Since there have been some questions about how to run the audio from yourreceiver into your Macintosh, I've created the following document to help.

I believe that the information contained here is correct, but thepossibility of errors always exists.Please note that in all cases, it is your responsibility to make sure thatwhat you're doing is correct. Consult with your computer's documentation, or contact Apple if in doubt. I cannot be held responsible for any damageto your computer.

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• The only mic I know to be compatible out of the box is Apple's PlainTalk microphone. The PlainTalk mic has an extra long plug, and the tip of that plug draws power from the Mac to drive a little inline pre-amp. Unfortunately, the PlainTalk mic is not the best mic for all purposes. It's omni-directional, and it's not very useful for speech.

There have been two styles of microphone inputs for the Mac over theyears, the older style Apple Omni-Directional Microphone andthe new style PlainTalk Microphone. The two microphone styles arenot directly interchangeable. In addition, some Macs (the AV modelsin particular) have RCA-style jacks, allowing the direct connection ofline-level signals.

The ATR3350XiS Omnidirectional Condenser Lavalier Microphone for Smartphones from Audio-Technica features a low-profile design engineered for accurate voice reproduction. It terminates in a 3.5mm dual-mono connector, and thanks to the included smartphone adapter, it can be used with iPhones, Android devices, and other smartphones.

Both microphone styles use a plug with three conductors. Following theindustry standard, these three conductors can be called the Tip (the endor point of the plug), the Ring (the middle conductor), and the Sleeve.

Both microphones use the 3.5 mm style plug, not the 1/8 inch styleplug, which is only 3.175 mm in diameter, and will be too loose.

Apple Omni-Directional Microphone PlainTalk Microphone

The older Mac models used the Omni-Directional Microphone, which producedlow level audio signals, typically around 20 millivolts. The PlainTalkMicrophone produces a line level audio output, typically 200 millivolts,up to 2 volts.

If you have a Mac which uses the older microphone style, and you want torun direct (line level) audio into your Mac, you need to attenuate theaudio level. Most Macs came with a small adapter that plugged into theMac, and gave you two RCA jacks which accepted line level audio.You should be able to build your own, using a suitable audio transformer(the Mac wants around 600 ohms, line-level is around 47,000 ohms). You maybe able to get away with a simple resistor-divider also. Not ideal, but itmay work.

As you can see, the power and audio signals are reversed between the twomicrophone styles.Also, note that the PlainTalk microphone is slightly (0.25 inch) longerthan the normal 3.5 mm plug (0.75 inch vs 0.50 inch).

You should not just cut a PlainTalk microphone to use the plug. Yougenerally don't need the extra plug length, since all it gives you is the+5Vpower, which is seldom needed. And, you run the risk of shorting outthe +5V, which would be bad.Just use a standard 3.5 mm plug. You may want to run the audio to both theTip and Ring, so it is fed into both the Left and Right channels.

One potential problem is that you may create a ground loop between yourcomputer and radio gear. This will show up as 60 Hz hum being fed into theMac's audio input. Try recording some 'quiet' audio (with your radio'saudio turned all the way down) using SoundEdit, or something similar, andmake sure that there isn't any hum present.

If there is, you may have to experiment with the wiring. One possibilityis to use transformer(s) to break the ground loops.

Another one, which I have used, is to just break the ground (common)between the audio input on the Mac, and the radio, relying on whateverother ground is present.

Omnidirectional Microphone. Apple Plaintalk For Macbook Air

But don't let all of this intimidate you. It's really quite easy to connect your Mac to yourradio. If you just want to get started quickly, you can always try setting your Mac's microphoneover your radio's speaker. No, it won't work great, but it will let you get started exploringthe fascinating world of digital communications with your Mac!

Which style microphone does my Mac use???

The following Macs use the new PlainTalk style microphones:

• All Power Macs
• All AV Series Macs
• Quadra 605
• Macintosh 630 Series
• Macintosh 6100 Series
• LC, 500 Series

Usb Omnidirectional Microphone

This list may not exhaustive.

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Omnidirectional Microphone. Apple Plaintalk For Macs

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