Electronics Tech or Engineers

[radar doctor]

I need a circuit design that i can build that will allow me to tap audio off my speaker output jack and hear it in my head phones. . Audio . attenuator ckt????thanks to all who come up with the circuit. . I have access to resistors etc please no solid state devices??

 

[KBennett]

All you need is some resistance in series with the head phones. Try 1K to start with or just put a 100K potentiometer in series and you can vary the signal. You may want to put a capacitor across the leads on the headphone side of the resistor to limit the low frequencies. Try a . 1uF ceramic disc or similar.



Edit: The capacitor needs to go in series, 2. 2uf non-polarized or similar. Parallel will cut the high frequencies.

 

[NPloysa]

Originally posted by KBennett

All you need is some resistance in series with the head phones. Try 1K to start with or just put a 100K potentiometer in series and you can vary the signal. You may want to put a capacitor across the leads on the headphone side of the resistor to limit the low frequencies. Try a . 1uF ceramic disc or similar.



Edit: The capacitor needs to go in series, 2. 2uf non-polarized or similar. Parallel will cut the high frequencies.

Kirk I have no idea what you just said

 

[Rman]

what system are you trying to accomplish this with? You want stereo sound right? Taking the input to a single speaker will not give you this. You going to have to get into the head unit and if that's the case normally there's already a headphone jack available. Just asking for some more info.

 

[radar doctor]

Circuit design

This is MONO, son wants to take sound off a speaker and feed it to his head phones so he can hear his Guitar?/Any help will be appreciated. . We are thinking we can get the audio off a output jack that would feed another speaker , go into a Budd Box , through the attenuator circuit to his head phones. . We need the correct attenuator circuit so he can vary the sound for his head Phones... .

 

[Rman]

he's using a guitar amp right? Most of the ones I've seen have a headphone jack. Theoretically you could just use the speaker out, but you'd want to wire it so when using the headphone out, the speaker is disabled.



I'd use larger resistors, typical 120ohm resistors might not attenuate the signal enough... . perhaps something like 470ohm or even 1k would work better. Headphones are very different from loadspeakers and generally require different circuits to drive them.



What are you using to amp the signal? Does your preamp have an out put for a headphone amp... . this is the ideal situation to be in.

 

[radar doctor]

Circuit

thanks for the concern. . Ill try to explain it better. He has a Amp and Speaker combination. . On this unit there are two output jacks that will drive other speakers. we want to put a antenuator network on one of those output jacks and drive the headphones so he can hear what is coming out of the main speaker as he plays the Gitar since he would be using the out put of the unit to drive external speakers we would not want to turn off that jack output. I would think we could antenuate the audio down to where we could drive a set of head phones. . Hope this helps. I need the values of the resistors and how to hook them up? Say for instance i wanted to use a 68 K and shunt it with a 680 ohm , then would we want to take the output off the 680 for the head phones or maby use a pot in there some where??

 

[KBennett]

Here is a circuit that should work for your mono application.



You will not need a shunt resistor because the voltage will be divided between the potentiometer and the headphones. If you are using stereo headphones the left and right headphone speakers will have to be jumpered together and then attached to the output circuit.

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[radar doctor]

Circuit

Thank you KB, We will give it a try...

 

[Rman]

a simple volume control box would work good. Ultimately its the same circuit as desribed above, it wold be enclosed and mountable which would suit your application well. I remember seeing one on ebay the other day. I'll check again tonight and see if it's there still.