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EQUIPMENT FORUMS >> ZH1 >> Zen Head now available in a KIT
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Message started by Steve Deckert on 11/10/08 at 14:56:34

Title: Zen Head now available in a KIT
Post by Steve Deckert on 11/10/08 at 14:56:34

For the DIY headphone enthusiast we have made our Zen Head available as a kit (less the fancy machined chassis) at a substantial savings!!!



https://www.decware.com/newsite/diy.html

Title: Re: Zen Head now available in a KIT
Post by Hotsauce on 11/11/08 at 13:06:35

OK, I'm in on this.  Placed my order last night.  

Since I'm doing my own enclosure, I'm going to add Li-ion battery and charging jack.  Ideally I'd like to be able to charge it off the same mini USB that my phone uses, but the voltage is wrong.  

John C.


Title: Re: Zen Head now available in a KIT
Post by DPC on 11/11/08 at 14:49:41

Steve,

The link is no working.

Title: Re: Zen Head now available in a KIT
Post by Steve Deckert on 11/15/08 at 17:17:44

fixed the link.

:-[

Title: Re: Zen Head now available in a KIT
Post by JimR on 12/17/08 at 12:06:55

John,

How did the kit turn out?  I just ordered one the other day.

Did you ever try the Li ion batteries?  I don't know how well suited to audio Li ion batteries are as I've never tried them.  Thinking SLA and a good regulator myself.

Anybody know what the mAH rating of a typical 9v battery is?  I've got a couple of new 1.3 AH SLAs here that I'd like to put to use.  Obviously this will not be a pocket amp :D.

-- Jim

Title: Re: Zen Head now available in a KIT
Post by Hotsauce on 12/18/08 at 01:51:26

I'm in the process of soldering it up now.  

If you get one, do all the small resistors first, then the bigger ones, then caps and switches last.  

I'm testing every resistor with the DVM, my sight isn't what it used to be, the kit has 1K, 10K, 100K, and 100 ohm resistors, it'd be too easy to get them in the wrong spot otherwise.   I know some of you can read resistor values from accross the room, but not me.  

The chips will go in last.  Thats the only part I worry about a little, but I have a good soldering station.  

I expect to have it finished this weekend, and fingers crossed, working.  

John C.  


Title: Re: Zen Head now available in a KIT
Post by Hotsauce on 12/23/08 at 01:00:33

Pictures soon, charging camera.  

With the board completed over the weekend, I scrounged the house for a 9V battery.  No luck.  I briefly considered raiding my DVM, but resigned myself to walking to the store in the snowstorm for a battery.  

I had checked the build every step of the way.   I double checked the polarity of all caps, and checked that the little IC insects wre installed facing the right way.  The board in marked, but I checked the image of Steve's build as well.  I also had to look to see which jack was input.  I decided to add a dab of hot glue under the big cap to keep it from moving, and also where the battery wires attach to the board as strain relief.

I bought 2 cheap mini jacks, and soldered up a patch cord using some cat5 wire I braided.  I plugged everything together and clicked it on.  With the source off, the slightest background noise at full volume.  

I lowered the gain, and hit play.  Whew, it works!   I lowered the source, and turned the gain up on the board, trying to find a sweetspot.  I quickly decided my headphones sounded better with the impedance set to 32K.  Gain set to normal.  I have the crossfeed on now for the novelty of it, still haven't decided if I like it better on or off.    Still trying to decide what the 'compatability' switch does, but it sounds more open in position B.  

As far as how it sounds, its quite suprising.  Its a transformation.   It reminds me of listening on my big rig.  The amp brings forth a level of detail that I thought my portable was incapable of.  I have the source(Google G1 phone) down, and the amp up.  Bass has a tighter more natural balance than before.  The highs are neither rolled off, or in your face.  There is enough power now that I can't turn it all the way up.  

I'm still drawing up my chassis, but I'm tempted to tape 2 sheets of cardboard over it so I can field test it on tomorrows commute.



