Merging Hapi MkII multichannel digital processor

I've been running a 5.1 system for years. Recently, I expanded it to 5.3 with the addition of two more subwoofers. This system is manageable with one of my eight-channel DACs.

Even more recently, I dipped my toe into Dolby Atmos, which made it necessary to lash up at least four more channels. That was a big problem, since neither JRiver nor Roon can support and sync more than one output device at a time, and the multichannel DACs I already owned tap out at eight channels.

I turned to the Arvus H2-4D Renderer, which offers 16 channels of digital output over AES3 and 16 channels of balanced-analog output. This worked, but piping everything through the Arvus meant forswearing DSP, including DiracLive. I really needed a DAC with at least 12 channels.

The Merging+Hapi has been around for years (footnote 1). It's one of Merging Technology's professional audio converters, intended for studio monitoring, at recording sites and in mastering studios that employ Merging's Pyramix software, which supports DSD recording and playback up to DSD256. The MkII is the latest generation.

Merging Technology has first-class audio performance in its DNA. Its founder, Claude Cellier, formerly worked for famous Swiss audio maker Nagra Kudelski, where he played a key role in the design and development of the Nagra IV-S and T-Audio TC analog tape recorders. One need only scan the Hapi MkII's specifications (see Sidebar 1) to be impressed with their depth of detail and impressive performance of this unit.

In its base configuration, the Hapi MkII supports eight channels of input or output via AES3, ADAT, or stereo S/PDIF (footnote 2). Expansion slots allow you to add up to two plugin cards, each of which can support eight channels of D/A, A/D, or two-way A/D/A.

The DA8P board (above) provides eight channels of D/A conversion, with balanced analog output—so, two such boards support 16 channels of D/A conversion. It is capable of converting PCM up to 384kHz and DSD up to DSD256, with extremely low specified noise and distortion and wide dynamic range. A bonus is the high output voltage, useful in a system like mine where the DAC drives the amplifiers directly.

The Hapi MkII seemed to be the logical next step for me. Support for more than eight channels meant I could, when called upon, play back music in Dolby Atmos—though in these auditions, the music maxed out at eight channels. I was attracted to the idea that I would be using it to review other equipment with recordings that were recorded and mastered on the Hapi or its big brother, the Horus. As they used to say in the TV commercials, "I just had to have it!" So I bought it.

Don't worry be Hapi
As befits a serious professional device, the physical appearance of the Hapi MkII is severe, clean, and neat. On the front left are two blue-illuminated buttons shaped like nested pyramids. The larger button is the power switch; the smaller accesses the setup menu. On the extreme right are 6.35mm and 3.5mm (¼" and 1/8") headphone jacks. Adjacent to these is a knob that serves as both a rotary control for navigating the menu settings and as volume control. To the left of the knob is an OLED used to display menu settings during setup and the volume levels of the various channels. It is all perfectly functional and strikingly similar to its sibling, the NADAC+8 (footnote 3), which, in contrast with the Hapi MkII, is intended for audiophile use. However, the Hapi MkII lacks the graciously styled chassis and superior control ballistics of the NADAC. The displays are similar, but the Hapi must squeeze bars representing 16 channels onto the same OLED screen that the NADAC uses for eight. The Hapi MkII also lacks a dedicated remote control. All those issues can be resolved by accessing the Hapi's webpage with a smartphone or tablet.

Except for the headphone jacks, all the connectors are on the back. At the far right is an AC power inlet and a jack for an auxiliary power supply, intended mainly for backup. At far left are two optical jacks for ADAT or S/PDIF input/output, two BNC connectors for Word Clock input/output, a DB-25 jack for AES3 input/ output—eight channels of each—a DB15 connector for various sync functions, and a pair of RJ45 Ethernet connections. In between are the two expansion slots; on my Hapi, they are occupied by two DA8P boards, populated by more DB-25 connectors serving up 16 channels of analog output—eight on each board. The pinout of these is industry-standard AES59 (Tascam Analog). I used Mogami Gold DB-25-to-XLR snakes to connect these analog outputs to my power amplifiers.

