Currawong reviews the ALO Studio Six

Currawong, Headfi's prim and knowledgeable moderator-extraorindaire, has, at long last, published his review of the excellent ALO Studio Six headphone amp. Generally, and with good reason, he is ecstatic. But without intending to detract from the original text, I will point out that while Curra and I both agree that the Studio Six is an unwavering delight of power and resolution for headphones, we each await an ALO Audio power amp. 

“The performance of the amp is so unwavering that even if one plugs 4 completely different pairs of headphones in, even IEMs, the performance through any single pair does not change in the slightest. The question I had at the end of it all was not about whether the amp is worth it, but why it didn’t have speaker outputs. Ken Ball’s reply to this question was to send me a custom cable with a headphone plug on one end and speaker banana plugs on the other.”

For those with short memories, here is what I wrote about the Studio Six.

Meridian prime time

Computer Audiophile's admin, Chris Connaker, has written up a beautiful piece on the Meridian Prime Headphone amp. More and more, Computer Audiophile have been writing about headphone amplifiers, proving that headphones are becoming accepted in the mainstream of audiophiledom.

“Meridian completes the hat-trick in 2013 with the release of its Prime Headphone Amplifier. First the Explorer, followed by the Director, and now the Prime. The Prime is truly the centerpiece for a great audio system. It’s well suited for the home or the office, for headphones or powered loudspeakers, and for digital or analog input. The Prime is a quality audio component in both sight and sound.”

— http://www.computeraudiophile.com/content/552-meridian-prime-headphone-amplifier-review-prime-power-supply-sneak-preview/

Colorware's Sennheiser HD800 and HDVD 800

Whether you send in your HD800 headphones and get Colorware treatment for 299$, or opt for a brand new set replete with Colorware's motley fingerprints for 1599$, there is but one reaction to the Senn/Colorware collab: whoa. (Channel Keanu Reeves to do it right.)

The Lego-dynamic duo also do the HDVD 800 headphone amp: post-sale whoa for 249,00$ or pre-sale whoa for 2099$. (Prices in USD.)

Whoa. 

Woo Audio's 234 MONO stuns Head-Fi

From their perch atop headfi's premier sponsor lounge, Woo Audio massage in the new 234 MONO headphone amp with tube switching key (TSK) tech that allows various power tubes to be switched out from the same socket. Perhaps more interesting is the fact that MONO is both a headphone amp and a speaker amp. Perhaps more interesting than that is the MONO's stunning organic design.

More details and rather fine photos at the MONO thread. 

Ω was rather impressed by their recent WA7 Fireflies. 

ohmage to the otomatsu BDR-HPA02 / Jaben balanced Beyerdynamic T1/T5P

Green thinking has kept automobiles out of my garage and garbage disposals out of my sink. It has forced me to master toilet paper origami. So when I say that my anus doesn’t generally pucker up when I hear about a new, hydro-sucking headphone amp, remember that I get by on two squares a day.

The flip side of all of that is simple economics. Headphone amps can cost a pretty penny. But after literally saving thousands of dollars on toilet paper since I was fifteen, and because the only tyres I buy new are for my Marinoni, I’ve begun to look more closely at investing in a mains-sucking amp for those carbon-footprint-be-damned days. Today’s subject, the rather top-flight Beyerdynamic T1/T5 and Otomatsu BDR-HPA02 combo from Jaben Japan, has piqued my interest because:

- It is economical.
 - It sounds damn good.
 - It comes with a Centrance DACport USB DAC.
 - No toilet paper required.

Think I'm shitting you? Read on.

Spec: 

Frequency response: 5Hz -80kHz 
Distortion: THD+N 0.0046％ 
Maximum output power: 1500mW x2 @45Ω / high gain
Headphone range: 16Ω - 600Ω High/Low ゲイン
Power: AC100V 50-60Hz 
Size: W230mm x D180mm x H80mm

The above spec list was taken shamelessly from Sasaki san’s amazing Music TO GO! blog.

