[TheSatelliteGuy]

I have owned my zenhead for about a year now. I bought it because I had already owned a Deckware preamp. I have been more than happy and impressed with it's preformance, so when Steve he made a portable, I had to try it. 75% of my quality listening is portably, and I own ten world class headphone amplifiers. I am more than familiar with the signatures of these amplifiers and what the synergy is with the headphones that I use is with them. Typically speaking I walk my dogs for two to three hours a day, and this ends up being great high quality listening time. My collection of modified dynamic headphones are usually only used portably, where as in the house I listen to one of my Stax setups.

When I first got the Zenhead, for about a half an hour I was floored with what I heard. Sounds stage was very wide, the up down, side to side, forward backward sound reproduction presented a noticeable wow factor. But it quickly went into burn in mode and had veils of sound around it that kept it from reaching it's potential. I put it on a Mystic Marvel pink noise generator and every 24 hours checked it. After a couple of days it still sounded muddled, so I put it back on pink noise for a few more days. It started sounding a little better, but still was muddled. A few months went by before I tried to A/B it with an Icube, a Headroom portable, TTJV portable, an rs71a, and a XinSM4 Maxed and it just didn't have the shine that was originally there.

A couple of weeks later I called up Steve at Deckware and I told him what I was experiencing. He said that the pink noise limited the caps and they weren't preforming to the best of their abilities. He also added that to make it reach it's caps, I should finish the burn in for another 100 hours on CD's. I followed his advice and started a CD burn in. He said that the variation and change would push the caps back up to their limit, and that the pink noise only handled a certain range. He also added that this amp takes 500 hours to break in.

After 24 hours of burn in, I checked the amp using a pair of Ultrasome 780AOL modified and instantly much of the muddle had vanished was replaced by a much clearer rendition of what was playing. By no means world class, but encouraging. After another 24 hours and listened to the same Cal Jader greatest hits and noticed a separation that was bigger than life. Each individual instrument on the right and left side sounded as if they were coming from a separate speaker, and I could almost tell the distance from each instrument. I put it back on to burn in for another 24 hours and when I checked it again it had truly returned to the original characteristics that it showed before it went into the burn in stage.

After 3-4 hours of listening to the setup, I got home with a big smile on my face. I was just ecstatic with it's abilities. Hearing being a very esoteric thing, we tend to accept what is available test was to see how it compares to something else. I grabbed my Headroom portable, plugged it in, and took a listen to a test track. If world class separation was equivalent to a 4 min mile run, the headroom was at about 5 minutes. It ran a good pace but the separation did not compete with the Zenhead. The sound stage also did not compete with the Zenhead. Then I swapped the it with a Icube, once again the Zenhead was well outpacing it's competition.

When I plug my DX1000 into the Zenhead, I realized that for portable listening there was a great synergy here. It made the DX1000's into something that can keep up with my home headphone amplifiers. I own a Headroom Desktop Maxed-out, a Triode 35e, and a Triode 88se. Granted if these amps represented a 4 minute mile run time, the Zenhead represented a 4.4 - 4.5 run time. Not bad for a portable.

The only three portable headphone amplifiers that kept up were: the Xin Reference, the Ray Samuels RS71a and the XinMaxedout SM4. I can't really say any of these amps are better than the other, but they are all in the same class. All I have to say is simply the Zenhead runs with any portable headphone amp around as long as it is given 500+ hours of correct burn in time.

As far as the Zenheads signature is concerned I would equate it to the sounds that I heard in the barracks during the Vietnam War. The sound litterally reminded me of the component equipment that was coming from that era. Really impressive workmanship on the part of Steve and his engineering.

As far as I'm concerned the size of the amp is no problem because I do listen to a lot of CDs. Those of you that are familiar with the amp know that it is larger than the other mentioned amps, but when it is in a grip bag, you never know the difference. When I asked Steve if smaller was coming in the future, he said "I am dedicated to sound quality first." It runs off of one 9v battery and that holds it up quite well. It has plenty of power to push the 990s, Sun 650s, and every other over the ear headphone that I use.

