Mini-Review: Mojo Audio Mac Mini Media Server

Spitting Bits

I’ve been using my trusty (dusty) MacBook Pro as a media server since I dunno when. Oh, right — since I retired my PowerMac G5, which means about 18 months or so. Way back in the day, I remember a lot of fuss and bother about the audio superiority of the PowerMac G5 floated by the Computer Audiophile crew. Namely, that it was the best thing since sliced bread.

Some folks, perhaps those that consider themselves more “objectivist” among the propeller-head crowd, may consider the very notion that a server would make an audible contribution at all as some sort of heresy. I mean, bits is bits, right? Yeah. Look — the whys and wherefores may be mysterious but as I’ve argued elsewhere, my lack of understanding doesn’t entail any particular ontological status.

So, before I go any further, let’s take a second and talk about why the computer might matter. Or not. Well, it’s not that the server doesn’t matter — it does — it’s just that some things have happened in the computer audio space that tend to make it all a little less important.

One is Asynchronous USB. Never heard of “async”? Hmm. Well, after you’ve done a quick tour, let me welcome you back by claiming categorically and without any serious justification that just about everyone has agreed that the spooling data into a DAC using the high-quality oscillators (clocks) in the DAC itself, instead of those in your crap-ass computer, is a better solution than relying on the clocks inside a computer. Async USB does just that, and a proper implementation does do wonders for the elimination of jitter, something DAC chips are notoriously sensitive to. Why this makes the server a little less important may not be terribly obvious, but here it is — a good computer design, with quality power supplies that regulate the CPU and other hardware — including the on-board oscillators — means that it will probably sound better than one without that good, quality power delivery.

My first DAC, a Cullen-modded PS Audio DAC III, was not asynchronous, it used adaptive USB (clocking came from the computer), and with that DAC, my G5 ruled the school. The combo was just more compelling than what I was able to get from my work machine, a MacBook Pro laptop, in pretty much every measure — scale, drama, detail, tone, blah blah blah. The difference in audio quality was clear and painfully obvious.

When I picked up my first asynchronous USB converter, a Legato from Analog Research Technology, the performance gap between the G5 and the MacBook narrowed considerably, though I pretended that the G5 was still clearly superior. It was easier that way. This became more difficult, however, when I upgraded to the Berkeley Audio Alpha USB, arguably the best-in-class USB to S/PDIF converter on the market. With the Alpha, distinguishing computer sources immediately became an exercise in frustration, especially when I added a non-stock USB cable, in this case, a fancy one from Acoustic Revive with the dual-leg/separate wire for power plugged into a USB-battery from King Rex. This completely removed the computer’s power supply from the connection with the rest of the system. As long as I had enough RAM on the system, I was good. I usually targeted 8GB — I don’t know if I needed that much, but Mac OSX always seemed to thrive with more, so why not. As for the why, well, I wanted enough to buffer a lengthy playlist (I’m lazy) of hi-res files.

Why the focus on buffering in RAM, instead of, say, spooling off the hard drive? Well, it has to do with “memory play” — all that stuff about power supplies also affects data retrieval off the hard drive. More paths, more CPU interruptions and more potential delays, to say nothing of the disk subsystem itself. With everything in RAM using the Pure Music audio player, I could ignore all that, and to good effect. Again, using the Pure Music “Memory Play” feature just sounded better. But using it also seemed to minimize the differences the two servers made in the system’s sound quality. Of course, I really only noticed the difference with some very large (hi-res) files, but whatever. So, with everything preloaded into the lowest-latency output portion of the computer (RAM) and fed to an external device that regulated all the timing, it turned out — for me — that the MacBook Pro was better than “good enough”. I honestly couldn’t tell the difference anymore, so I was ready to power down the big server.

As I started thinking about a more permanent replacement, my main concern was finding one that didn’t sound like landing aircraft (the G5 fans were … noisy). I settled on a MacBook Pro, in part because I was familiar with Mac OSX, in part because Gordon Rankin told me to, and in part because it didn’t need all the external bits that a Mac Mini needed: a keyboard, video/monitor and mouse — at least for configuration and troubleshooting. A MacBook Pro can be configured to kill the monitor output pretty quickly, in case that makes a difference, and I figured, compact is better than extra shit strewn all over the place.

I opted for the 13″ model, because it’s small, and got the cheapest one I could find. I swapped out the drive for an SSD, upgraded the RAM to 8GB, connected my old Firewire drive with all my music, downloaded and installed my then-and-still favorite player, Pure Music. Pure Music let me run my DAC in the then-cool “integer mode”, so I was off to the races. And all was sunshine and light. At least for a while.

Sometime shortly thereafter, I started running into the Widealabs Aurender at dealers and then at audio shows. Everyone was very impressed with its fancy oscillators, optimized OS, bright display and hunky case. I started to wonder if maybe, possibly, my off-the-shelf “server” wasn’t the all-that. Maybe I was missing something. Maybe I was missing out.

Doubts. They’re a pernicious bunch. Ah, the life and mind of an audiophile.

