[Freo-1]

I am fascinated by the rise of "audiophile" Class D amps, and the increasing respect they get from reviewers and listeners. If you have been "converted" to Class D, I would be curious to hear what amp converted you, and what your journey was before you arrived at Class D. Did you come from Class A/B solid state, or pure Class A, or even tubes? What convinced you that Class D was right for you?

I am most interested in stories where Class D just sounded so good that you no longer felt you were compromising by listening only or primarily to a Class D amp.

My story first: I have been a Class A/B solid state amp listener for most of my life, starting with high-current HK integrated amp from the 1980s, and later with an Anthem receiver (which I still think sounds fantastic), and most recently a beautiful Luxman L507-u integrated amp. I even dabbled in tube amps with a nice mid-priced SET amp (Tokyo Sound Valve 100/SE). But on a lark, I bought a used pair of Bel Canto Ref500M monoblocks, and later a Bel canto Pre3... and these have become the core of my primary listening system. I just find them to be as good as anything I have ever lived with: refined & balanced, powerful and liquid-sounding. What more can I ask for? The sense of sonic realism is startling when I first turn on a good recording.

Cheap Class D can sound lifeless and grey. But well-executed Class D can hang with the big boys! (Though I will admit that I have not spent much time with some of the BIG boys, like Pass Labs pure Class A solid state amps...)

Thanks in advance for your stories of how you arrived at Class D!

Regards,
Eric

For me, it was the introduction to Devialet Expert/Expert Pro.  I had Pass Labs gear when I first came across the Devialet Expert 400.  I was absolutely floored with sonic performance.  The speakers I has at the time were supported by Devialet Speaker Active Matching DSP.  I would up selling the Pass Labs gear and have not looked back. 


Currently own a Devialet Expert Pro 1000, which is an amazing performer.  Check out the measured performance specs, they are off the charts.  The amazing aspect of the Devialet is that there is zero congestion when the volume is turned up.  Add the fact is has a top of the line built in DAC, phono input, and supports a number of streaming options, including Roon, it's impossible to go wrong. 


The Devialet amp stage is unique, in that it uses Class A for voltage gain, and Class D for current gain.  It's the only amp on the market that does not employ post ultrasonic filtering for Class D (it does not need it). 


A Devialet Expert Pro 440 second hand can be had for somewhat reasonable money.  As for my 1000, they were both originally  D-Premier units, sent back to Devialet for upgrade.  Therefore, cost was manageable. 

[I.Greyhound Fan]

KMMD,

The Pass X250.8 runs in class A for the first 20-24 watts then AB.  With my Maggies even at loud levels never leaves class A except on bass heavy music, then the meter needle will cross midline (telling you that you are leaving Class A) occasionally during thunderous bass.  And my X250 leaves class A at around 15wpc unlike the 0.8 series which leaves Class A at over 20wpc.   I was shocked to see how little power you actually use.

I am not surprised that the Coda Amp has tighter bass.  Pass labs gear usually has a low dampening factor of 150 and you can tell it in the bass as it is more rounded sounding for lack of a better term.  My old Parasound A21 had a dampening factor over 1100 and it had tighter but less thunderous bass compared to my X250.  I prefer the bass of the X250 as real tight bass does not sound natural to me.

[kmmd]

KMMD,

The Pass X250.8 runs in class A for the first 20-24 watts then AB.  With my Maggies even at loud levels never leaves class A except on bass heavy music, then the meter needle will cross midline (telling you that you are leaving Class A) occasionally during thunderous bass.  And my X250 leaves class A at around 15wpc unlike the 0.8 series which leaves Class A at over 20wpc.   I was shocked to see how little power you actually use.

I am not surprised that the Coda Amp has tighter bass.  Pass labs gear usually has a low dampening factor of 150 and you can tell it in the bass as it is more rounded sounding for lack of a better term.  My old Parasound A21 had a dampening factor over 1100 and it had tighter but less thunderous bass compared to my X250.  I prefer the bass of the X250 as real tight bass does not sound natural to me.

I understand that the Pass Labs X series of amps run in Class A to a point before switching to A/B.  My CODA No 16 runs in Class A up to 100 watts.  Your X250 is driving a pair of Magnepan1.6QR’s, but I think you’re forgetting that I now have YG Acoustics speakers which are sealed box with aluminum cones.  YG’s are also not known to be low level listening speakers.  They need power to push those cones, and I’m moving from Carmel 2’s to Hailey 3’s as my main speakers.  I’m sure the CODA will drive the Hailey 3’s just fine at my listening levels, but I’m always looking for more.  I like feeling my mid-bass too.  Therefore I’m definitely open to Class D amps in my system. 

I was also the crazy fool who bi-amped my Maggie 3.6’s with the X250.8 and a pair of Bryston 9B-SST’s.  Now my plan is to use a pair of Carmel 2’s as my center channel and the Pass Labs amp to drive them…crazy plan again, but it’ll be a reality soon.

