Heaven 11 Billie MKII Integrated Amplifier Review

Heaven 11 Billie MKII Integrated Amplifier Review

This article first appeared in The Sound Advocate, a HiFi publication that offers “Sound component reviews and commentary For The Discerning Listener!”

Prices listed are in US$.

Since my band playing days were over, I sold most of my large gear to save space (and practicing in the house with 1000 watts of power was not conducive to a happy marriage). I now have a small practice amp with all the settings built into it, and it allows me to play when I want without needing multiple amplifiers, cabinets, or any other stuff taking up space in the house.

The ability to play my guitars and basses through the same amp while allowing the built-in DSP and app to find the tone and amplifier model I want to hear is excellent. It is light, small enough to set on a shelf, and does everything I want in an all-in-one amplifier. If I ever go back to playing live, I will never go back to the ugly, heavy amplifiers and cabinets I used before. I will choose something light, easy to transport, and sounds good. Sometimes, simpler is better.

In 2015, Heaven 11’s founder, Itai Azerad, faced a dilemma. He was showing his brother his new great-sounding amplifier, and while listening to it, his brother commented, “Yeah, sounds good, but I would never put that thing in my living room.” That was Itai’s a-ha moment. Sound is the most important thing, but if the product does not look good in a room, people will not want it. Itai had seen musical engagement plummet over the years. People in the ’70s and ’80s used to show off their equipment like a badge of musical honor. Today, non-audiophile people buy cheap Bluetooth speakers and sound bars to have sound in their homes without the distracting spread of boxes often associated with a hi-fi system. 

As such, Itai went on a mission to see why people had abandoned affordable, high-quality audio products in favor of these mediocre Bluetooth speakers and soundbars. When he looked at the products in the affordable high-end space, he saw a sea of me-to products that concentrated on features, menus, and unnatural V-shaped tunings (where bass and treble responses are purposely elevated, forming a V-shape on a frequency response graph) that destroyed the natural sound of music.

Another thing he noticed was that most of the amplifiers sold today looked more like cable boxes than supposed high-end audio products. As an award-winning industrial designer, Itai knew that to get people back on board with affordable high-end audio, he would have to make a product that enticed the sense of aesthetics and brought the natural sound of music to their ears.

The Heaven 11 Billie amplifier II was born to get people back into hi-fi and enthuse people who had never considered listening to their favorite music in a higher-quality setting. Itai employed the help of his engineers, Sylvain Savard and Denis Rozon, to design a musically engaging, easy-to-use package that both looked good and concentrated on musical enjoyment over features or screens.

Using a sound-first approach, they tried many different versions before finally landing on a combination of circuits that kept the essence of the music intact while allowing their amplifier to be relatively lightweight, run cool, and enable the amplifier to have the unique and appealing appearance that would attract younger music lovers.

Features and Design

The aesthetic design of the Billie was an exercise in keeping an industrial design that would be visually appealing while being more easily producible to keep the price down. Also, the aluminum body of the Billie is an aluminum extrusion that happens to be a standard size used in industry settings, so it is more readily available and less expensive than a custom cast piece. ( The MKII version reviewed here now uses Heaven 11’s custom extrusion made with T6063 vs the standard T6061 on the original Billie. This allows better heat dissipation and a better surface finish)

The company takes this extrusion in an anodized black or raw aluminum finish that is already visually appealing. All this gives the Billie a relaxed industrial vibe, all while keeping an elegant appearance. Heaven 11 then goes a step further and has their input selector and volume knobs customizable with different wood grains or stone materials, giving the Billie even more of an upscale appearance (my review sample was black with woodgrain knobs).

There are simple lights showing input selection and power. The front panel is straightforward, with a volume knob that also serves to turn the unit on, a source selector, a 3.5mm headphone jack, and a remote eye. This keeps things neat and keeps the theme minimal.

The back panel is equally as tidy as the front panel. Things are simply laid out, and include a mains power switch. These high-quality binding posts accept spade and banana plugs, two auxiliary inputs, a phono input labeled Vinyl, a Bluetooth receiver, and digital coax and Toslink inputs.

Itai and his engineers started the design of circuits inside the Billie with a very well-designed tube preamp section. They knew that tubes had higher measured distortion, but a tube preamp would have a higher musical engagement for this design. They designed a Mu-Follower tube preamp stage with 2 x ECC99 tubes [12BH7, 12AU7 compatible].

This tube complement has the benefit of using somewhat affordable tubes, with different tubes available for tube rolling, and the ability to use 12BH7 or 12AU7 tubes for different flavors. The other benefit is that preamp tubes are known for lasting years, unlike power tubes that only last a few years of listening and are expensive to replace. This allows the Billie to have most of the holographic and smooth sound nature of tubes without the costly servicing associated with power tube amplifiers.

