Publisher’s note: Heaven 11 has notified us that the MK2 has been discontinued at the time of press, making way for the launch of the MK3 in February, 2025. Follow-up Review forthcoming.
Here comes this curious integrated amp that I spied at AXPONA 2023 as it was playing through a pair of PAP Trio10 Heil Speakers. Named the Heaven 11 Billie Amp MK2, or Billie MK2, it is a little slice of Heaven. Though it is not perfect, it is awfully good, and I will explain what makes it heavenly.
Itai Azerod, the founder and product designer of Heaven 11, is a man on a mission to bring sensible, beautiful sounding gear to the world. He feels we have seen enough absurdly priced products that don’t sound beautiful, and I can understand his viewpoint. His standard is not measurements but musicality. When he speaks of the criteria for design of the Billie Amp, named for the singer Billy Holliday, he mentions that guitar players typically do not care about the circuit design of an amp but the sound, and whatever the design that creates the sound that the artist desire is fine. One example relating to guitar amps is the use of carbon resistors, which are the cheapest but claimed by guitar amp aficionados as the best sounding. Itai is attempting to address the demands of the performer who wants passion in music and the audiophile who demands precision in music. The two are not mutually exclusive, as evidenced by the Billie Amp. He is succeeding spectacularly!
Heaven 11’s design team includes two engineers. One of them is Denis Razon, who focused on the tube section and has worked on tubed products for high end companies such as Tenor. Tubes are used in this application to add second harmonic distortion which is perceived by the ears as pleasant, given that class D amps can sound brittle without it. The engineer working on the class D section and headphone amplifier was by Sylvain Svard. In this review I am not addressing the headphone amp, as I do not currently use headphones. Together, the team led by Azarod have created a product that combines industrial design sensibility and convenient functionality, with an homage to the golden days of audio – the era of tubes and non-auto-tuned vocals.
Itai did not wish to make another droll economical component but one that has sonic and operational character. In some respects, the Billie Amp has more in common with the console stereo of yore than a high end separates system, and that is by design. The goal was to make it simple and flexible such that people who don’t worship specifications would desire to play music at home. It’s not that specs are verboten, just overdone.
The Billie Amp merges an industrial aesthetic with tubes and American Oak dials ( or customer upgraded exotic wood or stone dials), and why not? In our home, we have a stuffed couch, an antique Tiger Oak vanity from a grandparent’s estate, and a Stiffel lamp all in one room. Pick the right pieces and it works nicely. Kudos for daring to bring unexpected elements together to make an appealing design!
Functionally, it also incorporates unusual but appreciated operations including 30-minute automatic shut off to preserve tubes and a switchable Preamp (variable)/Line (full) output to allow for the addition of a subwoofer or use of a different amplifier. One would not expect two sets of robust speaker binding posts, which served my itch to build many iterations of systems well. I put all the binding posts to work and stuffed them with both spade and banana speaker cables at the same time, all the better to bi-wire speakers with the clean and surprisingly potent onboard ICEpower 200AS2 module providing 120Wpc into 8 Ohms and 215Wpc into 4 Ohms. The Billie MK2 has a five-year warranty and 30-day return policy with receipt.
The preamplifier section uses a Class A Mu-follower design, and the 192kHz/32bit DAC uses the older ESS Sabre32 ES9018K2M chips. Why? Because the design team felt they sounded better. Having used enough gamma knife sharp DACs with the hottest chips or FGA programmable arrays producing tricky uber-resolution difficult to make musical, I support that decision! My long-term conclusion regarding resolution is that one can never have enough, but the caveat is that it must not be at the expense of color, tonality. I find the resolution and color of the Billie Amp with its pair of JJECC99 tubes, made by JJ Electronic of the Slovak Republic, to be agreeable and with plenty of incisiveness to satisfy all but the most assiduous listeners. As an upgrade for $139, customers may order these tubes with gold pins. A set was included and proved to be efficacious in enhancing the performance. Critical listeners would appreciate the benefit of the gold pin tubes. Those who wish to tube roll can employ 12AU7 or 12BH7 tubes. Internally placed voltage dongles to convert the MK2 version from 120V to 230V are available for $8. The Billie Mk2 responds readily to cable changes, even power cords.