[bgorman]

I bought a Nord Acoustics NC502, which representss insane bang for the buck.

I still run class A for my main system,  but have my eyes on the Apollon Hypex NC2k Premium Monoblocks, at least for a couple of subs (I am currently driving them with a McIntosh MC352, but it's a bit underpowered for my needs). The premium Apollons incorporate Weiss OP2-BP op amps, which I have to say are the best I have heard (well, I have the very similar OP1-BP in my Weiss DAC).

[RDavidson]

KMMD,

The Pass X250.8 runs in class A for the first 20-24 watts then AB.  With my Maggies even at loud levels never leaves class A except on bass heavy music, then the meter needle will cross midline (telling you that you are leaving Class A) occasionally during thunderous bass.  And my X250 leaves class A at around 15wpc unlike the 0.8 series which leaves Class A at over 20wpc.   I was shocked to see how little power you actually use.

I am not surprised that the Coda Amp has tighter bass.  Pass labs gear usually has a low dampening factor of 150 and you can tell it in the bass as it is more rounded sounding for lack of a better term.  My old Parasound A21 had a dampening factor over 1100 and it had tighter but less thunderous bass compared to my X250.  I prefer the bass of the X250 as real tight bass does not sound natural to me.

As a Pass Labs fanatic myself, something I’ve learned is that damping factor is certainly a spec that has some correlation to bass control, BUT it most definitely doesn’t tell the whole story. The XA25 has quite a full sound and definitely isn’t lacking bass volume nor definition (for its output rating). It has a damping factor of 500. I think this says bass presentation has more to do with amplifier design than specs. I can’t remember where I read it, but Nelson has said that a damping factor of more than like 100 (going from memory here) doesn’t have an audible effect. This correlates with other things I’ve read elsewhere that damping factor is basically a meaningless (and often misunderstood) number beyond a certain point. Marketing folks like to have fun with numbers, don’t they? Crazy high damping factor specs are just for bragging rights on paper. Go figure!

[kmmd]

Today was the first day at THE Show in Costa Mesa.  It was my first audition of Class D amps, and I’m impressed.

I liked both the AGD Productions / Ocean Way Audio room with the Solo monoblocks  and Evolution Acoustics / The Audio Association room with WestminsterLab Rei monos bridged.  I did like the Rei’s more.

[TomS]

Today was the first day at THE Show in Costa Mesa.  It was my first audition of Class D amps, and I’m impressed.

I liked both the AGD Productions / Ocean Way Audio room with the Solo monoblocks  and Evolution Acoustics / The Audio Association room with WestminsterLab Rei monos bridged.  I did like the Rei’s more.

But the Westminster REI's are class A, no?

I'll have another Coda 16.0 here soon. Best I've heard in my system when I demo'd it a few months ago.

[kmmd]

But the Westminster REI's are class A, no?

I'll have another Coda 16.0 here soon. Best I've heard in my system when I demo'd it a few months ago.

Yes they are sliding class A and cost about $12-13k more than the AGD monos.  I’ll listen to both rooms a bit more today.  The Evolution Acoustics room has an Ampex reel to reel deck which was phenomenal.  I’ll try to listen to the Grimm MU2 in there also.  The combination sounded natural, extended with proper timbre and separation.  The AGD’s sounded more weighty but not as extended or natural.  Of course these are my impressions and ears.👂

Enjoy your CODA 16!

[hk29]

My main speaker is Harbeth c7es and source is qobuz.  I mostly enjoy vocals (pop, indie, etc).   I've had Devialet 200 and NAD 268 which I felt both where on the dry side and never really got into them.  I went through a journey through SS AB (Naim Supernait 3, Electrocompaniet ECI 6 DX MKI) and Tube apps (Rogue Audio Cronos Dark, LTA Z10, and Line Magnetic 210).  I've never tried a class A SS.   

My favorites were Naim SN3 and Line Magnetic 210.  They both gave me the PRAT + "grit" / musicality through the vocal range (e.g., texture/ detail).

I've always preferred Tube amps, but the heat, tube rolling, expense, and manual biasing of the Rogue Audio was finally getting to me.  So on a whim I got the Axxess Forte 1 (which I just left a review: https://www.audiocircle.com/index.php?topic=189682.msg1984521#new)

Its a few days in but I'm really liking it.  It doesn't sound like Devialet or NAD - squeaky clean/dry/neutral/thin/uninvolving.  The Axxess does sound really detailed, precise imaging, but is smooth and musical - it has textured through the midrange and full bodied.   So far I'm not regretting moving from the Naim SN3 (my previous integrated) + LAB12 DAC1 (Tube R2R dac).    I've read the Axxess Forte uses the Pascal modules?   I also think my tastes are evolving from tube grit/holographic to increased details/space/imaging which is what I'm getting more from the Axxess over the Naim but haven't lost the midrange texture and body.   Let's see if I change my mind over the next few months

I'm curious about the AGD Audions, but they're out of my price range when you have include a preamp/DAC. 

