Improving VCO-1

[Arda Eden]

Hi there,
I have 2 of Thomas Henry's VCO-1 in my modular and I am very happy with those guys. The only thing missing is a sawtooth output. Is it possible to improve this circuit by adding sawtooth out?

https://www.birthofasynth.com/Thomas_Henry/Pages/VCO-1.html

[gabbagabi]

May you have a look here

https://electro-music.com/forum/topic-27934.html

[gabbagabi]

totaly unexpected i got access to a real computer,
not that fcking phone,
so i was able to draw something

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[Arda Eden]

I was not around for a while and haven't seen your reply. Now I am back and thank you so much for the schematic. I will add this improvement.

Another question is that:
The tempco on the original schematic is 3500ppm. I haven't got one but few 3300ppms. Will they also work? Can I use 3300ppm?

[gabbagabi]

Glad you are back!

i have no experience with tempc0s

why dont you just try it
and if you see that you cant life with the 5,71% error-
change it

good luck!
Keep well!

[Arda Eden]

Thanks. Actually, I realized that the schematics says it is 3300ppm. But on the website it is written as 3500ppm. Maybe a typo ... I used the 3300 and it works great. Now it is time to add the saw converter you drew.

[Gingoism]

IMO a "tempco" is usually a luxury and not a necessity unless you are a stickler for rules. Some of my poorly made VCO(s) which all use basic 0.1% resistors in place of "tempcos" are functionally solid with very few pitch drifts in different ambient temp settings.