SM70 Pro

About the SM70 Pro

The Monarchy Audio SM-70 Pro is a zero-feedback Class-A amplifier that uses a hybrid design combining IC op-amps and discrete MOSFETs. It delivers 25 watts RMS per channel in stereo mode and up to 120 watts RMS in bridged mono mode. The amplifier features a balanced XLR input for true balanced operation and can be switched between stereo and mono modes via a rear panel switch. It is designed to provide unbridled dynamics and clean clipping when overdriven, with distortion (THD) held below 0.05%. The SM-70 Pro uses a Burr-Brown OPA-2604 dual FET-input op-amp for voltage gain and employs local feedback only, avoiding global feedback to preserve sound quality. It has a frequency response of 20Hz to 30kHz ±0.5 dB and a signal-to-noise ratio better than 90 dB in stereo mode and 100 dB in balanced mono mode. The amplifier is well-regarded for its midrange transparency, dynamic contrast, and open soundstage, making it a strong performer especially with horn speakers and difficult loads. It weighs 24 lbs and measures 5" x 11" x 13" (H x W x D).