Sorta OT: Anyone have a layout for a headphone amp?

[markr04]

I have need for a headphone amp. Does anyone have a PCB layout for one? Or a link to one?

[littlegreiger]

General Guitar Gadgets has a headphone amp.
Here's the link: http://www.generalguitargadgets.com/index.php?option=content&task=view&id=134&Itemid=166

[markr04]

Thanks a lot! Do you happen to know how to mod that for 4 headphone outs?

[littlegreiger]

I don't know how to mod it for 4 headphone outs but someone here might.
Just curious but why do you need 4 headphone outs.

[markr04]

Just curious but why do you need 4 headphone outs.

So four people can monitor a mix/stage mix at once. Most headphone amps, aside from the Rockman-type units for guitarists, have 4-8 outputs for this purpose. Specifically, they're called 'headphone distribution amps', but most just say 'headphone amp' and, in my workplace, they're talking about the 4+ output type.

[littlegreiger]

I had an idea about adding more outputs. I think you could just add them by putting them in parallel. Just connect the tips of all of them together, and the other two lugs.  I'm not sure if this would work but you could try it.

[erix]

I have a bunch on my website:

www.hbci.com/~erix

Click the "Hi-Fi" link and then "Headphone Amps"

You can't just add output jacks on a single amp and expect it to be loud enough to hear. I would suggest using a simple opamp-based design for each output. This way each output has a seperate volume control.

An excellent btutorial on building this type of amp can be found here:
http://www.tangentsoft.net/audio/cmoy-tutorial/

Just make 4 of them and power them from the same source.

ok,
erix

[ezanker]

PAIA has a 6 output headphone distribution amp (http://www.paia.com/hda.htm).  You will find the schematic on the page.

Erik

[markr04]

I have a bunch on my website:

www.hbci.com/~erix

Click the "Hi-Fi" link and then "Headphone Amps"

That's a sweet site ya got there, Erix. Thanks for the link.

[Marcos - Munky]

Hey Erix, cool site, but there are some links that don't work.

[moosapotamus]

This looks like a really nice one...
http://www.cafewalter.com/ha1/index.htm

Also, a couple more here...
http://headwize.com/projects/index.htm

~ Charlie