Thoughtful design
Configurability is prized, as the user is given a legal sized sheet headed, “BILLIE REMOTE MK2,” and among the details it discusses 3 programmable inputs found on the uncluttered, svelte, remote control. An “EXTRA SETTINGS MODE” allows for thoughtful features to be programmed, including a child lock, maximum volume limiter, and selectable startup volume. Note that such features reset to default/initial operational settings if the rear power switch is turned off.
There are four operational modes available for curious system builders:
- All-in-one
- Preamp only (use Aux input and Preamp output)
- DAC/Preamp (use Billie Amp’s Digital input and Preamp output)
- Integrated Amp sans DAC (use Aux input and Billie Amp’s speaker posts/output)
The flexibility of multiple modes of use is an advantage, if you find a product like the Billie Amp that in several of its modes performs on the level of separates of similar price. A dizzying number of variations can be obtained, which can lead to a type of not-entirely-irrational angst about which one is the best.
I used several system configurations with the Billie MK2 during the time of the review, and they all performed commendably. There is so much flexibility in this product’s use and so many combinations of equipment that can be used with it that it would be presumptuous to declare one mode superior absolutely. Perhaps after a year of using this integrated in a variety of systems with a variety of speakers, I could proclaim the single best configuration, but at this point it would be premature. I will share about some of the review systems and for consistency in comparisons will largely report on setups with the PureAudioProject Trio15 10” Coaxial Speakers. My reference cable set from Iconoclast Cables were used throughout the testing process and were implemented in baseline comparisons. Upon occasion, once the baseline was established, I would compare exchange of one or two of the Belden BAV Power Cords for the Clarity Cable Vortex Power Cord, or the Snake River Audio Cottonmouth Gold Power Cable.
As part of the assessment of the DAC function of the Billie MK2, I compared the native performance to the alternative of bypassing its internal DAC in favor of an external one in a similar price range. Though the Eastern Electric Minimax Tube DAC Supreme is no longer available, especially with aftermarket opamps rolled in, it has held up well comparatively. I built in flexibility into a baseline system by using either the Bricasti M5 Network Player or the PS Audio AirLens as the digital streaming and file playback source. I alternated between the Billie Amp’s internal DAC and the EE DAC. I also alternated between the Billie MK2’s integrated tube/class D amplifier and use of it as a dedicated preamp along with the much more powerful Legacy Audio i.V4 Ultra Amplifier(s). Wow, that’s a lot of variety, and the little Heaven 11 component did not balk at any of these combinations but was unfailingly gorgeous sounding!
A brief shout out to Cardas for their impressively built SPDIF to BNC adapter which was used with the EE Minimax DAC. Over the years, Audioquest’s SPDIF/BNC adapters kept breaking three of them failed over the years, which prompted me to reject them and search for an alternative. The Cardas adapter was not cheap but built more robustly and to my ear made the DAC sound better. A reliable, good sounding SPDIF to BNC adapter is worth its weight in gold, as some systems including the Minimax DAC are better using the coaxial digital output than the USB connection. The reader should not expect that the SPDIF or USB connection will always be superior but is urged to do comparisons between all compatible inputs and outputs between components.
A notable setup, the Billie MK2 was spry and spunky when in use with the PS Audio AirLens, the Eastern Electric Minimax Tube DAC Supreme, and operating as an integrated amplifier only. This system vivified older recordings such as the Alan Parsons Project’s “In the Lap of the Gods”. Normally, this piece sounds tired, but the Billie Mk2 brightened and energized it such that it was closer in feel to a contemporary movie soundtrack. The bass was a bit light and I’m unsure whether this was due to the EE DAC, the opamps used in it currently, or the use of the Billie MK2 as a stand-alone integrated amplifier. However, inserting the Bricasti M5 Network Player in place of the AirLens brought more tonal balance across the board and more warmth. It had a touch less resolution, but overall, I preferred the tonal character. This convinced me that the prior brighter sound was not from the Billie Amp.
