⌈ BOULDER AMPLIFIERS is an American brand that for over 35 years of making perfectly sounding, made and finished audio devices, mainly solid-state amplifiers, has become a synonym for top-high-end. The only integrated amplifier in the lineup, the 865, was sold successfully for 12 years. However, the time has come for the veteran of the Boulder portfolio to be replaced by a new contender, the 866. ⌋

shall not repeat all the information about the brand itself, as you can find it in my previous reviews of Boulder products, especially in the one of the aforementioned 865 integrated (see HERE), and there is some more for you to find in the review of a set consisting of the 1110 line preamplifier and the 1160 stereo power amplifier (see HERE). So let's move on to the subject of this review, which is actually one of the two available versions of the 866.

As the manufacturer claims in his materials, modern technology is defined by capability. The more a product can do with today’s media delivery and do it well, the better. The point is in both, the type and number of features and in the ease of use. It can’t be denied that the trend introduced for good into the audio industry when the first CD player was presented, i.e. putting the convenience first, even at the expense of the sound quality, has led many people to look for solutions that are most versatile and offering them an option of operating them from a comfortable couch. The sound quality comes often only second.

After such an introduction, you may start to worry that Boulder had gone all in towards convenience to please the lazybones. However, take a look at the opening paragraph - the company has been working for 35 years to get where it is today and while gaining reputation takes a long time, one may loose it in a heartbeat. It should tell you that the American brand surely wouldn’t follow such a risky path. They took a step(s) towards modernity and convenience not for a second forgetting that even their "entry-level" model must set standards for others. I probably should mention it only when describing it’s sound, but anyone who has ever listened to any Boulder system would not expect from them anything less than an excellence.

| 866

So what does the American manufacturer actually offer with the new and so modern integrated amplifier? First of all, there are two versions available. In both cases we get devices featuring the same, characteristic, as always in the case of Boulder, extremely sturdy, perfectly made and finished chassis. As it was the case with 865 also 866 isn’t particularly big or heavy (unlike more expensive models). The original form makes it difficult to confuse this device with any other because, above all, of its tilted front panel, almost half of which is occupied by a large display. In fact, the new model looks more like a streamer than an integrated amplifier, also due to a small number of manipulators on the front (do you remember the Olive file players? - ed.).

Secondly, even heat sinks are quite unusual too as either they came from a mind of an artistically inclined designer who wanted to create a memorable design, or ... someone just took oblong pieces of metal of various shapes and fixed them to the sides of the chassis creating sort of an artistic composition. Regardless of which one is true (there are hundreds of other possible explanations), it actually looks really good and definitely catches the eye. Does it dissipate heat as effectively as traditional heat sinks, that have a larger surface to do their job? Probably not, and the amplifier gets a bit warm while in operation, but just warm, not hot, so I don't think that is going to be a real issue.

Basic or analogue version | When describing the 865 I emphasized that it was a "pure" integrated amplifier, i.e. without a built-in digital-to-analog converter, streamer or phono preamplifier - all in order to minimize the risk of any interference that could negatively affect the sound quality. Which worked great for the Boulder’s original integrated.

For those who like such puristic approach and who already have (or plan to have) their own high-end sources, the American manufacturer prepared another „pure”, fully analog version of the 866. Of course, this is a new, more powerful (200 vs 150 W at 8 Ω, and for 4 Ω the 866 doubles the power), more advanced circuit which retained some elements characteristic for the brand, such as the balanced signal path and only balanced inputs (i.e. XLR and it is worth noting that there are only three of them). At the same time, the company's decision-makers realized that today many people prefer more versatile solutions, not only at the budget price level, but also more and more at high-end level.

Digit-analogue version | For such customers Boulder developed the second version of the 866, the one we received for the test. The difference between it and the fully analogue version lays with a built-in D/A converter. The DAC features not only traditional inputs (Toslink, AES/EBU), but also highly sought after by most users today ones, i.e. USB (there are four of them) and LAN ports. As perhaps some of you have noticed, there is no coaxial S/PDIF input (BNC or RCA). The manufacturer has a simple answer for it - the AES-EBU is, according to Boulder engineers, superior in terms of performance, hence preferred by those who look for ultimate sound quality (meaning - Boulder customers, I suppose). Those who can’t live without it must look for an XLR/RCA adapter. Boulder offers a their own, but there are also other ones available on the market.

