added link to mic powering


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@2980 a1c6a512-1295-4272-9138-f99709370657
diff --git a/docs/FAQ b/docs/FAQ
index d27479b..4be10fd 100644
--- a/docs/FAQ
+++ b/docs/FAQ
@@ -629,4 +629,7 @@
               where the sound goes through, dc value) for feeding the FET of
               an electret condenser capsule (see above) (and this power could
               also used to feed a mic amplifier), but the archos hasn't
-              (it's a line in and no mic in!).
\ No newline at end of file
+              (it's a line in and no mic in!).
+     If you want to know more on microphone powering, read this:
+     http://www.hut.fi/Misc/Electronics/circuits/microphone_powering.html.
+     (As described, you need also amplification.)