I'm building the CGS48 VCO and also looking at the ASM-1 filter core
on which it's based. Unlike many VCO's it doesn't have any HF tracking
ajustment, so I'm wondering how well it tracks at higher frequencies?
The design looks simple compared with some other VCO's; but this isn't
necessarily a bad thing! I haven't heard any adverse comments on the
ASM-1 filter's tracking ability so I'd guess it's fine, I'm just
curious :-)
Also, there is a revision (V1.1) to the ASM-1 VCO here:-
http://home.swipnet.se/cfmd/synths/friends/stopp/asm1vco-1.1.pdf
It seems to be the same as the original ASM-1 schematic except that it
has an NPN transistor added between the output of LM311 (base) and the
18pf cap and 3k3 resistor (collector), the emitter goes to negative
supply rail. Any idea why this mod was added to ASM-1? Something to do
with sync perhaps? Just wondering if it would be beneficial to add it
to my CGS48.....
Allan
on which it's based. Unlike many VCO's it doesn't have any HF tracking
ajustment, so I'm wondering how well it tracks at higher frequencies?
The design looks simple compared with some other VCO's; but this isn't
necessarily a bad thing! I haven't heard any adverse comments on the
ASM-1 filter's tracking ability so I'd guess it's fine, I'm just
curious :-)
Also, there is a revision (V1.1) to the ASM-1 VCO here:-
http://home.swipnet.se/cfmd/synths/friends/stopp/asm1vco-1.1.pdf
It seems to be the same as the original ASM-1 schematic except that it
has an NPN transistor added between the output of LM311 (base) and the
18pf cap and 3k3 resistor (collector), the emitter goes to negative
supply rail. Any idea why this mod was added to ASM-1? Something to do
with sync perhaps? Just wondering if it would be beneficial to add it
to my CGS48.....
Allan