Rotel, well-known throughout the world as a manufacturer of affordable high-end components for music and home-theater audiovideo systems, has launched two new Class D power amplifiers, the RB-1091 and RB- 1092 both featuring ICEpower(R).
With the recently introduced RMB-1077, these two new switching-mode power-supply amplifier designs augment the Rotel Class D lineup to provide multiple power-amplifier options for the widest array of Home Theater and Hi Fi applications.
According to Mike Bartlett, Vice President and General Manager of Rotel of America, "Consumers today are looking for ways to put a large number of electronics into small spaces, especially in custom installations. When that occurs, heat becomes a problem. That's the beauty of Class D power amplifiers-you can achieve very high efficiency with lots of output power and very little heat."
Not all Class D amplifiers are alike. There are two categories: namely digitally controlled Class D and analog-controlled Class D. The former features a digitally generated control that switches a power stage. The latter amplifier design utilizes an analog input signal with a switching power supply. Rotel has taken this analog-controlled Class D design a step further with the implementation of two important technologies from ICEpower(R).
The first is Controlled Oscillation Modulation (COM). The COM circuit is analog throughout. A saw-tooth waveform modulates the analog input to generate the Pulse Width Modulation (PWM) signal that drives the switching output stage. This architecture yields lower noise and distortion than would an otherwise equivalent design based on a digital modulator.
The second improvement is Multivariable Enhanced Cascade Control (MECC). This circuit encloses the output filter within a feedback path, resulting in very low output impedance (high damping factor) across the entire audio band. Not only is the amplifier clean and quiet, it also has flat frequency response no matter what sort of speaker impedance is hung across its output.
Rotel's new RB-1091 and RB-1092 switching Class D amplifiers incorporate both COM and MECC. A 500-watt mono amplifier is found in the RB-1091, and the RB-1092 is a 2 x 500 watt stereo amplifier. They can be configured in various ways to provide from one to seven channels, or more, of extremely high power with very little heat.
These intelligent designs feature high-power output capability with a minimum of chassis height and represent one of the very few real advances in power amplifiers since the invention of the solid-state transistor. Both the RB-1091 and RB-1092 have also been designed with custom installation in mind, and include 12-volt triggers, detachable IEC power cords, five-way binding posts, and Neutrik Speakon(R) connectors, a quik-lock connector used in professional audio systems.