Adcom GFA-5300 Stereo Power Amplifier The Adcom GFA-5300 is a 2-channel solid-state MOSFET power amplifier (circa 1994) delivering 80 watts per channel into 8 Ω 8 Ω or 125 watts into 4 Ω 4 Ω . It features a high-current design with a toroidal transformer, 40,000 μ 𝜇 F filter capacitance, and a high damping factor of >350, providing 100dB signal-to-noise ratio and 0.18% THD. This video provides an internal view and overview of the Adcom GFA-5300 amplifier: