CH PRECISION A1.5

The A1.5 power amplifier shares far more with its larger sibling, the M1.1 Reference, than its compact size might suggest. Although smaller and lighter, it embodies the same modular, scalable, and sophisticated design approach that defines CH Precision’s reference models. Hidden within its chassis are four amplifiers in one, featuring a software-controlled, adaptable topology, user-adjustable input configuration and gain, selectable global feedback ratio, and a structure engineered to allow cost-effective future upgrades. The signal path remains incredibly short, fully discrete, fully balanced, and fully complementary, assembled with carefully selected components to the same exacting standards as the M1.1. Even the chassis retains the same footprint, construction quality, and mechanical grounding/stacking system, despite being lower in height.

The power supply is equally uncompromising: the transformer and reservoir capacitors are identical to those found in the M1.1, allowing the A1.5 to deliver generous output power — 150 watts per channel, conservatively rated. This makes it far from timid in terms of dynamics and sonic authority. While it doesn’t reach the extreme headroom capabilities of the M1.1 under the most demanding loads or in the largest rooms, its output proves more than sufficient — even ideal — for most real-world systems. This is where the A1.5 finds its strength: a precise balance of performance, flexibility, and affordability, offering a true taste of the M1.1 experience in a more manageable form.

Thanks to its transparency, resolution, and musically engaging character, the A1.5 pairs exceptionally well with a wide variety of high-end loudspeakers. In any other lineup, it would be considered a flagship model, given the performance it delivers. And when the time comes to expand the system — perhaps to drive more demanding speakers or push the dynamic envelope even further — the A1.5 proves ready to evolve. Adding a second A1.5 opens up advanced configurations: it can operate as a high-current mono amplifier, a high-power bridged mono, or in vertical bi-amping mode, where a single input feeds both channels.

This last configuration simplifies cabling and allows for independent gain and feedback settings for each channel, offering superior adaptability in controlling bass output and room interaction. Vertical bi-amping also maximizes dynamic range and overall system headroom, enabling the A1.5 to grow alongside both the speakers and the listener’s ambitions. What might seem at first glance like a compact stereo amplifier reveals itself to be a remarkably capable powerhouse — one that far exceeds expectations.

Technical specifications:

• Nominal input voltage: 2.2V RMS balanced; 1.1V RMS single-ended
• Input impedance: 94kΩ balanced; 47kΩ or 300Ω single-ended
• Output power: 2x 150W / 8Ω; 2x 275W / 4Ω; 2x 450W / 2Ω (stereo and bi-amp modes)
• Output power (mono mode): 1x 275W / 4Ω; 1x 450W / 2Ω; 1x 700W / 1Ω
• Output power (bridged mode): 1x 550W / 8Ω; 1x 800W / 4Ω; 1x 1200W / 2Ω
• Bandwidth: DC to 450kHz (-3dB) at 1W into an 8Ω resistive load
• Signal-to-noise ratio: >115dB (stereo and bi-amp modes); >118dB (bridged mode)
• Total Harmonic Distortion + Noise: <0.1% (0% global feedback); <0.01% (100% global feedback)
• Max power consumption: 1800W
• Dimensions: 440 x 440 x 198 mm (W x D x H)
• Weight: 47 kg