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What is the output voltage of the earphone conector?

Hello, i would like to know what is the output voltage of the iphone 5s earphone conector.

sorry for my english, i'm brazillian.

thanks

Posted on Sep 7, 2014 10:24 AM

Reply
13 replies

Sep 7, 2014 12:09 PM in response to iLeeo

I don't know the voltage, but I know that headphone jacks in general are often used to provide an audio feed to a "Line In' jack on a pc or other device for recording. (Don't use a "Mic" jack to "Line In".) I have a cassette/CD player and I take the feed out of the headphone jack into the "Line IN" on the back of my pc for recording from the player. It works well...

Sep 8, 2014 12:42 PM in response to iLeeo

iLeeo wrote:


Hello, i would like to know what is the output voltage of the iphone 5s earphone conector.

Here is a reasonably complete specification for the audio out (headphone jack)


The traces are color coded for the Left Channel and for the Right Channel. When they don't lie on top of each other, it's due to channel imbalance.

I loaded the CBS CD-1 standard test CD into iTunes as ALC files, synced my iPhone 5 via iTunes 10, and then played-out from the iPhone 5's standard Music app at maximum gain (volume) under battery power.


Output Voltage

Load

0 DBFS @ 1 kHz

200 kΩ

1.0158 V

600 Ω

1.0075 V

37.5 Ω

916.3 mV


Output Source Impedance

4.5 Ω.


Output Noise Levels

-106.8 dBV, A-weighted, playing zeroes (silence).

-116 dBV, A-weighted, idle.


Frequency Response

User uploaded file

iPhone 5 Frequency Response, 200 kΩ load, 1 V RMS output.

As expected, the iPhone 5's response is ruler-flat.

Let's expand the scale and look more closely:

User uploaded file

iPhone 5 Frequency Response, 200 kΩ load, 1 V RMS output, expanded scale.

Not bad; down only 0.01 dB at 20 Hz and -0.08 dB at 20 kHz, flatter than most labs can measure.

Let's plug in a headphone and see what happens:

User uploaded file

iPhone 5 Frequency Response, driving Ultrasone Edition 8 (32Ω).

The near-zero (4.5 Ω) output impedance of the iPhone 5 is much better (lower) than most dedicated headphone amplifiers, even most exotic audiophile amps, and therefore its response is not significantly affected by the headphones in use. Most dedicated amplifiers have about ten times the output impedance of the iPhone 5, and allow about a dB or two of false bass boost with the Ultrasone Edition 8. With the iPhone 5, the sound is accurate and well controlled.


Click here for full test results.

What is the output voltage of the earphone conector?

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