previous | index | next |
<< | topic list | >> |
> Hi Tim,<timothy@t...> wrote:
> Good idea, if you do try it let us know what happens. If it works
> please post a pic of the mod so I can try it.
>
> JOhn.
>
>
> > 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