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Note (!) - the USB ports are there only for connecting external hard drives or flash drives. What's more, ones with higher power requirements, such as NAS connected via USB, must use their own power supply. The Boulder is also a certified Roon Ready device which makes life much easier for the users of this software.

One has to be patient when turning the 866 for the first time on as the initial boot takes a while and when ready... it automatically switches to standby mode. So one needs to push the ON button and select an input, in my case it was LAN. Obviously before all that one has to connect the device to a power source and to one’s local network A device with Roon installed in it, if connected to the same local network, will recognize the amplifier immediately and allow you to play music directly to it via LAN. Really simple, isn’t it?

Roon is not the only option to play music via your local network, though. If you have a UPnP / DLNA server connected to the same network and sharing its library, you can play music directly to Boulder using any proper control application. I checked it with Bubble UpnP (I use a paid version, but the free one also works) and the Fidata app and both worked fine. By the way, it's worth knowing that the latter app can be used not only with the Fidata’s and Soundgenic’s own devices, but also with almost any network player / transport. It is quite advanced and you may need bit time to get used to it, but once you get a hold of it, using it is pure pleasure.

| Operation

Screen | This is still not the end of fun with this device. The front panel inclined slightly backwards features a large 7-inch color touchscreen. Regardless of whether you are using Roon or the UpnP server, as long as the files are correctly tagged and accompanied by artworks, all this information will be presented on the display, and the artwork will take up half of its surface. I really liked the visual effect of artwork being displayed in quite a large format - it looked much better than any icon assigned to other inputs (unless you replace them with some photos - more on that in a moment).

It is the display and the accompanying four buttons - volume up, down, mute and standby - that are the basic tools for device operation. At least initially as there is no remote. Wait, what?! No remote? !! Come on! It’s not for me! Well, there isn't. But take it easy. There is an option to buy additionally a set consisting of a dongle and a remote control, and you can even choose one of two available remotes. You just need to pay extra for it, which is completely unnecessary, if you ask me.

App | A dongle is a small thing that plugs into a USB port (it only takes one out of four available ports, which shouldn't be a problem) and it is a transmitter / receiver. You probably use one or more of them when connecting wireless mouse or a keyboard to your computer. But this is only an option, as a remote control is basically not really needed. That’s a modern device, remember? And as such the 866 can be operated using the aforementioned touch screen and buttons, or ... You can also download (from the manufacturer's website!?!) a free control application, both for Android devices and for iOS ones.

Don’t ask me why these apps are not available in Google Play or Apple App Stores - I have no clue. The only difference is that you have to allow your device to install an app that comes from „external/unverified source”. So just switch this option on and once the app has installed, turn the option back off (for safety reasons). From my experience, the Boulder app works well and it didn’t mess with my Android smartphone - so you should be safe :). The manufacturer also thought about additional facilitation that may be helpful to some users. If you want to connect a portable device with the Boulder application already installed on it to the 866, all you need to do is to scan a QR code from the screen of the amplifier, which can be displayed by selecting an appropriate option in the settings menu. So, in fact, we have a remote control for free, and we can use it to do everything, including turning the amplifier on and off, without moving from the couch or armchair. You wanted convenience? There it is.

WiFi | The Boulder team evidently tried to anticipate many different circumstances their new integrated would have to face. So they had even imagined a situation that someone wants to have this modern amplifier but play music from files stored on drives connected directly to the device, not in local network. Are you one of them? If so you can benefit from another facilitation. The tested device can be wirelessly directly connected to a mobile device (no external router needed). All you have to do is to turn the Boulder’s own Wi-Fi network on.

Such connection is to be used only to enable remote control using a phone or tablet with the app, but it is a good solution for those who cannot or do not want to connect the amplifier to local network. You can simply use an old phone that you keep in a drawer and despite the lack of a local (wireless) network, still be able to use it as a wireless remote control. However, you should know that if the amplifier is not connected to the network (Internet), it will not check for firmware updates. And these will keep your device up-to-date.

