Recommend a DIY headphone amp that will live on +4db?

[anticpunk]

Hey all,

I'm doing an install and the console has +4db cue sends, but no way for freelancers to directly plug phones in. The underside of the board has a good size cavity and there is a bi-polar 16V supply that is an easy grab. What I'm seeking is something I can build with minimal parts count, a single volume control and a single 1/4" stereo output to drive headphones.

There is an easy spot to mount the jack and control, just need a circuit that I won't have to worry about frying the first time it sees a decent amount of signal. Could be discrete or op-amp. Only criteria is +4db input, enough gain to drive headphones to a slightly-less-than-deafening level, and must run on not more or less than +/-16VDC.

Thanks!

Jay

[The Scum]

The totem-pole follower is the ol' standby, and easily swapped for whatever parts are handy. Many commercial adaptations of it through the years. See figure 11B here:
http://gilmore2.chem.northwestern.edu/p ... mp_prj.htm

The "Chu Moy" design is lower parts count, single (but more expensive) chip per channel.
http://gilmore2.chem.northwestern.edu/p ... y2_prj.htm

[Peterson Goodwyn]

The CMOY is barely a "design." Just run the inputs to a dual opamp and the outputs to a pair of headphones. Since you've got a bipolar supply handy you can even skip the virtual ground part of the circuit. With +4dB inputs you'll probably want a bigger value resistor in the feedback path for less gain, but that's about it. Simple as pie and should perform well!

The OPA2132 is kind of a pricey opamp, but any dual opamp should do. The NE5532 is $1.