modular guitar pedals idea - work in progress...

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modular guitar pedals idea - work in progress...

Postby heaterman » 07 Jan 2018, 18:47

Hello!

I am working on some kind of modular pedal concept. The Idea is to have VCA's LFO's envelope followers, sequencers, delays with different inputs/outputs to controll each other.
For example you could do a simple tremolo with one LFO controlling a vca. But then you can controll the first LFO with another one so that the speed changes according to the second... the LFO speed can also be controlled by an envelope so every time you hit a note the tremolo is going from fast to slow or viceversa.

Here are some videos to show what its all about:

1) This is a basic PT2399 delay. The Time is controlled by a 10 Step sequencer (CD4017 circuit). It can go from weird pitch shifting Vibrato to subtle chorusish sounds. It also has an output from the sequencer signal and an controll input for the sequencer speed.

[youtube]https://www.youtube.com/watch?v=nWvWzKZlO7M[/youtube]

2) Here's a ducking effect. It is done like that: The "Bassdrum" (coming from the boss loopstation) goes into the envelope follower (based on the mu-tron follower section) the envelope signal controls the VCA which squashes the guitar signal. The VCA is done with the Coolaudio V2164 chip using only one channel.
In the video you see these boxes from left to right: loopstation as the bassdrum source - envelope follower - one LFO - a second LFO - VCA (on breadboard) - to the far right you see a simple true bypass switch to bypass the VCA.


Link


3) Again the VCA, but now it is controlled by the first LFO, so it's a tremolo. Later, the second LFO varies the speed of the first one, so it is alternating between two pre-set speeds. In the end, the envelope follower is controlling the first LFO. Every time the bassedrum is hitting, the tremolo starts from a fast to a slow rate.


Link


It's all very prototype-ish, still a lot of work in progress... what do you think of it?

best,
David

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Re: modular guitar pedals idea - work in progress...

Postby aishabag23 » 08 Jan 2018, 07:09

This is very cool!
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Re: modular guitar pedals idea - work in progress...

Postby FiveseveN » 08 Jan 2018, 13:07

Cool indeed. I love it when people develop tools for sonic exploration rather than the next FF or TS variant.
Are you making these for yourself or planning on a comercial series? In any case, take a look at modular synths on the off chance you are not familiar with them; following the Eurorack standard would open up a lot of options.
Ignorance more frequently begets confidence than does knowledge. (Charles Darwin)

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heaterman (16 Jan 2018, 17:36)
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Re: modular guitar pedals idea - work in progress...

Postby heaterman » 16 Jan 2018, 17:36

Thank you!
At the moment i'm just doing them for myself... maybe i consider doing a small series if enough people would be interested, but that's definitely not possible in near future :cry:
And i'm not shure still how practical such a system is gonna be.
Still I have to fix stuff and experiment more. Some problem causes different control voltages. The envelope puts out a different voltage than the LFO and i'm trying two different VCA's (one with a vactrol the other with a 2164 chip) and they two need different voltages. So I'm working on getting these to work all together without having to readjust voltages every time I connect something differently.

FiveseveN wrote:... In any case, take a look at modular synths on the off chance you are not familiar with them; following the Eurorack standard would open up a lot of options.


Yeah! got the idea more or less from eurorack systems :P But I like to have these things working with 9v and like to have most stuff footswitchable. But like having the 5v standard for the control voltages would be a good idea to be somehow compatible.

Anyhow; here are the schematics so far, if anyone is interested. You can see, everything is very simple actually.

The VCA done with the Coolaudio 2164 quad vca chip. It gets quiter, if CV increases.
Image

The vactrol-based vca. It gets louder if CV increases.
Image

The LFO, a simple dual wave LFO, the speed can be controlled by an CV via the vactrol.
Image

And the envelope: Inputbuffer, then a Mu-tron follower, actually. It can go from high to low or low to high CV output. It needs a dual supply...
Image

Last but not least a delay. Just a basic PT2399 Delay but with following features/mods
-effects Loop in the feedback path
-momentary switch to select between a second delay time, this results in pitch shifting effects
-momentary switch to turn on a vactrol for bending like pitch shiffting effects
-CV input for the time setting
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