Roon | Let's go back to playing music using Roon. After selecting Boulder as the end point, we can start playing the music. The 866’s screen displays the artwork, title, title and time (total and current) for the track, and the resolution of the files. There are also touch function buttons for playback control on the screen. Obviously, when sitting several meters away from the device (unless you are a hawk eye) you won't see much, except for the artwork, but from up close it looks really nice. I do not have to tell Roon users about it, but those who do not know this software yet may want to know, that you can integrate for example Tidal in it and thus stream music from this service to Boulder, too.

| Menu

Volume control | The 866 menu offers its user even more options. For example, you can choose one of the four options for volume control. One of them is about the way the volume control level is presented. It is always shown in decibels in 100 steps, but the scale may begin at "0" and go up to „100”. You can also choose the "real" option, in which "0" means no attenuation, i.e. the maximum volume, and -100 maximum attenuation. In the menu you can also set a maximum volume - it does not have to be 100 or 0 dB (depending on the selected option described above). One can also set the default volume value, i.e. one that will be set when the device is turned on. And finally, one can define how the mute button should work, i.e. by how many decibels (in the range from 6 to 80 dB) it will lower the current volume level when used.

Inputs | Also for individual inputs you can use three different settings. The first is the so-called trim - this function allows you to reduce the volume of a selected input relative to all others so that they can be matched to the same level. Another one is called a theater mode - the purpose of it is to allow the 866 to be used in home cinema systems where the master volume control will be in the surround sound processor. When an input has been programmed for Theater Mode, the volume controls will be disabled and the volume level must be controlled by the surround sound processor.

And finally an Input image, i.e. a funtion that allows user to upload a photo of his source to replace the standard input icon. Obviously, you can use any photo you like. The menu of the tested amplifier also includes a number of system settings, including network settings, the option to update the software (the device connected to the network automatically informs user about availability of updates), and the factory reset function.

Audio files | Let me end this section of the test with a curiosity. Probably due to the raise for the highest supported files resolution, which we have witnessed in recent years in the world of digital audio, I, and probably and at least some of you, when dealing with a new "DAC" almost instinctively try to check what files and resolutions it supports. And so I tried to figure it out for the 866 - the good news is that one can play music from Roon directly to Boulder - hooray!

But the question remained - what kind of files and of what resolutions? As it turned out, one can look for this information in the device specification, manual or other materials available on the manufacturer's website in vain. So I turned to Roon for help as it is pretty clever and informs (usually correctly) about the formats and maximum resolutions supported by the given connected device (it can even automatically down-sample for them if necessary).

So I checked and found out that Boulder should accept PCM files up to 384kHz and 32bits. However, there was no information at all regarding DSD files. Usually this means that the device in question does not support DSD format. However, I decided to check this information and see what would happen if I played a DSD file. DSD64 - worked like a charm and the 866’s display showed the correct information regarding the files type and resolution. Next came the DSD128 - it was also played but according to the information on the display it seemed it was a DSD64 file. DSD256 - the same. In a word - the DSD64 format is supported, and the higher resolution DSD files should play fine too if the software player (Roon in this instance) down-samples them to DSD64. For those who may wander I will add that I even played an MQA file (by accident) and it was properly unfolded (by Roon!) and played as 24 bits and 352.8 kHz. In a word - it works too.

| SOUND

How we listened to it | Like all Boulders, the 866 was a bit problematic for me as it features only XLR inputs. So I could not connect either my LampizatOr Pacific DAC to the analog inputs, nor any of my phono preamplifiers. I ended up playing audio files via the LAN input and from an external drive (connected to USB port), but to have some reference, I also used the Weiss DAC501 digital-to-analog converter, that I had been listening to for more than 2 months. The latter also received signal from Roon over the LAN and was connected to Boulder with XLR cables.

To be able to use my J. Sikora Standard Max turntable with the KV12 tonearm of the same company and the Air Tight PC-3 cartridge, I asked the distributor, Soundclub, to lend me the fantastic Brinkmann Edisson mk II phonostage, I’d spent some time with before. Unlike my phonostages this one features XLR output.

Boulder drove both my pairs of speakers (in turns), the GrandiNote MACH4 and Ubiq Audio Model One Duelund Edition), but also the recently reviewed AudioSolutions Virtuoso S.