Knowing they wanted to keep the Billie light and small, the design team used a newer class D amplifier section. While they realized that some class D designs had problems sounding natural and often sounded cold and sterile in the past, they also understood that with proper design, they could use class D’s transparency to allow the tube preamp section to shine. I have noticed this through my time reviewing multiple types of gear. Class D amplifiers have a transparency that will enable the sound character of the components in front of them to shine through.

In my opinion, competently designed class D amplifiers have this ability more than other designs. My reference Pass Labs X150.5 is a class A/B design that is pure class A for the first 15 watts. It has its own sound signature, and while my DAC and Preamp are heard in the sound, the Pass has its character. Class D mainly seems to be minus any real sonic character, and its smaller, less parts-laden designs let more sonic flavor through from your other components.

Heaven 11 chose the ICEpower 200AS2 class D module (upgraded from the ICEpower 125ASX2 in the MKI design). With its built-in power supply, this module delivers a power output of 120 watts at 8 ohms and 215 watts at 4 ohms. This means that the Billie’s preamp and power amplifier sections have their own power supplies, allowing for better efficiency and lower noise. Along with higher power output, the Billie MKII offers several upgrades over the MKI version.

  • TUBE LIFE-SAVER: MK2 automatically shuts off after 30 minutes of silence.
  • UPGRADED REMOTE: MK2 comes included with the new MK2 remote.
  • VOLUME: volume control has 4 times the resolution of the previous generation, resulting in finer increments. The 30dB increase in attenuation means a lower minimum volume.
  • AMPLIFIER MODULE: MK1 used ICEpower 125ASX2. MK2 uses ICEpower 200AS2. Output RMS power increased from 120W to 215W@4Ω / 60W to 120W@8Ω.
  • TUBE PREAMP: redesigned to operate at double the voltage, the new preamp has a similar sound signature to MK1 while minimizing gain variability from tubes.
  • HEADPHONE AMP: rebuilt around the TI OPA1622 chip, the MK2 headphone amp has better dynamics and higher gain (142mW@32Ω).
  • COAX INPUT: new this year, a coax input with a sample rate of 192k@32bit.
  • BLUETOOTH INPUT: featuring AptX HD encoding, the module has better range and is 5.1 Bluetooth compliant.
  • PHONO STAGE: upgraded capacitors. Comes with high-gain jumpers for low-output MM cartridges (2-3mV).
  • SWITCHABLE PRE/LINE OUTPUT: the PRE-OUT can be switched to a max output LINE OUT. Both signal paths pass through the tube preamp.
  • CHASSIS DESIGN: MK1 was made using an off-the-shelf T6061 alloy aluminum profile. MK2 is machined using the company’s proprietary profile made of  T6063 aluminum. The T6063 alloy has better heat dissipation, thermal conductivity, corrosion resistance, and surface finish.

When viewing the inside of the Billie MKII, I was impressed by the clean design and attention to detail. These are often missed with more affordable high-end gear (they focus on features, not sound), and I appreciate them. The ease of installing the Billie MKII in my system and getting it up and running made me wonder why I have all these boxes myself!


Once I installed the Billie MKII, I let it play for about a week, casually listening for enjoyment while letting it do its thing before taking it seriously. After the master power switch is switched on, you turn the volume knob to turn the unit on to warm up.

When I first sat down after that time to finally give the Billie MKII a serious listen, I was interested in whether the amp would live up to its pedigree or be just another pretty box. I started my review using the Billie as a purely integrated amplifier with my reference Denafrips Venus II DAC and PS Audio Airlens as my sources. This combination of streamer and DAC has proven to be a killer combination and allowed me to see if the Billie could give me all of the musical magic this combo can provide.

Black Label Society’s Sonic Brew(20th Anniversary Blend 5.99-5.19 is not your typical reviewer choice of material. But I have said it before: The song “Spoke In The Wheel” is a well-recorded track, giving me a sense of what the Billie MKII could bring to the table. With this song, it starts with a warmish recorded piano accompanied by the bass guitar and drums.

This track had the warmth of the vocals and piano that I know, and the Billie let me hear all the details in this track. The bass was impactful without calling attention to itself, as many V-shaped amplifiers do. The Drums had significant impact, and the Billie MKII allowed the crash cymbals to have the full-bodied sound I hoped to hear. My reference Spatial Audio M3 Turbo speakers have compression drivers that are very rich in the treble when appropriately amplified. Zakk Wylde’s vocals had excellent tone and detail, showing that the Billie MKII was a tonally-balanced amplifier.

This track is fun to listen to at louder volumes and allowed me to see how well the ICE module could handle being driven hard. Reaching a screaming 95dB, I was surprised at how composed this amplifier could be. Yes, at a certain point near the top of the amplifier’s power delivery, the class D nature of this design did show up. At volumes that all but drove me out of the room, I could start to hear the edginess in the highs and a little strain in the midrange. But unless you like losing some hearing every time you listen to music, the Billie MKII will handle anything you throw at it.

