You'll find at first sight that the mic plug of the headset is for "PlainTalk Mic." So you cannot plug it in on PowerBook 2400 that has normal microphone jack, although you've upgraded CPU card to G3/240 or G3/320. I've made an adaptor for PlainTalk Mic, and now I successfully use ViaVoice 2000 for Mac on PowerBook 2400/G3 320.

1. The length of the mic plug (upper) is longer than usual stereo plug (lower).
   
   
   
2. PlainTalk Microphones need +5V power for their amplifiers, so I borrow it from ADB power line.
   
   
   
3. I altered a stereo jack to adapt longer plugs.
   
   
4. The power line of ADB is No. 3.

After checking wiring by use of circuit tester carefully, you'll enjoy ViaVoice2000 on PowerBook 2400.

Here is an example, please tell me how to get better results...

*There is an another way to achieve your purpose. (8.30.2000)


If you feel that noises are too loud, you can use three dry cells (= 4.5 ~ 4.8 V) or a constant voltage circuit (below) in place of the direct ADB power to remove or reduce the noises. (2.25.2001)



You should use 0.33 uF instead of 0.22 uF, according to the manufacturer's instruction.

Today's "No one has gone before"

E-mail: inachan

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Feb 25, 2001