Five Class AB channels for home cinema and multi-zone installations
Rotel RMB-1555 is a Class AB multichannel power amplifier rated at 120 W per channel into 8 ohms and 170 W per channel into 4 ohms with all channels driven, designed for home cinema systems and distributed audio.
The power supply is sized to support several loudspeakers at the same time, a more demanding condition than testing one channel alone. A large high-current toroidal transformer and British-made slit-foil capacitors provide the required reserve, while discrete circuits and trigger functions simplify installation in racks and dedicated cinema rooms.
Key features
- Five channels of Class AB amplification.
- 120 W per channel into 8 ohms with all channels driven.
- 170 W per channel into 4 ohms with all channels driven.
- THD below 0.03%.
- Large high-current toroidal transformer.
- British-made slit-foil capacitors.
- RCA inputs.
- Damping factor of 180.
Power with all channels driven
RMB-1555 delivers 120 W per channel into 8 ohms and 170 W per channel into 4 ohms with all five channels active. The all-channels-driven figure is important in a multichannel system because it describes supply capability when several loudspeakers demand current simultaneously during a dynamic soundtrack.
High-current power supply
A large high-current toroidal transformer supports the power section. Its reserve is sized for simultaneous channel use and reduces the risk that peaks on one loudspeaker take energy from the others, maintaining more stable behaviour across the system.
Capacitors and transients
British-made slit-foil capacitors support transients and bass when effects involve several channels, while low internal resistance helps transfer energy rapidly to the output stages without introducing a slow response under load.
Class AB and response
Declared THD is below 0.03% and frequency response runs from 10 Hz to 100 kHz within +0.5/-3 dB. A damping factor of 180 contributes to woofer control, particularly useful when several large loudspeakers are driven in the same room.
Inputs and AV processor
RCA inputs connect surround processors and preamplifiers with different outputs. The discrete output stages are designed for thermal stability and rack brackets are included. The power amplifier remains independent of decoding and can be retained when the upstream processor changes.
Trigger and installation
The 12 V trigger allows the power amplifier to switch on with the processor or a control system. Installation functions reduce the need for manual intervention when the unit is placed in a technical rack or dedicated cinema room.
Chassis and thermal management
The chassis measures 431 x 188 x 454 mm and weighs 21.8 kg. Heatsinks, power supply and amplification modules occupy most of the structure and are distributed to encourage cooling while keeping input sections away from the main sources of heat and magnetic field.
