[sdiy] ASM VCO tips wanted.....

[Ken Stone]

The first thing to do is make sure the trimmers are in an appropriate
position. I thought I had dead ASM oscillators at first - it was simply a
case of the initial frequency was set way too low.

Ken

>Hello all, I have my ASM here, and one of the oscillators wont oscillate.
I've gone over the thing numerous times and have replaced the 3140, 311, and
the FET (its now a 2n3819 this should be OK right?)
>here's the schemo:
>www.home.swipnet.se/cfmd/synths/friends/stopp/asm1vco-1.1.pdf
>(thanks Gene Stopp!!)
>
>anyway, all the panel controls and jacks check out OK, and all the
resistors and caps are the exact same as the other osc (which works)  The
voltages at the chips are all OK, and the trimpots are okay too.  
>The SAW out isnt stuck at +v, but instead I noticed that the voltage at SAW
out slowly decreases, and the rate of decrease increases when I reduce the
value of the cap on the FET.. : ) follow that?  heheh
>so it basically acts like a very low freq osc.  the panel controls have no
impact on this rate either... 
>
>so, if anyone has any ideas about this I'd be greatly appreciative!!  I'd
like to get it fully operational and now that Ive spent many hours mulling
over the circuit, i'm officially on a mission!!!!!!!!!!!!!!!!!!!
>
>thanks all,
>see ya at AHNE!!!!!
>
>~Steve M
>revtor at aol.com
>
_______________________________________________________________________
Ken Stone   sasami at hotkey.net.au or ken at cgs.synth.net
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
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