Hi all,

This morning I was having a quick look through the new Analogue
Systems group and noticed a comment that Bakis made about not being
able to get Doepfer envelope generators to auto-repeat. So, thinking
cap on and schematic of A-140 in hand I sat down, and after some
while I came up with a simple way to do it. With an extra diode,
resistor and op amp I have lashed it up on some breadboard and have
been playing with it for the last hour or so, and it seems to do the
job. All it does is sense when the envelope has got down to the
sustain level, and then generates a pulse that is fed back into the A-
140 retrigger input, and hey-presto, auto-repeat!

A little more thought suggested that the op amp currently used for
the inverted envelope output could be used to do this - thus with a
few pins, cutting a track or two, add a couple more components, and
this could be turned into a nice little mod to the module. The
new 'sustain level reached' signal would be output at the old
inverted output and fed back to the re-trigger input for auto-repeat -
if this was taken through an A-150 switch one could also select its
use via voltage control.

I haven't worked out the full details yet, but I expect it would be
about the same complexity as what I suggested to fix the problem with
the A-150 (anybody else actually had a go at doing that by the way ).
I thought I'd run it by people first to see what the interest is, if
any (what might seem simple to some may not be so for others...!).
(On the other hand I might just buy another A-140 and do it anyway.)

As for the A-141, I note that there are currently two unused op amps
already on the board, so it's conceivable that the same sort of trick
might work with it too - I'll have a ponder on that too.

Cheers,
Tim