The native Billie Mk2, operating as DAC, preamp, and amplifier, was richer and more impactful than I had anticipated. I expected it to have less fortitude than the Kinki Studio EX-M1+ Integrated Amplifier, but the Billie MK2 held its own. One would not expect such a diminutive integrated component to pack such a dynamic punch, but that is the beauty of a class D amplifier, especially one that puts out 215wpc into 4 Ohms. I was not disappointed in the character and dynamic punch of the PAP 10” Coaxial’s twin 15” woofers. The dynamic drive of the Billie MK2 is weaker dynamically than the Legacy Audio i.V4 Ultra’s massive 610wpc, but the lower power did not call attention to itself until the comparison was conducted directly. For those unaccustomed to class A or A/B amplifiers ranging from 100-200wpc, the Billie MK2 will seem generous, and for those who have been using lower powered amps, it will seem prodigious. It does not have the characteristic thinness or brittle character of some class D amps. It is richer and more tonally inviting than most of the larger class A or A/B amps I have used.
This is a vocal lover’s integrated amplifier. If you adore crooners like Eva Cassidy or Jazz greats like Al Jarreau, whose voices deserve to be showcased, the Billie MK2 can do so with aplomb. One of my favorite recent female vocal discoveries is Lady Blackbird, whose “Did Somebody Make a Fool Out of You” had me shaking my head with approval as she unwound the song. Itai may have called this component the Billie Amp, but I’ll nickname it the Lady Blackbird. I could connect to her spirit deeply with this setup.
Big fun, small package
After several weeks of assessment with a variety of configurations, I pulled the Billie MK2 out of the system to change speakers to the Aspen Acoustics Grand Aspen. I did not set the Billie Amp aside due to lackluster performance. Quite the opposite, I conduct reviewing by rotating the review product in and out of the system to compare it to other products. The four tower, 4-way Grand Aspen is a titan that uses up to four channels of amplification per side. The Billie Amp cannot handle that task, so it will be called upon when I return to a bi-amped speaker in a few weeks. For the moment, I’m relishing the just reviewed PS Audio AirLens and DirectStream DAC Mk2 as the front end to the Grand Aspen.
How does that pertain to the Billie Amp? I have been in the game for over 40 years, and my systems have steadily gained in stature and capability, from the early days of using a bookshelf speaker with a receiver to now regularly employing 6’ tall truly full range tower speakers powered by thousands of Watts and supplemented by the succulent Perlisten D212s Subwoofers. I want for little in terms of performance, which is the reward of budgeting for audio for decades, spending money on show attendance to select knowledgeably from the pool of products, and reviewing to access some of the best equipment in the world. How could a small hybrid class D integrated amplifier compare to preeminent amplification products? It turns out, very well! The Billie Amp has an uncanny ability to capture many aspects of sound quality that engender a sense of grandness. It does not betray itself as a budget component but fools the ear into thinking the system is fancier.
We all remember one hit wonders, songs that against the odds climbed the charts to become popular, then the artist or group bumbled their way into obscurity. I certainly hope that Heaven 11 is not a one component wonder! May the company have much success! Given the performance of its first product, I suspect good things could be coming in future designs.
The Billie MK2 did something wondrous that no other combination of equipment has achieved, it tamed the moderately sized but idiosyncratic Kingsound King Tower omnidirectional speakers. For that, I name it a one setup wonder type of component in a positive sense, as the component that achieved what had seemed impossible. I have tried a lot of expensive preamp and amp combos with the unusual King Tower. I do not recall how many sets of cables I have tried and could not tell you how many DACs have played through those speakers. I have used no less than six heavy hitting preamp and amp combos to find a perfect match. They are peculiar speakers, with upward firing (dynamic) bass and midrange drivers. The dome shaped super tweeter atop fires upward and outward. The sole horizontally radiating driver is the large, soda can-shaped ribbon tweeter, and its output can easily overrun the other drivers.
I do not know what magic Heaven 11 is pulling off with the Billie Amp, but this little number connected ideally, allowing the King Tower to reach its potential. It’s odd, with this typically more strident tower speaker the Billie Amp mitigates the beamy treble and softens it. With other more conventional speakers that may tend to be soft in the treble, the opposite effect is heard, drawing out the nuances of the treble in a complimentary fashion. I have not found any other integrated amp than can do such wonders, to optimize both the King Tower and other dynamic speakers. The King Tower speakers are such a great slice of omnidirectional sound for an affordable price that I have kept up the search to find the perfect match, and the Billie Amp is that perfect match! The Billie MK2 is so affordable and with such a complimentary nature that I would buy it if for no other reason than for use with this omnidirectional speaker. I have learned that when the right component comes along to maximize a speaker, you don’t let it go!
