Guitar Pedal Questions

[meblumen]

I have been getting bored with the usual flair of guitar pedals and sounds and hence have begun searching for something new and interesting, possibly even a new project. Anyway, I was searching the net and stumbled upon these: http://www.musictoyz.com/guitar/pedals/midfi.php
and was curious if anyone knew how they worked? More specifically, I'm really interested in the appregiator and random noise generator and how I might incorporate similiar ideas into my own ideas.

 

[adamasd]

They are just converting the guitar signal to a square wave so it can be easily processed and transformed. They can also add stuff since it is a square and have it sound like the original. Like in the Glitch Computer, it has a square wave VCO and some sort of arpeggiator. The second has some random sample and hold effects, and probably control circuitry, and another square wave VCO. The samples for the third one do not work, but I bet it is the same sort of thing. Read up on modular synths electronics, its all there.

adam

 

[StephenGiles]

But I think there may just be a sophisticated fundamental extractor tucked in there somewhere - which is not easy, not "just converting the guitar signal to a square wave".

 

[adamasd]

[quote author="StephenGiles"]But I think there may just be a sophisticated fundamental extractor tucked in there somewhere - which is not easy, not "just converting the guitar signal to a square wave".[/quote]

Yes there is more to it then just converting it to a square wave, but I doubt nothing as fancy as a sophisticated fundamentle extractor. PAiA did it with abit of compression and simple low pass filtering. A dual opamp, a NE571 and a couple transistors, works great, at least as I remember, it has been awhile since I played with this circuit.

http://www.paia.com/guitarfx.htm

The Roctave Divider, might be a good place to start for doing this sort of thing. I think the Projects for Guitarists book which they also sell at paia also has this circuit in it.

adam

 

[StephenGiles]

Why do it simply? The EH Guitar synth fundamental extractor was used in the later version of the deluxe Octave Multiplexer and tracked perfectly. I built both years ago so I can recommend it.

 

[adamasd]

Why do it simply?

Why do it harder then you have to? The PAiA method is nice and simple, and very effective, Never had any tracking problems with it.

adam

 

[meblumen]

Thanks for the help, I really appreciate it. I have done some searches here and via google/yahoo and have come up with an overwhelming amount of info. I'm no newbie when it comes to soldering and modifying some of my gear but have never really attempted to design anything before, especially of this nature. Anyone have any good beginner book recommendations, links or advice to consider. I think the idea of converting the guitar signal to a square wave (or other waveform) and then processing it is a really cool idea and one that has a lot of unexplored potential in the analog stompbox realm so if anyone has any ideas or things to consider feel free to lend a hand. Thanks again.

 

[moosapotamus]

[quote author="meblumen"]I have done some searches here and via google/yahoo and have come up with an overwhelming amount of info.[/quote]
Perhaps you ran across these...

Uglyface (scroll down)
http://www.geocities.com/tpe123/folkurban/fuzz/snippets.html

Crash Sync (scroll down)
http://www.hollis.co.uk/john/circuits.html

And, you might want to check out this place, too... :wink:
http://www.diystompboxes.com/smfforum/

~ Charlie

 

[StephenGiles]

[quote author="adamasd"]

Why do it simply?

Why do it harder then you have to? The PAiA method is nice and simple, and very effective, Never had any tracking problems with it.

adam[/quote]

Because I can!

 

[Gus]

Stephen

I wonder how many of the lab know you have been at effect sites for many years if I am remembering correctly. Charlie has been on the web for some time as well.

on to tracking

The rocktave might not track as well as the EH stuff(micro synth) I have heard both but not at the same time and I "remember" liking how the EH worked.

 

[adamasd]

Because I can!

haha, fair enough.

Stephen

I wonder how many of the lab know you have been at effect sites for many years if I am remembering correctly. Charlie has been on the web for some time as well.

I did, he has supplied quite a few vintage effect schematics to the guitar fx community over the years, along with corrections and a few of his own.

The rocktave might not track as well as the EH stuff(micro synth) I have heard both but not at the same time and I "remember" liking how the EH worked.

The EH does track better I guess, that is my problem with it, its hard to get it to screw up. Other then just playing multipul notes at once, which scews up in a very predictable way. The PAiA can track perfectly, but you can make it scew up. You can get it to scew up at predictable times, but what it will do when it scews up is not predictable. Which is a good thing to me, I like surprises.

adam

 

[khstudio]

I'm sitting on my watch so I can be on time.

That is funny :razz:

 

[StephenGiles]

If my heart had a window, would you see through the pane?