Усилители мощности стерео — CH Precision M1.1

CH Precision lists the M1.1 as a stereo power amp, positioned by the maker as the reference model whose design principles the smaller A1.5 later distilled. It is designed and coded entirely in-house with no off-the-shelf modules or outsourced firmware, and final assembly, testing and calibration take place in Switzerland.

Key specs that matter

Stereo and bi-amp operation yields 2 x 200 W RMS into 8 ohm, 2 x 350 W into 4 ohm and 2 x 600 W into 2 ohm at under 0.1 percent THD+N with a 1 kHz signal. As a monaural amplifier it gives 600 W into 2 ohm and 1,100 W into 1 ohm, and in bridged mode the figures are 700 W into 8 ohm, 1,200 W into 4 ohm and 1,600 W into 2 ohm. The bandwidth runs from DC to 450 kHz at minus 3 dB with 1 W into 8 ohm. Measured from 22 Hz to 80 kHz at 50 W, THD+N is below 0.1 percent with full local feedback and below 0.01 percent with full global feedback. Signal-to-noise tops 115 dB, or 118 dB bridged, and gain sits at +24 dB or +30 dB bridged.

Engineering and use context

Each five-pin output device carries a temperature sensor on its own silicon substrate, which lets the ExactBias system measure junction temperature in real time and hold bias steady through a galvanically isolated control loop. A massive, ultra-low-noise linear supply is built around an oversized high-current transformer and proprietary capacitors. The fully discrete, complementary Class AB output stage uses a wide-bandwidth, high-slew-rate design. Local and global feedback are adjustable in 10 percent increments, and in monobloc or bi-amp setups the channels can be set independently, so for example subwoofers and main loudspeakers can receive different damping. The amplifier can work as a stereo unit, a high-current mono-bloc, a high-power bridged mono-bloc or in vertical bi-amp mode, and a single stereo unit can be expanded to a pair of monaural units. Mechanical grounding and short signal paths protect the signal from noise and vibration. Inputs per channel comprise XLR, RCA and BNC, at 94k ohm balanced and 47k ohm or 300 ohm single-ended. The 440 x 440 x 266 mm chassis weighs 71 kg and takes power through IEC C20 and IEC C13 sockets, consuming under 0.5 W on standby, 165 W at idle and 2,200 W at most.

Pairing

A 800 x 480 AMOLED display, five buttons and an Android app manage the unit, and the finish can be silver, anthracite or champagne.

Alternatives

The CH Precision A1.5 is the compact stereo power amplifier derived from this design, rated at 2 x 150 W into 8 ohm and weighing 47 kg.