Doepfer

Hi -- 

I'm hoping to pull my 177-2 back off the shelf again, and wondering if Dieter or anyone else using this module might be able to help out with the questions below.  Thanks in advance!

Ernst


--- In Doepfer_a100@yahoogroups.com, "E_Karel" <ekarel@...> wrote:
>
> Hello Dieter,
> 
> Thanks for your earlier responses.  I dropped this thread and have been using my old 177, but I'd like to use the 177-2 if possible, so here are some more comments/questions:
> 
> --- In Doepfer_a100@yahoogroups.com, <yahoo@> wrote:
> >
>  > I suppose that it has to do with the bouncing of the contacts of your foot
> > pedal (i.e. that releasing the pedal is not a clean on/off transition but a
> > sequence of on/off/on/off transitions until the final state is reached). If
> > the A-177-2 is used to switch a signal (e.g. by means of the A-150) this
> > causes no problems but if the foot switch is used as a trigger (e.g. S&H or
> > clock circuits) this may lead to a problem. Especially older contacts may
> > generate a lot of bouncing. 
> 
> You're right about the 150, but when I use it with the 151 it goes crazy, and is basically unusable.  Each trigger causes a flashing of lights and moves an unpredictable number of stages in the sequence. 
> 
> > Maybe adding a capacitor to the inputs will
> > solve the problem. They would work like low pass filters that filter the
> > bouncing pulses. One has to try it out as it depends upon the bouncing
> > behaviour of the contacts. I'd start with ~ 100nF connected between GND and
> > the foot switch inputs.
> 
> Sorry, but I'm ignorant about these things -- how would I do this exactly?
> 
> 
> > > And isn't the behavior I mentioned in my second message quite
> > > strange?  I'll quote it again here:
> > >
> > > "If I have output #1 from the 177-2 double footswitch patched to
> > > the 165 trigger modifier input, and nothing patched from output
> > > #2, only pressing footswitch #1 shows up on the LEDs on the 165.
> > > Footswitch #2 appears to do nothing. So far so good. However, if
> > > I patch from the mini-mult of the 165 to the trigger input of the
> > > S&H 148, then even though only #1 registers on the 165, BOTH
> > > footswitches #1 and #2 pass gate on to the S&H."
> > 
> > That's indeed strange. I'll try to copy the behaviour in our demo system. It
> > probably has to do with glitches and bouncing and the different input
> > behaviour of A-165 and A-148 in case of glitches at the input.
> 
> Did you happen to get a chance to look at this?  
> 
> Thanks again!
> Ernst
>