Otomatsu BDR-HPA02 & Beyer T1/T5P: 248.000¥ (2.480,00 $US)

International users: refer to Jaben’s English website for details on how to purchase the combo for your country.

ohmage: haptics

The BDR-HPA02 is a simple machine. The front bristles with the bare minimum of audiophile flare: an aluminium volume pot, a couple of lockable Neutrik outputs, and a plastic power switch. The outputs come in the following flavours: 4-pin XLR, and 6,3mm stereo phono. The low-profile power switch feels great. Sometimes I fiddle that sucker on and off just for the pleasure of it. (My nipples explode with delight!) On the back, an ATX socket sits abaft the mains socket, a gain switch, and a single L/R RCA input sits abaft the volume pot. With the exception of the gain switch, ergonomically speaking, this amp is sound. It isn't, however, pretty.

ohmage: kitsch

There is nothing necessarily pretty about Beyerdynamic nor Aurora Sound. Evidence: heat sink styling, matte finish, camp stove volume pot. If anything, post steam punk minimalism ran amuck. Kitsch totally fled. Even the Beyer upgrade Cryo cable, a weaved tangle of savoir-faire, coils sombrely next to its mates. CMoy amps in gum tins are kitschier than this. 

ohmage and porridge: build quality and finish

Locking headphone ports, thick rubber feet, RCA jacks Titanically anchored in an Atlantic of aluminium and steel- these are the marks of a safe. Considering that you can force your way in with a good Allen wrench, the Otomatsu ain’t no vault. But its build quality sets it right in my carping eye. 

Beyer headphones are modular tanks. Take them apart, put them back together. A little scratch never looked so good. Destroying them takes a car.

As for amp finish quality...

This Oto - if I may call it that - looks like a garage project. Maybe it is. It is a little rough around the edges. (Indeed, fingering its edges a few times will sharpen your nails.) In comparison to its tasty power switch, the volume pot's mien is pallid. Its undamped, slightly loose action reminds me of a not-yet CLA’d Nikkor 28/2,8 Ai/S lens. It does the job, but it's not the lens you put on when the your camera geek mates come over to fiddle your film.

Onto the T5p and T1 mods:

Jaben’s T1/T5 wiring work is tip top. The mini XLR ports are perfectly capped and anchored into the headphones. The job is done so well, in fact, that I’m buggered as to why they don't licence their work to companies like Beyerdynamic. This can’t be the same Jaben that prints their amps with nonexistent websites, mislabels buttons, and on and on, can it? 

Sound

The T1 and T5 have been reviewed ad infinitum. Ergo, this section will focus on the Otomatsu amplifier. Where changes to the stock T1/T5 exist, they will be noted. 

Power

Both the T1 and T5 are easy to drive headphones. The BDR-HPA02 spits out enough voltage in low gain to burn the T1s and enough current to fulfil the more stringent requirements of the T5. Its output isn’t quite able to toast low-impedance planar-magnetic headphones but it certainly supplies enough power to get you into your very own Phonaks.

The BDR-HPA02's noise floor is pretty much even with pre-2009 iPods, if not lower. For a desktop amp, that is impressive. You may find that the output of your portable player or amp is even noisier. My Walkmans certainly are. Many portable amps, like ALO Audio's excellent Rx series, also output a noisier background.

For the record, both Woo Audio's WA7 Fireflies and Antelope Audio's Zodiac Silver have lower noise floors.

I can detect the barest hint of background noise via Audio Technica's ES10. That effect is compounded through Sleek Audio's CT7 / SA7. But there isn't a hint of noise with any proper headphone. 

At full volume and low gain, the BDR-HPA02 kept clean signals at the following decibel values via:

- Audio Technica ES10: BDR fed from 2V line out: 86-95dB with peaks over 100dB
 - Beyerdynamic DT880/600: BDR fed from 2V line out: 79-90db with peaks over 98dB
 - Hifiman HE-500: BDR fed from 2V line out: 79-90dB with peaks over 97dB
 - Beyerdynamic T1: BDR fed from 2V line out: 87-95 with peaks over 98dB

The BDR-HPA02 kept clean signals at the following volume settings and decibel values via:

- Grado PS500: from 2V line out: 86-93dB with peaks over 96dB @85% volume
 - Beyerdynamic T5P: from 2V line out: 82-92dB with peaks of 97dB @80% volume

The above merely illustrates that the BDR-HPA02 has power. 

• Beyer 600Ω DT800: set the volume pot to 50% for comfortable listening levels of ~75-80dB. 
• Beyer 300Ω T1: set the volume pot to 35% for comfortable listening levels of ~75-80dB. 

ohmage +1

Balance

The BDR-HA02 is a neutral-sounding amplifier. The stereo image is wide, especially when driving low current headphones like the T1 and DT880/250/600. It also favours no frequency band. It isn’t too wide. It isn’t too cramped. The most apt (and ridiculous) word I can think of to describe this amp’s soundstage ‘endless’. 