[AllanS]

It’s not just a matter of being converted to class D.  Like anything else it's the implementation.

Edit: spelling

[ethirolle]

It doesn't sound like Devialet or NAD - squeaky clean/dry/neutral/thin/uninvolving. 

I recently tried the NAD M10 v2, which is an interesting "future-fi" all-in-one format, and was well-reviewed by many... but I took an instant disliking to it after swapping it into same room/system where I was using my Bel Canto Class D monoblocks. Definitely dry & uninvolving. Maybe not a fair comparison, but it was an illustration for me that not all Class D is created equal, even $2K+ Class D.

I also think my tastes are evolving from tube grit/holographic to increased details/space/imaging which is what I'm getting more from the Axxess over the Naim but haven't lost the midrange texture and body.

Yeah, I wonder if Class D appeals especially to those who really have a taste/bias for space and air and soundstage, which is probably the case for me.

[ethirolle]

It’s not just a matter of being concerted to class D.  Like anything else it the implementation.

I definitely agree... and maybe this was part of my point in starting this thread. I was curious to hear from this community how folks had come to find that "Class D" no longer means what it used to mean (or what people assumed it meant: dry, thin, grey, etc), and - with good implementation, taking into account the particular strengths and weaknesses of Class D technology - could be considered true "hi fi"

[kmmd]

At some point I’d like to listen to more Class D amps.  They can be very good sounding, and I agree that design and implementation are the foundation.   So far I’d only consider the WestminsterLabs Rei, but at over $30k a pair, it’s a stretch.  There are many amps available in that price range new and even more in the used market.  I do hope to listen to Bel Canto’s.  Did you know that YG Acoustics uses their Class D amps in their active speakers?

[newzooreview]

I recently tried the NAD M10 v2, which is an interesting "future-fi" all-in-one format,

All-in-one has been around for more than half a century. There's one YouTuber who likes to say "future-fi" a lot. I think it's a way to appease his funding sources by equating consumer-friendly, all-in-one boxes with newer=better.

Regarding the topic of this post, the Hypex Nilai amp has been sounding amazing in my system. With my speakers, it sounds better than my Pass Lab XA25 and Benchmark AHB2. The thing that really struck me compared to other Class D that I've heard is how well the Nilai handles harmonics in acoustic instruments like pianos and violins. It has no mid-range glare, but it has excellent soundstage depth and details very deep into the mix. Timbre is excellent, and vocal are very natural and expressive. It's a kit, but I had VTV assemble mine and use WBT binding posts. I am extremely happy with this variant of Class D. I've tried ICE class D and GaN class D, and neither comes close to the Nilai in my systems.

I think class D is now better than Class A/B and Class A in $/watt, size, and efficiency (low heat). And the best of Class D is now on par with the best of Class A/B and A in each price range. Actually, I think the best Class D is better than the others within each price range until it gets to the level of a Gryphon or other Ferrari-priced equipment.

[AllanS]

...the Hypex Nilai amp has been sounding amazing in my system. With my speakers, it sounds better than my Pass Lab XA25 and Benchmark AHB2. The thing that really struck me compared to other Class D that I've heard is how well the Nilai handles harmonics in acoustic instruments like pianos and violins. It has no mid-range glare...Timbre is excellent, and vocal are very natural and expressive.

Having followed your discussions I suspect your ears are much more attuned to such things, but I use the same words to describe the NuPrime AMG STA in my system and will add that percussion is crisp.

[DannyBadorine]

I think class D is now better than Class A/B and Class A in $/watt, size, and efficiency (low heat). And the best of Class D is now on par with the best of Class A/B and A in each price range. Actually, I think the best Class D is better than the others within each price range until it gets to the level of a Gryphon or other Ferrari-priced equipment.

The independent measurements support what you're saying here. My subjective experience is the same.  I never liked the old Class D stuff except for subwoofers.  But now, with Purifi and Hypex modules, Class D is just better and more affordable.  I think it's difficult for people to wrap their head around a $1k Class D amp that is more accurate and more capable than a $10K Class A/B amp.

[hk29]

I recently tried the NAD M10 v2, which is an interesting "future-fi" all-in-one format, and was well-reviewed by many... but I took an instant disliking to it after swapping it into same room/system where I was using my Bel Canto Class D monoblocks. Definitely dry & uninvolving. Maybe not a fair comparison, but it was an illustration for me that not all Class D is created equal, even $2K+ Class D.

Yeah, I wonder if Class D appeals especially to those who really have a taste/bias for space and air and soundstage, which is probably the case for me.

And fast and clean.  But the Axxess still has body and texture that I'm used to on Class A/B.  As I listen to the Axxess more, its definitely sound brighter.   Its definitely "different" than class AB or tubes but I'm enjoying it a lot - I'm surprised.

And just like not all tube amps are the same (LTA - cleaner, more SS vs. Line Magnetic - tuby, holographic); but I did enjoy them all despite all the differences.  I can't say that for all the Class D amps I tried.