Magazine Archive

Home -> Magazines -> Issues -> Articles in this issue -> View

VCO

Article from Polyphony, July/August 1978


Here is a VCO system using one IC and a minimum number of parts.

This VCO can have a frequency range of approx. 80 to 10,000 hz by varing the .02uf capacitor. Using a 0 to 5v. input and the capacitor listed, the frequency range is about 300 to 4000 hz with a ramp output of about .5v p-p.

The LM324 used in this circuit is a quad op-amp and since one VCO uses only 1/2 of the IC, each IC can be built into two VCO's.

Construction is not critical and parts can be substituted. Also: One of the input 150k resistors can be replaced with a 500k pot. and a 50k resistor to give a wider frequency range and more flexibility when using multiple VCO's.

I don't know how linear these oscillators are, but for special effects where multiple VCO's are a must, these work quite nicely.


IC1: LM324 (Radio Shack #276-1711)
All capacitors : 9v. or better
All resistors : 1/4 watt or larger.

For two VCOs duplicate the circuit using these pin connections on IC1.


More with this topic


Browse by Topic:

Electronics / Build



Previous Article in this issue

Industry Notes

Next article in this issue

Patches


Publisher: Polyphony - Polyphony Publishing Company

The current copyright owner/s of this content may differ from the originally published copyright notice.
More details on copyright ownership...

 

Polyphony - Jul/Aug 1978

Donated & scanned by: Vesa Lahteenmaki

Feature by Russell Grokett, Jr

Previous article in this issue:

> Industry Notes

Next article in this issue:

> Patches


Help Support The Things You Love

mu:zines is the result of thousands of hours of effort, and will require many thousands more going forward to reach our goals of getting all this content online.

If you value this resource, you can support this project - it really helps!

Donations for July 2024
Issues donated this month: 14

New issues that have been donated or scanned for us this month.

Funds donated this month: £20.00

All donations and support are gratefully appreciated - thank you.


Magazines Needed - Can You Help?

Do you have any of these magazine issues?

> See all issues we need

If so, and you can donate, lend or scan them to help complete our archive, please get in touch via the Contribute page - thanks!

Please Contribute to mu:zines by supplying magazines, scanning or donating funds. Thanks!

Monetary donations go towards site running costs, and the occasional coffee for me if there's anything left over!
muzines_logo_02

Small Print

Terms of usePrivacy