“You can build a premium system with this $2k integrated”
Most of the time when I see such a statement made by other reviewers, I scoff and turn the page. I have handled enough $2K products to know that the price of $2K and the descriptor “premium” are mutually exclusive. Now, with the Billie Amp I am forced to revise that conclusion, to not hold it absolutely. It is easy to assign a rating of premium sound to a budget component when revising the criteria, that is lowering the bar sonically, to ensure the component clears it. You will need to trust me that I have not done so regarding the Billie Amp.
In assessment of systems and products, I do not subscribe to the philosophy that it is all about tone, wherein frequency extension and scale is neglected in favor of the magical midrange. I demand a reference system that does it all. Can the Billie Amp be part of such a system? Yes, it can, and I will show you how to do it. It will require making a monetarily imbalanced system, one in which the price of the speakers is multiple times that of the price of the Billie Amp. In the instance of the PureAudioProject Trio15 10” Coaxial Speaker which has an MSRP $8,190 with mix of black and white baffles, the Billie Amp is one fourth the price of the speakers.
Here is a secret of building audio systems; do not be constrained by the misnomer that you must fiscally balance the system to achieve the best sound. It is not necessarily to your advantage to pay approximately the same amount for all elements of the system, i.e., source, preamplification, amplification, speakers, and cable set. The primary consideration is the relative capability of the speakers to the rest of the components. At the lower end of the cost spectrum, buying speakers that are the same price as the components will severely curtail performance. As an example, if your components cost $1,000 each, buying a speaker that also costs $1,000 will most likely get you either an average quality bookshelf or a poorer quality floor standing speaker, neither of which will get you anywhere close to SOTA sound.
On the other end of the spectrum, matching premium speakers with ultra-expensive components is potentially excessive. As an example, if you were to spend $200K on speakers, you may achieve similar or even better results with components that cost half that much. At that price level, the speakers should be capable of SOTA sound, which for me is at a minimum 20Hz to 20kHz +/- 3dB. There is such a variance in performance of components, especially when mixing brands and models with different feature sets, that likely a combination yielding premium sound at half the cost of the speakers can be achieved. As expected, comparisons must be conducted to vet the systems. Perhaps half of Dagogo readers would subscribe to that direction, and half would be unhappy unless upscaling the entire rig.
This system building rule is amplified when considering a simplified system such as an all-in-one product like the Billie Amp. Because the Billie Amp performs at such an unexpectedly high level, it allows the budget to be skewed toward the speakers, allowing vastly higher performance than if a person were to spend an equivalent amount on speakers, DAC, preamp, and amplifier, opting for specification-constrained (especially in the low end) bookshelf or small tower speakers. Finding superior combinations is a matter of comparison, not guesswork. Having done the comparisons, I assure you that the Billie Amp is of a caliber that it is worthy of being paired with fine speakers, even ones that cost higher multiples than the PAP Coaxial 10”!
Does that decision to anchor the system with the Billie MK2 constrain potential upgrades? Not in the least. Since the Billie Amp offers flexibility in system configurations and is exemplary sounding in all those configurations, the audiophile can fearlessly upgrade speakers, then selectively advance the system with a dedicated component. As an example, while the Billie Amp was darling with the PAP 10” Coaxial Speakers, switching things around and using the Billie Amp as an integrated amp only along with the PS Audio DirectStream DAC Mk2 lifted the performance in terms of resolution and expansion of the soundstage. Same speakers, bigger, better result. Note that it took adding a component that is four times the price of the Billie Amp to achieve it! For some, that would be a worthy result, but for most the performance of the Billie Amp would be sufficient. My point is that this diminutive integrated is not to be construed as absolutely performing on a level of upper end components, but it competes very well with systems comprised of moderately priced separates that I have used.
