Cgs synth

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]
>>
>
>
>
>
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>
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_______________________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
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