potentiometer help

tecmo super bowl · Post by **tecmo super bowl** » Sun Jan 14, 2007 9:04 pm

im rigging up some better speakers to listen to music through for my cell phone that will be running through the headphone jack, and i want to add a seperate volume adjuster on them in addition to the one on the phone.

i know i need a potentiometer for this but i dont really know what type to get or how to do this or anything at all about this and need some help

the speakers will be running through the headphone jack but wont be used as headphones, but like the speakers in a tv where everyone can hear

codeman · Post by **codeman** » Mon Jan 15, 2007 2:35 pm

There is a way you can use just a potentiometer to adjust the output volume, but you would only be able to adjust it down, not up. If you want some sort of gain i would suggest doing a google search for "op-amp non-inverting amplifier" Then you can replace one of the resistors you see in the feedback network with a potentiometer and you have adjustable gain

tecmo super bowl · Post by **tecmo super bowl** » Mon Jan 15, 2007 6:27 pm

i did what you said but only came up with some technical info that i didnt really understand, being new to this stuff

I thought you could just add a potentiometer on and it would amplify the signal but i guess i was wrong.

So just to clarify - what i need is a way to adjust an amplification, that i have to create, of the signal coming out of the headphone jack without modding the phone itself. And i need this explained kinda thoroughly cause i dont know what im doing and this has turned an easy soldering project into something more difficult for me

any comments to help me would be great, thanks

timmeh87 · Post by **timmeh87** » Mon Jan 15, 2007 8:24 pm

easiest solution: buy a cheap pair of computer speakers with a built in amplifier, plug into headphone jack.