Stereo Class AB power and a high-current power supply
Rotel RB-1582 MKII is a Class AB stereo power amplifier rated at 200 W per channel into 8 ohms and 323 W per channel into 4 ohms, with a large toroidal transformer using independent rectifiers for the two channels and RCA and balanced XLR connections.
The design is built around an oversized power supply and discrete output stages intended to drive demanding loudspeakers. A total filter capacity of 60,000 µF uses slit-foil capacitors. The internal layout limits interference between the two channels and keeps current paths short, while the available inputs allow use in traditional or balanced stereo chains.
Key features
- Continuous power of 200 W per channel into 8 ohms.
- Continuous power of 323 W per channel into 4 ohms.
- Class AB amplification with THD below 0.03%.
- Large toroidal transformer with independent rectifiers for the two channels.
- Total filter capacity of 60,000 µF with slit-foil capacitors.
- RCA and balanced XLR inputs.
- Damping factor of 800.
- Frequency response from 10 Hz to 100 kHz within ±0.5 dB.
Power and drive capability
RB-1582 MKII delivers 200 W per channel into 8 ohms and 323 W per channel into 4 ohms, retaining suitable 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
A large toroidal transformer with independent rectifiers for the two channels forms the core of the supply. It is sized to support transients without compressing dynamics, because loudspeaker drive depends on available current as much as on nominal power.
Energy reserve
A total filter capacity of 60,000 µF uses slit-foil capacitors. The filtering components release stored energy quickly and support bass during 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 800 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. XLR is useful with long cable runs or installations that are more sensitive to noise.
Loudspeakers and system control
The loudspeaker terminals accommodate substantial cable sizes and a 12 V trigger synchronises power with a compatible preamplifier. After the transformer the two channels follow a near-monoblock arrangement, with star grounding on a copper plate and ten high-current bipolar transistors per channel. The amplifier can therefore work in a traditional chain or a centrally controlled system.
Chassis and cooling
The chassis measures 431 x 144 x 407 mm and weighs 17.6 kg. Much of the mass comes from the transformer, heatsinks and output stages, while the mechanical layout keeps heat-generating components away from the more sensitive input sections.
