Decware Zen Head portable headphone amp review

Discussion in 'Headphone Reviews' started by dalethorn, May 2, 2013.

  1. dalethorn

    dalethorn Active Member

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    Youtube review: Decware Zen Head Stereo Headphone Amp review by Dale - YouTube

    Summary: Outstanding sound, awesome build, excellent value retention.

    This latest edition** of the Zen Head amp is my first Decware product, so I'm not familiar with any previous editions or versions of this particular amp. That said, I've had very few hi-fi audio products that were hand-made as this amp is. My last such hand-made product was the Grado PS-500 headphone, and neither that nor the Zen Head were a disappointment. Since I've had disappointments in the past, I always brace myself for another one when ordering an unfamiliar item, especially if that item isn't an off-the-shelf product from a big seller like Amazon etc. No need for concern here though - the Zen Head is a very high quality amp, and from what I've seen in cases where users upgrade to a more expensive amp, these get snapped up pretty quickly and they retain their value.

    **Based on my experience in ordering the Zen Head amp and waiting for it, these amps are built to order, hence what you get is always the latest edition.

    The Zen Head is approximately one inch longer than the latest iPod Touch (5g) including the protruding volume control knob, and about 3/8 inch wider. The thickness is slightly more than one inch, so it's not as thin as some of the newer popular portable headphone amps, but it's still a low-profile box, so how well it serves for on-the-go portability depends more on how it's enclosed for carrying than its absolute size. The enclosure is a very strong aluminum - strong enough apparently to withstand being run over by an automobile. I will not be testing that feature myself - in fact I intend to take very good care of this amp, so if I upgrade to something else I'll get back what I paid for it.

    There are 4 things to note on the front panel besides the 2 screws that keep the internals attached to the outer case: 2 standard 3.5 mm mini-jacks - one for input from a typical music player headphone jack and the other the headphone output. The other 2 items are the heavy-duty on-off rocker switch and the power status LED (solid green when the battery has sufficient power). The mini-jacks are a tight fit for my cables, and from what I can see they'll take quite a bit of yanking with no chance of getting loose. Make sure you have good strain reliefs on your input and output cables, because you won't get any slack from the Zen Head's input-output jacks. The rear panel is a sliding cover for the battery compartment, which contains a standard rectangular 9-volt battery. One battery was supplied with the amp, and Decware recommends premium replacement batteries. I bought "Energizer Max" replacements for my use.

    Many or most of the newer popular portable headphone amps today contain lithium-ion rechargeable cells, and play time is usually quoted at around 10 to 12 hours. According to Decware, the better 9-volt batteries will provide about 50 hours of play time with the Zen Head, and the use of rechargeable 9-volt batteries is discouraged. I haven't tried rechargeable 9-volt batteries myself, but if I were inclined to do so I'd get the 8.4-volt** (not 7.2-volt) types, although based on the low mAh values I see, those might not provide enough power to operate the amp for a reasonable length of time, and changing batteries isn't extremely convenient. In fact, the slight inconvenience in changing batteries was probably intentional, to keep the user alert to the danger of attempting to connect the new battery backwards.

    **9-volt rechargeable batteries are typically 7.2 to 8.4 volts, following the convention for AA or AAA etc. batteries, where the alkaline cells are rated at 1.5 volts and rechargeables at 1.2 volts.

    According to Decware, a major design objective for the Zen Head was to eliminate every possible component or feature in the signal path that was not absolutely necessary to achieve high amplification with the purest possible sound. Power safety circuits that protect the amp's components from (for example) a battery connected backwards are also excluded from the Zen Head, so the above notes about inconvenience in changing the battery are a good heads-up. Fortunately, the standard 9-volt batteries used by this amp have terminals that connect only one way, so any attempt to connect the battery backwards would require not looking at what's being connected while pressing the battery terminals against the amp's connector panel (i.e., unlikely - mistakes shouldn't happen with this design).

