[X4U] Microphone Input - iMac 24

[David Ledger]

At 20:07 -0400 2/8/10, Ken Johnson wrote:
>Wanting to use Skype on my iMac 24, but cannot seem to get the 
>external mic working.  It's OK on the built-in mic, and the 
>headphones are OK.  Yes, I have checked Sound Preferences, but get 
>nothing on external mic / line.  When I use a line-level input, it 
>works fine.
>
>So - my question - how do I get the external mic working for Skype, etc?

What sort of external mic?

Low impedance mics produce a very low output, but when used with 
balanced line cables and matching transformers they gave had the best 
interference rejection you could get cheaply 35 years ago (when I 
last worked as a professional theatre sound technician).

Some mics need 'phantom power', where the device the mic plugs into 
applies dc volts to the connection through a highish resistor. Don't 
think an iMac supplies that.

Many mics produce an output level close to line level. that's the 
sort of mic you want.

I have several mics from Sun workstations that won't produce a squeak 
with a Mac.

David


-- 
David Ledger - Freelance Unix Sysadmin in the UK.
HP-UX specialist of hpUG technical user group (www.hpug.org.uk)
david.ledger at ivdcs.co.uk
www.ivdcs.co.uk