LARGE SCALE TOROIDAL CORE TRANSFORMER
Smaller and lighter than conventional transformers, toroidal core transformersare remarkably effective for large power output.The RB-2000 use toroidal transformers which give superior regulation and littleleakage flux leading to excellent high power output and low hum.
The 2000 series uses 3 sets of protection circuitry to protect both the amp itself and the speakers from possible overload damage. One is electronically controlled ASA (Area of Safe Operation) detecting circuitry that employs a relay to protect the output transistors and the speakers in case of accidental overload. The second is a DC feedback power limiting circuitry that serves to protect the transistors when impedence load falls below 4 ohms. The Overload Indicator light located on the front panel of the amplifiers informs the user when the above circuitry goes into operation. The third is teh separate relay which overcomes the problems of loud pop-noise and abnormal in-rush current when turning the power switch on.
In general the biggest drawback to Class A amplifiers, which have no switching and crossover distortion, is thier low efficiency. ROTEL, however, employs a new system that maximizes the superior sound quality of Class A amps while at the same time ensuring maximum output.
Class A operation, which is amazingly distortion free and provides excellent sound quality when
listening to regular music, automatically switches over to Class B operation when more power is required by a large signal. By adopting this ideal system, where Class A operation handles average music signals and Class B ensures a broad dynamic range during peak signals, the 2000 series Class AB pholosophy proves its true worth: distortion is held below 0.01% even during
maximum output. (Class A operation below 5 watts, as previously mentioned, are remarkably distortion free).
QUICK RESPONSE PEAK LEVEL POWER METERS
The RB-2000 amplifier comes with a large independent meter for each channel. Quick response and reliability is ensured by the accuracy of the meter itself from minute to large power inputs in conjunction with IC's employed in the circuitry. ROTEL integrated amps employ a LED BAR CHART PEAK INDICATOR that operates independently for each channel from -20 to
+ 1 dB (or -40 to -19 dB), and 26 LED units record the instantaneous signal peaks. This digital indicator not only means maximum speed of response, but also an ultramodern simplicity that blends with the overall design.
The 2000 series uses DC amplifiers with excellent response at very low frequencies and makes maximum use of its DC circuitry design. As is becoming standart in precision equipment, ROTEL's DC amps have eliminated all capacitors (which give unwanted time constant) from the signal path and the negative feedback loop, stabilized the DC range and greatly improved transmission characteristics, enabling superior low frequency performance.
On the other hand, negative aspects of DC circuitry such as DC drift due to fluctuations in input and in power supply have been eliminated in the 2000 series by stabilizing the differential's mid-point electric potential, using circuit technology to achieve a DC balence, and securing an adequate CMRR (Common Mode Rejection Ratio) value. As a result, the audio enthusiast is even free to enjoy the full dynamics range of organ music, with all its low frequency signals.
Power amplifier part
Output power (both channel drive):
140 W/ch (4 Ω, 1 kHz)
120 W/ch (8 Ω, 20 Hz - 20 kHz)
THD: 0.01% (at the time of an output power 20 Hz - 20 kHz)
Cross modulation distortion: 0.015% (at the time of an output power 8Ω)
Frequency characteristic (1 W/ch; 8 Ω):
DC in : DC -100 kHz +0 -1 dB
AC in: 5 Hz - 100 kHz +0 -1 dB
Input sensitivity/impedance: 1.5 V/50 kΩ
Dumping factor: 100 (1 kHz)
S/N ratio (IHF-A network short-circuit): 110 dB
Crosstalk (10 kHz): 65 dB
Slew rate: 40 V/muS
Square wave rise time: 2 microS
Max. power consumption: 900 W
Dimensions (W x H x D): 482 x 143 x 430 mm
Weight: 18 kg