The data source used with the Hapi MkII must be RAVENNA/AES67-compatible (footnote 4). In my system, this is achieved by running a MAD ASIO driver package supplied by Merging on my PC. The Arvus H2-4D Renderer mentioned above is another example of a RAVENNA-compatible data source. Any Dante (footnote 5) device is also compatible. Merging makes it RAVENNA-capable. The RAVENNA/ AES67 Virtual Audio Device (VAD) serves the same function for Mac OS.


Data arrives at the Hapi by Ethernet. At first I plugged the Hapi to a local Ethernet switch, shared by my PC/server and LAN. This worked, but I experienced frequent signal interruptions and excessive buffering. Merging says that RAVENNA operations do not demand anything from the network beyond 1Gbps capability; they add, however, that RAVENNA hogs (my word, not theirs) bandwidth, so they recommend keeping it on a separate LAN, apart from other domestic or studio operations. I have a managed switch on order. Until it arrives, I will connect the Hapi directly to my PC's second Ethernet jack with a CAT6a cable, creating a private domain. This worked.

Physically connecting the Hapi and server to the LAN is one thing; making the logical connections is another. This task has become much easier since my previous Merging experiences, with the NADAC+8 and Anubis. Partly this is because I have learned from those experiences, but most of the improvement is due to the fact that the Merging ASIO Device—"MAD" for short—is a greatly enhanced, more stable version of the earlier RAVENNA/AES67 ASIO Driver, and the Aneman tool, which allows the user to map specific channel connections among multiple RAVENNA devices, is more coherent, consistent, and better documented than before.

Still, the Hapi MkII is not "Plug-and-Play." The Aneman tool shows all the available devices. The user drags the selected ones into an active zone, shown in the upper left of Aneman's "Matrix View" (see image). The available inputs are stacked on the lower left, the available outputs are arrayed across the upper right, and the matrix of their intersections is at the lower right. The blue squares show the mapping of my PC server's source channels to the Hapi's output channels. The complete freedom to route the channels is especially useful for active multiamping of multiple multiway speakers or, as in my case, for the independent EQ of several subwoofers in a multichannel system. You can even route some channels to the AES3 or S/PDIF digital outputs rather than through the DAC, in case you're using active loudspeakers.

All this may seem intimidating, but it is manageable with a bit of attention and effort, and the setup is flexible and stable. If you need to reboot the server or the Hapi, this setup is preserved.

Up and running
Now that I set it up, as a 16-channel DAC with channels mapped, the Hapi serves as a 16-channel DAC—nothing more—so I have little direct interaction with it. JRiver or Roon serves as the user interface, just as before. Choose the album or track on the server and it plays without hiccups. Transitions between PCM and DSD are seamless. Once it's set up, it's easy to forget about the Hapi MkII.

That same, self-effacing character extends to the sound.

Let's begin with a recent recording of Robert Schumann's Kreisleriana, Op.16, and Humoreske, Op.20, performed by Jimin Oh-Havenith on an album bearing the title inSANE (24/96 5.1 FLAC download from Audite). The title probably alludes to the various mental disorders Schumann was diagnosed with during his short life, but no explanation is offered in the booklet. These are beautiful performances, presented in a close-up perspective but with an open acoustic ambiance. I was struck by the warmth, weight, and richness of the piano. Pictures in the booklet confirmed my suspicion that it was a Bösendorfer, recorded with a microphone array tightly clustered around the instrument. The recording venue was Konzerthaus Liebfrauen, a 500-seat concert hall converted from a Baroque church built in the middle of the 18th century, in Wernigerode, which is midway between Hanover and Leipzig in central Germany.

You can never know with certainty whether the playback of a recording is accurate unless you were present at the performance and possess eidetic acoustic memory, but via the Hapi, what I hear is a Bösendorfer right there where my center speaker sits and, by gum, it sounds as if I am hearing it in the hall I see in pictures.


Footnote 1: The name Hapi was originally used by legendary audio designer Bill Hegeman for several versions of his preamp.

Footnote 2: The base configuration would be adequate for users with eight or fewer channels and active, digital-input loudspeakers, such as the Kii Three, Dutch & Dutch 8C, KEF LS50 Wireless II or LS60 Wireless, or the recently reviewed JBL 4329P.

Footnote 3: NADAC is short for network-attached DAC; see Jon Iverson's NADAC report and my take here.

