You need to cancel your previous signal before you create the new one.. 
my $startsmp = $mw->Button(-text => "Sample/Change Rate",
                                -command => sub{  
                                            if ( not defined $smp ){ $
+smp = $mw->repeat($srate,  \&samp)}
                                            else { 
                                                $smp->cancel;
                                                $smp = $mw->repeat($sr
+ate,  \&samp)
                                            }
                                }
                                );

[download]

In reply to Re: Tk::Repeat - Variable Rate? by ~~David~~
in thread Tk::Repeat - Variable Rate? by transiency

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