But even Kraftwerk must quit sometime.  

The DT880 and T1 are one thing; a portable headphone like the ES10, or a low Ω home phone like the ES500, is something completely other. When driving low Ω loads, the HPA02‘s stereo image audibly compresses. Mids step forward a little, high and low stereo detail tapers off. But I’m not about to bag that. The mixing, or relaxing of stringent channel separation can be a good thing if only because it is closer to what your ears naturally hear. It also helps that even under stress, the HPA02 doesn’t botch things.

Both the wide stereo separation, which is present under low current loads, and the more compressed stage care of high current loads, sound great. 

ohmage +1

Tracking

How about this question: can an amp that was designed to push enough voltage into a pair of 300Ω cans maintain requisite left/right balance normal listening levels? 

Yes. With normal to high-impedance headphones, balance is 100% perfect. 

How about IEMs?

Even when fed by 2-3V line level outputs, the BDR-HPA02 is able to sustain perfectly balanced signals at modest volume levels. Because noise levels are rather low, you can even enjoy the odd couple. True, your IEMs will force reproduction errors from the HPA02, but that’s never stopped eager audiophiles before. 

ohmage +1

Bass vs. Mids

Both the HPA02‘s single ended and balanced outputs spit flat signals. Grip, control, and wide spatial mapping are pillars upon which the HPA02’s output builds itself. Under the yoke of normal loads, bass never intrudes into the mids. Even when lower impedance headphones are plugged in, bass relinquishes control in only the minutest of steps. Oddly, upper bass and lusty mids get the nod under these circumstances. 

Yay?

I’ll say. No matter the headphone, the HPA02 plays smooth. It errs on the side of liquid rather than grain. I think it will have its fans. 

ohmage +1

Bass vs. Highs

Again, when driving high-impedance loads, both bass and highs step forward on even footing. Stereo width is enormous. Detail in all frequencies is top notch. Only when low Ω headphones and earphones are plugged in does do audible artefacts creep in. But at no time does this amp sound bad. 

ohmage +1

Vs. Low-Impedance

Output artefacting is gone by about 30 Ω, but in order to achieve peak performance, headphones with a minimum of 50 Ω input impedance are required.

porridge +1

Vs. High-Impedance

This amp is home with semi-high to high ohm headphones. It has plenty of voltage at low gain for all but the skankiest of wannabe-speaker headphones. It is limited only by current, and that, only when low Ω headphones are connected. Given the right headphones, hallelujah!

ohmage +1

ohmage: Balanced vs. single-ended

Both outputs appear to cover similar voltages. Both supply adequate channel balance. The killer point of this balanced system is that the tame little T5, and the somewhat powermongering T1 change hats a little. The first time I heard the Jaben balanced T5 I just about ate my headgear. Bass, closer to the DT880/32, wider stage. Control is similar. But that bass. Oh that bass. 

The T1 doesn’t get any more liquid, it just opens wider. Even my wife liked/loved it. For a time, she wouldn’t let me take it back. I passed by the T1s specifically because its midrange tends to dominate my favourite band, the mid-highs. Well, this T1 (at least with this amp) is a perfect beast.

ohmage +1

Today I powered through three sheets of Bounty and drank half a bottle of vodka. It’s one of those ‘be-damned days. It’s been a glorious couple of months with the BDR-HPA02 / Beyer system. Jaben have a good thing to sell you. You have a good couple of things to think about. 

Namely: if you have a system already, is it worth it to upgrade? I can’t say ‘yes’ here unless you are a collector. What about if you are getting into headphones, or are making the big step up to desktop audio? Absolutely. Newbies: don’t waste time and money on cheap, throwaway upgrades that you will upgrade again and again. Go to the limits of what you can reasonably afford and don’t look back. Don’t hamstring your savings, but invest for the long term. This HPA system is great. The inclusion of a DACport means that you can listen to your favourites from iTunes. Concurrent single-ended and balanced output allows you to compare and contrast the two. A package deal lessens shipping costs and obviates sea-saw decisions.

