Ha ha that's awesome! Everytime I think I'm beginning to understand how trannies work in a circuit, I hear something like this and I realise I have absolutely no idea.
Cheers
Dean
Cheers
Dean
--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> Transistors can be funny things. I made the 116 with every transistor except
> for the LED drive in backwards. The bloody thing works.
> Ken
>
> >Thanks, i just checked and i'm using 5089's with the 3906 so i'll change
> those out.
> >Also, i have the 5089's oriented the same way as the silkscreen which i
> just realized is backwards to the actual pinout.I thought i checked the
> pinout of the transistors before installing them so i must have missed those.
> >
> >This probably explains why i could only tune it to about 3500 hz before it
> would stop cycling ?
> >
> >Thanks guys, i was ready to accept it as it was so this will make it that
> much better !
> >
> >--- In cgs_synth@yahoogroups.com, Jason Nanna <jasonnanna@> wrote:
> >>
> >> Hi, I just debugged a DUSG yesterday that had this very problem. Check
> >> your transistors, specifically the NPN's in the current source. I had used
> >> 2n3906's in combination with 2n5089's and I got this very behavior. I
> >> believe either it was the combination or, much more likely, the transistors
> >> were installed backwards - looking at the datasheet for 2n5089's it looks
> >> as though the silkscreen package outline on the PCB is in the opposite
> >> orientation. I don't think I ever checked these before installing.
> >> Anyway, I swapped them out with 3904's oriented the correct way. These
> >> are (ordinarily) the same as the pinout for 5089's, and opposite the
> >> silkscreen on the PCB.
> >>
> >> One thing I noticed is that I still got the rise time to modulate, but the
> >> knob had to be full CW and I needed some significant CV in.
> >>
> >> On Sun, Feb 17, 2013 at 9:55 AM, adematteo <adematteo@> wrote:
> >>
> >> > **
> >> >
> >> >
> >> > Hi guys, I am noticing that the rise time on my dusg's doesn't seem to
> >> > have very much effect in a typical way.
> >> >
> >> > I know this circuit is not a typical envelope generator so i'm curious if
> >> > it's just the way this circuit works, but if i feed a trigger in and have
> >> > the rise time set to full cw position it still fires exactly when it gets
> >> > the trigger but it does take the sharp edge off.What i would expect is that
> >> > i would get a slow rising voltage ?
> >> >
> >> > Like i said just trying to figure out if i should expect this behavior or
> >> > if i did something wrong when building it.
> >> >
> >> > Thanks, Tony
> >> >
> >> >
> >> >
> >>
> >>
> >> [Non-text portions of this message have been removed]
> >>
> >
> >
> >
> >
> >------------------------------------
> >
> >The CGS Modular Synth home page: http://www.cgs.synth.net/
> >Yahoo! Groups Links
> >
> >
> >
> >
> _______________________________________________________________________
> Ken Stone sasami@... otherunicorn@...
> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
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>