Footnote 4: A bit of pro-audio nomenclature: To interface with data sources, Hapi uses RAVENNA/AES67, an open-source audio-over-internet-protocol standard developed for the broadcast industry. RAVENNA is bidirectional and supports multicasting and proper synchronization: All devices on the network derive their own, locally generated media clocks from the network clock distributed with Precision Time Protocol (aka PTP).

Footnote 6: Dante is another audio-over-IP technology that is widely used in the pro-audio world.

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ARTICLE CONTENTS

COMMENTS
Auditor's picture

Kalman,

Very interesting review

This is perhaps a dumb question, but here it goes...

Do you know whether it's possible to connect an SACD transport or a universal player to the Merging processor? I'm thinking of transports or players that are still in production today.

The idea would be to have the possibility of playing the multichannel layer (in native DSD!) directly from SACDs without having to rip anything or buy downloaded files.

Thanks!

Kal Rubinson's picture

I have thought of one way. It involves adding an external box to accept the HDMI output from the Oppo and convert it to 4 AES/EBU (XLR) outputs. Such a box is one from AudioPraise (https://www.stereophile.com/content/audiopraise-vanitypro-hdmi-audio-extractor).

Another possibility is one of several devices from Meridian (even the old HD621) which are available (new or used) and which can easily be adapted to the task. However, I am not sure whether or not these will force DSD-to-PCM on the output.

Scintilla's picture

In order for this to work, you would need a translation layer between the output of the transport and the input of the hapi. An Oppo bluray player can output DSD into a device that can accept it. But the Hapi has a network interface. I think the easiest way to do this would be a software playwer like HQPlayer or JRiver which can accept the input from the Oppo via an HDMI port and then output to a network interface. I have used HQPlayer for playing CDs live like this from a transport and then back out to a network endpoint device that provides an input to my DAC. I don't see any way to just directly connect a transport to the DAC without this translation layer because I am not aware of any transports that will output over ethernet. You will literally need a computer in between the transport and the DAC.

Kal Rubinson's picture

Yes but, as you note, getting the DSD stream into the computer from a stock-standard disc player is the bottleneck. Sony has made it difficult to move DSD wherever you want.

Auditor's picture

Thanks to both of you for your replies!

I didn't think it was possible, but I was hoping there might be a (simple) option out there I didn't know about. It seems not.

jimtavegia's picture

I have an Sony X700 that has the SACD logo but it actually converts it to 44.1 pcm. Many are having major issues with the X800 model. It also has an HDMI audio only, but I am guessing that is for a Home Theater receiver with HDMI in.

georgehifi's picture

Don't get it. Why not get the product reviewed they make that suits Stereophile readers more.
Like this stereo/streamer dac.
https://nadac.merging.com/product/merging-nadac

"The 8 channels of the ESS Sabre ES9008S Reference D/A converter are merged into 2 channels for improved linearity, greater dynamic range and a lower noise floor."

Cheers George

Kal Rubinson's picture

You are right but we already did that.
See:
https://www.stereophile.com/content/music-round-77
https://www.stereophile.com/content/music-round-90-mergingplayer-pl8

georgehifi's picture

Stereophile is looked at by most/many of it's members I believe for it's measurements which are objective.
So then they can get a "feel" for themselves, if the subjective review is close to the money or not.

Cheers George

Kal Rubinson's picture

Agreed and, as here, now my occasional multichannel reviews now will treated that way going forward (where feasible).

Scintilla's picture

I do think that there are getting to be many more multichannel listeners and many read Stereophile. Kal is not an outlier, rather he is leading into the future of hifi here. But as I have previously noted a few times now, I think the Monoprice HTP-1 is a much better approach for playing multichannel and Atmos material than these free-standing DACs. It already has Dirac with an option for multi-sub bass control, and soon Dirac active room treatment. It employs state-of-the-art AKM 4493s, is quiet, extremely clean and sets up and works with so much greater ease. And because it is a full-featured HT preamp, also provides volume control and switching in an integrated package. It just doesn't do DSD in multichannel from a disc and that could have been the case but they didn't set it up that way. I transcode all my multichannel files in Roon to 24/48 for input and procesing by Dirac. And you get all this for $3999 plus software licenses. In my system, I run parallel front-ends for theater/multichannel and stereo and share the L/R fronts and amplifier between them. I switch the amplifier inputs between the two front-ends with a selector. Best of all worlds and a lot less involved than separates for the same multichannel functionality. As a bonus, I get a great home theater experience. I am waiting for Kal to catch up... :)

georgehifi's picture

"I do think that there are getting to be many more multichannel listeners and many read Stereophile."