To top it all off, Jaben has stepped up. The craftsmanship they’ve shown in their cables and connection hardware is impeccable- I ain’t shittin’ ya.

ohmage: 10

porridge: 2

ohmage to the ALO Studio Six

Big things come in bigger packages. (And big packages generally must be scooted down the hall in push-pull spouse trains.) ALO Audio's debut desktop amp is leviathan big. Still, I managed to plop it on top of my HiFi all by my lonesome. There, at the summit of my living room, it perches from a spiritual position I believe it truly earns: the top.

Spec:

Headphone impedance compatibility range:
8 Ohms to 600 Ohms
Maximum rated output power:
1,000 milliwatts into 8 to 32 Ohms
Amplifier input impedance:
95k-Ohms

Amplifier input Voltage for full-rated output voltage into various headphone impedances:
1.00V RMS  input for 4.0V RMS output into   16 Ohms
1.30V RMS  input for 5.7V RMS output into   32 Ohms
1.70V RMS  input for 7.5V RMS output into   75 Ohms
1.85V RMS  input for 8.3V RMS output into 150 Ohms
1.70V RMS  input for 8.2V RMS output into 300 Ohms
1.65V RMS  input for 8.1V RMS output into 600 Ohms

THD+N (1kHz input) at 1V RMS output into stated load impedances:
32 Ohms: 0.26%
150 Ohms: 0.12%

THD+N (1kHz input) at 250 milliwatts output into stated impedances:
32 Ohms: 1.0%
150 Ohms: 2.0%

Frequency Response -3dB (Referenced to 1kHz, 250 milliwatts output) into stated impedances:
32 Ohms:   6.0Hz to 39kHz
150 Ohms: 16.5Hz to 36kHz

Frequency Response -1dB at full-rated (2.83V RMS) 1,000 milliwatt output into 8 Ohms:
15Hz to 20kHz

S/N Ratio:
78dB (unweighted) below full 2.83V RMS output into 8 Ohms

ALO Audio Studio Six: ~4.900$ USD and up

ohmage: haptics

The Studio Six pushes a Sasquatch-sized footprint into your HiFi station, but its interface is as easy as falling off a log. The front panel is graced by two large rotating knobs. The one on the left clicks between three positions which correspond to inputs. The glorious one to its right is the volume pot, which is as smoothly damped as a Leica lens. The bastard child of Rockwell and Knobfeel would glory in its silky, one-fingerable operation.

The back panel arrays gold-plated RCA inputs directly behind the input selector knob. A mysterious port dubbed Accessory Power Connection sits below. Opposite it are the volume switch and accompanying ATX port.

The Studio Six is single-ended, in and out.

ohmage: kitsch

Here at KitschWatch, we approach things like glitter, buffed plastic, chromed polyurinethane, and so on, with thumbs turned way down. My nose says that ALO, too, are anti-kitsch. The Studio Six is laser etched, bolted, and bent to precision. Its knobs are precise and damped, and its inputs are so firm in the chassis they are practically part of it.

ALO make one thing very clear: that you know this amp was made by them. It was designed and built in the USA, and it is made to last.

ohmage: build quality and finish

Hinted at above is a build that amounts to nothing less than ponderous quality. It is a quality that, on the one hand, conjures up the lastingness of a WWII German tank, and on the other, the iterative polish of a Leica M. Every piece is solid, perfectly balanced, and just as impeccably as it is produced, it is branded with ALO's now famous marque.

The power indicator in its silver ballast warmly glows in orange, matching the Studio Six's glowing valves. The knobs reflect light in gentle waning crescents. Even the bolts that secure the headphone outputs and RCA inputs are secured at the same angle. In photographs, the Six intoxicates.

Its balance between simplicity and utility is almost poetically Leitz.

Unfortunately, the Studio Six sticks out so much because the importance of beautiful and precise manufacturing has been supplanted by expedience and outsourcing. The non-artisan's motto of "as long as it performs well..." resounds in clangy, ill-finished lumps of metal and plastic, as devoid of unity as they are of vision.

At least they perform well...

Since the very beginning, ALO Audio instilled into every product the goals of craftsmanship and precision. And most of their line performs as good or better than the competition.

The one improvement I can think of is adding corresponding ticks to the input selector knob.

Sound: ohmage

Typical ALO amps can be divided into two camps: the benchmarker and the powerhouse. The Rx series forged new benchmark ground at its launch its inception, toppling many a top performer along the way. More recently, The International, and it similarly housed brother, The Continental, have impressed with power and warmth.

