Magazine Archive

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

Dod Mod I: Envelope Follower


With the stock 440 envelope follower, the resonance of the filter is fixed. However, there is a simple modification you can do to create as sharp a peak as you want - even to the point of oscillation.

Open up the case and examine the circuit board; you'll see a TL022 dual bifet op amp. A 430k resistor (may be 470k in some units) runs parallel to pins 5 through 8 of the TL022.

To add a variable resonance option, simply add a 100k trimpot in series with the 430k resistor. The easiest way to do this is to disconnect one end of the resistor, and re-connect this lead to the middle terminal of the trimpot. Then, connect either of the other trimpot leads to where the resistor lead used to be.

Once the trimpot is in place, rotate the dial until you get the response peak you desire. That's all there is to it.

(David DiFrancesco is an engineer with DOD Electronics.)



Previous Article in this issue

Pickup Switching Trick

Next article in this issue

Dod Mod II: Chorus


Polyphony - Copyright: Polyphony Publishing Company

 

Polyphony - Jan/Feb 1981

Donated & scanned by: Mike Gorman

Previous article in this issue:

> Pickup Switching Trick

Next article in this issue:

> Dod Mod II: Chorus


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 November 2020
Issues donated this month: 2

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

Funds donated this month: £48.00

All donations and support are gratefully appreciated - thank you.

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