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Boulder Amplifiers 866

Name: Boulder Amplifiers 866
Brand: Boulder Amplifiers
SKU: 866-integrated
Rating: 4.7 (31 reviews)

View at Boulder Amplifiers

Built-in DAC

Network Audio

Ethernet

Wi-Fi

USB Audio

XLR Input

Balanced Line Output

Remote Control

Roon Ready

How do you follow up one of the most successful products in the history of a company? With a product that improves upon the original in every way, and the Boulder 866 Integrated does just that.

Power is up to 200W per channel. Manufacturing is substantially more efficient. Weight has been reduced. New circuitry gives you greater current output at maximum power. External IP control has been added. There are versions for traditional systems as well as modern streaming media users. And a dedicated Boulder app easily enables you to manage everything.

And here’s the best part: the sound is everything you would expect from a Boulder. It’s powerful, clean, clear, quick, and true to the sound of the original recording and the intents of the artists involved. In fact, there’s absolutely no reason not to take home an 866. It’s everything you could want and more.

To download the 866 control app for Android devices, click on the download link provided below the specifications section.

To download the 866 control app for Apple devices, click here.

Two versions are available to suit any system: all-analog for more traditional systems and analog+digital for the streaming digital media listener

Excellent power, dynamics, and control from 200W of amplifier power into any loudspeaker load

A full-color touch screen displays all of the available inputs and setup features in addition to the amplifier's status and setup modes

A dedicated Boulder app controls the 866 and makes custom setup adjustments, including adding photos of your sources to the inputs shown on the 866's front panel, optional RF remote for volume control and switching inputs also available

In-house manufacturing efficiency improvements have made the 866 an incredible value in comparison to previous integrated amplifiers

New protection circuitry enables the 866 to deliver greater current at maximum output without fear of damage to the amplifier's electronics

The analog+digital version of the 866 adds digital inputs for USB, Ethernet, AES3, Toslink, Air-Play, plus Roon integration

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 0.25" (6 mm) thumbscrew binding posts are included for secure speaker cable connections and optimal sound quality

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Overall Score 94/100

Deliciously Crispy

Boulder Amplifiers 866 — compact power, surgical detail

The Boulder 866 condenses flagship-class amplification, DAC/streaming and a bold industrial aesthetic into a single chassis. Reviewers praise its transparency, near-silent background and neutral, highly resolving timbre that reveal deep inner detail while retaining natural musical weight (The Absolute Sound, Positive Feedback). Sonically it pairs muscular, tightly controlled bass and abundant headroom (200W/8ohm, 400W/4ohm) with a rich, articulate midrange and relaxed, non-fatiguing treble for an immersive, three-dimensional soundstage (What Hi‑Fi?, HiFi News). Build and finish are distinctly premium, and the integrated DAC/streaming options make the 866 an excellent one-box solution for audiophiles seeking power, clarity and streamlined system design.

Audiophilepure

"Some integrated amplifiers might offer slightly more functionality as a system hub, but Boulder’s 866 is well specified, impressively built and a knockout performer."

Enjoy The Music

"The Boulder 866 is a star performer and a true standard of excellence."

Audiophilepure

"The Boulder 866 makes an incredibly compelling overall case."

Positive Feedback

"The thing that struck me on first listen, and the quality from which all the other strengths seem to spring, is the sheer transparency and articulation of the 866."

The Absolute Sound

"The 866's ability to preserve all the subtle musical details with no homogenization or obscurations or micro-details made listening deep into the mix easy."

What Hi-Fi

"For starters, the 866's control over bass is exceptional."

The Absolute Sound

"The ergonomic beauty of the Boulder 866 is that with one chassis you can accomplish everything required (except transducers, a turntable system, and a couple of cables) to assemble a complete high-performance playback system."

HiFi News

"This integrated amplifier has a smooth, easy-on-the-ear presentation that's seductive and addictive."

Positive Feedback

"From the get-go, I knew that the 866 was something special."

Audiophilepure

"If you’ve been a fan of Boulder’s sonics and build-quality but have been unable to field the space for their generously sized components, the new 866 could be the component of your dreams made into reality."

Audiophilepure

"The Boulder 866 delivers the goods flawlessly at all volume levels."

Audiophilepure

"Do not let the relatively compact stature fool you—this thing is a beast."

Audiophilepure

"The 866 DAC grabs this digital file and makes it something special."

Pros

Exceptionally transparent, low-noise presentation that surfaces micro- and macro-detail without sounding etched or grainy.
High sustained power and control—ample headroom and tight, authoritative bass even at high SPLs.
Top-tier build and distinctive industrial design with a usable touchscreen and comprehensive network/DAC features for a single-box high-end system.

Cons

Front-panel touchscreen can be sluggish or overly sensitive for some users; startup/menu responsiveness has been called out.
Limited legacy/unbalanced connectivity: no standard RCA S/PDIF input and USB-A ports accept storage only (no USB-B computer audio).
No dedicated aluminum remote included out of the box (third-party RF remote available as an option), which may frustrate users preferring a hardware handset.

Sound Quality

93/100

Dynamics

93/100

With 200W/8Ω (400W/4Ω, huge peak capability) and very low measured distortion, reviewers report effortless headroom, slam and control even at high SPLs — 'never sounded stressed', 'could endlessly turn up the volume', 'muscle amp attributes' (The Absolute Sound, What Hi‑Fi, HiFi News). Performance matches high expectations for a Class A/B, high‑power design.

Soundstage Imaging

93/100

Across reviews the 866 is credited with excellent imaging, three‑dimensional staging and pinpoint separation — 'consummately immersive', 'clearly delineated and three‑dimensional', and measured wide channel separation (What Hi‑Fi, HiFi News, Positive Feedback). Reviewers describe abundant air and precise image placement.

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Build Quality

93/100

Build and industrial design receive strong praise: milled aluminium chassis, engraved labeling, staggered heatsink fins and a rock‑solid feel noted repeatedly ('solid as a rock', 'fit and finish second to none') (HiFi News, Positive Feedback, Audiophilepure). Construction and thermal design match the high‑end positioning.

Features Connectivity

95/100

The 866 is richly featured: three balanced XLR inputs, multiple digital inputs (Ethernet, USB‑A x4, AES3, Toslink), integrated Wi‑Fi/streaming (Roon, AirPlay), optional high‑quality internal DAC/streamer and software update capability — reviewers call it an all‑in‑one system solution and 'a triumph of audio design and engineering' (HiFi News, Positive Feedback, Audiophilepure). This broad connectivity places it at the top end of the features scale.

Value for Money

91/100

Multiple reviewers state the 866 justifies its price and that the optional integrated DAC 'competes with DACs many times its price' and that the unit 'pushes the envelope' for integrated amps; phrases such as 'incredibly compelling' and 'highly recommended' appear repeatedly (Audiophilepure, Positive Feedback, Enjoy The Music). The consensus is a justified premium rather than bargain.