The sound of the Studio Six is a marriage of the two. It has limitless power, but on the other end, it is nearly limitless in headphone driving performance.

Power

If ALO's main aim was bragging rights, they nailed it. Studio Six supplies limitless power to the widest variety of headphones I have observed in a single full-sized HiFi headphone amp. High-ohm HiFi favourites like the T1, HD800, DT880, and Maddog, run flawlessly from minimal casual listening volume levels to maximal in-the-next-room-and-still-loud volume levels. At no listening volume does any headphones crackle or sizzle.

I have not tried the K1000 with the Studio Six, but I suspect it may have found its first non-power amp match.

More impressive is the Studio Six's ability to drive current-hungry PS500, LCD-2/3, HE-500, and their like, at any volume, sane or insane, with the same purity of signal. The is no audible nor measurable drop in output performance with any modern or classic home headphone. This trend continues on down the line until, at last, you reach inner ear monitors and portable headphones, whose high-current requirements take their toll on an amp that primarily is designed for home headphones.

The effect is a slight loosening of the Studio Six's otherwise tight frequency response. Low ohm portable headphones gain a slight boost in the 100Hz range, and armature earphones throw the Six off at the crossover level to the maximum of about 2dB at maximum. Put into context, such artefacting is laughable. The Six is better able to drive low ohm earphones than ALO's own Continental series of portable headphone amplifiers is. Ditto a large number of dedicated earphone amplifiers out there.

I ran a torture test consisting of the following array: DT880, PS500, HE500, SM2 (yes, those amp-killing earphones) and noticed no untoward current or voltage drops. Of course,  concurrent parallel playback of multiple headphones only makes sense when every model is the same. But the Six demonstrates that it an handle anything in any combination.

As for input power, you can basically hook up anything from an iPod to strong line-level mixing boards and should experience no input overload.

Balance

The Six spreads it power quite evenly. It has gentle low and high pass filters on either frequency extreme independent of loads. They measure at less than minus 2dB and start rolling off at 100Hz and 12kHz respectively. I don't think they could be considered audible without a rigorous (and placebo inducing) dose of measurebating.

Tracking

Personally, I find most impressive the Six's almost flawlessly ability to track between any headphone. Naturally, there is no detectable left/right difference for any typical HiFi headphone. Even sensitive IEMs track at usable levels. The volume pot, whose long gain throw allows fine left/right tuning is part of what makes this possible. The other part is the Six's overall modest gain that defers control and power to the volume pot.

Bass vs. Mids

Valve-based amplifiers tend to smooth out some details, preferring warmth and 'musicality' to minutia. The Six's clearest and most powerful frequency is its midrange where signal clarity and strength are best. Signal noise is very low for a valve amp. More impressive is the Six's ability to separate left from right with keen precision. Stages are vast, but not cutting.

Small details are clear but don't draw untoward attention. I found the Six loves live. Neil Young is probably one of its favourite artists. But the Six is no slouch when it comes to modern electronic music, either. Decent rise time puts it in good standing for trance, IDM, and double-speed John Denver discs.

Of prime beauty are chimes, high strings, cymbals, and the brassy, shimmering, strumming like. Bass is slightly less clear, bit its performance follows the same general principles. It is wide, fast, and able to resolve the important details. But by a hair, mids are king, and they are absolutely stunning.

Bass vs. Highs

These frequencies really are equal. Both contain a little more of that special dose of musicality that the mundane reviewer would read as valve distortion. There is no way around it: valves output more THD per volt than their solid state brethren. Those who like that distortion, like it a lot.

I have begun to prefer valves for live performances, and, more recently, for violin concertos and IMD Forum purchases. Why? Reality. Headphones tend to dissect things too much, unnaturally hiding left/right information, especially in complicated recordings. The Six doesn't cross feed channels, but the warmth from its valves smartens up otherwise too-headphoney of signals.

Vs. Low impedance

As mentioned above, Six is absolutely rock solid. Only very low ohm earphones can trip it up, and only just. Most valve amps throw good voltage swings but don't hold up quite so well when driving variable loads.

Vs. High impedance

Again, no problems here. The Six is more than able to toss around your least sensitive, voltage-hungry cans. I've encountered no headphone (or combination of headphones) that even remotely trips this amp up. It is more than capable of turning any headphone into desktop speakers. In fact, I am confident that the Six could run sensitive speakers with little problem.

