865

Integrated Amplifier

High-performance sound had always meant separate components, a lot of cables and large space requirements. Simple, integrated solutions fell short of the mark when it came to sound quality. In short, convenience came with compromise.

Until Boulder’s 865.

Features

  • Massive, shielded, toroidal transformer and multiple filter capacitors for immediate power transfer

  • Efficient heatsink design means high power in a small chassis without excessive heat

  • Four pairs of inputs, each capable of custom configuration and naming

  • One pair of auxiliary outputs that can be set for fixed (to drive secondary systems) or variable operation (to drive a subwoofer or additional amplifier)

  • Fully balanced input circuitry for maximum resolution and sound quality

  • Rugged, easy-to-connect, high-current speaker terminals require no tools

  • Boulder's own precision stepped volume control, the same as in the 2010 preamplifier

  • Input and preamplifier sections are housed in steel casework to eliminate interference from other portions of the amplifier

  • Supervising microprocessor controls all preamplifier functions, monitors protection circuits, and communicates with other Boulders

Specs

865
Integrated Amplifier
  • Continuous Output Power, 8 / 4 ohms

    150W

  • Peak Output Power

    300W into 4 ohms

  • Balanced Line Inputs

    4 pairs

  • Auxiliary Balanced Outputs

    1 pair (switchable: fixed or variable)

  • Loudspeaker Output Connectors

    1 pair/channel, 6 mm/.250-inch wingscrews

  • THD at Continuous Power

    20 Hz to 2 kHz: 0.0035%, 20 kHz: .018%

  • Signal-to-Noise Ratio (re: 150W/8 ohms)

    -108 dB, unweighted, 20 Hz to 22 kHz

  • Frequency Response, 20 to 20 kHz

    +0.00, -0.07 dB

  • Frequency Response, - 3 dB

    0.015 Hz, 95 kHz

  • Maximum Input Level

    6.0 Vrms

  • Input Impedance

    100 kΩ balanced, 50 kΩ unbalanced

  • Common Mode Rejection (Balanced Only)

    60 Hz: 90 dB, 10 kHz: 70 dB

  • Crosstalk, L to R or R to L

    -112 dB or better, 20 Hz to 20 kHz

  • Crosstalk, Adjacent Inputs

    -112 dB or better, 20 Hz to 20 kHz

  • Volume

    100 dB range in 0.5 dB steps

  • Maximum Voltage Gain

    46 dB

  • Gain at Auxiliary Outputs

    Balanced: +4 dB, unbalanced: +2 dB

  • Control Systems Supported

    Boulder Link, 12V Trigger In & Out

  • Weight

    Amplifier: 47 lbs. (21.3 kg)
    Shipping: 54 lbs. (24.5 kg)

  • Power Requirements

    100, 120 220-240 VAC, 50-60 Hz
    3W Standby, 850W maximum