GregS wrote in message
...
In article , "N Cook"
wrote:
N Cook wrote in message
...
Anyone come across the situation where presumably some crud that was
otherwise safe in the bottom of the voice coil slot is now shifted and
causing distortion.
Owner in the habit of transporting face down - to avoid anything
falling
onto the front face.
Any opinions on transporting face-down or cures. ?
Try operating for a while horizontally perhaps but face up or face
down.?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/



The problem is now more likely the owner having stored it in a damp
garage
for a few years , unused.
There were numerous spiders webs and insect cocoons inside the amplifier
and
spot rusting of the metalwork of this combo.
So probably insect cocoon or rust flake has got in the coil gap or even
cone
distortion due to damp differentially affecting/distorting the cone.
Presumably "palpating" the cone in different clock positions to feel for
rubbing would be the best disgnostic.

If there is any paint inside there, it can peal and fall off into flakes.
I
saw one gap all rusted once.

greg

I've not literally been able to get my hands on this one yet - still with
the owner , he decided to aquirt the universal solve-all in there - WD40.

If it is salvagable from WD40 etc and if the oproblem is due to damp
affecting the cone , is this being a 15 inch cone more likely to have cone
distortions than a 12 inch for the same sort of damp?
Intuitively I could expect a large cone to be more likely to have a twisting
type distortion than a smaller cone, having a greater proportion of
unsupported edged length to surface area.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/