Personal favourites are the Grado PS500, the T1, and the LCD-2, each of which sing so wonderfully through the Studio Six.  

The Studio Six isn't just an amp. It is a statement, that punctuated by precise engineering, utilitarian design, and excellent performance, has other amps blubbering. No, it isn't a balanced amplifier. It is The single-ended amp, tweaked and perfected. ALO proved yet again that they are not merely product designers. They are tinkers. They are engineers. They are artisans. And crowning their panoply of amps, cables, and more, is the Studio Six, an exact, performance-oriented amp which proves that ALO are in it for nothing less than to change the industry.

ohmage: 4

porridge: 1

Welcome Home ALO Studio Six

Little ol' me put up a new impressions thread at Head-Fi. The subject is ALO's Studio Six home headphone amplifier. It is priced at 4.900$ USD, making it one of the most expensive headphone amps out there. 

For the uninitiated, Head-Fi is an English-language resource for headphone fans from around the globe. It is also the largest of any such endeavours in any language. Its creator, Jude Mansilla, is clever and level-headed- the ultimate sort of geek. He also has impeccable taste in portable studio lighting. It is a dream come true to be featured again on Head-Fi's home page. (If you're keen, the other featured article was Ω's FitEar Factory Tour.)

Thank you. 

Anyway, back to the Studio Six. Several days after posting my impressions, Headfi decided to feature the thread on its homepage. The new feature system is clever: it focuses the entire HF population on articles the admins feel are important. When I go to HF, I tend to hit up two places: my messages, and the features section.

Why? 

Because when the "what's better" headphone war ends, that's where the party will be. And I'll be thumping along with the rest of them. 

As for the Studio Six, it will warm up Ω's office for a good month or two.  (I sort of wish it had been released in the Fall when temperatures begin to drop. July hot plus valve hot do not say summer fun as well as an endless supply of Corona and chicken wings.)

Let's get back to the Six. 

Unique to it are four headphone outs, run in parallel. Each one runs a lot of power. Power alone is naff. Sensitive headphones run well because the volume pot is almost perfect. Left/right tracking are spot on even at low volumes. Six runs nill-level signal noise, though valve hum does get into sensitive earphones.

For its intended use, however, WOW. Three letters. Horrible grammar. But 'nuff said. 

I've not finished reviewing this amplifier. I take care in supplying ohmage to gear I feel is worthwhile. If something is crap, I'll not even write porridge to it. Fully accurate? No. I'm nearly as human as the next geek- nearly. (My penchant for liquorice and Sambuca lowers my status as an organism- at least according to my dear, beloved wife.)

Next week, expect a full review from this mostly-human. It will hit these shelves sometime next week. It will basically say that I'm impressed. Not only is Studio Six beautiful to look at, it is nearly as perfectly designed as a large headphone amp can be.

And, it's made its way to Head-Fi's featured page - a home befitting such leviathan an opus. 

ohmage to the Antelope Audio Zodiac Silver

Three years ago, Zodiac hoofed it to the desktop audio scene with professional ostentation: five digital inputs, precise clock matching, iDevice-compatible USB DAC section, a good selection of analogue outs, and a historied name. Given Antelope’s professional CV, it was no surprise that they’d be thorough with their audiophile DACs. 

Specifications
 Up to 192 kHz sampling rate (only with USB & S/PDIF) 
Antelope Oven Controlled Clock with Ultra Low Jitter 
Built in 64-bit Acoustically Focused Clocking eliminates jitter from all digital inputs 
Anti-thumping Speaker & Ear protection on power up & source change 
Computer Data (USB), 2 optical Digital (TOSLINK), 2 coaxial - SPDIF (RCA). 
Stereo analog outputs – balanced (XLR), unbalanced (RCA) 
Dual-stage headphone driver architecture for superior matching with professional headphone coils 
Large volume control for analog outputs and a separate volume control for headphones 
Input select button easily toggles between inputs 
USB compatible with Windows 7/Vista/XP/2000, Mac OS X and Linux without driver installation 
PC/MAC/Linux software control panel 
Audiophile Power Supply (optional) 
Meets FCC and CE requirements 

Antelope Audio Zodiac Silver: ~1.900$ USD and up

ohmage: DAC functionality

Antelope Audio’s professional roots allow them to skip the skimp and deliver more than the typical USB and single-SPDIF input. Zodiac Silver duals up RCA coaxial and toslink SPDIF connections as well offering USB input. The best part about the latter is that it runs as close to plug and play as possible. Windows PCs, Macs, iPads - as long as you have the cable, you get audio. 

