sorry in advance if i'm wrong on this as its been awhile since ive tried samp.
(people will need to know which version of samp you have.)
but as noones answered i'll have a go at answering.
1. in samp preferences youll prolly find a setting that points to where all your plug ins are located.
mebe also samp scans for new plug ins also.
if a certain favorite plug in isnt showing up in the plug in list, its prolly cos you havent put it in
the directory possibly that samp has been told is for plug ins.
thus youll prolly have to browse to tell samp where the plug in is located
i would suspect.
2. on the track itself , if i remember ...each track has a dialog.
called an OBJECT EDITOR.
heres the object editor...figure 3. audioMIDI.com : Review by Fabio D. Garcia
notice you can insert plug ins in the editor.
in fact each seperate audio clip has a dialog in samp if i remember where you can insert fx.
so try calling up the tracks dialog and you should be able to insert an fx on a trak useing the
try this in mixer view. one of these ideas might work.
select a trak you want an fx inserted on.
bring up the plug in list. try dragging the plug in to the trak or double cliking on it.
this stuff should all be in the samp manual.
if i remember the samp manuals are very detailed.
in summary i suspect you can insert fx on a track two ways.
in the traks dialog as well as in the mixer.
sorry if this dont help much.
i just did some googling after typing this n there is lots of info bout samp on google also.
ps..in the manual or pdf you should see a whole section on "effects and plug ins"