If you don’t need mono blocks (and/or are not a fan of the “tube” output stage)

the stereo Tempo is uses the same technology as the mono models and is said to sound virtually the same as the Audions for $2K less.

I believe that the much more expensive Vivace also sound very much like the Audions. Just a bit more full sounding. And the top line Grande Vivace is also very similar to the lower models just another bit more full and twice the output.

If going for the upper models, the Grande Vivaces are the ones to get.

I do agree that they are revolutionary. 

I have the AGD Tempo di Gan.  It's excellent.  I too would be curious to hear it pitted against Atmasphere's amps under controlled conditions, but there really isn't anything I want to improve at the moment, so that's not a priority.  Either it, or the Audio Envy Mega PC that I put on it, took a little while to break in, but then everything snapped into place.

If anybody has the Atmasphere classD amplifiers in the Seattle area, let’s get together and do a comparison.

I've been anxiously awaiting to hear the Atmasphere class d amps from my dealer in NH for months now. He keeps telling me soon but I just might look at AGD instead. 

@rsf507 

Hello, just let us know.

Both models,  Audion and Tempo, are ready to ship

Not sure what your budget will allow but I've owned the Rogue;

Sphinx 2

Cronus Magnum 2

And now the Pharaoh II integrated.

Rolled RCA Clear Tops in it and couldn't be happier. 250 watts into 8 Ohms and 400 into 4 Ohms. New Class D Hypex N-core amp and tube preamp. Breathtaking! 

Step by step, it can be more relevant now to compare an AGD amplifier with LSA Voyager GaN350. I didn't see any negative feedback on the Voyager so far on Audiogon  from people who own it (including myself), whereas I read some on an AGD amp (that costs a few times more). Once we know what are objective advantages of AGD over the Voyager (if there are some), we may consider other more expensive candidates; otherwise, it seems to be just a kind of subjective  speculation. 

Thanks agdproduction I'll have to see if my dealer can get one in for evaluation. I've been waiting over 3 months for the Atmasphere amp and each time they say it's almost ready another 3 - 4 weeks go by and nothing.