Onkyo Integra M-506RS Stereo Power Amplifier 150W Super Servo

CONDITION

This unit is in excellent condition and works properly. All of the meter lamps illuminate beautifully.

ABOUT THIS ITEM

The Onkyo Integra M-506RS is a high-end stereo power amplifier made in Japan by Onkyo, produced in 1983 as the top-of-the-line model in Onkyo's Integra series. It delivers 150 watts per channel into 8 ohms with exceptionally low total harmonic distortion of just 0.002%, a very wide frequency response from 1 Hz to 100 kHz, a high signal-to-noise ratio of around 122 dB, and a high damping factor of 180 for tight, controlled bass. Its centerpiece is Onkyo's Super Servo circuit design, which analyzes the amplifier not just as an electrical circuit but including the acoustics of the playback sound field, using a Super Servo Integral system to reduce the influence of the speaker's back-electromotive force to −20 dB or less and thereby suppress time-difference distortion. A newly developed Super Turbo system, combining a delta-turbo circuit and a turbo-filter circuit, suppresses modulation noise from the power transformer and expands the dynamic range by more than 20 dB. A three-point sensing bias circuit across the pre-driver, driver, and final stages keeps distortion low, the speaker outputs use gold-plated silver-contact relays for high-fidelity switching, and large VU-style peak meters with logarithmic compression and peak-hold complete the design. Beautifully built with wood side panels, the M-506RS remains a superb and highly capable vintage power amplifier.

・Power Supply Voltage: AC 100V, 50/60 Hz (Japanese domestic model). Please use a suitable step-down transformer in 110–240V regions.

— Grape Japan