If that's the case then maybe the name needs to be changed to "Multiphile" as I believe most dedicated here still have stereo as their main hiend system.
The surround sound sure for the TV in the loungeroom.

Cheers George

Scintilla's picture

So, multichannel isn't of interest to you. It is to many others. You are free not to enjoy multichannel without commenting on those that do or those that express interest in such products, George. You may as well tell the kids to get off your lawn from your porch...

georgehifi's picture

"George. You may as well tell the kids to get off your lawn from your porch..."

No you seem to be on it, going for the personal dig now, so you get off it.

Archimago's picture

"Stereo" from the Greek origins means "solid" as in presence, formed, hardness, concreteness, three-dimensionality.

I know, since the 60's with LP 2-channel, while we typically think of stereo sound as left and right, realize that since the 1940's some of the earliest non-mono playback systems have been 3-channels or more.

I don't think there's a need to change the name Stereophile even if in time there are more multichannel audiophiles!

Kal Rubinson's picture

I've been trying to promote that logic for quite a while. Seems always to be worth repeating.

Archimago's picture

Keep persisting Kal. It's important and IMO the future of audio.

Kal Rubinson's picture

I am trying. ;-)

georgehifi's picture

"I am trying"
http://tinyurl.com/2x35r59f

Without them the review is just subjective, might as well go read "Absolute Sounds" then for some poetic license

Cheers George

Kal Rubinson's picture

Hey, George, my comment was posted in response to Scintilla's post urging a wider/different coverage of multichannel.

...........and it's not your lawn or his.

georgehifi's picture

I cut my grass yesterday, we needed measurements on the http://tinyurl.com/yvqxrxve to keep the "reviewers subjective comments (you) honest", without them like I said it becomes an Absolute Sounds poetic justice type of trust me spend your hard earned money because I said it's good.

Cheers George

Kal Rubinson's picture

Cheers.

Anton's picture

Go, measure!

Nobody stopping you.

JohnnyThunder2.0's picture

you can spend some more time on sites where you agree with the editorial policy than this one where you troll every review with your know it all bs. Stop telling the people at the magazine how to do their jobs. Get a job of your own so we can troll that site. You are rude. Annoying. Hang out on ASR. Stop polluting our site with your trolling nonsense. You do it to every review. You have been called out as a troll on this site before. You're well known as a troll in comments sections and in forums. I wouldnt be proud of that honor.

JohnnyThunder2.0's picture

Find another site to troll. Spend all your days and nights on the ASR site. you do realize that you are in the minority here, don't you. All the major audio sites and magazines are subjective based. You just have ASR. There are no magazines for your kind. No one would read it. People dont read boring negative critiques. YOU BRING THE NEGATIVE. Don't bother. You're going to lose these battles because the magazine and its approach will not change. We like it as it is. Go away troll. ASR is waiting for you.

georgehifi's picture

Yet again just with personal attacks, instead of the topic, sure seems with those statements you make, you can't read/understand measurements.

hollowman's picture

I haven't read this review carefully enough perhaps ... but ... The multi-chnl capabilities of the Hapi device reminds me a bit of this:
https://www.stereophile.com/content/tony-faulkner-engineered-law-average...

Back in 1994, T. Faulkner did comment on combining channels to perform math averaging, down to two channels.
The lab metrics done by JA look outstanding!

Kal Rubinson's picture

I haven't read this review carefully enough perhaps ... but ... The multi-chnl capabilities of the Hapi device reminds me a bit of this:
https://www.stereophile.com/content/tony-faulkner-engineered-law-average...

Back in 1994, T. Faulkner did comment on combining channels to perform math averaging, down to two channels.

I do not see any commonality between a down-mixing algorithm and a discrete multichannel processor. If you do, tell us more.

shaynet98's picture

Kal,
I noted the use case for Atmos recordings and am wondering how you configured your system to allow Atmos decoding from PC?
Cheers!
SHayne

Kal Rubinson's picture

Although I referred to use with Atmos in this review, I did not actually include any Atmos content in it. I acquired the Hapi in time for the review of the Arvus H2-4DA decoder (Stereophile.com/content/arvus-h2-4d-multichannel-dolby-atmos-digital-processor) but I no longer have the Arvus.

