>> krmsr, krmso, kerr, kcps    lpread  ktimp, "A_aarde_luid.lpc"
>> asig     buzz      krmso, kcps, int(sr/2/kcps), 1
>
> There is a problem in these two lines of your orchestra.  The third input 
> to
> buzz is an i-rate value, i.e. it only is evaluated when the instrument is
> initialized.  So the expression int(sr/2/kcps) is only evaluated once,
> before the variable kcps has a value.  This can create unpredictable
> results.
>

Sorry, but it's not. Manual says

ares buzz xamp, xcps, knh, ifn [, iphs]

Victor