Rotel RB-1590 Power Amplifier Black

The RB-1590 is Rotel’s most powerful stereo power amplifier, sitting at the top of the company’s amplifier range. Rated at 350 watts per channel into 8 ohms (both channels driven simultaneously) and 648 watts per channel into 4 ohms, it delivers the kind of current and headroom that demanding loudspeaker loads require to perform at their best.

Power Supply

At the heart of the RB-1590 are twin custom-wound toroidal transformers, each dedicated to its own channel. These feed a power supply built around eight British-made BHC slit foil capacitors, chosen for their low-loss characteristics and rapid charge-discharge behaviour.

Circuit Design

The internal layout follows a true monoblock topology: left and right channels are electrically and physically separated, sharing only the chassis and mains inlet. This approach minimises crosstalk between channels and improves stereo imaging. The signal path accepts both balanced XLR and single-ended RCA inputs, with separate gain structures for each: 23.5 dB via XLR and 27.5 dB via RCA.

Performance

Total harmonic distortion is held below 0.03% across the full 20 Hz–20 kHz bandwidth, with intermodulation distortion similarly below 0.03%. The signal-to-noise ratio is 120 dB (IHF A-weighted), and the damping factor of 300 ensures tight control over loudspeaker driver excursion. Frequency response extends from 10 Hz to 100 kHz within ±0.5 dB.

Build and Connectivity

The RB-1590 occupies a full 5U chassis height (221 mm front panel) and weighs 38.1 kg. Rear-panel connections include balanced XLR and RCA inputs, two pairs of 5-way speaker binding posts per channel, and a 12-volt trigger input for system integration. Protection circuitry covers thermal, overcurrent, and over-voltage conditions. A dual-stage power-on relay reduces surge current at switch-on. Rack ears are included for installation in equipment racks.