Re: Sound on a PPC

Craig Miller (cvmiller@uhunix.uhcc.hawaii.edu)
Fri, 28 Oct 1994 14:29:53 -0400

>> <<<
>> Can anybody tell me how to get the mike to work on a powerPC mac? We get the
>> video to work fine, even with the 68x software (now using the PPC version
>> (beta 12)). But no sound. Not even a rise in the sound level bar in the audio
>> panel. I suspect that you need a special mike for the ppc (7100), or a
>> special control panel. Anybody have a clue?
>> >>>
>>
>> You need a line-level mic. You are using a mic-level mic. Line-level audio
>> equipment signals are much stronger. Your personal stereo outputs a
>>line-level
>> signal to your headphones.
>>
>> If you have a portable mixer that outputs a line-level signal, you can attach
>> the mixer to the mic. and attach the other end of the mixer to the mac.
>> I should work fine.
>>
>> But otherwise, I'd just go out and buy a line-level mic.
>>
>> Jason Whong
>> whong@ithaca.edu
>
>Jason:
>
>Huh? All he needs is a PlainTalk mic (~$24).
>
>Regards,
>Stan Borinski stanb@netsol.com +1-703-742-4796

<<Caution Speculation Ahead>>

I am sure Stan is right. Here is my speculation was to why Apple changed
things. If you look at the Plaintalk Mic you will see that the connector is
unusually long. On older Macs that actually put DC voltage on the connector
to power up the mic (it is a powered mic). However this was the same type
of connector used by your headphones, and when you plug headphones into the
mic input, you would hear scratch sounds as you plugged and unplugged them
(the DC being applied to the head phones). This either annoyed people, or
did damage to the headphones (or the power supply in the Mac), so Apple
went to a different connector which is deaper and does not apply DC to
regular headphones when inserted in that hole.

I believe that this input is still at Mic levels (although I may be wrong
about that).

Craig...

------------------------------------------------------------------------------
Craig Miller 808/539-3661
Digital Media Lab Coordinator 808/539-3833 fax
University of Hawaii cvmiller@uhunix.uhcc.hawaii.edu

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