[sdiy] Re: [AH] Farfisa VIP organs

[JH.]

>Your post inspired me to dig out my old VIP233. It still had packing tape
>wrapped around it from when I moved a number of years ago. It was good to 
>open
>the case and see the face of an old friend. The drawbars look  like various
>flavors of Italian ice, or maybe spumoni ;). I removed the top  aluminum 
>cover.
>Pressing an upper key vertically lifts a  plastic bar with five springy
>horizontal wires evenly  spaced apart in vertical line with each key. The 
>springy
>wires are pulled up against five contacts at the same  time. I assume each
>contact bus represents a different frequency  division associated with the
>drawbars (and maybe one for the percussion?).

Thanks for looking this up!

>Congrats on your recent acquisition. I think you'll be happy. I think  this
>type organ could be easily modified to be something like  a Moog Opus 3.

I don't even have it yet (will pick it up on Sunday), but I already think 
about modifications.

The dividers seem to be quite different from the Compact series.
There, a frequency divider /2 is made of another oscillator roughly tuned an 
octave lower,
and sync'ed to the higher octave. I wonder what this means for the vibrato, 
which is
applied to the highest octave, and then propagated down from oscillator to 
sync'ed
oscillator. My first impression is that the lower octaves might be modulated 
with a
certain phase shift (speaking of the LFO modulation), compared to the higher 
octaves.
Is this true? Can anybody confirm this?

The VIP, OTOH, seems to have ordinary frequency divider chips. Flipflops, 
probably.
Butb then again, wide range frequency changes ("Syntheslalom") would hardly 
have been
possible with the Compact frequency dividing method.

JH.