    The Zen Head is supplied with a heavy plastic bag that will protect the amp from most common annoyances like dust and dirt, as long as the front panel is inserted first. There is no impact protection with that bag, but given that the amp is rated for automobile tire impact, that's probably not a serious concern. A 3.5 mm miniplug-to-miniplug cable is supplied, and Decware recommends connecting the headphone output of portable music players etc. to the Zen Head's input jack. I use a 3-inch FiiO LOD cable from my iPods and iPhones since the LOD bypasses the volume control of the iPod/iPhone, thus removing one more unnecessary feature from the signal path. Decware claims that the Zen Head was designed to work best from various music players' headphone jacks, and in cases where the headphone jack is the only output from those music players, that's a prescient design decision.

    To test the Zen Head's sound, I played WAV-format music tracks I ripped from my CD's, or in some cases converted from high-res downloads. When I started playing my first tracks I was expecting a good clean neutral sound, and that's exactly what I got. No disappointments. My intended application for this amp was to use with the iPod and iPhone, playing 'WAV' tracks and connecting to the i-device LOD (Line Out Dock), so the only other amps I felt a need to compare to were those that connect similarly and provide corresponding functionality. The other amps I chose were the new FiiO E12 and the v-moda vamp verza. The E12 is very similar in being strictly a headphone amp, while the verza is an Apple-compatible DAC plus headphone amp. The verza has an advantage in terms of its DAC, whereas the Zen Head depends on the DAC that's built into the i-device. But while the verza has that advantage, it likely gives up much of that advantage to the Zen Head in the headphone amp that follows the DAC in the signal path.

    I didn't find any huge differences between these amps, and of course a good amp should sound fairly neutral with well-behaved headphones. I didn't hear a major difference in the low end using these headphones: Beyer DT770LE, ATH ESW11Ltd, v-moda M100, and Soundmagic HP200. Differences were there, but all 3 amps had similar bass detail and impact. The high end was where the most important differences showed up with the 4 dynamic headphones I noted. After listening to the Zen Head for awhile and then switching to the E12, I heard a slight loss of spaciousness and high frequency extension, which are likely related. I expected an analogy between the Zen Head and the verza, but that wasn't exactly what I heard. The verza sounded slightly crisper as though there were more detail (but not greater extension), but I couldn't be certain of that because my application requires using the verza with iPods and iPhones, which limits the resolution compared to using the verza as a computer USB DAC and headphone amp.

    My summary of the above comparisons is: Expect the Zen Head to have a clean tight bass with great impact when the music source and headphone are up to the task. Midrange is no issue - it's completely free of any colorations or other annoyances that I can detect. Highs will probably be somewhat limited by the portable music players, but of course the Zen Head can be connected to a computer DAC which would relieve most or all of that limitation. The amount of volume provided by this amp will vary according to the headphone used, and also depending on how the internal toggle switches are set. Decware states which settings they recommend, and the following is my analysis and the specific settings I used in evaluating the sound.

    The Input Impedance switch can be set to 10k or 32k ohms, and the Interstage Gain switch can be set to High or Low. Decware recommends using Low with 10k and High with 32k, but my amp was set to 10k and High when I got it. I listened for a few minutes with that initial setting, and didn't hear anything that sounded wrong. The Output Impedance switch can be set to HiZ or LoZ, and Decware's description of these is: "HiZ is direct coupled to the headphone, and LoZ is capacitor coupled". Decware further states that HiZ should sound more neutral or lean/analytical, while LoZ should sound more spacious or lush. The 4th switch is the Crossfeed switch, which according to Decware is "Crossfeed done right". I don't doubt that they are in fact doing it right, because although I didn't hear an obvious difference with the few tracks I played with the initial settings (Crossfeed set ON), there wasn't a significant loss of space or detail either way.

    I can't say precisely how much background noise there is in the Zen Head, but with my favorite music tracks playing at substantial volume and then pressing pause on the music player, the amp is not only silent, but I have to advance the volume control from approximately 11:00 or 11:15 to 15:00 to hear the slightest noise. Whether you would ever hear amp noise depends on the volume of the music track itself and your high frequency hearing. Try this test: Pressing thumb and first 2 fingers together, rub those fingers back and forth against the thumb about 3 inches from each ear canal. If the sound (with dry hands) is like fine sandpaper with good high frequency content, you would have to have extremely low-volume music tracks to hear even the slightest noise. If the finger sound is dull, no worries.
     
