1. Home
  2. amps-preamps
  3. 197619-139155

Expanding the Class D Conversation: How Would You Characterize Their Differences?

Expanding the Class D Conversation: How Would You Characterize Their Differences?

I'm currently trialing the NAD M23 (1st gen. Eigentakt-based), and I find it intriguing enough to want to understand it better — which means understanding the broader sonic landscape of class D. So I'm crowd-sourcing.

In a recent exchange, the estimable Ralph Karsten (Atma-Sphere Music Systems) made two comments that stopped me cold. For those who missed it, here's what he said:

"IME, class D amps vary in sound more than tube amps, which is to say, quite a lot."

"IMO there is a bigger difference between various class D amps than you hear between various tube amps. IOW just because you heard one class D amp says nothing about how the next one might sound."

Link: https://forum.audiogon.com/posts/2885828

As I think through this more carefully, these are genuinely important claims. My own experience with tube amps confirms that they produce audibly distinct characters across topologies and designs. If Ralph is right and class D exceeds that range, then generalizing from one class D experience to another is even more hazardous than I assumed.

One specific question for Audiogon members:

If you have a Class D amp or have compared class D amplifiers, how would you describe their character(s)?

Here are some criteria I use:

  1. Frequency balance — Is the tonal response even across bass, mids, and treble, or does it favor certain regions?
  2. High-frequency texture — Are the highs extended and smooth, or edgy, grainy, and fatiguing?
  3. Bass definition — Is the low end tight and articulate, or loose and bloated?
  4. Midrange character — Does the midrange feel present and natural, or recessed and thin?
  5. Transient speed — Does the amp respond quickly to dynamic attacks, or does it sound sluggish and rounded?
  6. Dynamic range — Does it scale convincingly from quiet passages to loud ones, or compress the difference?
  7. Soundstage width and depth — Does it create a convincing three-dimensional image, or sound flat and narrow?
  8. Image specificity — Are instruments and voices placed precisely, or do they blur and wander?
  9. Background noise floor — Is the silence between notes actually silent, or is there grain, haze, or hash?
  10. Long-term listenability — After an extended session, do you want to keep listening, or has something been quietly fatiguing you?

If you can include relevant system context — room, speakers, preamp — please do. Those variables will help me interpret what the amp itself is contributing.

I'm less interested in rankings than in understanding what Ralph mentioned, namely the [vast] range of sonic signatures class D is capable of. Eigentakt, Hypex, Pascal, Purifi, GaN-based, etc. — all fair game.

Price is no constraint here — I'm interested in the full range of what's out there.

hilde45
mahgister's avatar
mahgister
15,045 posts
 

The best thread i read about class D impressions.

And i trusted the OP  well done experiences  and descriptions and anyway even if there is no comparison with my low cost class D amplifier i precisely added a pre-amp with tubes for these  same reasons which compensate for my first negative  impressions (the same as the OP) and  i added all other optimization devices  to reach with them  some " minimal acoustical satisfaction threshold" with the system/room i had optimized. 

If i had more money then i perhaps will bought  a class D amp + a tube top pre-amp....smiley If i was Bill Gates i will buy probably a S.S. amplifier paired with a top tubes pre-amp.... But only someone with  experiences i dont have here can gave an answer ... I know how to optimize but i never did extensive costlier class amplification and pre-amplification comparisons... it is why this thread is so useful and interesting ...

 

I appreciate my class D Edifier once optimized with Schumann generators , Buffer/filters , E.Q.+DSP,galvanic isolation+DDC all with many linear supplies and a small acoustic corner controlled by Helmholtz resonators grid and diffusors in nearfield...

But right out of the box my low cost class D correspond at his quality level with the exact description of the OP comparison...

The relation S.Q. price in my case is superior to most system in this price range  with class A or A/B  or low cost tubes, non optimized in a non controlled room for sure . Then i am happy...

 Audio wisdom is learning how to do the best with what you have, the rest is music...

iamsportsdoc
5 posts
 

Excellent thread. Thanks to the original poster.

For some reason one of Merrill Thor monoblocks stopped working recently. I have enjoyed them for many years. They replaced a Modwright KWA150 amp. Whereas the monoblocks provided more bass definition, I lost some warmth of tone especially in vocals. Also, it felt as if some connective tissue holding the music together had been diminished. I’d say that the soundstage lacked some depth as well. This seemed more apparent streaming digital and less so listening to vinyl. I decided to audition a pair of Laiv GanM monoblocks while I try to figure what happened to the Thor unit (modified Hypex). My initial impressions are very positive. Listening to jazz, instruments such as trumpet, sax and bass sound more natural. There is more reverb of instruments, longer decays when appropriate.  The soundstage has improved back to front and extends beyond the sides of the speaker cabinets. The connective tissue of the soundstage has also improved and it’s easier to get a sense of the environment in which the music was recorded. I’m not sure whether all this is due to GanM tech or implementation, but to these ears, some of the drawbacks of earlier Class D have been addressed.  Has anyone else had a similar experience with newer Class D implementation? Anyone else auditioned the Laiv GanMs? Thanks

hilde45's avatar
hilde45 OP
5,997 posts
 

@iamsportsdoc Thanks for the note about the Laiv GanM monoblocks. I’m seeing a list of $4494 which is much below the AGD Audion III ($7850) and the price I was just quoted for the Atmasphere monoblocks ($6300). Who knows how the sound compares and also the latter two are US made, so that might be a reason to consider spending a bit more. (Not trying to trigger *that* conversation!) I know Jay Iyagi channel sang Laiv's praises, but he sings just about everyone’s praises so that’s not much help. And they've not been out that long so I am not sure about reliability, service support, etc.

Funny how your Orchards just went up and quit on you! Not cool!

rhale64's avatar
rhale64
25 posts
 

I just wanted to say Earthbound I am glad to see you like the Orchard Audio Amps. Op the Ultra modules are the more powerful modules that can output more watts. But they are slightly slower switching. So the 25 modules that Earthbound has for demo are the newer technology faster switching modules. In fact I believe they may be the fastest switching modules out. And also it wasn't the Orchard amp that stopped working it was one Merril Audio amp that is also a class D amp. Just wanted to clarify that.

hilde45's avatar
hilde45 OP
5,997 posts
 

@rhale64 Thanks for the info and clarification! 

More to discover