866

About the 866

The Boulder 866 Integrated is an entry-level Boulder amplifier designed to make the company's engineering accessible to a wider audience without compromising performance or build quality. Available in two versions—all-analog and analog+digital—the 866 delivers 200 watts continuous power into 8 ohms with peak output of 250 watts, an increase of 100W over its predecessor, the 865. The amplifier features a fully-balanced audio input path, a precision stepped attenuator for analog volume control, and a full-color touchscreen display for input selection and setup. All assembly and testing, including circuit boards and metalwork, is produced in-house at Boulder's facility. The analog+digital version includes an internal DAC on a removable circuit board that can be upgraded or replaced, plus comprehensive digital streaming capabilities including Roon endpoint compatibility, Apple AirPlay 2, Bluetooth, and support for online music services. The 866's sophisticated protection circuitry allows it to deliver greater peak current without risking damage to the amplifier electronics. Custom heatsinks with a mathematical formula design manage heat dissipation while controlling resonance and ringing.