Io Distorter

electricteeth · October 18, 2011, 12:04:20 PM

I have been on this forum for a few months but haven't posted much because everytime I had a question it was already asked and answered by someone else!

This is my 3rd post and my first attempt at a design! I hope it is liked....
So, I play alot of keyboards/synths and when I run them through distortions and fuzzes I tend to get alot of line noise when not playing. I set my mind to developing a distortion that could get really heavy and then gate at the end. It took me a couple of days to figure out but I got it! It sounds great with keys and my guitars with noisy pickups. It has lots of great gating and tone destruction options and I was surprised to hear how well it could be tamed with a 1m pot and small cap for a feedback loop. I got the opamp circuit (741) idea from forrest m mims basic comparator circuit. The tran is 2n3904. Here is the schematic and some soundclips later after I do some other stuff.

I also screwed up on the schematic. Switch the 47k and 470k around.

electricteeth · October 18, 2011, 12:19:51 PM

QuoteI was surprised to hear how well it could be tamed with a 1m pot and small cap for a feedback loop.

By tame I meant still distorted as *)(&(*&

slacker · October 18, 2011, 01:00:12 PM

Looks cool, look forward to some clips.

CynicalMan · October 18, 2011, 03:39:16 PM

You might want to add a 1-10M resistor in the feedback loop of that op amp. Some op amps won't work properly without DC feedback. You also might want to put a 10k resistor in series with one of the sides of the 10k pot. That way it will go from gated to non-gated, rather than gated to non-gated to gated.

electricteeth · October 18, 2011, 09:24:22 PM

I am going to try those things as soon as i hit the breadboard tomorrow or the next. For now here are some sound clips of what I have so far!

http://soundcloud.com/rick-deckard-sfpd/io-distorter

PRR · October 19, 2011, 01:19:59 AM

> add a 1-10M resistor in the feedback loop of that op amp. Some op amps won't work properly without DC feedback.

I suspect he does not want "work properly". He wants the opamp to idle slammed against its rails so it will shut-up the hissing. With signal, it bangs itself off the rails and "*)(&(*&" gets through. Brutal, crude, but effective for what he wanted.

electricteeth · October 19, 2011, 08:19:55 AM

Exactly what I was looking for. A huge sounding distortion that shuts up when not receiving signal. I tried the suggestions and though it did clean everything up quite a bit, It also brought it back to a more typical sounding circuit and also cleaned up the functionality. I have decided not to use those modifications in my version but I am drawing an updated schematic and I will be sure to include them for a more cleaned up sound. Thanks for the help. Next time I get on the breadboard I am also adding an oscillation loop to see what kind of noises this baby can make on its own. I am currently using a 741 op amp but I also want to see what it sounds like with a 386 in there!

CynicalMan · October 19, 2011, 08:29:51 AM

Quote from: PRR on October 19, 2011, 01:19:59 AM
> add a 1-10M resistor in the feedback loop of that op amp. Some op amps won't work properly without DC feedback.

I suspect he does not want "work properly". He wants the opamp to idle slammed against its rails so it will shut-up the hissing. With signal, it bangs itself off the rails and "*)(&(*&" gets through. Brutal, crude, but effective for what he wanted.

I know, but I've had TL0** op amps that wouldn't even pass signal without DC feedback. YMMV.

electricteeth · October 19, 2011, 08:51:13 AM

@Cynical
Your post was very very very helpful! I think i will try a tl082 in the circuit as well!

Also, you guys are probably light years beyond this but I have been referring alot to forrest m mims III's mini notebooks. Everyone of those circuits is a pedal waiting to happen! Check one out if you haven't yet!

electricteeth · October 19, 2011, 09:11:59 AM

Also, the "Io" is a reference to jupiter's moon of the same name! Nerdy? Yes! Cool? Yes!

artifus · October 19, 2011, 11:17:30 AM

subjective? here's to being human!

electricteeth · October 19, 2011, 12:50:38 PM

HERE HERE, Also, I am "she" not a "he"

artifus · October 19, 2011, 01:51:34 PM

go girl!

WGTP · October 19, 2011, 02:08:01 PM

You might find this interesting. Lots of cool stuff there.

http://folkurban.com/Site/TMKtoomanyknobs-710.html

electricteeth · October 19, 2011, 02:13:39 PM

Too many? This looks like just enough knobs.

Totally going to build this on the bread. THX. Also, once I wrap up my work on the Io i am going to start working on a pedal that utilizes logic gates. I have had alot of fun running things into different logic gates at school when no one is in the lab and getting neat fax machine sounds. I wonder if I can make a pedal with that Idea?

artifus · October 19, 2011, 02:19:25 PM

handmade electronic music

electricteeth · October 19, 2011, 02:26:14 PM

This community is awesome. Everyone is so helpful! I am trying to learn things on my own the hard way but it is wonderful to have people to fall back on and a group to contribute to. Been building fuzz' for people in my hometown for a few years and just recently got interested in designing my own stuff. I promise to post all schematics first here for free! Everybody is so helpful and thank you so much! I thought I would post my Io Distorter and everyone would be like: "lame" but it seems that everyone is receptive to what I am going for with it.

PRR · October 19, 2011, 11:45:22 PM

> wouldn't even pass signal without DC feedback

It's a tricky field. Often if you jam a BIG signal in, bigger than guitar, something comes out. This has a sorta-hi-gain booster in front. An added trick is that 10K bias pot. An additional factor is that it has no DC path for the "- in" pin. I'm not, on my own, sure it would work; I accept electricteeth's report that it does, as "tone destruction", for her, with those specific parts.

electricteeth · October 20, 2011, 08:40:46 AM

Bingo! Through further examination I am realizing that though the tone is unique and mangled the way I like it, its not for everyone. It totally works with other parts too. Tried some different transistors in there. They all sound the same. Today I am going to try a 386 and a 082 in there and see what i can get. The current circuit may not get a different sound with those component changes but then again it might just be money! We will see. I have time for the breadboard today after I go to kittery and pick up some awesom 7" of my band that just got pressed (whispers) so excited. Im 27 and still haven't been on vinyl until NOW. Also my boss called and gave me the day off randomly. Awesome. Can't wait to be pedaling all day!

electricteeth · October 20, 2011, 08:43:12 AM

@Paul R
Check out the sound clip I posted of it. Obviously there is much to be desired still while I continue to tweak it but there is prove that it is in fact a working circuit. I wish there was a meow emoticon

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Io Distorter