  2. UKCoachCalipari

    UKCoachCalipari New Member

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    Question

    Hi Dale

    Not sure if you remember me from a few months back or so.

    I finally bought a e12 to pair with a IPOD Classic 5th which I am happy with.

    I got a deal on a Zen Head that I could not pass up on eBay. You may have seen the listing. The seller, which you probably know from the forums, also through in a Headstage USB DAC.

    Should I be content with this DAC or aspire for a FIIO X3 or X5 when released?

    What is a good DAC to go with the Zen?

    Do you recommend sending my Zen to Steve for updating?

    Do you think you will ever do an Apple iDevice Round-up for sound quality. I could swear that my 5th Gen IPOD Classic 30gb sounds better than my IPHONE 5, but what about the last Gen IPOD Touch that had the 30-pin? I favor the 30-pin because it seems like a cleaner cable run than the Lightning with adapter but that's just me
     
  3. dalethorn

    dalethorn Active Member

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    Hi - the problem with the many options is, to thoroughly review each combination would take years, never mind the expense. Ideally I like to have the DAC and headphone amp in a single enclosure, to eliminate the output wiring from the DAC, the input wiring in the amp, and the interconnect cables. If the DAC/amp is good enough, the shorter signal path will pay off in better cleaner sound. I use the iPhone5 and iPad Mini and latest iPod Touch with the FiiO LOD cable to the Zen Head for best sound. I also use the v-moda Verza DAC/amp that's Apple compatible. The Cypher Labs DAC/amps also support Apple i-devices. I wouldn't update the Zen Head - no point to that. If it works without problems, it's as good as it's going to get. I don't have an interest in iPod Classics ever since I found that they don't work as well with low-impedance headphones as the newer devices. The Lightning cables I have are as clean from the new devices to the Verza DAC/amp as the 30-pin from the old devices, so my guess is if you hear a difference it's probably an impedance difference between the old device and new devices.
     
  4. UKCoachCalipari

    UKCoachCalipari New Member

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    My next prospective purchase(s)

    Well, I am slowly moving up the latter starting with V-Moda's and a E12, now the ZH with a budget DAC. Since the V-moda M100 is great for my Bass-Heavy House/Garage/D&B, I suppose I should now aspire for a HP that favors Jazz, Classical, and Spoken word. You have touted the B&O H6 which I had on my shortlist even before your review. I read some luke-warm reviews which made me back off a bit, but my interest is now rekindled

    So in that price range, what is a good duo of HP's to pair with the Zen/E12 or is the e12 now redundant?

    I was thinking about selling the E12 to go towards a 2nd pair of HP, JLS Standalone ODAC or maybe a O2+ODAC Combo. I am not sure if Amps/AmpDacs are as specific to Audio Genres as HP's and a would like to maintain balance between my HP and Amps, maybe one combination is better for classical/Jazz, while the other is Housy/Techno centric.

    Does handling impedance matter when the device is outputing LOD?
     
  5. dalethorn

    dalethorn Active Member

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    I wouldn't trust the lukewarm reviews of the H6, unless you think the reviewer's reputation for advocating the highest fidelity is stellar. Very, very few are that way. I wouldn't use the E12 with a really revealing headphone like the H6 - kinda defeats the purpose. The E12 has more power than average, but the E07k or E17 (among lower-cost amps) would be better with the better headphones. Even better for the H6 would be a good USB DAC/amp. The O2 plus ODAC in a single enclosure should be totally neutral, and the best combo below $500 to $600 USD. DACs and amps generally have one (1) percent of the negative effect or genre-specific effect on sound as do headphones. The E12 moreso, but I don't have a technical explanation for that. LOD is simply a Line Out (as opposed to headphone out) that Apple devices have, and most other portable music players do not have a Line Out, which compromises their sound. The high-priced music players probably have Line Out ports.
     
  6. UKCoachCalipari

    UKCoachCalipari New Member

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