MINE!!! This is sweet! Is it tube powered? I suppose I could assume it is but I thought I'd ask to be sure. What's the estimated battery life? What kind of batteries does it use? Does it have a DC input as well for home use? This excites me!

Jason

If only 45v batteries were still in use. I know a collector that has a 3 tube pocket fm radio. 1.5v heaters and a 45v battery for the plates. 5 9v batteries might be a hard sell.

So Steve, is this only for 300+ ohm headphones, or can this be used with low impedence headphones as well??

Jason

Jason - It is not tube powered but I have taken great pains to voice it to sound more like tubes than solid state.

Terry - It is using Burr Brown Op amps, specifically the OPA2132 and it uses a pair of them.  They are socketed so it is possible to try a few others.  I prefer the FET input of these and the warm relaxed signature.  Unlike common FET op amps these are free from phase inversion and overload problems during high output. The particular ones I chose are $18.00 each putting them near the top of the list for expensive Op amps... but then when you want things to sound good...  ;)

Jason - It will drive headphones between 12 ohms and 600 ohms without issues. It will also maintain the same frequency balance meaning that certain impedances won't sound overly heavy while others sound overly thin.  In addition long cables can be used without problems. As you probably know the longer cables introduce higher capacitance and that typically has side effects but not with the ZenPod.



Jason - It uses a single 9 volt battery that can be accessed without having to unscrew stuff giving it an ergonomic advantage over all it's competition. Battery life is around 40 to 50 hours.  I have provisions for a DC adapter but not sure if I will implement it or not. Without getting long winded here, the sound quality pales in comparison to the battery.  Also, good old cheap alkaline batteries sound better then rechargeable ones.  The natural progression would be to have the unit charge itself while the DC adapter is used so many people would do that at the expense of sound quality.  This is another way the ZenPod outclasses its competition in my view.  It is an audiophile product,  not a bells and whistles item.

60 - I'm not going to say that can't happen, but I've been walking around with it in my shirt pocket for a week now and it's not happened yet.  Also the volume is a smooth increase, not super touchy so that helps.  You can put any 6 mm knob on it though, so if it were a problem for someone its a problem that could probably be overcome.

Looks like a cool little product!

I'm not sure I'm in the market for one.

But I just might buy some stock in a 9-volt battery company because Morph is going to go through them like water!  ;)

Giorgino,

Had the same experience.  The reasons are probably many, but in my experience the MAIN key is cross-feed. There seems to be at least a million wrong ways to implement cross-feed including not having it. A lot of these portable headphone amps are grossly over complicated... you know, press the button and hold for 3 seconds to turn it on for 3 hours,  press twice to turn it into a flashlight...  surface mount circuits with processors and DSP attempts at adjustable cross feeds, selectable gain levels, selectable impedance settings. Christ I just want it to work... woops got off on a bit of a tangent there.  

The cross feed is the key, and it must be done correctly.  The lack of cross feed in most headphone devices is why most people learn to hate headphones. Can't blame them either. Nothing worse then a total lack of imaging combined with super wide stereo effect that makes it sound like the music is playing inside your head. The cross feed circuit I use is the only one that to my ears works correctly and sounds natural.  And no I didn't invent it, just smart enough to try everything published and recognize what worked once I heard it. I still have to write the paper on it and probably should before I start selling these things.

You know when you've been listening to a good set of headphones on your head for 3 or 4 hours and literally have to force yourself to pry them off ...   that's good sound.   This is happening even with MP3's on an IPod!  The cross feed was the deciding factor in making this true.

Don't worry I'm going to make everyone listen to it at the DECFEST whether they want to or not.  Most won't want to because they've learned to hate headphones for the reasons I mentioned above.  They will likely be pleasantly surprised.  First of all, headphones are never better then what drives them.  When done correctly they smoke even my best stereo gear in the listening room in so many ways.  It is a real rush with this portable to hear sound that good and then walk outside and work in the yard while listening because something inside you says this should be impossible.



Steve

Steve Deckert wrote on 09/06/07 at 02:16:46:


How does the CSP2 handle this with its headphone output? I always wondered. Can these opamps possibly be in the same league?

buzz

Hi Steve,

How have you found using the mp3 player with the ZenPod.  Do they jumble around in your pocket?

Would it be worth supplying a small velcro strip to keep the units joined together?

I listen to my I-Pod while I'm on the train or in the car and often have the unit on my lap or resting next to me.  Having a method of joining the two may stop one of them being dropped or wires becoming tangled.

Simon

WOOT!

I'm interested!

No doubt there'll be matching a silver litz interconnect. Looks great - I'm game...
Steve - What price bracket are we looking at for the Zen-Pod?

Now, for some recommendations for great sounding portable head/earphones...

Jet-Lee wrote on 09/17/07 at 19:48:15:

Wow. It's great how we all have such different ideas of likes. Makes hifi very interesting and I guess that's why there are so many different products in the marketplace.

