So I’m curious if there is a schematic out there for a project taking a standard guitar pedal 9v dc, and then converting it to 12+/12-
I’m assuming you’d have to double it to 18 (possibly with a 1044 chip), then reduce it to 12, then also make it negative but it seems like there would be current wasted in the process.
I’d like to make it as compact as possible so as to fit in the circuit of a guitar pedal but it needs to be through hole, not SMD. This will be for a design I have in my head of making a guitar pedal with resonant filter, LFO and envelope
Any ideas on this and any schematics you know of would be appreciated!
If you redesign your idea of “a resonant filter, lfo and envelope” into one that needs no negative voltage, you probably end up with a simpler circuit.
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Well the concept is to have the input function as the oscillator so it could be a guitar, drum machine, simple keyboard etc.
Then the LFO and envelope both specifically affect the filter (I’m thinking MS20 based) with amount controls for each.
Eventually I’d have both the high and low pass filters with LFO and envelope for each.
This could be on the right track for doing the whole thing with 9v+ only!
Well none of these circuits by necessity have to be powered with 2 power supplies. It’s a matter of finding or designing single power supply versions of them.
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MAX1044 is a charge pump. It can give you a handful of milliamps, enough to power a LED maybe but that’s about it.
9 V batteries are pretty useless for anything that uses current (they provide maybe 0.5 Ah, so you’ll get a few hours out of one if you boost to ±12 V and pull 50 mA out of it), so odds are you need an adapter anyway – and if that’s the case, any reason you cannot use a 12 V AC adapter?
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Agreed. Now that I found this 9v filter I just need to find simple ASDR envelope and LFO circuits that do not require bi-polar power supplies. Thank you for steering me this direction
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there’s Cusi Sound who make a 9V (battery) modular project so maybe some ideas ?
his 9V channel
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You can use a 9v power supply with virtual ground for some of circuits (+4,5v-4,5v). I use it a lot, if you want some information or 9v modules schematics dont hesitate to tell to me !!
Synthnerd have a lot of 9v projects.
I have schematics in some posts of my insta page too (look in the descriptions or on pictures)
http://www.instagram.com/saint_et_moudulard
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Some of us don’t have Instagram accounts, so unfortunately cannot see yours.
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Yes I want to create a page in an another support ! (but Instagram have a good Diyers community too)
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Electric Druid ?
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Too bad that electric Druid stuff is in the EU. I’m in the US so it’s less financially viable for me for anything other than a prototype.
Looks amazing though!
Free world-wide shipping for orders over £30 can go a long way 
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@Blackhawkamps I use this adsr with 9v and negative rail of opamp to ground, it work fine, no problem.
If you want to use 1Meg pots, just increase the 2.2u to 4.7u and the 220 to 100 ohms.
https://www.schmitzbits.de/adsr.html
Maybe you can mod it for add a lfo loop mode.
An another 9v adsr with cd4013 cmos (I have not test it)
If you are interested by A/R A/D envelopes generators, this is very simple to build them for a single supply.
How signal would you need in your lfo ? XR2206 or icl8038 function generators modules from aliexpress work good for this application with a little hack/mod.
https://www.instagram.com/p/CE2q9mvBwSF/?igshid=swyc5cd4zleb
https://www.instagram.com/p/B_cgq1Uh79B/?igshid=5iya402rxnox
For a clock/trigger/gate/pulse signal I use a simple PWM circuit with the bad 555 as a square lfo with a gate to trig mod who is integrated on the same module.
https://www.instagram.com/p/CHnkzRCBL9-/?igshid=13duia5j72l3
The 555 lfo from @Dud and casper electronic is cool too for a little 9v synth set.
Tell to me if you want more informations 
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