That was a year ago, and no, I never did get my hands on the Aurender. Honestly, I’m not sure I’m going to bother. The price on the entry-level S10 is $6,500+, rather daunting for what could be a relatively minor incremental improvement. I mean, I’ve heard that song and dance before and found that good software and a good converter pretty much made the server irrelevant. In light of that, $6,500 seems a little spendy — especially for a box that isn’t specifically designed to support USB as a connection to the DAC (the forthcoming W10, at $15k, is the Aurender that is optimized for USB). But who knows. Maybe it’ll be a “game changer”.

But the Aurender is simply the fanciest server-only solution I’ve run across. There’s a lot of other options out there, from Weisss, from Auraliti, and more — in fact, this segment looks like someone kicked over an anthill stuffed with aspiring entrepreneurs.

I’ve also heard reports of users getting big gains from modding what they already have, instead of ditching for an all-new front end. Like, say, swapping out the Mac Mini power supply for a linear PSU. Again, good clean power feeding the board could only yield improved performance and therefore improved audio quality, right? Right — maybe. But this is interesting. What if it did matter? What if you could take an off-the-shelf Mac and “do something” to it to level it up, not just a little, but to “world-class”?

Well, that’s what I wanted to find out. Enter, Mojo Audio.

Power Play

I met Ben Zwickel of Mojo Audio at CAF this year. Ben makes power cords, power supplies and fully configured media servers leveraging that most perfect of computer brands, Apple’s Mac. Having spent most of my professional life having to cope with Windows machines, I have a soft spot for Macs. Love ’em. Can’t get enough of ’em. I’ll never do Windows again, if I can help it — and no, Linux isn’t all that much better. Anyway, that’s why all the computer servers I mentioned above are Macs. Mac = awesome.

Okay, fine, yes — I’m overstating it for a reason. The reason? Apple’s iTunes. Is iTunes the world’s greatest music player? Probably not. But it is, arguably, the most important thing that has happened to audio since … well, since Napster. iTunes was a game changer. Think it was the iPod that made Apple the most highly valued company in history? Wrong. It was iTunes. iTunes is king — and it’s what even the most computer-illiterate wannabe/future computer audiophile is already familiar with. If you’re a prospective audio server modder, tossing iTunes out is, at best, a great way to miss out on the bulk of your prospective customer base. Yes, there are better clients. Audirvana, for example, makes your system sound better. But Pure Music is better still (my opinion, of course), and part of that happy-happy joy-joy on my part is due, perhaps, to not having to do anything to the terabytes of already-ripped CDs currently in my audio library. Forcing a happy, comfortable consumer into a new paradigm is, historically, a loser. So, why bother? I got iTunes!

Which is one reason I find the Mojo Audio solution interesting. It uses an off-the-shelf Mac Mini. It then takes that Mini apart — ripping out the stock switching PSU and replacing it with an on-board power-filter and an interface to an off-board, super-duper, linear PSU. And that’s pretty much it. Pretty much. The Mojo Mini is minimally configured — Audirvana is pre-loaded, for example, and pops up automatically after a reboot. So, a user simply selects some tracks and Bob’s your Uncle.

Ben sent me a brand new unit that I promptly hooked up (after I went and bought a $150 HDMI/DVI monitor — I already had a spare mouse and keyboard) and ran in for 2 weeks. After that point, I ran through my usual demo tracks. After some pretty exhausting (if not exhaustive) testing, I can jump right to the punchline — the Mojo Audio Mac Mini Server is the best computer source that I’ve heard in my system to date.

I’m annoyed by this. Honestly, I was hoping the differences, if any, would be small enough that I could pretend I didn’t hear them. I don’t want to have to get another server …. Anyway, that’s my problem.

So, before I get into details on the Mojo, let me say this — the level of improvement over my MacBook Pro is audible, even if it isn’t exactly “night and day”. This is becoming something of a common refrain, it appears, but then, marketing and hyperbole tend to have lunch on a daily basis, so perhaps that isn’t surprising. No, the difference is a bit more obvious than, perhaps, the difference between two power cords, but the differences do tend to fall along the same scale.

Tone is more fleshed out. It’s like that picture of the two girls I referenced recently. In comparison to the system fronted by the Mojo, when fronted by my laptop, the system seems bleached, a little lean, thinner. This is what was most annoying — I mean, it sounded fined — great, even — last week. Now, it’s meh, because with the Mojo, the sound feels more organic. Resonance and harmonics all seem more realized. Again, before you get all hot and bothered, I’m compelled to say that this is a subtle thing, and something that I didn’t key on immediately.

Reaching for specifics, the Stockfisch Records release of Chris Jones’ Roadhouses & Automobiles album is, in a word, wonderful. It has nice dynamics and is very clean, open and a pile of other adjectives that apply to recording and mastering (feel free to pick some at random, and chances are, they’ll apply). Stockfisch, as a label, really does a wonderful job with the sound quality of their product, so I keep coming back. The fact that I like the music helps, too, I guess. Anyway, I’ve talked many times about the low-frequencies that the Chris Jones disc develops, and how what I guess are the harmonics — when the loudspeakers are able to present them — really round out that low-end, producing a nice, threatening, moaning kind of rumble. It’s not just deep, it’s really full and deep. “Room filling” is one way to put it. “A 200lb Rottweiler with the neighbor’s cat” was another that I thought colorful, but useful. When the system get’s it right, that’s kinda what it’s like. Meaty. Threatening. With a little bonesnapping on the side.

