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What potentiometer to use as audio control in car stereo? Answered

Hello all

I am working on installing a tablet into my car instead of the original head unit. But since the tablet will be permanently mounted inside the dash, I have no way of turning the volume up or down on the tablet, therefore I need to install a potentiometer into the audio cable that goes into my amplifier. 

I have tried with a dual LIN 100kOhm potentiometer, which worked to an extend, but not as well as I had hoped. 
It did turn the volume up and down, but it couldn't turn the volume all the way down as I had hoped it would be able to.

I just want it to be able to turn up quite loud, but also turn all the way down, so I don't have to pause the music everytime I want it to be quiet. 

Cheers!

Mathew

Discussions

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Josehf Murchison

1 year ago

How did you wire in the pot 1. 2. or 3.

Click on the Image to see all three.

Answer 21.bmp
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Mat_HolmJosehf Murchison

Answer 1 year ago

I'm not 100% sure, as I have used this for reference as to how to wire it.

potentiometerradioshack01.jpg
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icengMat_Holm

Answer 1 year ago

If shield is signal ground input then it will work..

If shield is chassis connect and signal ground is different then it won't work !

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Josehf MurchisonMat_Holm

Answer 1 year ago

OK so you have 3 wires from your tablet.

One wire should go to ground.

The other two should go to channel a signal and channel b signal.

Channel a shield and channel b shield should go to ground.

Then the two inside pins should go to to the amp with a ground wire.

Like this schematic with three wires from the tablet and three wires going to the Amp.

Answer 21b.bmp
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icengJosehf Murchison

Answer 1 year ago

Sounds like a variation of # 1, because Mat said

he "couldn't turn the volume all the way down"..

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iceng

1 year ago

+1 to each D. J. S.

The way to get noisy turn static out of a used pot is to drop a bit of CarbonTetraChloride fluid into the wiper track of the pot, is all that I can add.

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steveastrouk

1 year ago

You need a LOG or audio taper pot as a volume control.

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Jack A Lopez

1 year ago

The phrase is, "worked to an extent". "extent" is a noun. "extend" is a verb.

Anyway, the signal coming out of your tablet is probably intended for driving headphones, and there exist potentiometers for attenuating headphone audio.

Some headphones come with a little thumb wheel potentiometer built into a little plastic bulge in one part of the headphone cable itself.

This instructable,

https://www.instructables.com/id/Universal-EarbudH...

considers a few different ways to wire a potentiometer, volume control knob, into a headphone cable.

By the way, if all you want is to know is the size (in ohms), and character (linear taper, or log taper) of this kind of potentiometer, I think I have a few of these heaphone-cable-lump style pots, in my box of dumpster-scavenged, broken headphones.

Upon request, I can put the multimeter probes on, one or more, of these, for to give you some numbers about their electrical characteristics.

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Downunder35m

1 year ago

Use a potentiometer with build in switch ;)
Getting hard to find these days but were and still are used in small analog and portable radios...