Stereo Class AB power and a high-current power supply
Rotel RB-1590 is a Class AB stereo power amplifier rated at 350 W per channel into 8 ohms and 648 W per channel into 4 ohms, with dual high-current toroidal transformers and RCA and balanced XLR connections.
The design is built around an oversized power supply and discrete output stages intended to drive demanding loudspeakers. Eight British-made BHC slit-foil capacitors provide the energy reserve. The internal layout limits interference between the channels and keeps current paths short, while the available inputs allow use in traditional or balanced stereo chains.
Key features
- Continuous power of 350 W per channel into 8 ohms.
- Continuous power of 648 W per channel into 4 ohms.
- Class AB amplification with THD below 0.03%.
- Dual high-current toroidal transformers.
- Eight British-made BHC slit-foil capacitors.
- RCA and balanced XLR inputs.
- Damping factor of 300.
- Frequency response from 10 Hz to 100 kHz within ±0.5 dB.
Power and drive capability
RB-1590 delivers 350 W per channel into 8 ohms and 648 W per channel into 4 ohms, retaining substantial reserve as loudspeaker impedance falls. Declared total harmonic distortion remains below 0.03%, accompanying an output section designed to combine current, control and linearity.
Power supply
Dual high-current toroidal transformers form the core of the supply. The power section is sized to sustain transients without compressing dynamics, because the ability to drive a loudspeaker depends on available current as much as on nominal power.
Energy reserve
Eight British-made BHC slit-foil capacitors are selected to release stored energy quickly and support bass during more demanding passages, while limiting internal losses and supply-voltage variation under load.
Class AB and bandwidth
The output stage operates in Class AB and declares a frequency response from 10 Hz to 100 kHz within ±0.5 dB. A damping factor of 300 contributes to woofer control and transient precision, while the topology maintains bandwidth wide enough not to constrain the audio signal.
Inputs and preamplifier
RCA and balanced XLR inputs allow connection to preamplifiers with different topologies and output levels. Balanced connections are particularly useful with long cable runs or systems where reducing sensitivity to picked-up noise is important.
Loudspeakers and system control
The loudspeaker terminals accommodate substantial cable sizes and a 12 V trigger synchronises power with a compatible preamplifier. The channel topology is essentially monoblock after the power-supply section and includes thermal, over-current and over-voltage protection. The amplifier can therefore work in a traditional chain or a centrally controlled system.
Chassis and cooling
The chassis measures 431 x 237 x 456 mm and weighs 38.1 kg. Much of the mass comes from the transformers, heatsinks and output stages, while the mechanical layout keeps heat-generating components away from the more sensitive input sections.
