The Enduring Case for Class A/B: Why Experience Keeps Bringing Listeners Back

By Dan Wright, Founder - ModWright Instruments

Amplifier technology has never stopped moving. Tubes gave way to solid state. Solid-state spawned Class D. Each generation brought real advantages: efficiency, power density, compact form factors, and measurements that would have seemed impossible a decade earlier.

And yet something interesting keeps happening. Experienced listeners, people who have heard a great deal of gear over many years, keep coming back to well-executed Class A/B designs. Not out of nostalgia. Not because they haven't heard the alternatives. Because of what Class A/B does for music that other topologies haven't consistently replicated.

Specifications Tell Part of the Story

The audio industry has always had a complicated relationship with measurements. Technical performance matters, nobody serious would argue otherwise. But a perfect measurement doesn't guarantee an emotionally convincing listening experience, and experienced listeners know this intuitively even when it's difficult to articulate.

The qualities that make an amplifier truly satisfying, ease, flow, harmonic integrity, dynamic realism, and a sense of dimensionality are real. They're just harder to capture on a test bench than distortion figures and frequency response curves. Music should feel natural and unconstricted. That's a different standard than accuracy on paper.

What a Well-Executed Class A/B Design Actually Does

The fundamental advantage of a refined Class A/B amplifier is continuous analog operation, output devices working in a linear region that preserves the signal's character rather than switching it. Combined with genuine current delivery capability, this allows the amplifier to stay composed under complex musical passages and difficult speaker loads.

Microdynamics stay intact. Harmonic decay resolves naturally. Spatial information in the recording survives the amplification process rather than getting compressed or smeared.

Music isn't a steady-state test signal. It's dynamic, layered, and constantly shifting. The finest amplifier designs handle those shifts as if they require no effort at all, because to a well-designed amp with real current reserves, they don't.

The Power Supply Is the Foundation

Behind every truly capable Class A/B amplifier is a power supply built for the job, and this is where many designs that measure well on paper fall short in practice.

Two things matter here: transformer capacity and capacitive reserve. The transformer must be able to supply instantaneous current on demand. The energy storage must be sufficient to keep the amplifier stable and controlled when music makes sudden, dramatic demands.

When both are right, the result is authority and ease under load, the amplifier never sounds like it's working hard because it isn't. In many ways, the power supply determines how naturally and effortlessly music flows from a design.

Why Listeners Stay

There's a quality that keeps experienced listeners returning to great Class A/B amplifiers that's genuinely difficult to describe without sounding vague: a sense of body and weight to instruments, harmonic completeness, and three-dimensionality to the presentation.

The sound feels relaxed rather than forced. Engaging rather than fatiguing. Listening sessions extend naturally because attention shifts away from analyzing what the system is doing and back toward what the music is saying. The gear recedes. The emotion comes forward.

That's what serious amplification is supposed to do.

ModWright's Approach: The Shortest Path to the Music

At ModWright, amplifier design has never been about chasing topology or technology for its own sake. The question has always been simpler: what is the shortest, most natural path to signal integrity?

That means preservation over correction. Simplicity over unnecessary complexity. Solving problems at their source rather than compensating for them downstream.

At the core of every ModWright solid-state amplifier is the Solid State Music Stage, originally developed by Alan Kimmel, built around transformer coupling, a single gain stage, and zero global negative feedback. The design maintains signal integrity from the start rather than managing problems that were introduced earlier in the chain.

This philosophy carries through in everything we build, including how tube and solid-state technologies complement each other in our hybrid designs. The topology changes. The goal doesn't.

Class A/B Isn't Going Anywhere

Amplifier design will keep evolving. Class D will keep improving. New topologies will emerge and earn their place.

But well-designed Class A/B amplification remains deeply relevant, not because it resists progress, but because it keeps delivering something listeners value: music that sounds emotionally convincing, naturally presented, and deeply satisfying over time.

The goal was never the technology. It was always the music. And the path that gets listeners there most directly is the one worth building.

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