Given the FX's relatively modest power output and pure Class A design, it is best suited to driving efficient, high-quality speakers. Pairing it with speakers that are too demanding could push the amplifier into clipping and compromise its renowned sound quality. Ideal system configurations for the FX could include:

Musical Fidelity has packed the FX amplifier with proprietary engineering solutions aimed at reducing distortion and maximizing current delivery.

: Reviewers describe the audio as quiet, clear, and natural, devoid of noticeable noise or hum.

An automatically adjusting bias system that shifts between Class-AB (high efficiency) and pure Class-A (low distortion) depending on signal level, heat sink temperature, and program material dynamics—without user intervention.