Stereo 90 Magnum

About the Stereo 90 Magnum

The Rogue Audio Stereo 90 Magnum is a robust, high-performance stereo tube amplifier delivering 90 watts per channel. It uses KT-88 or KT-90 output tubes in a Class A/B push-pull topology, complemented by 12AX7 phase inverter tubes and 6SN7 signal tubes per channel. The amplifier offers a mode select switch allowing operation in triode or ultra-linear modes, balancing power output and distortion characteristics to suit different loudspeakers. The Magnum version includes premium upgrades such as HexFred diodes in the bias supply, upgraded screen grid resistors, polypropylene bypass capacitors in filters, bypass coupling capacitors, PRP resistors in critical spots, Cardas binding posts and RCA jacks, upgraded wiring, and upgraded signal tubes. It is a heavy and solidly built amplifier weighing approximately 60 pounds, with a frequency response of 5Hz to 50kHz ±1dB and total harmonic distortion typically under 0.1%. The amplifier is designed and manufactured in the USA and is known for its warm tube sound with excellent bass performance, especially in ultra-linear mode.