Hi Tim,
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.


--- In Doepfer_a100@yahoogroups.com , "Tim Stinchcombe
<timothy@t...>" <timothy@t...> wrote:

> 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