When fronted by the Mojo, the bass just gets firmer. Not deeper, not fuller, firmer. Bloom, not boom. As if the strings on the bass were being struck a little more precisely, if that makes sense. On “Roadhouses & Automobiles”, those sweet intro guitar decays last a little longer, the cymbal strikes have more metal, and the crickets come “on song” across more of the song, and a little more obviously when they do. It’s not much. But it’s noticeable, though. Kinda like comparing the focus from a photograph taken with an f-stop of 2.8 and one with an f-stop of 4. The detail just goes a little deeper into the image, or rather, a bit more of it is in focus. Perhaps there’s less blur in the background. Perhaps the image stands out a little less. But, hey, is that a forest? I thought it was just a tree!

What I’m really trying not to say is this: “it’s like a veil has been lifted”. Gah — what utter nonsense. But I wouldn’t be surprised to read another reviewer put it just that way. There’s less noise, less grunge, less whatever obscura you tend to favor in your analogical soup kitchen of audio clichés. But, yeah. Just like that. The Mojo fronted system was just more resolved than the system was without it. It wasn’t life changing, but it was there. The question then becomes, is the mod worth it to you?

Mojo Audio has some options, though the website is a bit confusing, so let’s see if I can chart it out.

• Base price: $1,800.
• Full Monty: $3,200 (includes a new external linear PSU, the highest level of filtering available at each critical juncture, an audiophile-grade power cord, and all the RAM and SSD space your Mini can eat)
• External PSU only w/ basic filter package: $800
• External PSU w/Full Monty filter package: $1,200
• Remove Apple stock switching PSU, replace with basic ingress power filtering: $200
• Remove Apple stock switching PSU, replace with best ingress power filtering: $500

So, if I’m reading the site right, if you send in your fully configured Mini, for $1,700 you can get the best power delivery to that Mini that Mojo can make ($500 for the tear down and $1,200 for the new PSU). Alternatively, you can have them buy a new one and build it for you for more or less the difference in cost of the Apple hardware, with some nominal fee to do all the modding. Obviously, any of this makes your AppleCare policy pretty much useless.

Just an FYI, but as of this writing, Apple still doesn’t offer an SSD on the Mini — an upgrade that some audiophiles consider non-optional — so if you’re terrified of converting your new server into a shapely aluminum brick by following some online video DIY guides, this might not be a bad option.

If I were the kind of guy looking to get an edge over the current off-the-shelf offerings, a linear PSU modded Mac Mini is my kind of upgrade. I get to keep Mac OSX. I can use iTunes (if I want), or use Pure Music or Audirvana or whatever other player captures my imagination — and either use it or iTunes to manage my library. There are no fans, so the Mojo System is always dead quiet (something I can’t say about my MacBook Pro) and the thing never gets warm. You’re still going to need a monitor, a keyboard and a mouse, at least up until you get comfortable with doing some kind of remote control software — and there are plenty of options for when you feel like exploring. The Mojo is pretty much a no-brainer.

There are some other options out there, like the Paul Hynes PSU, but the mod from Bolder isn’t — the owner has stopped modding in favor of brewing craft beer (how awesome is that?!?). Anyway, I’m sure there are others out there doing this, but I haven’t any of their work to hand to do any kind of meaningful comparison. This is really the only thing that’s keeping it off my Most Wanted list at this point — I just haven’t heard enough of the competition to know its value. All I know at this point is that it is clearly better than what I have. And that’s saying a lot. Call it a “Challenger“, then, for now.

Okay, so that wraps my mini-review of the Mojo — two thumbs up! Wish I’d had more time with it, but it’s now has to wing its way to another reviewer. Just between us, I licked it before I packed it. That’s how I roll.

Associated Equipment

Mojo Audio Mac Mini Media Server, as tested

• OS X v10.7.4
• 2.3 GHz Intel Core i5
• 4GB RAM
• 120GB SSD
• Level 2 AC Filter
• Level 2 DC Filter
• Level 2 Internal Filter
• Enigma power cord
• Cost: $2,390.70

Testing gear

• Berkeley Audio Alpha USB to S/PDIF converter
• WyWires LiteSP AES cable
• Berkeley Audio Alpha DAC Series 2
• Wyred4Sound STP SE preamplifier
• Odyssey Audio “Klaus Special” monoblock amplifiers
• Joseph Audio Pulsar loudspeakers
• WyWires Silver v3 speaker cables
• High Fidelity Cables CT-1 interconnects
• Triode Wire Labs Seven Plus on amps, Ten Plus on preamp
• WyWires Silver power cord on “everything else”
• Stands, platforms, footers from Symposium Acoustics and edenSound Audio.
• Speaker stands from Reference 3a.
• Equipment rack from AudiAV.