Moving on, I wanted to see how well the internal DAC inside the Billie MKII could handle this track. I installed the Airlens to the Billie MKII with a coax RCA cable to enable the internal DAC to do the conversion, and I was quite surprised by what I heard. The Billie MKII’s internal DAC uses an ESS SABRE32 ES9018K2M DAC chip, which is an older chip design but it proved surprisingly capable.

Some will say the company should have used a newer chip, but I will say this: a DAC’s sound is much more than the conversion chip inside it. The sound using the internal DAC had good tone and body, keeping a good portion of the soundstage and imaging my reference DAC produced. No, it is not as good as my reference DAC. The sound was slightly more brittle, and the bass did not have the depth and impact of my Venus II, but the built-in DAC’s detailed nature combined well with the musical and holographic nature of the tube preamp in the Billie MKII. Most people could be happy with the built-in DAC in the Billie MKII and not worry about adding anything.

But with the added auxiliary inputs, you could upgrade DACs at any time, and the Billie MKII will scale with that change. While testing the internal DAC, I connected my phone to the internal Bluetooth receiver on the Billie MKII to see how it performed. Knowing the limitations of this technology concerning sound quality, I was pleasantly surprised that the sound was entirely serviceable for people wanting a quick and easy connection method for background music or when they have parties and want to connect their phone for easy music navigation.

Next, I wanted to see how the internal phono preamp would sound compared to my separates reference, the Darlington Labs MP-7 and SU-7 combo. I played one of my Tone Poet classic jazz records from Blue Note, John Coltrane’s 1957 album (Blue Train), an excellent record and a fun listen. Starting with my Pro-Ject X2B turntable and Audio Technica AT33PTG/II cartridge, I used the Darlington Labs SU-7 as my step-up unit to bring the level up to where the Billie MKII’s moving magnet phono preamp could be used

Playing each track proved that the internal phono stage inside the Billie MKII complements the preamp section inside the Billie. The bass was clean and musical, the treble had good detail and air, and the instruments had good definition and placement on the soundstage. When I switched back to my Darlington MP-7, the soundstage width and image focus increased, and the overall sound was more prominent with more realism. This tells me that the internal phono stage is very good and will complement most people at the Billie MKII’s price level. But, if you have the itch to upgrade the phono section and go outboard, the Billie MKII has the quality to show you the difference

One thing I noticed while listening to the Billie MKII was that its low-volume performance is excellent. In my listening sessions, I tend to listen to the Billie MKII at lower levels than many other amplifiers I have had in this system. Some amplification gear needs to be at a specific volume to sound its fullest. I am unsure if it is the tube preamp section or the class D section, but the Billie MKII does low-volume listening rather well. I spent many sessions listening at lower volumes than usual and felt satisfied with my system’s level of detail and bass-treble balance. This is worth noting for late-night listeners who must listen at lower volumes.


Using my Venus II DAC and Airlens Streamer, I compared my reference Hegel P20 preamp/Pass Labs X150.5 power amp setup with the Billie MKII. I have often said that the super clean and muscular P20 preamp is a great companion to the harmonically rich and warmish-sounding Pass Labs X150.5 power amplifier. They complement each other well and give me the harmonically rich, muscular sound I love. Knowing that combo well, after I listened to it then switched to the Billie MKII, the difference in presentations between the two setups was interesting.

My reference Hegel/Pass combo does sound larger with a larger soundstage, but the difference is not immediately apparent. While the X150.5 gives the bass a rich and detailed performance with good dynamics, the Billie MKII delivers good bass impact but less punch. The details are all there, but the bass is a tad leaner and more about texture than impact. The midrange is excellent out of both amplifiers and while the Hegel/Pass combo has a lot of harmonic richness, the tubes in the Billie MKII are very present in the midrange. The Billie has most of the hallmarks of excellent tube gear in the midrange.

Guitars have great tone, while male vocals have good body and weight without being shouty or chesty in the bass registers. Female vocals seemed to hang in the air and sound magical with both combinations. The midrange is where the Billie MKII held its own to my much costlier reference combo. The treble was interesting as the Billie MKII had a very detailed and airy treble response, and only when driven hard in the treble did I notice that a class D amplifier was doing the heavy lifting. In comparison, the Hegel/Pass combo never strained and gave cymbals a slightly more realistic body, allowing a more realistic experience.

To my surprise, the Billie MKII did not suffer what many integrated amplifiers suffer from in its price class. Quite a few of the integrated amplifiers I have heard in the $2,000 and under class are clean and offer good power, but soundstage and imaging seem to be a second thought with the design. Instead of layering in the soundstage, they create a wall of sound that takes away from the natural layout of the players on the stage. My Hegel/Pass Combo does this excellently, and in a slightly smaller and less outlined way, the Billie MKII does it as well!