I started the listening sessions from a position of the person who purchased the analog-digital version of the Boulder 866, i.e. one who intends to use the built-in DAC. So that’s what I did and only later I also listened to Boulder with external sources to assess how good the built-in converter is.

I remember that the first amplifier of this brand that I reviewed, the 865, although it was just an entry level device from Boulder’s lineup, made a great impression on me. While conducting the second review of the preamp/amp set from the higher, 1000 series, I already knew more or less what to expect and the listening sessions confirmed it - the sound was, in general terms, similar, only better. Which was perfectly fine because it proved company’s a coherent vision of the sound applied to products from different price points.

Digital inputs in Boulder amp – this is a DAC and streamer

On the other hand, such a philosophy, followed by many top brands, means that the „wow” effect, the breath-taking experience is usually reserved for the first product of said brand one listens to. It makes the biggest (at least) first impression, even if the next components offer objectively better performance. And that's probably why the 866 did not bring me to my knees from the first listening session. It was not love from the first sight, but rather one of those cases when with each subsequent album, hour and day of listening, the feeling grew, because I was more and more impressed with this device’s performance and potential. And finally, at some point, I said aloud (to the surprise of members of my family, and probably some neighbors): "it sounds damn good!" (not necessarily using exactly these words ...).

I guess it took me a while to fall in love because the Boulder is not an intrusive device, it does not impose its own character on the whole system, it does not wow listener with any one prominent sonic feature, but rather, it delivers a complete, coherent, top class performance and still lets music take the lead. This is one of those seemingly banal, but absolutely key features of any audio equipment (that is, it should be, but it rarely is) - it is supposed to be only a tool, not a star itself. At least if the ultimate goal is to experience music in the best possible, most realistic way.

The tested amplifier politely, but firmly, invites you to the world of music. If you resists, it will drag you in, and once you’re there it will take a step back leaving you with a unique experience, making only sure that you get what you deserve. And what you deserve depends on your musical choices. Because they will primarily decide about the quality of what you will hear from speakers. So if you choose some mediocre recordings, technically, or musically, Boulder will deliver just that - mediocrity. It won’t try to hide recording’s flaws, it won’t do a thing to make it sound „nice”. "Sh.t in, sh.t out" as the Americans like to say. Theoretically, this is what the high end audio is about - the high fidelity, isn't it? That’s what you will get introducing this integrated amplifier to your system.

Boulder will play every recording, both a super-duper audiophile one and prepared for mp3 players with unwavering confidence. It seems that I’ve anthropomorphized an audio device, but I can live with it. This self-confidence is not unfounded, as it stems from its enormous potential and its constant willingness to faithfully present whatever we send to it. Also from the ability to use every piece of information about tone, dynamics, texture, space, acoustics, etc. and to combine it all together into a coherent, and if there is enough of it, also fluid, dense, and at the same time fabulously clean and transparent, whole. It is also based on this inner calmness of the 866, i.e. the lack of even a trace of nervousness in the sound and the ability to perfectly control driven speakers. So the result, sound one hears from speakers, depends on the quantity and quality of information provided for Boulder by a source. It’s in the owners interest to support the 866 with the best possible source component(s) playing high quality recordings. Does the Boulder’s build-in DAC fall into this category?

DAC | Usually DACs built into amplifiers are sort of an add-on, sometimes a really nice one, but the higher the shelf the main devices comes from, the more its performance and that of an add-on differ. But a reputable company, such as Boulder, did not build the whole device around the idea of direct playback of files from local network / external disk, in order to fail its customers by using a low quality (or too low) converter inside.

So if you use a high quality Ethernet cable to connect Builder’s input with a good source component via a nice switch (for me it was the Silent Angel), to send a high quality signal, you can expect a high-class performance. You’ll be truly impressed, I know I was! It will be so good that you most likely won’t even consider using an external DAC, unless you have a LOT of money to spend.

In most cases the three line inputs can then be used to connect, for example, a turntable (via a phono preamplifier, of course), a reel-to-reel tape recorder, a CD or a SACD player, while the audio files will be played directly from a network source. Preferably with Roon on board, because this software will solve the issues of Tidal, MQA files, or down-sampling of unsupported resolutions. And the other digital inputs can be used to upgrade sound of devices such as a TV set, set-top box, game consoles, and so on, to enhance user’s the experience.

