Modern Class D amplifiers now boast 90% efficiency and 0.0001% distortion, yet many listeners still hunt for the FX. Why? Because the FX reminds us that high fidelity is not a number. It is the illusion of a live performance. By sacrificing power for purity, and features for focus, Musical Fidelity created an amplifier that does not just reproduce music—it understands the importance of the first watt.
The FX is proof that in audio, as in life, it is not about how much you have, but how well you use the little you need. It is the unassuming titan: a black box that holds a masterclass in restraint.
Because of the low-feedback, high-bandwidth design, the FX handles leading-edge transients—the strike of a piano hammer, the snap of a snare drum—with startling realism. There is no smearing. But the real magic is in the micro-dynamics. At low volume, late at night, the FX retrieves the subtle decay of a cymbal or the breath of a saxophonist with a delicacy that 200-watt behemoths often crush under their own authority.
On paper, this was a failure. In practice, it was a liberation. Michaelson understood a dirty secret of the audio industry: high global negative feedback, the tool most engineers used to achieve high wattage with low distortion, was the enemy of transient response and harmonic integrity. The FX was designed around a different principle:
