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The microprocessor allows each individual input to be alphanumerically labelled or named as well as programming the input's individual gain/level, balance, start-up volume or Theater Mode configuration for home theater integration. Power output is a healthy 150 watts continuous into 8Ω or 4Ω with a THD of 0.0035% from 20Hz to 2kHz and 0.018% at 20kHz. Frequency response is 20Hz to 20kHz +0.00dB and -0.07dB. Input impedance is specified at 100Kohm and voltage gain is 46dB. Volume control range is 100dB adjustable in 200 steps of 0.5dB via the unit's main or remote control. The remote is an attractive 'S'-shaped piece carved from solid aluminium that can control all the amplifier's functions and seconds as a weapon against intruders.

The entire unit is impressive in every aspect of build, finish and operation. All buttons are solid and function with a reassuring feel. The volume control is a pleasure to use, its operation inspires confidence again in the engineering involved in the overall design. The same high standard continues on the inside. The surface mount technology (SMT) circuit board is picture perfect in layout and design and all circuit components are of the highest quality. A clever touch is the removable modular connection section that makes servicing, upgradeability and alternate configuration a simple affair.


Flicking the switch will activate the 865's display to read "Waiting for amps", your speakers will discernibly hum for a couple of seconds, then click loudly and at that point the display will change to show the amplifier has automatically switched to the last chosen input. Now you're ready to go.
O Brother, where art thou?
The 865 amplifier's sonic character is actually a tough one to pinpoint and in a way that reviewers have bad dreams about. I actually mean that as a compliment. I mean that the 865 is such a clean, neutral and honest transmitter of what's fed into it that to describe its sonic traits in such an inadequate medium as language seems harder than chain-gang labor. In other words, the 865 does what the ideal amplifier should do: transmit the information from the source to the speakers in an effortless manner without imparting its own signature or personality.
So the listening impressions with the Boulder were an exercise in intellectually extracting descriptive information. For starters, well-produced guitar-heavy music as presented by Ani Di Franco in her live recording Living in Clip sounds clear and detailed without a trace of hardness or brightness. Ani's violent strumming cuts through and provided the mated speakers are adept at dynamic contrast, the Boulder will pass the shadings unscathed and without reduction.
Resolution is directly derived from the 865's high level of accuracy. Ani's vocals stand out in relief to the guitar and in turn to the bass and drums. Each instrument is clearly discernable,
separated from the mix and occupies a focused solid point within the sound field. The precision with which the Boulder places images in the soundstage is laser sharp but such exactitude comes at the marginal expense of lateral and stage depth. Images are spread a little shallower and narrower but with sharp relief in front of the speaker plane.

The old stalwart recording Harry Belafonte's Live at Carnegie Hall is the perfect tool for illustrating this trait. When Harry wanders the stage, he's uncannily present, his movements accurately traced within the sound field - just on a slightly smaller stage. And when Harry let's fly his big, raspy chords, the 865 follows without faltering, meeting the dynamic challenge without raising a drop of sweat. The Boulder also lives up to its insinuated name with big and powerful bass that can "shock and awe". Red Hot Chilli Pepper's Suck my Kiss rams home the message. Some amps have trouble resolving the closely-miked kick drum and Flea's
simultaneously slapped and plucked bass. Such amps tend to homogenize the two into a single bass thread. The Boulder is able to distinctly separate the two while maintaining their individual slam, brutality and detail.
Massed instruments such as violins in large orchestras, say in Sibelius' Violin Concerto, are displayed with utmost fidelity. The impression is one of many instruments playing together and in 'concert' with the rest of the musicians, not as the sonic equivalent of a single bulbous mass. However, when Zuckerman hits his lone stride, the 865 cuts him center left, present within a life-size image and with his instrument reproduced with a fidelity of detail and timbre that becomes emotionally moving.


Boulder moves
One of my all-time favourite CDs and one that I would take to that imaginary island of the lonely audiophiles is our own ACO's (Australian Chamber Orchestra, arguably the best chamber ensemble in the world) interpretation of some of Astor Piazzolla's most intoxicating tango masterpieces - Tango Jam. This writer was lucky enough to be in a prime listening position at the Sydney Opera House when this extraordinary music was performed by maestro Richard Tognetti and his group of outstanding musicians. One of the highlights of this concert -- aside from Tognetti's own masterful violin virtuosity -- was the genius of James Crabb, incomparable talent on the classical accordion as opposed to the Argentinean bandoneon.
The musicianship here is out of this world -- these guys are alien muso body snatchers -- and it's a credit to the communication skills of the Boulder and in turn the connected speakers that this virtuoso skill is transferred to the listener. Every note is discernable, every inflection and delicate nuance easily appreciated and therefore enjoyed.
Just as easily communicated are the tempo variations in what is probably the highlight of the CD, Concierto para Quinteto (although I would just as soon pick another piece should I ponder such trivial matters.) The gradually building atmospheric first movement sets the tension of
the piece that in turn is released by the onslaught of the fast-paced allegro, which gives way to a ponderous adagio-like mid section finishing in a climactic eruption of instrumental emotion that leaves the listener both elated and damn near exhausted. A hifi component that slows the music down or sweetens over the detail or has a tipped-up treble-heavy balance will detract to varying degrees from this wonderful music and therefore from the emotional connection. Not the Boulder. The 865 delivers all music unscathed, untouched, unsoiled. I'm talking rosin in the violin strings, plucks on the double bass and air rushes in the accordion bellows.

Finale
How can I comfortably suggest that a $11.5K audio component represents good value? Well, when you take into account the fanatical build quality and engineering, the comprehensive feature list and the conveniences of an all-in-one package as opposed to the cost of a separate preamp/amp combo and the interconnecting cables, you might start to realise the relative value offered by the 865. What's more, sonically the solid-state Boulder 865 integrated amplifier is a clean, crisp and tight performer that never strays into sterility. It delivers an image that's scarily real in terms of spatial accuracy and life-like presence and controls your speakers with an iron fist in a silver/grey glove. If only all chain gangs were this easy to work in...

Quality of packing: double boxed plus foam protection
Reusability of packing: reusable ad infinitum
Ease of unpacking/repacking: can be done by one strong person
Condition of component received: as new
Completeness of delivery: all as should be
Quality of owner's manual: informative and complete
Ease of assembly: no assembly required
Website comments: informative and comprehensive
Warranty: 5 years
Human or web interactions: supportive and helpful distributor
Boulder website