Pros and cons of this rare gem
The Billie Amp MK2 is a rare gem, a retro-minded, thoroughly suitable contemporary integrated that has exemplary user features to enhance the ownership experience. No product is perfect, and there are a couple quibbles I have with the MK2. While the speaker posts are impressively robust, the RCA jacks are functional but unimpressive. Most owners may not use the Pre/Line output, but I did to connect my Perlisten D212s Subwoofers. The Pre out function worked flawlessly, and it allowed me to maximize my enjoyment of the Billie MK2 by building prodigious speaker systems. This is an exceptional feature, for few affordable integrated amps include a Pre/Line out function allowing for integration with an HT system. When I inserted an RCA cable from a less than 90-degree angle, the jack did not hold it with authority, but allowed the RCA plug to angle off slightly. I do not like RCA jacks that consist of thin metal sleeves over plastic housings. I urge Heaven 11 to replace these posts, even if it adds to the cost of the unit. No one wants a busted post, and trust me, I handle equipment with kid gloves. Yet, similar posts have weakened or broken if a too-tight fitting RCA cable is used. I fear for Heaven 11 regarding the brutes who mishandle equipment, and for Itai who would have to deal with their claims that the post just broke. Putting bomb proof posts on the unit is a win/win except for cheapskates, who would grouse about paying more for such improvements. Having said all this, I experienced no operational issues with the connections. Also, to be fair, most users will not be building multiple systems as I do.
The other caveat I have with the Mk2 is not a failure, but an operational idiosyncrasy associated with the VOLUME control. The overall feature set and operation of the unit is highly commendable, especially the programmable volume and max volume functions associated with power On/Off. The slightly off-putting oddity of the VOLUME control is that when the remote is used to lower the volume, it spikes momentarily before it falls. It is irritating when listening at higher levels, to reduce the volume and hear it burp upward as if someone quickly realized they turned the volume knob the wrong way. I do not believe I am imagining this phenomenon. Itai may wish to monitor it. Maybe it is a glitch associated with the attenuator employed in this build. If a similar quality attenuator without the momentary uptick could be found, that would be ideal. This is not the sort of thing that puts an end to my love affair with the Mk2, but it might be improved as a running change to the build.
That’s it for the negatives, but everything else is a positive! The aesthetics, build quality, nuanced operations like the winking tubes in warm up and mute modes, flexibility of its operation, and the succulent sound make this a no-brainer buy. It is the sort of product that if you have a well-worn system or a touchy speaker that could use some TLC, the MK2 is worth a one-month trial run to experience its form of beauty. My guess is it would not be returned to Heaven 11. Hobbyists who are on rung one or two and wish to climb higher should not second guess it.
As for me, the Billie MK2 will drive my Kingsound King Tower omni speakers. It will also see a lot of time with the PAP 10” Coaxial Speakers. But it will be in other nifty setups, too. It’s a little box with premium sound and with big system building potential, rare qualities in an affordable component!
Associated Components:
Digital Source: Bricasti M5 Network Player, Wireworld Starlight CAT-8 Ethernet Cable
Analog Sources: Realistic LAB 400 Turntable with Schiit Audio Mani Phono; Nakamichi CR-1A Cassette Deck
Streaming Music Service: Tidal; Qobuz
Interface: ROON; Audrivana
DAC: COS Engineering D1 DAC Plus Pre-Amplifier; Eastern Electric Minimax DSD DAC Supreme with Burson, Dexa NewClassD or Sparkos Labs discrete opamps; Exogal Comet DAC and PLUS power supply
Preamp: Kinki Studio EX-M1+ Integrated Amp (preamplifier mode)
Amps: Legacy Audio i.V4 Ultra; Kinki Studio EX-M1+ Integrated (amplifier mode); Exogal Ion PowerDAC (used exclusively with Comet DAC)
Integrated: Kinki Studio EX-M1+; Heaven 11 Billie Amp
Speakers: Legacy Audio DSW Clarity Edition; Kings Audio King III electrostatic speakers; Pure Audio Project Trio15 10” Coaxial version and Horn1 version; PureAudioProject Quintet15 10” Coaxial version and Horn version; Kings Audio King Tower omnidirectional; Aspen Acoustics Grand Aspen; Wharfedale Opus 2-M2 Monitors
Subwoofers: Perlisten D212s Subwoofers
IC’s: Iconoclast RCA and XLR Generation 2 with Ultra-Pure Ohno Continuous Cast Copper conductors; TEO Liquid Splash-Rs and Splash-Rc; TEO Liquid Standard MkII; Clarity Cable Organic RCA
Speaker Cables: TEO Cable Standard Speaker; Snake River Audio Signature Series Speaker Cables;
Digital Cables: Clarity Cable Organic Digital; Snake River Audio Boomslang
USB: Clarity Cable Supernatural 1m;
Power Cables: Clarity Cable Vortex; Snake River Audio Signature Series; Belden BAV Power Cord
Power Conditioning: Wireworld Matrix Power Cord Extender; Tice Audio Solo
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