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 !
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]
>