Another comparison I wanted to make was between the Billie MKII and the brand new Orchard Audio Starkrimson Stereo Ultra 2.0 DMC amplifier. My Hegel P20 preamp runs this 500-watt per channel beast, which proved to be a good combination and offered a very polished window to the music. I will be doing a complete review of this exciting new class D GaNFET amplifier in the next couple of weeks, so keep posted for that review.

Comparing the Hegel/Orchard Audio to the Heaven 11 Billie MKII showed that, indeed, the Hegel/OA combo is much cleaner and more detailed, but the retail price of the Hegel P20 is $3,500 and the Starkrimson is around $4,000. With a cost of $1,939, the Billie MKII held its own very well and had qualities that some enthusiasts might prefer. The Hegel/OA combo took home the win in the bass department with some of the best bass detail I have heard from an amplifier, aside from that of the Mola Mola Perca, which I reviewed earlier this year. The midrange was more of a fair comparison, as its tube preamp makes the Billie MKII sound rather beautiful in the midrange.

The Billie’s midrange was denser and meatier than the Hegel/OA combo, and the lower midrange had more body, bringing out more tonal accuracy in down-tuned guitars, bass instruments, and male vocals. The Hegel/OA combo was leaner and more detailed. This comparison will come down to what is important to you. Both choices present music effortlessly with excellent sound, but while the Hegel/Orchard Audio was an exercise in ultra-clean, effortless detail, the Billie MKII offered the more organic and soulful presentation.

In my opinion, if you could combine the fabulous tube preamp section in the Billie MKII with the effortless, clean, and detailed delivery of the Orchard Audio Starkrimson Ultra, they would have an absolute killer best-of-both-worlds preamp/amplifier combo worthy of about any speaker in existence.


I have been in this hobby for a long time. In my 40 years of learning all things audio, I have learned that spending big money alone rarely leads to audio bliss. The best approach is to take the time to choose components that complement each other, have sound engineering, and are made by manufacturers who keep their original vision of sonic excellence at the forefront of every design they make.

I think Heaven 11 is a company that has held on to its original vision of providing great gear at realistic prices that will get people excited again about music reproduction. In this vision, I say that Heaven 11 has succeeded, and for the price, I can’t think of too many products offering their level of musical performance in their price class. If you are new to all of this and looking for quality affordable audio, or a veteran tube lover who wants to get back to basics with a one-box solution that will give you much of the harmonic richness of a tube amplifier without the maintenance and high tube-replacement costs, the Heaven 11 Billie MKII is highly recommended by The Sound Advocate.

Review System:

  • Speakers: Spatial Audio M3 Turbo S open baffle / REL T9x subwoofer
  • Digital: Denafrips Venus II / Modified PC-based music server/streamer / PS Audio Airlens Network Streamer
  • Analog: Pro Ject X2 B turntable / Darlington Labs MP-7 and SU-7 phono preamp / Audio Technica AT33 PTG/ii cartridge
  • Amplification: Hegel P20 preamp / Pass Labs X150.5 power amp
  • Conditioner: PS Audio Quintet
  • Cables:
    • Iconoclast Series 2 SPTPC speaker cables
    • Iconoclast Generation 2 ETPC XLR cables and Gotham 4/1 RCA interconnects
    • Iconoclast BAV REL subwoofer cable

Heaven 11.com

HEAVEN 11 AUDIO | 207-7080 Alexandra Street, Montreal, QC H2S 3J5 Canada

Price: $1,939.00


  • POWER: 215 watts RMS @ 4Ω | 120 watts RMS @ 8Ω
  • AMPLIFIER: Class D ICEpower 200AS2
  • PREAMP: Class A Mu-follower, JJ ECC99 tubes (12BH7, 12AU7 compatible)
  • INPUT VOLTAGE: 120-240 V | 50-60 Hz (factory set via dongle)
    • 1 x Vinyl in (MM, 2mV-6mV)
    • 2 x RCA in
    • 1 x TOSLINK optical input
    • 1 x S/PDIF coax
  • WIRELESS INPUT: Bluetooth: aptX HD | AAC on iOS
  • DAC: ESS 9018K2M DAC | 192KHz-32bit
  • HEADPHONES OUTPUT: 1 x 1/8″ (3.5mm) 142mW @ 32 ohm
  • SPEAKER OUTPUT: 1 x speaker pair: 5-way binding post
  • DIMENSIONS (L X D X H): 14.25″ x 8″ x 3″ | 360mm x 204mm x 75mm
  • WEIGHT: 12 pounds | 5.4 kilos


  • Power cord
  • MK2 Remote

For more, visit The Sound Advocate, a HiFi publication that offers “Sound component reviews and commentary For The Discerning Listener!”

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