Doepfer

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