I'm trying to create an exponentially decaying envelope.  However, I
want to control the curvature of the envelope.  I'm trying to modify
the frequency and the amplitude of a simple sine wave.
I tried the following, but it didn't even come close to working.

gisin   ftgen 1, 0, 2048, 10, 1
girise  ftgen 1, 0, 256, 5, 1, 256, 0.001

instr 2
 ifreq  = 1000
 kfreqmod envlpx ifreq, 0.01, p3, p3, girise, 0.1, 0.1
 kampmod  envlpx  ampdb(p4), 0.01, p3, p3, girise, 7.9433, 7.9433
 adm  oscil   kampmod, kfreqmod, gisin
          out adm
endin

Is there any easier exponential envelope opcode?

charlie