I hate that kind of "in the head music experience". It feels to me very claustrophobic and I feel like I've got a head-cold.

Any further thoughts as to the price point Steve?

Jet-Lee wrote on 09/18/07 at 16:53:02:

Are you serious in saying that people's different taste (likes) in hifi presentation is "unfortunate"? Are you therefore advocating a single way of presentation being the "right" one? Would be grateful if you can clarify what you mean.

I gotcha, Steve. Thanks!

Giorgino...What I meant was exactly as it's said. Unfortunately, the reason some poser businesses are in business is due to opinion and not fact.

The ZPOD is coming along fine.  I plan to put it in production after the fest.  Look for it sometime in late October/November.

Steve

Of all the sets of headphones tested with it, the Zen Pod refused to drive mine!  I asked Steve about this and he was unsure.  He tested them with 10ohm and 250ohm headphones, driving both just fine. However, my 32ohm headphones clipped the output.  He's looking into it.  However, I don't want to make it sound like a failure, or a bad product. On Steve's 250 ohm headphones, the difference between the ipod directly and the Zen Pod was astonishing!  The Ipod just didn't have the juice to drive em.  Volume all the way up was acceptable, but bearly. With the Zpod, however, there was plenty of volume.  The bass changed as well.  It took on an effortless quality, sounding more natural and smooth with more headroom.  Even on my friend's Sennheiser PX100s, the bass improved considerably.  We tried close to 10 sets of headphones of varying impedences.  The 32ohm Grado's were driven wonderfully.

As far as basic functionality, I suggested he change the headphone output to 1/4" for duribility reasons.  The volume knob and power switch were the only other functions and both were easily accessable.  The box was larger than the nano, but not huge.  I believe the same battery was in the unit for the whole fest and every time I walked up to it, it was on.  Steve estimated around 40hrs per battery, and it seemed very possible.  Changing the battery was simple enough.  The power switch was a little difficult to turn off, especially if you have large fingers.  It'd probably just take some getting used to.

Jason

That's the great thing about Decfest: people can test out new Decware kit and Steve can get initial feed back for further development before launch.

Indeed.

Here is the list so far re: headphones + ZPOD

Phones that it liked:

Grado RS1 / 32 ohm
AKG K27i / 35 ohm
SEN PX200 / 34 ohm
BOSE OE
SEN PMX100 / 34 ohm
MODA EAR BUDS / 15 ohm
BEYER DT770 / 250 ohm

Phones that it didn't like:

SEN HD485 / 32 ohm
AKG 701 / 60 ohm

Having had a few days to ponder it, I suspect these two phones are causing an oscillation.  

This is a rather high fidelity unit.  Had anyone listened to it on the tube output CD player vs the IPod,  I think they would have been amazed.   So the question becomes do we add more parts to improve compatibility at the possible risk of changing the way it sounds... or not?   I'll keep working on it.

I do like the idea of going to a 1/4 inch jack - for several reasons.  

Steve

if its designed as a portable unit id say most typical headphones likely to be used will have the smaller 1/8th jack?

stick with highest possible fidelity.and ignore the odd pair of phones that dont match.
.02 cents from me  :D

Thanks for the info morpheous85. No worries about the crossfeed/listening via CDP. You guys had such a lot of toys and distractions. . I have the Senns HD650 (good) , PX200 (ok but not special), AKG 271 (very good) and soon RS1. Hopefully, one day Stax Omegas or Senn Orpheus will be in the collection. There's a lot to be said for headphone listening with no issues of cabinet sound, room acoustics. crossovers etc. I suspect that I'll eventually move fully into headphones. It's just that darned acoustic melon effect from headphones!

Since reading Steve's thread, I've been reading up on portable headphone amps and there's a world of the stuff out there. Crossfeed and non and some with sub-miniature tubes. All fun stuff!

I really should get out more...  [smiley=waaaht.png]

BUMP!    :)



Jason

Has anyone tested this on a Shure SE530 (36 ohm)? So far Shure SE530 is my favorite travel phones with a MP3 player. I am really interested in buying something like this ZenPod, but I want to make sure it will work with my headphones (AKG K 701 seems to be already crossed out from the list. I also have Grado SR-60 and Grado SR-80. If those were tested as well, let me know).

I have a pair of SE530 and a Zune (has better sound than iPod), but I wanted to improve the sound of it and was looking for something like this. I tried out the HeadRoom Total BitHead and DIY CMoy pcoket amp. Neither of them which I was impressed with.

I thought about buying a CSP2 as a dedicated headphone amp for my office, using the computer/Zune as the source, but I think CSP2 does not like Shure SE530 or AKG K 701, and don't feel like forking up for a Senheiser HD650.

I am willing to be a beta tester.

I am welling to be a beta tester as well.