CH_A1 Amp


As the driving force behind recreating the full musical experience, the task of the power amplifier may seem desperately simple but is indeed highly complex. Achieving our simple goal of ‘add nothing, remove nothing’ to preserve the full musical emotion has resulted in a ground breaking new amplifier topology. Housed in a chassis similar to the C1 and D1, the A1 sets new standards in terms of performance, flexibility of adjustments, industrial design and pure enjoyment. The A1 is based on a novel proprietary amplifier architecture which optimizes the critical matching of the amplifier with the speaker. It can be operated either as a stereo amplifier (2x 100WRMS under 8Œ©), as a monaural bi-amping amplifier (2x 100WRMS under 8Œ©) or as a bridged amplifier (1x 350WRMS under 8Œ©). A sophisticated mechanical chassis design and full USB based firmware update support contribute to make the A1 a real long term enjoyment.


Analog inputs
Inputs type Balanced (XLR), one connector per board
Single-Ended (RCA & BNC), one connector per board
Input impedance Balanced: 94kΩ
Single-Ended: 47kΩ or 300Ω
Input stage JFET input stage
Ultra-low noise, discrete fully differential stage
24dB range adjustable gain in 0.5dB steps
Amplification stage Ultra-low noise full discrete class AB design
5 pairs of complementary output transistors
Bias Patent-pending bias circuitry for constant bias operation
Feedback User-adjustable local vs. global feedback ratio, from 0% to 100% with 20% steps
Bandwidth DC to 450kHz (-3dB) at 1W into an 8Ω resistive load
Signal to Noise Ratio Better than 115dB in stereo and bi-amp modes
Better than 118dB in bridge mode
Total Harmonic Distortion + Noise Less than 0.1% with 0% global feedback
Less than 0.01% with 100% global feedback
Analog outputs
Binding posts Two pairs of Argento binding posts for loudspeakers connection
Monitoring Non-intrusive DSP-based protection of the amplifier
Instantaneous voltage & current values are permanently monitored for each channel
Protections Short-circuit protected
Disconnected loudspeaker detected
Over-temperature of the heatsink, fans are activated if needed
Over-temperature of the output transistors
Power supply
Transformer 1’200VA single transformer, oversized for low-noise operation
Power capacitors 2x 47’000uF/63V 4-poles capacitors
Regulators Non-regulated symetrical power supply for the power stages
Eight local regulation stages for input/driver stages
Seven local regulation stages for the logic/display
Display 480×272 pixels, 24bits color, AMOLED
Mains operation Selectable 100V, 115, 230V AC, 47-63Hz
Power supply consumption <1W (standby), 1200W max in operation
Dimensions/Weight 440 x 440 x 120mm (W x D x H), 43kg
Remote control Ethernet interface, TCP/IP control




The CH Precision A1 amp quickly dismissed the checklist criteria. It was immediately apparent that Class A was met—and exceeded—in most categories. I will present two musical examples to demonstrate the range of this amplifier. Read more