@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.
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.
- ...
- 355 posts total
I had Mola Mola Kaluga amps along with my Makua, Tambaqui and Revel Salon 2 speakers. I was initially blown away by their dynamics, bass control and speed, noting the Salon 2's are not easy to drive. But compared to my Audionet class AB gear, I soon grew fatigued and bored with the system. While 'musical' is hard to define, they lacked it. I replaced these amps with a pair of Audionet Max mono's, and by direct comparison, much better. More engaging, less fatiguing, more delicacy and sparkle, still all the speed and resolution. Initially called the 'perfect' amplifier, Mola Mola now lauds their Ossetra amps, siting significant improvement to their implementation and design of class D. But nothing looks better than either amps sitting to each side of the Makua preamp!
|
@fastfreight Interesting observation, but perhaps that is at least partly due to the Kaluga being based on the older Hypex NC1200 platform. Putzeys & Co. are now two generations ahead, and the Ossetra is quite different all around (for a price). Class D tech is fast moving.
|
@hilde45 - During during Covid, I decided it was time to invest in a sound system. Little did I know I was embarking on an expensive journey exploring all sorts of equipment - class a, class ab, and tube amps. Luxman, Gryphon, Conrad Johnson, Qualiton, Linear Tube Audio… Let’s just say I have tested my wife’s patience. As I grew tired of tube amp maintenance, I recently purchased a pair of used AGD Audion mkiii class d amps. I had grown used to the rounded glow and warmth of tubes, so it took me about a week to finally honestly assess the AGD amps on their own merit. Going through your list, the frequency balance is wonderful, the image specificity is great, and transient speed makes the music exciting and energizing. I just find myself drawn into the music. These AGD class d amps sound as good - and better in many ways - than my class an amp. I’m no longer fixated on listening to my system and driving my self crazy. If you have not already, check out the AGD amps (I’m sure Ralph Karsten’s class d amp is also great btw)… I’ll keep a tube amp to swap in every once in awhile, but the AGD mono blocks are now my reference amps in my living room. |
- 355 posts total