Significant Difference Between a Well-Made Class D Amplifier and a GaN-FET Amplifier!
No, you won’t hear a significant difference between a GaN-FET amplifier and a sophisticated, classically designed silicon Class D amplifier in a direct blind test! My skepticism regarding psychoacoustics is entirely justified. Many reports on the internet are based on the classic “buyer bias” (those who spend more money hear more). Looking at the topic purely from a technical and sonically neutral perspective, it can be summarized as follows:
Why there is no audible difference. Both are already “perfect” in terms of measurements: Modern, well-designed silicon Class D amplifiers (like modules from Hypex NCORE/EVAL or Purifi Eigentakt) already reduce distortion (THD+N) and noise so far below the human hearing threshold that they sound absolutely transparent. While a GaN FET can technically reduce these values even further, our hearing cannot distinguish between “inaudibly distorted” and “even more inaudibly distorted.” The switching frequency is too high anyway:
GaN transistors switch at approximately 400 kHz to 800 kHz. A well-designed classic Class-D amplifier also switches well above the human hearing range (up to 20 kHz). The output filter smooths this signal into a clean analog waveform in both systems.
So why do manufacturers use GaN at all?
The advantage of GaN lies primarily at the engineering level, not in the soundstage:
Simpler circuit design: Because GaN transistors have no reverse recovery charge, they inherently generate fewer switching errors. Developers need to use fewer workarounds (e.g., complex negative feedback loops) to obtain a clean signal.
Even less heat:
GaN operates extremely efficiently. You can pack an enormous amount of power into the smallest space without the chassis getting hot.
The bottom line:
If you already own a well-made Class-D amplifier (for example, with Purifi or newer Hypex modules), switching to a GaN amplifier won’t offer any real sonic improvement.
The “GaN sound” in this direct comparison is primarily excellent marketing.
The sound of both systems is largely determined by the quality of the input stage (op-amps) and the stability of the power supply, not by the transistor material.
Who told you that a thousand times???
Boris and I. But keep living in your YouTube matrix and believe everything you read on YouTube from supposed “experts.” 
You in connection with social media (like YouTube):
In network culture, such people are often referred to as “armchair psychologists,” “hobby experts,” or “internet theorists.”
This means they acquire half the knowledge they read or see in videos and act as if they’re all there is to it. When they try to distort other people’s reality or manipulatively impose their own views, psychology sometimes refers to this as gaslighting, a milder form of invalid communication.
Who kept posting this?
Boris, who wanted to open your eyes.
Cheers
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