The Abandoned Idea Dumping Ground

[Taylor]

I thought it might be cool to have a spot where we post ideas for circuits that, either we never finished, decided they were too stupid to pursue, just couldn't figure out, couldn't find a use for, etc. As we all know, "one man's trash is another man's treasure" - sometimes those with more conservative tastes stumble onto something accidentally that sounds terrible and noisy to them, but others love anything that sounds terrible and noisy.

I reckon anything from a vague idea to a full schematic shall be game. If we get enough ideas, I'll build them all together in one box and call it "The Dump".

My first idea is to split a waveform into negative and positive halves, then delay one half with a BBD, and add them back together. By slightly delaying one half of the waveform, I think you can get some nasty crossover distortion, and by delaying it further, I think you could get some really crazy intermodulation happening. I started trying it out using precision rectifiers to split the wave, but didn't really get anywhere with it. I'm not even positive it would work as I imagine it. If it were a great idea, I'd post it in a regular thread. Being that it's a half-baked, dubious idea, it's perfect for The Dump.

Maybe, like physical junk, someone else can repurpose all the sub-par ideas we've got lying around in the shed/attic/brain. Anybody else?

[TELEFUNKON]

BBD is overkill - try delaying with a two-stage phaseshifter first 
Be aware, that the positive and the negative halfwaves will not neccessarily be "interconnected" anymore,
but will look sheared off, and sound like that. Which sure can sound interesting though, especially when phased against each other. (Fuzz-Phase).

[earthtonesaudio]

Hmm... an idea dump... how much space ya got?!   

One I breadboarded a while ago but never got to work: buffer>split to two channels, one low gain, one very high gain (square wave type clipping)>mix with a difference amplifier, so they are subtracted from each other rather than added as in a conventional summing amplifier.  One input keeps the polarity, the other input inverts it, so the idea is that you'd subtract the sine wave from its inverted square wave copy to get a very "pointy" harsh octave-up sound.
I made one side a comparator and it was just awful.  Way too much output from the comparator side which overwhelmed everything else.  If I was gonna do it again I'd just put a simple diode clipper on the "square" side.
Difference amp: http://www.play-hookey.com/analog/difference_amplifier.html

[newfish]

Another phase-split idea. (Is there a theme developing here?)

JFET splitting phase into a difference amplifier.  Works pretty well, but is just too noisy.

[frequencycentral]

Nice idea. This thread will grow and grow. My often abandoned idea is the elusive low voltage submini tube phaser, which I have attempted more times than I care to remember - the last attempt was a nice deep vibrato but no phasing. I conclude I'm not clever enough, but learning all the time. I'm planning another attempt as we speak. I don't know quite why I keep banging my head against it so obsessively. Probably because I know it can be done, and so it shall one day be done.

[newfish]

Obsessive is probably the right word for this sort of thing.  Average bedtime when there's a build in the works is about 1 am.

[jacobyjd]

Still kicking these ideas around:

-Adding a fuzz to my sequencer build--want to figure out a way to add a 'smooth' control using an LDR controlled by the sequencer...but it's a voltage divider, and I couldn't figure out how to make that work with an LDR. Bleh. Dropped it in favor of a resonant LPF, which fits the concept better, since it will largely be a filter/modulation effect anyway. Currently it's looking like Wah, Trem, LPF, and Delay/arpeggiator. Just have to decide on an output mixer design.

-Simulating a tape echo with pt2399s--This is a great idea, but i don't really need one, so who knows if I'll do it. The goal would be to not only simulate, but to enhance functions and add features that were previously unavailable. Also, would want to add envelope-based modulation from the clari[not] into the mix to simulate worn tape, etc.

-not stompbox related, but some day I'd like to return to the concept of a mechanical synth--meaning using 16 identical electric motors, each with their own magnetic pickup (basically a guitar pickup pole magnet with custom bobbin and winding), and a speed control for the motor--increase the speed, you increase the pitch of the tone produced via the pickup. Then sequence the whole thing. Voila: Electric motor techno. Got the idea when I was adjusting my pickup height with a small electric drill one time. Abandoned because electric motors are freakin expensive when purchased new, and I'd need identical ones to make the whole thing work. Just not feasible at this time.

[newfish]

I once saw someone play a Sewing machine.

It was one of the old foot-treadle kind, used to drive a rosin wheel over some strings - a bit like a Hurdy-Gurdy.  Sounded great!

[Meanderthal]

 Oil can delays...

[appliancide]

-not stompbox related, but some day I'd like to return to the concept of a mechanical synth--meaning using 16 identical electric motors, each with their own magnetic pickup (basically a guitar pickup pole magnet with custom bobbin and winding), and a speed control for the motor--increase the speed, you increase the pitch of the tone produced via the pickup. Then sequence the whole thing. Voila: Electric motor techno. Got the idea when I was adjusting my pickup height with a small electric drill one time. Abandoned because electric motors are freakin expensive when purchased new, and I'd need identical ones to make the whole thing work. Just not feasible at this time.

