Stereo Power Amplifier

There is a solution for those in smaller living spaces, for those that have efficient systems, or for those who like the 866 Integrated sonically but prefer separates. The 861 Stereo Power Amplifier checks all these boxes. The 861 being the newest expansion of the 800 series is the same exact size as the 812 DAC Preamplifier it makes for an attractive combo both visually and audibly. All the boards and chassis are still made in Boulder’s dedicated facility in Colorado. You get the high performance, the expertise and craftsmanship in a manageable package.

The 861 is Boulders first amplifier in its size and it punches well above its weight class. Don’t believe us? You should really listen for yourself.

If you are curious of where you can hear one, reach out here.


  • 75W peak power per channel into 8 ohms, 110W peak power into 4 ohms, 200W peak power into 2 ohms

  • New protection circuitry enables the 861 to deliver greater current at maximum output without fear of damage to the amplifier's electronics

  • Space saving design is the same footprint (width and depth) as the 812 DAC Preamplifier

  • In-house manufacturing efficiency improvements have made the 861 an incredible value in comparison to previous amplifiers

  • Smaller carton packaging means easier transportation, unpacking, and installation

  • Along with assembly and testing, every circuit board and piece of metalwork is produced in-house at Boulder's dedicated facility for unparalleled quality assurance

  • Boulder's traditional in-house 0.25" (6 mm) thumbscrew binding posts are included for secure speaker cable connections and optimal sound quality

  • IP control, and networked HTML page

  • Software updates to the internal control and housekeeping systems available as needed with automated online downloads or manual USB port installation


Stereo Power Amplifier
  • Continuous Power, 8 Ohms


  • Peak Power, 8 Ohms


  • Continuous power, 4 Ohms


  • Peak Power, 4 Ohms


  • Peak Power, 2 Ohms


  • Balanced Analog Inputs

    1 pair balanced via 3-pin XLR

  • Outputs

    .25" (6mm) Binding posts

  • Distortion, THD


  • Equivalent Input Noise (EIN), 20 kHz

    2.6 μV

  • Input Impedance

    100kΩ Balanced

  • Frequency Response, 20 Hz to 20 kHz

    +0.00, -0.04 dB

  • Frequency Response, -3 DB

    0.015 Hz, 150 kHz

  • Maximum Analog Gain

    26 dB

  • Power Requirements

    100V, 120V, 240V, 50-60 Hz

  • Power Consumption

    550W Maximum

  • Dimensions


  • Weight

    22 lbs