Rose RA180

In terms of power amplifier design, Class D is theoretically a topology that provides full linear output at 0% distortion and 100% energy efficiency. In order to achieve the perfect Class D design theory, the speed and precision of the switching operation must be guaranteed.

To solve this problem, the RA180 has implemented perfect linear output by applying a gallium nitride FET instead of a silicon FET to significantly improve the dead time, which affects switching speed and precision, to less than 1/10. The perfect linear output goes beyond the limits of existing Class D and creates a natural sound like an analog amplifier.

Four new mono amplification modules

The RA180 supports stereo and provides two channels each for left and right. The amplifier module supports 200 W (4 Ω, 8 Ω) to produce 400 W stereo channels. In addition, BTL mode is supported and speaker operation is possible by configuring 2 channels 400W + 400W.

Two independent amplification modules per channel support bi-amplification to respectively drive high, mid and low frequencies, reducing the effect of back electromotive force generated by the speaker to create a more natural sound.

Generous design that even produces the super tweeter zone

It is known that the human hearing range has an upper limit of 15 kHz to 20 kHz. Temporarily elevated treble extends well beyond 20 kHz. If the sampling rate of the sound source is 88.2 kHz ~ 192 kHz, the frequency range of 40 kHz ~ 96 kHz is recorded.

The RA180 contributes to the realism of the original sound because it faithfully reproduces a wide frequency range by designing a wide frequency response so that even high-resolution sound sources are not filtered with an output range of 20 Hz to 100 kHz (+/-1dB).

PHONO amplifier with variable equalizer

It supports MOVING MAGNET and MOVING COIL inputs with a simple switch selection. To accommodate various recordings, it is equipped with a BASSTURNOVER low band and ROLL OFF high band selection function and provides high purity equalization values using 0.1% error range parts for high precision calibration circuits.

The RA180 contributes to the realism of the original sound because it faithfully reproduces a wide frequency range by designing a wide frequency response so that even high-resolution sound sources are not filtered with an output range of 20 Hz to 100 kHz (+/-1dB). It is equipped with a high-efficiency active equalizer (OP-AMP type: 12 dB slope), not a gentle 6 dB slope passive (CR type).

High efficiency power supply

The power supply circuit developed exclusively for RA180 is suitable for power supply without using Silicon FET. Silicon carbide FET technology (high voltage, high heat resistance) is applied to provide high efficiency with high yield and low heat generation. In addition, it responds to fast loading by applying a self-designed 2.5 kW class PFC circuit and a large capacity capacitor. In terms of figures, it has a damping factor of 200 or more and a high-efficiency 1,000 W power supply, and it is a relaxed design that faithfully supports powerful bass and wide treble.

Technical Specifications

Technologies

• Next-generation Advanced D (AD) class amplifier
• Improved sound linearity with new gallium nitride (GaN) material
• Bi-amplification compatible with 4 independent amplification modules
• Amplifier module supporting up to 100 kHz for super-high frequencies
• High-efficiency 1,100 W power stage
• Symmetrical power supply
• Phono amplifier with variable equalization

Audio Performance

• Output power:
  • 4 × 200 W at 4 and 8 Ω
  • 2 × 400 W in bridged mode
• Input sensitivity:
  • Balanced: 2,000 mV
  • Unbalanced: 1,000 mV
  • Phono: MM 5 mV, MC 0.5 mV
• Input impedance:
  • Balanced: 44 kΩ
  • Unbalanced: 47 kΩ
  • Phono (MM / MC): 47 kΩ
• Bandwidth (0 dBr ± 3 dB / 8 Ω):
  • Speaker output: 10 Hz - 90 kHz
  • High-frequency speaker output: 10 Hz - 90 kHz
• Frequency response (1 W ± 1 dB / 8 Ω):
  • Speaker output: 10 Hz - 90 kHz
  • High-frequency speaker output: 10 Hz - 90 kHz
• Total harmonic distortion: 0.005% (50 W)
• Damping factor > 150

Connectivity

• 1 stereo XLR input
• 1 phono input (MM or MC)
• 3 RCA inputs
• 1 fixed subwoofer output (non-variable)
• 1 ground terminal (for turntable)
• 1 12 V trigger input
• 1 infrared (IR) input

Physical Characteristics

• Aluminum chassis
• Power supply: 100-230 V AC 50/60 Hz
• Dimensions:
  • Without feet: 430 × 350 × 110 mm
  • With feet: 430 × 391 × 130 mm
• Weight: 16.7 kg