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Lunchbox synth

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Crammed a digital delay, spring reverb and function generator into a lunchbox. The fact that it says korg is sort of a synth geek joke. _ Big thanks go out to tonepad.com and generalguitargadgets.com for being such great resources for this beginner. All boards etched by me using press-n-peel blue and RadioShack etchant.

audio samples are here for all settings full and here for a little restraint
noahh2 years ago
I remembered your synth when I was at Goodwill looking for an enclosure for a project and bought a lunchbox for it. Thanks for the cool idea.
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pstretz (author)  noahh2 years ago
<3 your project! sounds great, glad I could help inspire. :)
riverreaper2 years ago
ive an old casio key board i just gutted ive plans to put it in somesorts box , with were the keys press down on swiches {is a 2 parter} on the surface along with its other pad switches , im still searching for a good containr . im wondering if any of the digital delay, spring reverb and function generator would work hooked to it as well for added sounds , it has midi in/out but my kore2 synth is already in use with upgraded devices . have you seen any keyboard hacks that look easy ?
I love this. I was thinking about building a lunch box synth but with the control panel inside instead of using the metal lid. Then it would be its own case as well.
pstretz (author)  AmericanPringles3 years ago
That's a great idea! Also it'd be a little easier to assemble. ;) I'm finding that the solid core wire i ended up using for convenience is starting to break since everyone wants to see inside and they flex when I open the door. :( I recommend using a clear plexi/acrylic for your panel so everyone can see the guts without taking the box apart. Also post a pic or a link when you get yours done. I'd LOVE to see it! Happy Making!
rapyourself4 years ago
Hello there, I'm making an experiment based on non-newtonian fluids and I need to build a analog frequency emissor, i mean like this: http://lab.andre-michelle.com/wavepole-synthesizer, but analog, something like what you got here..I don't understand much about electronics and i tougth maybe you could help me or recommend a site that could be useful to me..thankz
pstretz (author)  rapyourself4 years ago
 I'd be happy to help.  Please PM me about what you need to do and we'll see where to go from there.  :)
what do you mean by PM? I'm sorry, but I'm not english and I'm not familiar with some terms :( sorry again
pstretz (author)  rapyourself4 years ago
Sorry.  PM is Private Message.  You can do this by clicking on my user name and then click the Private Message me button.  :)
Nucleus5 years ago
Hey, does this synth can modify INPUT of music? Example "Cigar Box Guitar"
pstretz (author)  Nucleus5 years ago
No, not by design, but you could hook it up to a ring modulator as the carrier signal or if you just wanted the reverb and delay, you could put a switching jack to bypass the function generator and plug in any sound you want.
Dr_Stupid5 years ago
did you choose Korg as the lunchbox because of Korg and their synthesizers? or was that just by happenstance?
pstretz (author)  Dr_Stupid5 years ago
that's absolutely why i chose it. I was looking for a space themed lunchbox, but when i found this, it was too good to pass up. :-) I hope to put together a kit similar to this soon.
Orannis5 years ago
XD Korg. I need to try this.
Axlzero4516 years ago
I got the korg joke. Does that make me a synthesizer geek?
tmurder6 years ago
how did you power the whole thing? looks like dc from a wall converter. how then, did you get the -9v for the reverb?
pstretz (author)  tmurder6 years ago
i just used a charge pump converter IC. very handy circuit to have lying around. all the details here
tmurder6 years ago
are you using an xr2206?
pstretz (author)  tmurder6 years ago
I just used 1458 op amps because that's what I had. really anything that makes sound would work. you could replace what i have here with an atari punk console if you wanted to.
tmurder pstretz6 years ago
fantastic! this was exactly my solution, i've already made one. thanks for the inspiration!
pstretz (author)  tmurder6 years ago
i'd love to see it. please post a pic. :-)
tmurder pstretz6 years ago
er i meant i had built the atari punk console. still waiting for a few parts in the mail.. i'll post a pic when its all done :)
I'm impressed, thanks for sharing this. PLZ PLZ PLZ make an instructable, so many builders here want to get more familiar with these kits.
pstretz (author)  conceptualstratagem6 years ago
will do. it'll take a little while though.
bowmaster6 years ago
PLZ PLZ PLZ Make an instructable
pstretz (author)  bowmaster6 years ago
will do. it'll take a little while though.
tmurder6 years ago
what does your function generator look like? or, can you point me to diy plans/resources on building one? i didnt see any on tonepad
pstretz (author)  tmurder6 years ago
function generator i used was found on page 10 of this pdf. i took each output and used a 10K pot and 10K resistor to make a mixer like-a-dis i didn't bother with the op-amp so i connected used the audio out where R7 is. that way i can mix the 3 waveforms together and get a different sound. hope this helps. i want to add an envelope filter and then create a pcb layout so the whole thing is on one board and has a single header for the wiring. instructable will be posted when i choose a filter i like.
The all-out sample sounds way "Forbidden Planet". Sweet!
pstretz (author)  incorrigible packrat6 years ago
thanks
You're welcome. I thought of a splendidly obscure synthesizer reference; if you used an old "Tears for Fears" lunchbox, featuring Roland Orzabal and that other guy. Only a select few would get the joke. Of course everyone else would merely mock you for having a "Tears for Fears" lunchbox (not that there aren't far worse bands to have lunchboxes of).
Awesome job! If you post it as an Instructable, I will have to show this too my friend, great job.
Patrik6 years ago
That's great - excellent choice of lunch box! :-D Is that a red LED for the mastodont's eye?
pstretz (author)  Patrik6 years ago
no, it's a momentary switch so I can trigger the audio to the digital delay. The switch in the mastodon's mouth switches from continuous output to momentary output. that way I can change frequency without hearing it then push the button and send the audio to the delay. _
gmoon6 years ago
HaHaHa...that's marvelous! (I've got an X-Files lunch box I might use for something similar...) But many unanswered questions: -- What's the signal input? Is it self-contained "twiddling" or some other signal source? (probably internal , triggered with that big red button, right?...) -- Schematics? -- Sources (reverb tank, etc?) -- More / better documentation?
pstretz (author)  gmoon6 years ago
there is no input. I'm using an op amp function generator into a resistor matrix for creating sound, it passes through the delay, then reverb. You can mix the amount of sine, triangle, or square wave with the 3 knobs at the top. The red knob is pitch/frequency. I didn't have complete instructions for this and that's why it's a slideshow, not an instructable. the parts I had lying around so really it was just like $15 for the lunchbox. Ask any questions you need to and I'll do my best to answer them.
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