In the end, the Zenhead is worth the time and effort that goes into the burn in process, and anyone who owns one that hasn't reached it's full potential, keep going. If you have any experience or constructive input towards this amp, feel free to post a reply.

 

[priest]

Thank you very much for taking the time to write this fantastic review. I have always been tempted by this amp, but I can't justify it given my limited need for portability. Given the equipment you have, your recommendation means alot, and I may end up coughing up the dough.

 

[ZenTriode]

Saw Satelliteguy's post above and thought this might be a good time to talk about burn-in.

All equipment, tube or solid state, needs to burn-in when it's new before it reaches peak performance. Some gear takes longer than other. Of all the parts inside an audio component, capacitors are the primary item that need burned-in. Specifically, the film and the dielectric that make up the capacitors have to "seat" before the time constant of the cap becomes stable. This process is the result of using the cap, and cycling it on and off for extended periods of time. The best approach is 5 hours on, and 5 hours off, repeated at least 5 times. This brings the caps up to temperature and then allows them to return to room temperature. This expansion and contraction accelerates the process.

Some caps take longer than others, for example, polyester film caps take much less time than polyurethane film caps (found inside the Zenhead) but polyester film caps, while smooth and forgiving sonically, do not have the resolution or focus of good polyurethanes. As a basic rule of thumb, the better the capacitors used, the longer they take to burn-in, and the greater the sonic reward.

Once caps (and other parts) have burned-in, they stay that way. The initial burn-in process does not have to be repeated for the life of the unit. However, if you let an audio component sit unused in the closet for several months, you will find it takes at least a few hours to get with the program.

Frequency balance, dynamics, clarity, focus, and sound stage are all effected during the burn in process. Each of these aspects will go from good to bad on independent cycles during the process. This is why something brand new might sound great for about 30 minutes and then become confused sounding shortly thereafter.

When Satelliteguy used a pink noise disc to burn the unit in, he unknowingly trained the caps to favor pink noise, which is not music. So on music, the unit sounded less than stellar. There are many burn in CD's available these days that claim to accelerate the process, and while they do accelerate the initial stage of the process, they will actually delay or even prevent the final stage of the process from happening. There is no substitute for real music when burning in an audio component, even it takes a bit longer. Be sure if you use some magic burn-in tool, that you finish the process with real music.

The Zenhead needs at least a couple hundred hours to get through the burn-in process. So does almost any other audio component that I've ever owned. The reason it seems like a big deal with the Zenhead is because of the transparency of the design. By the simple fact that it IS so transparent sounding, the difference between being burned-in and not burned-in is DRAMATIC. An identical product that was not as well implemented and with half the transparency would logically have only half as much difference between being burned-in and not burned-in. Or appear to take only half as long to burn-in.

Hopefully this helps people understand why things need burned-in and why the results vary.

Steve Deckert / DECWARE

 

[ZenTriode]

You can find more info on the ZenHead at this link:

Decware's Audiophile Product Page

 

[coryloew]

Hi there,

I have also had a Zenhead for a few months now. Not sure how many hours are on it, but presumably around 100 as I use it daily. Contrary to others, I typically use my Zenhead as a pre-amp for my main stereo system. My main source is an Ipod Classic with a Sendstation line-out adapter. Considering that I only use my Ipod Classic as the source, does this send enough voltage to the Zenhead to allow it to have a proper burn-in? Should I be using a higher voltage output from something like a CD player?

The clarity that I am getting from the Zenhead is excellent, but I do not typically experience this large soundstage(with headphones) that some people talk about. When using the Zenhead with headphones, I am typically using Grado SR-60's. I have the crossfeed set to off. Does using the crossfeed allow for a larger soundstage? I stopped using the crossfeed right away because it seemed to rob the music of some detail and clarity. Any thoughts?

By the way, this is another big recommendation for the Zenhead. It does wonders to my Ipod's typical sound.

Thank you.

Cory

 

[Skylab]

Nice review, SatelliteGuy. The Zenhead is indeed a very nice portable headphone amp.