[sdiy] best soundign vco design?

[Scott Gravenhorst]

"Roy J. Tellason" <rtellason at blazenet.net> wrote:
>On Friday 11 June 2004 11:02 pm, Mark Romberg wrote:
>
>> what about the nat semi ICL 3038?
>
>I didn't know they made that part...
>
>> it outputs square, sine and tri simultaneously and isnt quite as hard to
>> find as the 13600/13700. there's a decent looking schem for a VCO in the
>> application notes that you can get from NS.
>
>Got a link to that app note?  I got one of these parts at Radio Shack some 
>time back and built a crude function generator around it,  but never thought 
>about using it in a VCO.

I think he meant the ICL8038.  It's generally considered a crap VCO if you
follow the data sheet schematics (the IC gets hot and it isn't very linear in
response to the CV), however, Thomas Henry designed this 8038 VCO: 

http://www.midwest-analog.com/diylvco.html .

It's a _linear_ VCO, not expo and is claimed to perform very well, however, I
think it may be rather inconvenient to interface using an expo CV.  Other VCOs
are considered better for expo.  I do linear, so one day I will try this, but
so far, I have not found the requisite "round tuit".


---------------------------------------------------------
- Where merit is not rewarded, excellence fades.
- Hydrogen is pointless without solar.
- What good are laws that only lawyers understand?
- The media's credibility should always be questioned.
- The only good terrorist is a dead terrorist.
- Governments do nothing well, save collect taxes.

-- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
-- Linux Rex         | RedWebMail by RedStarWare
-- FatMan: home1.gte.net/res0658s/FatMan/
-- NonFatMan: home1.gte.net/res0658s/electronics/
-- Autodidactic Master of Arcane and Hidden Knowledge.