For comparison with the build-in converter, I used the aforementioned Weiss DAC501, a device which more or less falls within the price range suggested by Maciej Chodorowski from Soundclub (about 30,000 PLN). The Swiss converter is an excellent device, and the built-in DSP featuring a number of algorithms allows it, despite its inconspicuous size, to compete even with many more expensive competitors.

As it turned out, when conducting comparison without engaging the Weiss’ DSP, the advantage of the Swiss converter over the built-in in American amplifier is relatively small. The Weiss is a bit more precise, faster, controls lower end of the band even better, there is more musical plankton in the sound, i.e. the tiniest information coming from the deepest layers of recordings.

The Boulder presents a bit more forward sound, although there was nothing to complain about regarding the spaciousness of presentation in either case (even if compared to LampizatOr Pacific the sound was not quite as vivid and present). Both devices delighted me with a similar momentum, energy, dynamics, resolution, and at the same time they were both very smooth, open and their presentation was very well composed. The more significant difference could be noticed only when Weiss’ DSP was engaged, but even then spending an additional amount of more than thirty thousand zlotys on this external DAC would not be so easy to justify.In a word - the built-in Boulder DAC firmly stood the ground against an external, top class competitor that costs half the price of the whole 866.

What’s more, the new integrated delivers an even better organized sound, presented in an even more refined, more transparent way, probably also with a better "kick" than the model it replaced in the lineup, i.e. the 865. And the latter featured no on-board DAC. Which means that Boulder now offers a better, more powerful amplifier for the same price as 865, and it includes also a very, very good build-in DAC and the ability to play files straight from the local network, or from directly connected USB discs. How did the Boulder engineers achieve that? I have no idea, but they deserve hell lot of respect because they did a great job! Especially that the analogue (i.e. with no build-in DAC) version of the very same amplifier, which performs significantly better than its predecessor, today costs less than the 865 did 2 years ago (!).

To further confirm that this is an excellent amplifier I kept listening to it using, this time, my analog rig with Janusz Sikora's turntable and tonearm and Air Tight cartridge, supported by the excellent Brinkmann Edison mk II phonostage. Yes, this fantastic analogue system pushed the Boulder to its limits (at least I think it did) as it performed even better than with any digital source before. Considering the total cost of this rig it should not have come as surprise. I won't even bother to write about bass, midrange and treble, because with an amplifier such as the 866 it makes no sense. It simply delivers a complete and coherent musical spectacle with each high quality recording.

Each time the spectacle was different, tailored to the needs of a particular recording. When a momentum, power and ability to convey a unique atmosphere of a Witches’s Sabbath on the Bold Mountain (Mussorgsky) will be needed - Boulder will make your walls (power) and heart (climate!) tremble. If you decide to play the incredibly rich with information, amazingly natural sounding, live performance of the Blicher Hemmer Gadd trio or Ray Brown's band - it won’t be a problem either. You will find yourself in the venue surrounded by a spontaneously reacting audience, having performers almost at your grip. You will be able to effortlessly follow the performance of each virtuoso and delve into the absolutely natural, yet precisely rendered sound of their instruments, or simply let yourself be carried away by vivid emotions, tapping out the rhythm and humming along. Whenever you will feel like listening to an opera with, for example, the wonderful Leontyna Price, or maybe with the amazing Luciano Pavarotti - Boulder will remind you right away why you love these extraordinary, rich, incredibly expressive voices and it will let you immerse yourself in a story told by them, forgetting about the whole word.

You won’t be that lucky if you choose, say, U2’s Joshua tree (even the special, anniversary, not-so-cheap edition). I love music created by this band, but the better system I own/test, the less often I listen to it, because the quality of these recordings is so-so (to say the least). Boulder did not fail to make me aware of this fact, pointing out from the very first track, for example, how flat the recording is, in terms of dynamics and soundstage depth, how much it lacks in terms of sound purity (even if part of this effect was probably intended). I survived one side of this record but gave up the rest, because I could not focus fully on the music, as I was too distracted by the technical flaws of the production. The same happened with every other recording of a lesser quality, no matter if it was played from vinyl or files.

