Ladies/Gents:

I just completed two modifications to my Analogue Systems
RS-60 ADSR that you should really think about adding if you
also own one, as almost everything you need to do these is
already on the board :

1) Range switch

I added a ala Doepfer range switch which is three position
(ON-OFF-ON). the wiper of this switch goes to the positive end
of C8 (4.7 tantalum cap). On one of the other two contacts of the
switch I put another 4.7, onto the other I put a 15 mf tant. The
positive leads of both of those is what goes to the switch. The
other send of both those go to ground.

I was able to double the overall lenth of the envelope twice over.
When the switch is in the center position, there is no change to
the range from the stock EG. When flipped down the envelope is
twice as long as stock, when flipped up it four times as long. I
made measurements using the comparator signal coming from
pin 7 of IC2B as a reference of when the envelpe is complete, to
wit:

With the EG in 'HOLD' mode and Attack and Decay both full up,
single cycle lengths were:

CENTER POSITION (no effect): 21 seconds
DOWN POSITION (cap x2): 45 seconds
UP POSITION (cap x3) 1 min, 35 seconds

Of course, you could play around with even larger caps (which I
am going to do this weekend), to get the different range switches
to totally take off. One thing I dig about the Blacet EG - it will
allow single cycles up to about an hour and 45 minutes (and
eveything in-between). This may sound silly, but for long control
voltage sweeps, it's terrific.

2) Final Pulse out

I added an output jack which gives you a positive high out when
the envelope is sitting idle. So, at the end of the cycle this output
goes high. This affords me to link two EGs together for complex
envelopes or use the EG as a super gate delay (with delays up
to 1:35 presently). It really is quite useful.

To do this, I simply took the comparator signal coming from pin 7
of IC2B, ran it through an NPN transistor, then through a 1K
resistor to the jack. I

There is plenty of room on the panel to add these two functions
(they are right in line with the center switches, looks great).

If you are handy with such things - you might want to try this at
home.

best,

Peter