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Simple audio jack question

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jenniferkpj

New Member
Hi everyone. I am trying to test my audio jack. It's a 3.5mm TRS audio jack. There are five pins on the audio jack: 1) Ring shield, Ring, Tip shield, Tip, and Ground. I tried using a sine wave (500Hz) generated by a function generator and send it to the tip; then I connected the rest of the 4 pins to ground.
However, I did not get any output from the headphones. I tried leaving the 2 shield pins floating, and just connect the signal to the TIP, and put Ring to ground, it didn't work either.

Is it possible to get an audible signal out of a sine wave generated by a wave generator? I thought headphones are similar to a stereo that the headphones should convert the electrical signal to audio format.

Would it be possible that I might need an amplifier for the output?
My function generator doesn't let me set the power or current of the wave...only let me set the voltage.

Thanks!
 

MikeMl

Well-Known Member
Most Helpful Member
Try feeding the hi side of your generator to TIP, and generator ground to SLEEVE. Leave the generator ground on SLEEVE and move the generator output to RING1, RING2, Ring3. I suspect that your headphone is stereo. Regular stereo phones use Tip for Right, Ring for Left, and Sleeve for common. I dont have a clue what the other rings do.

Set your generator for a couple of volts at 1KHz. Even my 600 Ohm generator will produce some audio into 8 Ohm headphones. btw- the thing on the end of the headphones is called a PLUG. The thing it plugs into is the JACK.
 
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solis365

New Member
well the current would be dictated by the impedance of your load.

V=IZ

if youve got 8Ω speakers, then I = V / 8Ω
what are you setting your voltage to? if its not high enough then your speakers probably aren't getting enough power.

as far as I understand, the black rings aren't connections, just insulators. unless you have specific shielding connections, in which case its not a standard TRS. if you have separate shield connections for each line, then ground them all. if that doesn't work then find a manual on your type of connector and find out what the shields should be.

if they are stereo headphones, the longest connection on the plug (on the shaft, farthest from the tip) should be shield, and this should be grounded. the signal may be applied to either of the other two connections, one being left and one being right.


my guess is power though, so try increasing your voltage a bit, make sure you dont blow up your signal generator either, as some speakers can be just 2Ω... also, your signal generator and your ground connection should share the same ground.
 

jenniferkpj

New Member
Simple audio jack

Thanks for the replies. I used the audio jack from sparkfuns: SparkFun Electronics - Audio Jack 3.5mm

and I bought their breakout board for the jack:
SparkFun Electronics - Audio Jack Breakout

There's no SLEEVE for my breakout board...but a GND. I assume they both mean the same thing.

The input voltage I used was 10 Vpp...I used 5 Vpp and went all the way up to 10...I am not sure what the resistance of my headphones is...but I assume it to be either 8ohm or 16ohm. My headphones are common earphones...the small ones. Could this be a problem? Because the audio jack I bought is a stereo audio jack.....

I tried using your suggestions but still can't hear anything....
 
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Sceadwian

Banned
Most headphones are between 16ohms and 32ohms.
At 10Vpp you should be getting something. Try every combination of pins on your connector you may be using the wrong ground.
 
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