inline volume controller

[damiendmk]

Hey guys,

I wanted to build an inline volume controller, and this is what is came up whith. However, the volume is incredibely low (input from PC) and I only got sound on the left side. Furthermore, the sound is really distorded, it's like a low-pitched static noise from an old TV, you can barely make out what you'ree listening too. Also, the solder didn't stick to the wires very well. I was using standart apple earpods. I intend to use it from an apple tv (3rd gen) to some speakers that don't have a volume knob. I soldered 

[Enderman]

The wires are coated in an insulating resin or film or whatever you want to call it.

You need to sand that off the wires where you want to solder them together.

[Huntsman]

^ That, or solder for longer to try to melt the resin.

[damiendmk]

that worked. However, i got a different problem now: as soon as i increase the volume more than 2mm, i don´t hear any more voices. Is that a problem with the resistor or with my soldering?

[DragonTamer1]

You don't hear voices or you don't hear anything at all?

[mariushm]

The soldering is really ugly... and by design those potentiometers on cable will reduce the volume of the audio. And yeah, those cables have an enamel which insulates the copper wires and makes it hard to do proper soldering.

 

If you feel adventurous, you could build yourself a tiny audio amplifier with a chip that has digital volume control, to keep things simple and not affect the quality of the sound due to volume control. For example, you could use TPA6021 : http://www.digikey.com/product-detail/en/texas-instruments/TPA6021A4N/296-18249-5-ND/807039

It needs at least 4v to run, so it could work with 3 alkaline batteries or from usb power and it's super easy to build on a tiny prototyping board, and you can control the volume with just a simple potentiometer (a 1k or 10k or 100k one, between +v and ground and the middle wiper going into the

volume control pin.

Check the datasheet on that page as it has example circuit (you just don't connect speakers), you can buy all the other components from the page (all 0.47uF and the 10uF one can be ceramic rated for 25-50v or higher, the 330uF are electrolytic 6.3v or 10v or higher... the rest are plain resistors...super cheap.. 3$ for the amp IC , 0.5$ for the capacitors and resistors, maybe 2$ each for the stereo jacks if you want to buy them from Digikey, they have them all ... maybe 2-3$ for 3x AAA/AA battery holder  so about 10$ for a fun project.