I judge my system in different ways, but if I don't enjoy listening all day, it ain't worth it.
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:
- Frequency balance — Is the tonal response even across bass, mids, and treble, or does it favor certain regions?
- High-frequency texture — Are the highs extended and smooth, or edgy, grainy, and fatiguing?
- Bass definition — Is the low end tight and articulate, or loose and bloated?
- Midrange character — Does the midrange feel present and natural, or recessed and thin?
- Transient speed — Does the amp respond quickly to dynamic attacks, or does it sound sluggish and rounded?
- Dynamic range — Does it scale convincingly from quiet passages to loud ones, or compress the difference?
- Soundstage width and depth — Does it create a convincing three-dimensional image, or sound flat and narrow?
- Image specificity — Are instruments and voices placed precisely, or do they blur and wander?
- Background noise floor — Is the silence between notes actually silent, or is there grain, haze, or hash?
- 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.
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- 355 posts total
I took a chance on a pair of Purifi 1ET9040BA (2nd Gen) monoblocks to power large floorstanders in a large room. I elected to go with VTV's Sparkos-designed vacuum tube buffer (Weiss op amps and NOS 6922 tubes). That added to the cost, but absolute no regrets there. They deliver ample power effortlessly, are balanced, articulate, and create a generously rendered, holographic soundstage. I find no audible artifact or stereotypical characteristics that one can use to identify this particular configuration as a class D amp. Everyone who's heard them has been duly impressed. Modular designs like Purifi leave it up to the builder to provide their own buffer, and this impacts the overall sound character. One should be aware of this. As with linear amps, there will always be audible distinctions between the inexpensive consumer models and the best offerings, but already the best offerings are pretty damn good, are reasonably priced with respect to their linear competition, and only continue to get better. |
@ted_b That's a great report. Thanks so much. Quick question -- does it ever get "shouty" or do you find a need to "turn it down" ever? My NAD toes this line on a bunch of tracks, where my Pass is not at all shouty (and I'm level matching very carefully). My NAD has the Eigentakt 1 module. Thanks. |
I replaced a very expensive SMc Audio amp and a pair of tube monoblocks with a pair of Bel Canto Ref 500 monos. I don’t feel as though I gave up any midrange magic or involvement factor by doing this. They are neutral yet still full and dimensional. Of course these are based on earlier ICE modules, but I actually preferred them to the latest 601 monos. I am using a Don Sachs DS2 preamp and I think it’s a very good match. I was a Class D skeptic but I’m convinced now they can compete with other high end amps. |
@hilde45 My in-room response at my listening position is gently tailored to fit the Harman curve. I had another class D amp here previously that exhibited the stereotypical characteristics one associates with class D amps - dry, clinical mid and high frequencies with a bit of timbral color and some "glare" despite the identical in-room response. The soundstage was fairly wide, but less well defined along the periphery and without much depth. This was not so much an issue for EDM perhaps, but potentially fatiguing for more "organic" music genres. In contrast, my current setup delivers timbral accuracy and resolving mid and high frequencies with finesse. |
- 355 posts total