Sampling rate information is displayed on the large cyclopean LCD at the top of the Zodiac. Source input is controlled by depressing the source button. Cyclops will sync with the source, then give you its sampling rate. Switching is automatic.

porridge: haptics

Antelope Audio’s team need to be introduced to knobfeel. Both the big, analogue line-level knob, and the headphone output knob rotate loosely, rocking slightly back and forth before engaging. Camera lens aficionados will recognise the same wishy-washiness in Nikon’s line of cheap AFD lenses. 

Perhaps the biggest chink in Antelope’s otherwise well-designed armour is choice of knob sizes. Why adorn the front panel with two 6,3mm headphone jacks and advertise Zodiac as a DAC/headphone amp when headphone volume is controlled by the fiddliest control on the amp. The massive nose controls (of all things) the rear analogue outputs. All eyes are on it. It does its job (despite the wiggle), but draws far too much attention to itself. If Antelope had advertised Zodiac as a preamp rather than a headphone amp, such criticism would be nothing but hot air. 

But it’s not. Because the headphone volume pot is tiny, and off-centre, it is a bugger to turn. Blazes, I've perfected the art of swearing during this review. Antelope: if you’re going to market a device as a DAC and a headphone amp, make sure the control that is most often used is well suited to its purpose. And while you are at it, indicate  headphone output levels in cyclops. Thank you.

ohmage: kitsch

Forget blinkenlights, flash and trash take a back seat to comprehensible controls. Zodiac's brushed aluminium frame is elegant. Its digital lights glow in mature tones. Minus knob trouble, impeccable control layout. There’s virtually nothing to learn, nothing to scratch your head about, nothing that requires a double take (aside from ol’ big nose, that is). 

Antelope utilise small fonts, sparingly apply bolds, and balance the ink. While engraving would be welcome, the ink does its job. The choice of newspaper-style fonts isn't the best for desktop/HiFi audio, but let's be clear, Antelope designed a pricey DAC that looks, acts, and feels like the real deal. 

ohmage: build quality and finish

Bemoaning Zodiac’s workmanship is suicide. The Zodiac a solid box, with well-anchored ins and outs of all types. Stood against Woo Audio’s (admittedly cheaper) WA7, it laughs at Woo’s wobbly connections and jittery glass roof. there is more air in its packaging than necessary, but the core components: documentation, cables, power supply, are well padded. 

Zodiac’s guts are physically split into separate analogue and digital layers. The USB driver immediately pops up in your iDevice or computer's, labelled Zodiac, not speaker, or SPDIF. Irrespective of input, clock changes are accounted for immediately. There is no power thump in either analogue or headphone lines. 

The only oink in the ointment is a frail complaint at best: Zodiac’s lightweight design means that plugging in certain headphones will require two hands. The el-cheapo wall wart power supply does more to critically cheapen this otherwise wonderful package.

Sound

While primarily a DAC, Zodiac has a much-spouted about headphone amplifier. First, let's attack the DAC.

ohmage: DAC

The Zodiac DAC is yoked to a semi-aggressive low-pass filter. Highs plod a steep roll off from 12kHz to 20kHz. I'm not complaining. Low-pass filters proliferate in certain audiophile circles. Combined with high levels of harmonic distortion, certain aggressive low pass filters can soft and cushy. The Zodiac does not. It's not got enough harmonic distortion fleecify your favourite music. Despite the attenuation in the highs, Zodiac bristles with upper frequency range detail. Certain nuances may be toned down, but all the good stuff is there, and is lovely. Space between instruments - thanks to fast attack and decay times - is preserved, museum-grade. Placed in a grating, sibilance-prone system, Zodiac soothes.

Typically, systems with fast treble roll offs are hard to recommend for anything but relaxing, wine-sipping listens. Typically, those systems push harmonic distortion to plus levels. Orchestral music, chamber music, and even trance, retain all the speed necessary to render lively, accurate tones.

ohmage/porridge split: Antelope Audio’s low-pass filter is particularly well-implemented. It is stable and retains detail. But it still is a low-pass filter. Music lovers who want absolute reference sound will have to move on

What I expected from Zodiac was: unforgiving, gruesomely detailed, sibilant sound. Why? Because Antelope Audio equipment is used in large studios. Because their clocks are generally conceded to be extremely accurate. Because I am an absolute impostor. 