Title: Re: Zen Head now available in a KIT
Post by JimR on 12/23/08 at 02:10:26

Hi John,

Sounds great.  Can't wait to get started on mine.

I'll still be interested to hear what you have to say when you try the Li ion batteries.

-- Jim

Title: Re: Zen Head now available in a KIT
Post by Hotsauce on 12/25/08 at 13:09:34



The completed board.



Amp, G1 source, solder station, Koss Portapro, and Senn woodies.  

John C.  


Title: Re: Zen Head now available in a KIT
Post by Lon on 12/27/08 at 22:04:33

Well done!

Title: Re: Zen Head now available in a KIT
Post by Crazy Bill the Eel Killer on 04/05/10 at 18:49:27

Hello Steve,

I now use my Senn HD600's for 99% of my listening. I used to use my SE84 amp ( to great effect except for the hum issue I had, see my post in the ERR section for details on that ), and I'm now using my NAD 3020A since the SET is in pieces. But it's a little too bright for me.

So I decided I need a dedicated headphone amp, and everything I've read about your little gem convinced me that I need it. I've just got to decide whether I want the full kit or just the circuit board. I'll figure that out in a couple of weeks and give Devon a call to order. Which brings my inquisitive mind to the following.

This will not be a portable unit, so I am not constrained to the single 9v battery PS. I still think Iwant to use a battery supply, but I have two questions regarding the implementation.

IF I have to use 9v, I plan on stacking six 1.5v D cells in series to get the required 9v, and obviously tying the ground between batteries 3/4 to get the +- 4.5 volts you use. Is there any benefit to keeping the cap banks after the battery, or should I cut the circuit board traces and apply the +- 4.5 v directly from the batteries w/o caps ?

Second, since I'm not going portable w/ this, I'm not tied to the +- 4.5v supply. I'm not at all familiar w/ opamp circuits, and yours in particular, so unless you tell me I'll blow something up, I'd like to go up to a +- 12v supply and listen. Hopefully there's no technical reason that would not work. It would be fun to play around and listen.

Third, is a battery PS the cat's meow for circuits like this, or would a  diode based highly regulated +- PS be the ticket ?

Thanks for all of your help, and of course for putting this in kit form so nuts like me can play around.

Cheers,              Crazy Bill


Title: Re: Zen Head now available in a KIT
Post by Crazy Bill the Eel Killer on 04/06/10 at 15:11:39

Hey John,

Just noticed your Woodies. I've been playing around with closing off the rear of my HD600's after finding that website, and there is no doubt they bring a pretty substantial improvement to my ears. Haven't built an actual Woody yet, but shaped a pr out of cardboard and taped them to the rear of the earpieces to see how it might sound. It really brings, to my ears, a large improvement to the bass/lower midrange, and an increased sense of space and air. When I actually get some time ( yeah, in my dreams ), I've got some nice birds-eye maple that I'll fashion them out of. Would love to hear how you think they improved yours.

Cheers,              Crazy Bill

Title: Re: Zen Head now available in a KIT
Post by ddemy on 04/06/10 at 18:34:00

Hello Bill,
You may want to consider one of these 9V battery eliminators. It was actually suggested to me by Steve, durring one of our conversations about the Zen Head power options if not going to be portable; but still have the portable option available if ever desired in the future ...  Regards, ddemy

http://www.qcavionix.com/be-9ac.php?cat=20504


Title: Re: Zen Head now available in a KIT
Post by Crazy Bill the Eel Killer on 04/07/10 at 14:16:36

Hello ddemy,

thanks for the link, but it definately will never be a portable unit. If for some reason in the future I have a need to go portable, I'll just build another one. I just want to make my implementation of this circuit as good as it can be, and we all know that will be realized by the quality of the PS. I've always assumed that a battery PS would be the best implementation for an opamp circuit, but after doing some research on the Net I'm not so sure anymore. Theres a few highly regulated +- supply kits of very high quality to be had. I'll probably go to a different forum that specilizes in opamp designs and see what's there. If I find any usefull info, I'll post a link here.

Cheers,             Crazy Bill


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