On Sun, 4 Jul 2004 16:58:57 +0100, "Keith G"
wrote:


"Don Pearce" wrote


Keith - where's the MP3 of the hum? Maybe we can speed up the
tracking-down process.


OK, here's a clip from the record I've got on atm - Branford Marsalis
'Scenes In The City':

http://www.apah69.dsl.pipex.com/keith_g/show/hum002.mp3 2.5 Mb/1:49

The hum is before, during and after this 'end of track/beginning of next
track' snatch of music - which is to give you a sound level reference.

Recorded with an open mic, so it's a bit 'boggy' - no 'Line Out' luxuries
here, I'm afraid!! :-)

(Recording's another thing I've got no clue about! - Also not me best
speakers....!! ;-)





Mmmmm... that hum is 100Hz, not 50, so it pretty certainly comes from
the power supply rails, not stuff like ground loops. Do you have a
spare fat electrolytic you could hang across power supply in parallel
with the one already there? See if that kills, or at least reduces,
the level.

d
Pearce Consulting
http://www.pearce.uk.com