Like to bould a little portable headamp. Any sugestions?

Hi, after i reaized my great new Koss headphone needs some more power than my laptop and iPod are able to give, i thinking about building a little portable headamp.
I checked the sound with my HiFi which seens to have enough power and it was impressive.

Can anyone tell me how i can make a little headamp for portable usage?
It should be really small and parts schould be easy to get.

Tank you.


PS: Analog techinque is more or less voodoo for me. So i can not even estimate which parts or plan would be best. But i can solder... ;)
There are some headamp plans on the net. But they talk all verry technical. I'm looking for an answer like 'Build this or this its easy, good and cheap' or so. :)
 
You could try either of these designs. The cmoy if the simplest of the 2 but both are very simple.

I have built the a47 for my Grado headphones and the amp outperformed the headphone socket of an Arcam a85 (~£1000).

These designs are cheap, simple and pretty good considering the effort required to build them.

http://tangentsoft.net/audio/cmoy-tutorial/

http://www.feistworks.com/ben/a47/default.asp

I hope this helps.

Mike

PS. Very compact versions of the cmoy can be picked upcheaply on ebay. Search for cmoy.
 

jcx

Member
2003-02-17 7:38 pm
..
for basic info thru advanced projects go to http://www.headwize.com/

faqs, library projects, forums...

You need to answer a really important electrical question before deciding on a circuit and should view with suspicion any advice that doesn’t come qualified with the impedance of the headphones you want to drive

"cmoy" headphone amplifiers are simple unbuffered op amp circuits and few of the recommended op amps can drive low Z 16-32 Ohm headphones better than the iPod
 
Most Koss headphones are 60-250 ohms and should be driven easily by the designs I mentioned. The a47 was designed to handle more difficult loads (16-32ohms)

Deep-Thought asked for small portable designs using easily sourced components. Cmoy type amps are a great way to start diy amp building. They are so cheap and easy and will outperform most headphone outputs on 'hi-fi' amps IMHO.

Of course there are better souding designs out there and headwize is an excellent place to look.
 
Tank you. I will have a look for your sugestions.

Acutally it is a Koss Porta Pro which has 60 Ohms. Nothing verry big, but enough for the faint Apple products. :)

Any doubts about the MINT http://tangentsoft.net/audio/mint/ which also looks verry neat?
Here the "Choosing an Op-Amp" chapter seens to be more unspecific but in fact its verry depending on the market situation anyway.
 
Deep-Thought said:
Any doubts about the MINT http://tangentsoft.net/audio/mint/ which also looks verry neat?
Here the "Choosing an Op-Amp" chapter seens to be more unspecific but in fact its verry depending on the market situation anyway.

The mint is also a nice design. It incorporates buffers makeing it better able to drive difficult loads, and adding a bit of refinement to the sound. It does, however, involve a bit of surface mount soldering. This is not really hard, but it does require a fairly fine tip to your iron.
 
I think about put the amp in my wrecked old iPod case.
This neat device has a scroll wheel with a fork light barrier (I think 2bit graycode)

I like to replace the potentiometer with a digital potentiometer which i can control via the crohlwheel.

I'm sure there must be some decoder for a rotary encoder to a poteniometer. Any ideas which chips i can use?
I don't like to build a decoder by myselfe because i would have not many space left. A single chip would be great. :)