9303

About the 9303

The Hafler 9303 is a solid-state, professional stereo power amplifier from Hafler's TransNova series, designed for both studio and high-fidelity home use. It is rated at 150 watts per channel into 8Ω in stereo and 225 watts per channel into 4Ω, with 450 watts into 8Ω in bridged mono operation. It delivers a 20 Hz-20 kHz frequency response at rated power with 0.07% THD over that band and typically 0.005% THD at 1 kHz at full power into 8Ω. The amplifier's damping factor is specified at 800 at 1 kHz, 80 to 20 kHz, and 20 to 100 kHz into 8Ω, providing strong control of loudspeaker loads. Gain is 29 dB, with input sensitivity around 1.22 Vrms for 150 W into 8Ω and about 1.06 Vrms for 225 W into 4Ω. The 9303 uses true differential input amplifiers with balanced and unbalanced inputs, employing J-FET input stages and lateral MOSFET output devices derived from Hafler's TransNova topology for high stability and fault tolerance. It offers rack-mountable two-rack-space construction, measuring approximately 19" W x 12.5" D x 3.5" H and weighing about 36 lbs, and was manufactured in the USA for 120V, 60Hz AC mains. Performance highlights include full-power bandwidth from approximately 0.15 Hz to 300 kHz, >100 dB A-weighted signal-to-noise ratio, 150 V/µs slew rate, and a high common-mode rejection ratio around 75 dB at 1 kHz. The 9303 is widely regarded as a robust, warm-sounding, high-current amplifier with smooth treble and strong bass impact, suitable for demanding speakers and both home and professional environments. Some reseller and review materials describe the unit as THX certified, but this appears in secondary literature rather than primary Hafler documentation, so THX certification status should be treated as unverified.