It was different though, with decent, although still non-audiophile-quality albums. Because when I cued the AC/DC’s Live in and I turned the volume up accordingly, the minor technical flaws of this recording, while still present, ceased to play a major role. The tested Boulder is a master of timing, and thus of pace and rhythm which serves such music greatly. Additionally it is capable of delivering powerful, focused bass notes that (when necessary) go really, really deep, and even in such imperfect recording are surprisingly well differentiated. And when the Aussies start to rock and the audience joins them, the only thing that matters is this incredible, unique, tremendous energy flawing from the speakers and filling the whole room.

Let me close this review with the issue that’s just been hinted. The American amplifier likes and can play really loud. I'm not talking about some crazy volume levels (I do have neighbors and many of them stay at home during pandemic), but in my case it meant, say, 10dB louder than usual. The thing is not that the tested amplifier sounds worse when playing at lower volume levels - it sounds brilliantly no matter the volume setting, without losing any of its many advantages or musical details. But when you add these additional 10, sometimes even 15 dB, the sound gets ... even better, faster, more energetic and the "fun" factor increases too. Yes, I do realize that we always perceive louder sound (at least up to a certain level) as better than quieter, but that's not the point. In many cases when you push the volume up you loose some clarity, you risk the sound getting overdriven. In this case it just gets better at higher volume without any negative effects, because the 866 exercises a perfect control over the loudspeakers thus delivering astonishing performance.

| Summary

Does Boulder have any weaknesses, you can ask after all the praises? Surprisingly, I can point out a few, but only two of them, purely functional, really count for me. First of all - the touch screen. Its operation is quite... capricious. That is why I suggest that you should admire the screen, because it looks great, but control the amplifier using the app installed on a mobile device. The second issue remains the same in all of the amplifiers offered by this brand - the speaker outputs that accept only spades. They are very solid, large nuts make fixing spades very easy and once fixed they stay firmly in place. Which is all great! But if your favorite speaker cable is terminated with bananas then ... you have a problem. You can either re-terminate them, use adapters or buy another cable - none of these solutions are perfect.

I was also under an impression, but without a direct comparison I can’t be sure of it, that the new integrated gets warmer than its predecessor. During winter, this can be bonus - it will keep the room warm, yet with the current summer temperatures it’s hard to call it an advantage. Another downside, though is it really a flaw (?!), is the fact that Boulder does not tolerate lesser quality recordings well. As a result, those that with other amplifiers (that do not adhere to the high fidelity rule so much) can still be enjoyed, with the tested integrated sometimes are hard to listen to. Although even in their cases sometime it’s the music that wins if the performance or the atmosphere of the recording are good enough.

On the other hand, whenever you give the 866 a chance to spread its wing and "feed" it with the best quality recordings and a high-quality signal, it will repay you with a jaw-dropping performance that will keep you at the edge of your sit even for hours at time. The fact that even after many hours of listening I did not feel even the slightest fatigue is the best proof of how good and natural sound comes from the new Boulder. It does combine these two sonic qualities of being natural and neutral at the same time. Sorry! What I actually meant was that the 866 serves MUSIC using a neutral yet natural sound! And it is able to achieve that not only with excellent external sources, but also with a built-in D/A converter. It's just a damn good, impressive machine! And while it is an entry level proposal from Boulder it may as well be the end of the road for many demanding music lovers.

Technical specifications (according to the manufacturer):

Output (continuous): 200 W / 8 Ω | 400 W / 4 Ω | 700 W / 2 Ω
Peak power: 250 W and 400 W
THD: 0.01%
Frequency range:
-0.04 dB: 20 Hz-20 kHz | -3 dB: 0.015 Hz-150 kHz
Analogue inputs: 3 x XLR
Digital inputs (available in digital-analogue version): Ethernet, USB x 4, AES/EBU (a converter to S/PDIF RCA available as an option), Toslink (optical), Wi-Fi (for control)
Speakers outputs: spades only
Volume control: 100 dB range in 0.5 dB steps
Max. Analogue gain: 40.4 dB
S / N (150 W / 8 Ω): 108 dB
Input impedance: 100 kΩ (XLR)
Power consumption (max): 1000 W
Dimensions (W x H x D): 440 x 190 x 390 mm
Weight: 24.5 kg