How to mod in a stutter effect

[PubliusValerius]

Hey guys, I'm completely new to this, but do have some experience with basic electronics, soldering, etc. I'm fascinated with the possibility of modding and building my own pedals.

What I want, is a true stutter effect, that simulates switching a pickup on and off at controlled rates. Similar to a tremolo without the volume swell, and that clips completely in to completely out. I have several old stompboxes I could potentially mod if you think that's a good idea. One is a DOD chorus pedal that would be cool with the stutter. Or if there's another route to go, let me know.

The only pedal on the market I know of with exactly the effect I'm after is the mooer mod factory switched to stutter. Is there any info you guys could share? What component would simulate this effect? Any help would be appreciated. Thanks!

[Jdansti]

It seems that a tremolo that cuts the signal on and off with a square wave would do it. I've made one with a 555 timer and it is very choppy.  The problem with the 555 is that it's difficult to get rid of the ticking sound that this chip produces. Any LFO that gives you a square wave, in conjunction with a vactrol (LED/LDR pair), should do it. It would be nice to have control of the amount of time the signal stays in and how long it stays off for each cycle.

[smallbearelec]

My Tremulous Bear

http://diy.smallbearelec.com/Projects/TremBear/TremBear.html

will do this (and much more), though it's not a beginner-level build. If you pursue the idea, the article covers the tweaks I included (some learned from the residents here) to control the inherent ticking of the chip.

[PubliusValerius]

Thanks for the replies and info. I have experimented with some square wave trems, and I can't find exactly the choppiness I'm looking for. They all still have some level of swell in my opinion. I haven't tried them all by a long shot though.

I found a perfect song with the sound I'm after. The beginning intro to know your enemy by rage against the machine is what I want. It completely cuts in and out at a controlled rate, like the signal is being totally cut in and out. Check it out: http://youtu.be/zSHtniUl8V4

[PubliusValerius]

Smallbear, the third sound clip example in your pedal is what I want. That's awesome. Thanks for sharing!

[jimsreynolds]

I think what you are after is a 'kill' switch'.  This is a momentary button/toggle switch wired directly into the guitar itself.  The switch is 'on' normally and turns 'off'  when you actuate it.   You could build one into a pedal pretty easily but it is actually easier to use on the guitar,  certainly very easy to install.

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[chuckd666]

What about like... a Vox Repeat Percussion/EQD Hummingbird kinda thing? They have a great stutter effect at high depth.

[PubliusValerius]

What I was after is not something you activate manually. I wanted a pedal that, when the footswitch is depressed, activates a on/off  true square wave tremolo with a knob to adjust the rate. I ended up purchasing a BBE Tremor, which is an exceptional classic tremolo - but gets really close to what I was looking for when the depth is jacked up. It still has a little bit of the "swell" effect  present that I wanted to completely get rid of, but it's serving its purpose for now. It does have a wonderful warm classic Fender trem tone though.

[Kevin Mitchell]

The DOD chorus circuit seems to use a bucket brigade device (BBD). I'm not sure what version you have but looking at this schematic I would say the LFO is putting out something close to a sine wave and is restricted from producing a real square wave. To experiment what I would do is isolate pin 5 (2nd + input) of the LFO opamp instead of it going to the 220k and rate control you could connect that pin to the other + input (pin 3) of that opamp. That should give you a square wave. I have a good amount of tinkering experience with such traditional opamp LFOs. But since the DOD seems to be a BBD based chorus it may not produce the deep optical tremolo sound you seem to be after. If you would like to take a crack at it I'll gladly sketch something up with your cooperation.

If that doesn't work out for ya I'd suggest the trem lune. It works for me and is a very simple circuit if you're up to it.