I have always wanted to do something similar. For my version, I pictured tuned pipes like a rhodes that would be played with vibrator motors.

Have you seen this guys stuff? http://www.youtube.com/watch?v=DCZOWexy3Bo&feature=related

[jacobyjd]

-not stompbox related, but some day I'd like to return to the concept of a mechanical synth--meaning using 16 identical electric motors, each with their own magnetic pickup (basically a guitar pickup pole magnet with custom bobbin and winding), and a speed control for the motor--increase the speed, you increase the pitch of the tone produced via the pickup. Then sequence the whole thing. Voila: Electric motor techno. Got the idea when I was adjusting my pickup height with a small electric drill one time. Abandoned because electric motors are freakin expensive when purchased new, and I'd need identical ones to make the whole thing work. Just not feasible at this time.

I have always wanted to do something similar. For my version, I pictured tuned pipes like a rhodes that would be played with vibrator motors.

Have you seen this guys stuff? http://www.youtube.com/watch?v=DCZOWexy3Bo&feature=related

I've checked out some stepper motor music before--never gotten into actually doing it. All of that seemed pre-programmed, and while it's pretty cool, I want something I can play rather than program. I'm sure that's doable with stepper motors, but I'd like to go a more lo-fi route I think

[edvard]

I know this idea has already been implemented *somewhere*, I just don't know where.
I called the idea "dog-ear distortion" and the idea was to simply take a signal and clip the tops with diodes, but instead of throwing it away to ground, I'd take the tops and feed them into an inverting amplifier which would then through a mixer with the clipped signal and so instead of clipping, you'd get a kind of "folding" of the waveform peaks. I also figured that at higher gains, it would get into frequency-doubling territory, but I saw that as a side benefit.

I tried it once, but it didn't work at all like I planned so I figured I was going about it wrong and then got distracted with something else.

[Nasse]

http://hem.passagen.se/robin2/im/hyperfuzz.gif

[cathexis]

I had a long-standing plan to make a wah pedal with a rolling pin (yeah, the kind you use when baking) instead of a treadle. You'd wah the wah by sliding your foot instead of wiggling... I've made lots of different wah pedals to get around making a treadle - LDR variants, sequenced, probe style, envelope controlled etc. I've doodled some around those flex sensors, even. I think the Soul Kiss finally made me give up, a true drool-fest. Now I have three empty wah shells waiting in my stockpile, ant the rolling pin wah probably will never be...

LARS

[earthtonesaudio]

Audio converted to AM by a high frequency (~20kHz) sine, through a 50+ pole Chebyshev highpass or bandpass filter, to make a flanger without a square wave anywhere in the system.  Delay time would be controlled by altering the carrier frequency, and the nice thing about using the filter's group delay is a very small change in input frequency results in a large (exponential) change in delay time, making hypertriangular sweep of the delay time the default with no added circuitry.

All I need is about 400 matched components, and I'll be all set.

[JKowalski]

-not stompbox related, but some day I'd like to return to the concept of a mechanical synth--meaning using 16 identical electric motors, each with their own magnetic pickup (basically a guitar pickup pole magnet with custom bobbin and winding), and a speed control for the motor--increase the speed, you increase the pitch of the tone produced via the pickup. Then sequence the whole thing. Voila: Electric motor techno. Got the idea when I was adjusting my pickup height with a small electric drill one time. Abandoned because electric motors are freakin expensive when purchased new, and I'd need identical ones to make the whole thing work. Just not feasible at this time.

That's called a hammond organ:

http://www.nshos.com/hammond2.htm



Cept it only uses two motors, they all share the same drive shaft

[jacobyjd]

-not stompbox related, but some day I'd like to return to the concept of a mechanical synth--meaning using 16 identical electric motors, each with their own magnetic pickup (basically a guitar pickup pole magnet with custom bobbin and winding), and a speed control for the motor--increase the speed, you increase the pitch of the tone produced via the pickup. Then sequence the whole thing. Voila: Electric motor techno. Got the idea when I was adjusting my pickup height with a small electric drill one time. Abandoned because electric motors are freakin expensive when purchased new, and I'd need identical ones to make the whole thing work. Just not feasible at this time.

That's called a hammond organ:

http://www.nshos.com/hammond2.htm



Cept it only uses two motors, they all share the same drive shaft

Huh. Well.

I THOUGHT OF IT FIRST!!!111!!!   

[deaconque]

Audio converted to AM by a high frequency (~20kHz) sine, through a 50+ pole Chebyshev highpass or bandpass filter, to make a flanger without a square wave anywhere in the system.  Delay time would be controlled by altering the carrier frequency, and the nice thing about using the filter's group delay is a very small change in input frequency results in a large (exponential) change in delay time, making hypertriangular sweep of the delay time the default with no added circuitry.

All I need is about 400 matched components, and I'll be all set.

um, what? 

[earthtonesaudio]

um, what? 

Sorta like a continuous-time analog of a BBD.

[deaconque]

um, what? 

Sorta like a continuous-time analog of a BBD.

gotcha, i can understand that.