On Jun 19, 1:14*am, "N_Cook" wrote:
spamtrap1888 wrote in message

...
On Jun 18, 8:03 am, "N_Cook" wrote: Hearing it again I would say its more open looped amp motorboating. Cant
analyse for frequency etc until tomorrow. Needless to say have not been
able
to induce any noise like this.

Further info from the owner
" It's whenever there isn't a signal that the buzz persists. I first
noticed
it when i stopped playing in the middle if a song and i heard this murmur"

140K MP3 , 5 second file, is (theoretically ) now on/off this host

sitehttp://www.diverse.4mg.com/ampbuzz.htm



(minimal htm page to get round "forbidden" remote linking stuff )

Your search - buzz site:www.diverse.4mg.com/amp- did not match any
documents.

+++++
I've added an underscore version there of bothhttp://www.diverse.4mg.com/amp_buzz.htm

maybe an oscillogram there later today

Just sounds like something's ungrounded, like when you plug a 1/4 in.
phone plug into a jack, before the ground connection is made.