Doepfer

Ah! So it's actually partly due to the fact that I use the square 
wave as a gate, and I can't get a square wave from the ADSR? That 
makes sense of why I couldn't use the triangle as a gate, even though 
it goes through the same voltage range. Fascinating! Thanks for the 
information.

--- In Doepfer_a100@yahoogroups.com, <yahoo@...> wrote:
>
> > -----Ursprüngliche Nachricht-----
> > Von: Doepfer_a100@yahoogroups.com
> > [mailto:Doepfer_a100@yahoogroups.com]Im Auftrag von Florian 
Anwander
> > Gesendet: Mittwoch, 29. Oktober 2008 10:57
> > An: Doepfer_a100@yahoogroups.com
> > Betreff: Re: [Doepfer_a100] Re: Gates
> >
> >
> > madrayken schrieb:
> > > Of course, you're correct. I'm using the self-triggering Quad 
ADSR,
> > > so I can send the D-Gate out to a multiple and send one back to 
the
> > > ADSR and the other to the S&H. My interest is purely academic: 
how is
> > > my ADSR peak different from an LFO? I use the two 
interchangeably in
> > > all other cases.
> > > LFOs go from -2.5 to +2.5v.
> > > Envelope gates are at +10v.
> > >
> > > Both these work to trigger the S&H.
> > >
> > > Envelopes themselves go from 0v to +8v, yet these never trigger
> > > gates.
> > >
> > > Specifically: having read the manuals, I can't see anywhere 
where a
> > > gate is considered to be a shift from +ve to -ve voltage, but 
this
> > > would appear to be the case. Am I right?
> >
> > Ok, this becomes understandable. But I have no dedicated answer 
for you.
> >
> > The only thing I could imagine is, that the trigger threshold for 
the
> > S&H is quite low (lets say at 0.5 Volts) and the Quad ADSR 
assumingly
> > does not return completely to 0 Volts when in self-triggering 
mode. (I
> > know this from other makers envelopes, e.g the ADSR of my Formant 
does
> > not go down to 0 V completely. You have to work with an negative 
offset
> > at the VCA to make it silent).
> >
> > Florian
> 
> To obtain a correct function only "digital" signals (i.e. gate, 
clock or
> rectangle LFO signals) should be used as gate sources. But in a 
modular
> system even analog signals (envelopes, non-rectangle LFOs, random 
signals,
> audio signals ...) may be (ab-)used as gate sources. In these cases 
the
> correct gate function cannot be guaranteed because all depends upon 
the
> circuit that is used in the gate input section. For some gate 
inputs only a
> certain level has to be reached to trigger the corresponding 
function (e.g.
> A-148 in T&H mode, A-112 sampling module gate, A-140 ADSR gate). 
But for
> other gate inputs even the rise time is essential (e.g. A-148 in 
S&H mode,
> A-143-2 ADSR gate) because a capacitor is used to generated an 
internal
> trigger signal (kind of AC coupling). The rise time of a "digital" 
signal
> (e.g. clock, rectangle LFO) is always sufficient. But if an analog 
control
> signal is used and the rise time may be not sufficient and the 
circuit will
> not trigger. You may find out that an ADSR can be used for some of 
these
> gate applications if the attack time is short enough but the gate 
function
> will no longer work if the attack time goes beyond a certain value 
(there
> may be even an intermediate state where the functions works  
randomly now
> and then).
> 
> Hope this helps
> 
> Dieter Doepfer
>