4 Pole Audio I/O Connections For Macbook Pro... Post: 302809377

Sponsored Content

Operating Systems OS X (Apple) 4 Pole Audio I/O Connections For Macbook Pro... Post 302809377 by wisecracker on Sunday 19th of May 2013 02:47:08 PM

05-19-2013

Registered User

4 Pole Audio I/O Connections For Macbook Pro...

Disclaimer:-

You take this information and use it ENTIRELY at your own risk.
I and this site hold no responsibility for any errors either in this text or with your electronics capabilities...

The reason I have given this away is/was because I needed an audio input for a simple MacBook Pro
Python Audio-Oscilloscope I am developing.
(This is also shown in a different guise at the end of the AudioScope shell script too.)

BEST VIEWED IN PLAIN TEXT!

Machine:- Apple MacBook Pro 13 inch.

OSX 10.7.5...

Vintage:- August 2012.

Common 3.5mm, 4 pole, Mic/Ear socket cable for external MONO audio input, (and
stereo audio output)...

Code:

Plug required, (or similar)...

http://www.ebay.co.uk/itm/3-5mm-Mini-Jack-Right-Angle-90-Degree-Solder-4-Pole-Male-Plug-Connector-/320770305756

Resistor, 2K2, 1/8 W, 10% tolerance...

(2 x Resistors, 33R, 1/8W 10% tolerance...)

Code:

This is the wiring for the auto-switching of the Mic input to external...

Pins.               Wiring.
-----    TIP        -------
 1 ---->  O  <----- Left Audio Output +ve.
 2 ---->  H  <----- Right Audio Output +ve.
 3 ---->  H  <----- Mono (Mic) Input, Active.
 4 ---->  H  <----- Common To All Inputs And Outputs.
         ---
        |   |
        |   |______
        |__________|=========

For the auto-switching capability a 2K2 resistor must be connected across Pins 3 and 4. [Mono (Mic) Input, Active and Common]...

Test by plugging into the socket and check that the "System Preferences > Sound" switches over to external input and output.

You now have two audio outputs at low impedance and an analogue audio input at around 2K2 _impedance_.

Do NOT drive the input with more than 100mV AC and do NOT connect to a DC _supply_ either.

Do NOT load the audio outputs with less than 33 Ohm resistors.

Do NOT assume that Common is connected to GND, Ground, of the computer, although it may well be.

I am assuming that if you are capable of doing this that you are also capable of doing the subtle level tests etc...

(C)2012, B.Walker, G0LCU. (Issued as Public Domain for all.)

Enjoy finding simple solutions to often very difficult problems... ;o)

wisecracker

View Public Profile for wisecracker

Find all posts by wisecracker

3 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

force mounting usb drive on macbook pro

alright, this might seem a dumb question, can't say i'm too familiar with these applications. i have a 250mb zip drive that i just got for my macbook pro (i know it's archaic, i have a drum machine that uses 100mb zip disks) and it is recognized in system profiler as a 250mb iomega drive, but it...

2. Solaris

Retina display Macbook Pro and Solaris compatibility

Has anyone attempted to install Solaris 11 on a Macbook Pro with the new Retina display? I'm considering setting up a triple boot scenario with Windows 7, Mac OS X and Solaris 11. My goals are to learn the OS better and to gain daily exposure to it by running it as a desktop OS whenever possible.

3. Hardware

No sound device in Solaris 11 running in Parallels (MacBook Pro)

I'm new to Solaris. I was able to installed Solaris 11 running GNOME. I tried to detect sound/audio but the message given that "No volume control GStreamer plugins and/or devices found". There is no dev/audio but there are audio drivers such as gstreamer installed when I checked using Solaris...

LEARN ABOUT DEBIAN

pommed

POMMED(1)						      General Commands Manual							 POMMED(1)

NAME

       pommed - Apple laptops hotkeys event handler

SYNOPSIS

       pommed [options]

DESCRIPTION

       This manual page documents briefly the pommed daemon.

       pommed is a daemon handling the hotkeys found on the Apple laptops, like the MacBook Pro, MacBook and PowerBook laptops. These hotkeys con-
       trol, through pommed, the LCD backlight level, the audio volume, the keyboard backlight level (only on  the  MacBook  Pro  and  the  latest
       PowerBook)  and	the CD/DVD drive ejection. Additionally, pommed monitors the ambient light sensors found on the MacBook Pro and the latest
       PowerBook to automatically light up the keyboard backlight when the ambient light level gets too low.

       pommed can optionally support the Apple Remote Control, too (this option is disabled by default and only available for the MacBook Pro  and
       MacBook).

OPTIONS

       pommed accepts the following command-line options.

       -v     Print version information.

       -f     Run in the foreground, printing log messages to stdout.

       -d     Run in the foreground, printing log messages to stdout and debug messages to stderr.

FILES

       /etc/pommed.conf
	      The configuration file for pommed. See the comments in the file for the structure of the file and the available options.

AUTHOR

       pommed was written by Julien BLACHE <jb@jblache.org>.

								    2007-01-09								 POMMED(1)