Electrets have a fet amplifier in them which needs a steady supply.

Look at the back of the mic insert and you'll see one of the connections is
joined to the outer case - this is the 0V connection.  The other is both
power in AND signal out.  You connect +V through a current limiting resistor
to this contact.  You also connect a small capacitor (103, 104) from this
contact to 'mic in'.

Most 'mic in' sockets are 2 wire, so the resistor and capacitor are already
in place inside the recorder, you just have to find which way round the
power is (it is ALMOST always tip = +V, ring = 0V).

Bye.

-----Original Message-----
From: Randy Glenn [mailto:picxpert@YAHOO.COM]
Sent: Monday, 7 February 2000 12:13
To: PICLIST@MITVMA.MIT.EDU
Subject: [OT]Hooking un an Electret Mic to a tape recorder


Sorry about starting an OT thread, but I have nowhere else to ask.

I have here a brand-new, low-quality microcassette recorder, blessed with a
Mic jack. After choking on RadioShack's prices for a tie-clip mic ($35!??!!!
In your dreams...), I decided I'd like to hook up the 2-wire Electret
element I have here.

Which brings me to my question: How do I hook up this element? Does it need
any support circuitry? Where do I hook up the two terminals (one is ground)
on the mic to the miniplug?

Thanks in advance,

-Randy Glenn
E-Mail: PICxpert@yahoo.com
Web: http://i.am/PICxpert

Currently wondering why I can't get in to Safe Mode - where's a Mac when you
need it?


__________________________________________________
Do You Yahoo!?
Talk to your friends online with Yahoo! Messenger.
http://im.yahoo.com