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HELP! I need an awnser for my project Answered

Hello everybody, I would like to make a little divice that i could conect my telephone with true bleutooth and that at the other end of the divece there is a jackplug cable. If i plug that cable into a amplifier that it will play the music i send into the device. I tried to start this with my old bleutooth speaker. I took it apart and then conected the 2 cables that usally go to the speaker to a jack plug and plugged this one in my amplifier. And it workt only the music was really bad. so do i need to amplify this singnal or how could i solve this? the output to the speakers that go in to the jackplug are 3Watt. If i made it work im going to make a tutorial on it. Thank you, Mistercrazyboy21


Thanks a lot!! But I can't see that you are using resistors in the first instructable. Didn't need some?


4 years ago

I guess english is not your first language?

If I understand correctly you want to re-use an old BT speaker to feed the signal into a stero amplifier?

In this case you most likely use an audio input on the amp - they use a low voltage input of around 0.7V and require no real power.

You are most likely overloading the input, which in return causes the bad sound quality.


Depending on the impendance of your original BT speaker system you can try a resistor divider to feed the line input on your stereo amp.

For example:

Original BT speaker 3W and 8Ohm for the speaker.

With a pair of 4 Ohm resistors in series on each output you give the BT system what it needs but you would still have far too much voltage going into the stereo amp.

Since the BT speaker does not really need the full power output a resistor divider with a 10kOhm and 1kOhm resistor would work better.

The input for the steroa amp is taken off the 1kOhm resistor.
The circuit below is pretty low quality as it is only text but you should get the basic idea.

BT speaker + -----------
--------------- Line in pos

BT speaker - -------------------------- Line in ground


You are right, English isn't my first language. Sorry for the bad English you are right about what I thought. I will try your solution. Thank you very much!!!


If you need better quality and an adjustable input you can search for line in adapters.

In the old days they were pretty common but with all digital....

Anyway, if you have a multimeter use it to make sure the input to the stereo amp does not go over 3V, 2-24V would be good.

And you should use resistors of at least one Watt to be save from overheating.

When setup right you should only need minimum loudness from the BT speaker and the stereo amp does the rest.

If you need to use high volume levels on the BT speaker for proper loudness try to increase the resistor connected to the Line In.