I found with my Steiner VCFs that the transistor gain makes a big
difference. Look through the archives to find my posts on measuring
transistor beta for the 2N2222.
-Richard Brewster
sasami@... wrote:
difference. Look through the archives to find my posts on measuring
transistor beta for the 2N2222.
-Richard Brewster
sasami@... wrote:
>Sounds like a problem withthe two transistor amplifier stage - there isn't
>enough gain. Check you have all the right parts in it.
>
>Ken
>
>
>
>>Put the synthacon VCF together, and it seems to be working, but it will
>>not self oscillate. It doesn't seem like the resonance is working
>>correctly. The res definitely changes the amplitude, and sharpens up a
>>low-pass filtered square wave somewhat, but you cannot seen any
>>overshoot or ringing at the top or bottom of the square wave. I
>>reduced the 1k resistor just before the variable resistor to 330 ohms,
>>and it is a little more "agressive" sounding now, but nothing like I
>>was expecting, and nowhere near self-oscillation. Any ideas?
>>
>>I have the REV-1 board, which doesn't seem to have any problems with
>>polarized components being in backwards.
>>
>>Any help would be much appreciated. I have a scope, and am pretty good
>>at de-bugging, so I may figure this out given enough time...
>>
>>best regards,
>>-gerald
>>
>>
>_______________________________________________________________________
>Ken Stone sasami@... or sasami@...
>Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
>Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>
>
>