In fact, I have no audio system at all at the moment because it is in storage while our apartment is being renovated. Further adventures with Atmos (and other immersive media) will resume when that is completed.

David Harper's picture

Good review as usual. Looks like you've stimulated some commentary and a little controversy here. Good man. When people don't have any important issues to concern themselves with unimportant ones become important.

Desertpilot's picture

Hi Kal,

I appreciate your investigation into equipment needed for Atmos/Auro3D music. I've been content with my ExaSound S88 (5.2 system) for a few years now. I've tried Atmos/Auro3D using 2L's BluRay discs through my Marantz AV8805 processor. It works but I am not so impressed enough to step up to the equipment reviewed here.

Side note: Brendon at TRPTK is releasing both discreet Atmos/Auro3D requiring a decoder and all channels in separate WAV format (huge files) that do NOT need a decoder. We are in a "golden" age for music recording/reproduction!

Marcus
Las Vegas, NV

Kal Rubinson's picture

Brendon at TRPTK is releasing both discreet Atmos/Auro3D requiring a decoder and all channels in separate WAV format (huge files) that do NOT need a decoder. We are in a "golden" age for music recording/reproduction!

Indeed! Brendon is releasing 9.1 (96kHz FLAC, Auro 3D) and 5.1.4 (352.8kHz WAV, Atmos) which are not really "all channels" but the mixdown to that layout. However, given the resolution and the spatial enhancement, they are good enough for me.

hollowman's picture

OFF-TOPIC: Stereophile forum gone? new
Submitted by hollowman on December 26, 2023 - 4:34am
This is the only place on Sterophile to publicly post on this SERIOUS issue/development with Stereophile.

Its long-time running Forum and all content seem to have been VANISHED.
Many of us have contributed time and effort into our posts in the Forum. For almost two decades.
It's OKAY for Stereophile to discontinue the FORUM as Stereophile deems necessary. But please leave the content in place. It's disingenuous to disappear it from existence without proper, public notice.

ChrisS's picture

...here.

Kal Rubinson's picture

????

ChrisS's picture

...

Kal Rubinson's picture

Silly exchange about a now-corrected typo is now over.

hollowman's picture

Freudian algo on that iPhone keypad! (now manually corrected)
Maybe a deliberate cosmic event to flesh out that troll, ChrisS, who read that post carefully and completely, picked out a typo, but weirdly neglects the elephant in the room.
The issue with the Forum is not a joke.
And ... Kal, you lost all your Forum posts and threads, too, over the last two decades. All that investment and effort. Poof!
So why should anyone post in these Comments section, henceforth, if all our content faces a similar existential threat?!

ChrisS's picture

With respect to T.S. Eliot

We are the hollow men
We are the stuffed men
Leaning together
Headpiece filled with straw. Alas!
Our dried voices, when
We whisper together
Are quiet and meaningless
As wind in dry grass
Or rats' feet over broken glass
In our dry cellar...

Anytime, anywhere, we all go POOF!

jimtavegia's picture

Of course with your extensive collection of SACDs I can see why when the digital industry seems to lack the will to keep hi rez alive. Thanks for all you do to keep us informed.

Peprita Heart's picture

Dear Mr. Rubinson ,

In your article there is a photograph of the Horus and Hapi in a rack . Could you please tell me who manufactures the Network switch underneath the Hapi ? If I missed it in your equipment list , I am sorry .

Kind Regards ,
Peprita

Kal Rubinson's picture

I do not know. That picture is a stock photo chosen from Merging and I did not use a switch during this review period. The physical connection between the server and the Hapi was a direct cable link.

The switch I am now using (described in my next review) is a Cisco CBS350-8. It is one of the switches that Merging recommends and for which Merging provides full installation instructions at merging.atlassian.net/wiki/spaces/PUBLICDOC/pages/4819248/Cisco+CBS350-8+Auto-configuration.

Peprita Heart's picture

Mr. Rubinson,

Thanks , I look forward to the review of the switch .

Take Care,
Peprita

Kal Rubinson's picture

I will not be reviewing a switch but I will be using the switch as part of the review setup.

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