Detail, space, and vitality trot through every musical fibre the Zodiac has. While its overall sound is decidedly digital, it is digital in the best way possible: tight, fast, transients, clean decay and ascent - the DAC in this silver box ploughs effortlessly from genre to genre.

Bass is as acrobatic as mids, nothing is left lingering after the note has retired. In part, this lends to an impression of  lightness. Don’t let that fool you. Zodiac fully resolves the lows. It simply doesn’t smear them. 

ohmage: Zodiac delivers speed and space. No music will outpace it

Both the RCA and balanced XLR outputs are admirable performers. Systems with weak inputs will benefit from big nose’s accurate attenuator. In fact, Zodiac plays as well with  home HiFi setups as it does with portable kits. Tralucent T1 owners, ALO Rx owners, and the rest of you, balanced or unbalanced, Zodiac's attenuated outs allow perfect matching for all of your gear.

ohmage: the line attenuator is excellent. It should match every system out there, beefy or lean

porridge: headphone amp

However, not all is well. Despite boasting a wonderful pair of sheathed headphone jacks and a good amount of marketing impetus, Zodiac’s headphone amp section is only fair. 

Let's get the good stuff out of the way. Firstly, Zodiac's headphone output is as black as black can get. It surpasses the Woo Audio WA7, no matter how sensitive the earphone. In fact, it pummels most made-for-IEM portable headphone amps out there. Likely, you will more annoyed by the hum of your computer than you will any overt noise from the Zodiac. 

Secondly, channel balance is good even at low volumes, making IEM usage a realistic option. Slightly marring this IEM-friendly image, however, is Zodiac's aggressive gain. Even at a volume of 0, sound trickles through sensitive transducers. The gain only further emphasises this. Antelope suggest that you keep your source output high for best performance. Right they are. But IEM users should probably dial down their computer volumes. SPDIF signals often don’t have attenuating circuits. Grin and bear it, earphone folks.

porridge: gain is aggressive for sensitive earphones

The other issue IEM uses will face is audible drops in resolution and dynamic range. Zodiac simply doesn’t offer enough current into tiny IEM loads. 

Portable headphones of middling impedance: Audio Technica’s ESW11LTD and Fostex TH600, represent a sweet spot of sorts. Though restricted slightly, bass performance rebounds to near no-load levels. Gain and channel balance are right on. Zodiac only begins to strut its stuff after 50Ω. As is the case with many headphone amps, no-load levels of resolution are served by high Ω headphones of varying sensitivities. The DT880 600Ω matches the Zodiac’s penchant for detail and space. Sometimes, sibilance is the price you pay for a detailed-sounding headphone. Zodiac pushing, sibilance is a thing of the past. And the sacrifices are few. 

porridge: Zodiac’s headphone amp can't push great resolution into low Ω headphones or earphones of any type

Fed by even the most modern of recordings, Zodiac produces very little IMD when driving Beyer's 600Ω DT880 to 100% of its volume pot. On the opposite end, Zodiac's headphone circuitry isn't able to push the same headphone to speaker-loud levels as can the ALO National or International. Yes, those two are mere battery-powered headphone amps but they are designed ground-up for headphones, Zodiac isn't.

ohmage: voltage levels for high Ω headphones are amply supplied with current

First and foremost, Zodiac is a DAC. Serving up sound from a rush of 1’s and 0’s is a job it does very well. It has the hardware and software to support it. Sample switching and source detection are perfectly implemented. Even ol’ big nose is a great addition. This Antelope is detailed. Its fast signature is flattering all the time. At times it inspires awe. But Zodiac won’t replace your stand-alone headphone amp no matter how much you want it to. 

Maybe it shouldn’t. Discrete headphone amps are always best. Same with DACs. Same with power amps. Maybe this is Antelope’s attempt at steering the all-in-one-box-happy crowd back to reality. If so, good job. The DAC alone is worth the ticket. That you get a headphone amp thrown in is a simple kindness.

ohmage: 8

porridge: 3

RMAA benchmarks can be found here.