DAC, Preamplifier, Headphone Amplifier

Through the worldwide success of the 866, Boulder has expanded the 800 series with the 812 DAC, Preamplifier, headphone amp.

By applying the design philosophy from the 866, and over 35 years of experience designing DAC’s, preamps, and amplifier circuits, you get a device that has precision, top of the line performance. Plus the quality and reliability you would expect from a Boulder product, in a refined package.

The 812 is Boulder’s first headphone amp, and we didn’t hold back. It has a separate sophisticated headphone amplifier circuit, four types of connections, and headphone sensitivity settings within the Boulder Controller app. With 200mw into 8 ohms and 80mw into 600 ohms, the amplifier section in the 812 will drive any headphones or multiple headphones at once. It is a headphone enthusiast’s dream come true.

It can be used just as a preamp, a DAC, a headphone amp or any combination of the three. With all the features and its versatility, the 812 is perhaps the highest value product Boulder has ever produced.

The 812 is something for long-term Boulder fans, headphone enthusiasts, or for someone starting their first Boulder system. We wanted to create something accessible and multifunctional that could fit into any sound system or become the system itself. The 812 accomplishes that.


  • Sophisticated headphone amplifier. Allows for 1/8" mini, 1/4", 4-pin balanced and Pentaconn headphones.

  • Streaming capabilities, Roon endpoint, UPnP playback, Air-Play functionality and Bluetooth.

  • A software-enabled fixed DAC out option.

  • A dedicated Boulder app controls the 812 and makes custom setup adjustments, like headphone sensitivity. Optional RF remote for volume control and switching inputs also available

  • Two pairs of balanced analog inputs. One pair of balanced analog outputs. Two Toslink optical inputs, one coaxial input and one USB-B input.

  • 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.

  • In-house manufacturing efficiency improvements have made the 812 an incredible value in comparison to previous preamplifiers and DACs.

  • Stylish headphone bay cover to keep dust out of headphone jacks.

  • Easily switch between headphone and preamp mode with the output exchange button.


DAC, Preamplifier, Headphone Amplifier
  • Connections

    •4-Pin XLR Headphone Connector
    •1/8” Headphone Connector
    •1/4” Headphone Connector
    •Pentacon Headphone Connector

  • Connections

    •2 Pair XLR Analog Inputs
    •1 Pair XLR Preamplifier Output
    •4x USB Host
    •2 Optical Digital Inputs
    •Coaxial (RCA, SPDIF) Digital Input

  • Software Features

    •Based on 866 DSP Filter and DAC topology
    •Configurable Headphone Sensitivity
    •Available Fixed DAC out
    •HTML Programming
    •Control through Boulder Controller App
    •Input Trim

  • Hardware Features

    •Switch Between Headphone and Preamp Outputs
    •Volume Knob & Chassis Machined In House
    •100 db Optically Encoded Volume Control
    •Innovative Protection Circuits

  • Maximum Input Level

    6.0 Vrms

  • Maximum Output Level

    14.0 Vrms

  • THD+N, 2V Output, 2khz

    .0017% (-95.5 dB)

  • Maximum Voltage Gain

    19.4 dB

  • Volume Range

    100 dB

  • Volume Steps

    1.0 dB

  • Frequency Response 20 Hz to 5 kHz

    +0.00, -0.03 dB

  • Frequency Response, -3 dB

    .02 Hz & 250 kHz

  • Clip to Noise Ratio


  • Input Impedance

    100kΩ Balanced

  • Output Impedance

    100Ω Balanced

  • Power Requirements


  • Power Consumption

    50W Max

  • Headphone Amp Section

    32Ω 200mW Output

    2k Hz 20k Hz

    0.0010%. 0.0053%

  • Headphone Amp Section

    150Ω 200mW Output

    2k Hz 20k Hz

    0.0010% 0.0034%

  • Headphone Amp Section

    600Ω 80mW Output

    2k Hz 20k Hz

    0.0011% 0.0043%

  • Dimensions

    12”x12”x 3.5”

  • Weight

    14 lbs