[sdiy] sh3a vco?

[Louis van Dompselaar]

The LM3216 is just a binary divider of sorts, fed from the VCO.  They  
generate sub-octaves
by dividing and combining square waves.  The "saws" and pulses are  
generated by just a few components
from the squares.  In the service manual the key is 3-2 Filter Board.   
Quite a misnomer, but that
is where the divided squares are manipulated and combined.

The SH3a does have a transistor ladder.  I repaired one just a short  
time ago.



Op 23 okt 2009, om 14:16 heeft Dan Snazelle het volgende geschreven:

>
>
> after watching a video of this synth, i am very interested in  
> knowing how they implemented the multiple
> sub octaves, each one having a choice between pulse or saw.
>
> i suppose this might be similar to scott's WAVETHING. however, the  
> schematics i could find, the only VCO stuff i could find was a chip  
> marked
>
> LM3216
>
> is this some sort of TOG with internal wave select? or am i  
> overlooking something on the schematic?
>
> also...i am assuming my schematic is for the SH3 as there is still a  
> transistor filter shown.
>
>
> any help with this appreciated. it seems like a great way to thicken  
> up a single vco machine.