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

@decooney 

I see that Herb at Stereophile really liked the Laiv monoblocks -- 

https://www.stereophile.com/content/gramophone-dreams-107-laiv-ganm-monoblock-record-doctor-vi-20th-anniversary-edition

Before the LAiV Harmony GaNM amp arrived, I had developed a yawning disinterest in class-D, plus an irrational disdain for fast-acting "high conductivity" GaN-FET transistors. (Last time I checked, free electrons were moving pretty fast already in 1000V vacuum tubes like a 211 or 845.) And everyone knows I’ve never been persuaded by weight, cost, and energy-saving switching power supplies. True to my boomer roots, I’ve stuck to old-school class-A linearity, plus wide bandwidth, tidy transfer functions, clean squarewaves, and lots of standing current.

What I care about most is tone, transparency, tactility, and having enough current and voltage to push the smallest recorded sounds and subtlest captured rhythms through diverse speakers. Which means I am laughing at my own foolishness, because I think I’m getting every one of these "care abouts" with class-D GaN-FET amps driving my Falcon LS3/5a’s. I need the unnamed wizards behind these amps to explain why these things I once mocked are now thumbing their noses at me and mocking me back.

Based on what I’ve heard in my studio and what I’ve read on LAiV’s website, I am guessing the GaNM amps are operating at a sampling frequency that’s so high it does not require feedback, and as a result, current and voltage remain in phase. That probably accounts for the extra punch and transparency. I’m also guessing that in lieu of feedback, there is some amount of DSP shaping or controlling the output signal, and that processing is affecting how I perceive the GaNM amp’s force, density, and transparency. That’s all just speculation, but I don’t care if it’s true. This amp is the closest thing I’ve found to that mythical amp that will drive any speaker. At this moment, it’s my favorite amp with the Falcons. I did not see that coming.

LAiV’s GaNM monoblocks have converted my class-D disinterest into "Oh my God, hallelujah!" Seriously recommended.

So...interesting to me. They’re $4694, GaN, monoblocks, and a really amazing deal if they sound good. Just reading about them now.

@hilde45   Might want to look at Jay's Iyagi comparison on Youtube between AGD Audion's vs Laiv.   In a nutshell Laiv has more muscle but comes up short in every other category. 

@riaa_award_collectors_on_facebook 

Thanks -- I'll take a look. AGD came up short for me too, but at $7850 I might have had higher expectations for it than for the LaiV. Still, for that $$ the LaiV should sound good enough to keep. The NAD v. 1 Eigentakt failed that for me, and the v. 2 is around $5k (though prices are going up, I think). Still need to try the Atmasphere, which at $6320 is a fair bit more than the Laiv.

Appreciate the reference.

Researching and comparing any online notes that can be found for studying Tube / Class A amp designs vs. different ClassD designs while attempting to understand any loss that still might occur through the Analog signal → pulse encoding → switching → analog reconstruction process. 

Reference to good old standard Tube / ClassA SS amps, with:

• Continuous waveform (no encoding)
• Natural harmonic structure (2nd/3rd order) harmonics
• No switching or reconstruction

Hearing in midrange: Flesh-and-blood vocals, wet texture, where decay trails linger naturally, slight bloom around, close to "realness"

-vs-

Reference to "older" ClassD architecture and designs, having:

• Tiny timing errors = loss of microtexture
• Harmonics don’t decay as naturally
• Can sound:
  • “dry”
  • “flat”
  • or slightly “synthetic”

-vs-

Reference to newer ClassD architecture and designs, having:

• Faster switching (GaN)
• Lower dead time → fewer timing errors
• Higher switching frequency → easier filtering

Listeners reportedly hearing:

• Much better "inner detail"
• Cleaner "harmonic structure"
• Less “digital glaze”

But still:

• Not truly continuous like tubes or Class A
• Still a reconstructed waveform

👉 Findings:  "approaches analog" flow — but "doesn’t fully become it"

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AXPONA 2026 - ClassD?

It will be interesting to read and view show reports after Axpona ends to learn just how many ClassD amps are presented in the show rooms.  So far, still seeing lots of tube amps and Class A/AB amps there viewed on the walk-thru videos over the past few days. Hoping others who attended post more here with updates, Thx. 

I had Claude AI do an analysis of Axpona, and here's what it came up with:

Axpona 2026

Definitely Class D:

•     AGD Productions (Room 724) — Guerra's own GaN Class D monoblocks (Vivace, Audion)
•     Atma-Sphere (Popori Acoustics, Room 690) — the GaNFET Class D monoblocks we've been discussing
•     Bel Canto (Room 1130) — long-established Class D specialist (REF series)
•     Buckeye Amplifiers (Room 712) — builds exclusively around Purifi Eigentakt Class D modules
•     Devialet (Rooms 318, 550) — Class A/D hybrid topology (ADH)
•     Dutch & Dutch (Rooms 472, 476) — active speakers with built-in Class D
•     Fosi Audio (Rooms 558, 560) — budget GaN/TPA Class D amps
•     Gato Audio (Room 731) — Class D integrated amplifiers
•     Hypex (Madisound, Room 348) — the NCore and Fusion Class D module maker itself
•     Kii Audio (Room 1441) — active Class D speaker systems
•     Lyngdorf Audio (Kyomi Audio, Room 1527) — Class D with RoomPerfect DSP
•     Mola Mola (GTT Audio, Room 1627) — Kaluga Class D monoblocks
•     NAD (Lenbrook Group, 1-Schaumburg E) — Masters series using Purifi/Eigentakt Class D
•     Orchard Audio (Philharmonic Audio, Room 705; VPE Electrodynamics, Room 502) — GaN Class D specialist
•     Purifi (Madisound, Room 348) — the Eigentakt Class D module maker itself
•     Aavik (Audio Group Denmark, 2-Epiphany) — Class D integrated amps

Very Likely Class D:

•     Anthem (Room 394) — their STR and MCA series use Class D
•     Axxess (2-Epiphany) — Audio Group Denmark's Class D integrated line
•     PS Audio (1-Schaumburg A) — Stellar series uses Class D
•     Primare (Fidelity Imports rooms) — Class D amplification throughout their electronics line
•     T+A (1-Schaumburg G) — their MP 3100 HV and PA 3100 HV use proprietary Class D