[sdiy] minimoog envelope effect on a SEM (?)

[jhaible at t-online.de]

This is *untested*, but you should get the recently
discussed Minimoog envelope effect on a Oberheim SEM-1A
with the following modification:

Change C13 (1nF) to 6.8nF
Change R113 (33k) to 15k

Same for C11 and R91

Let me repeat that I have *not* tested this, so you do it
on your own risk. I have checked it in simulation on my
own VC-HADSR which is based on the SEM envelopes, so it's
likely that it works on a real SEM, but the test was two
steps apart from reality (derived circuit, and simulation).

If someone wants to try it, I recommend soldering new 33k
resistors on top of the original ones (to get approx. 15k)
and 6.8nF across the existing 1nF ones (to get slightly
more than 6.8nF), so you can always revert the mod.

I'm sure I'll try it myself on the JH-720 some time, but this
is your chance to have the results faster than I (;->).

JH.