is there a way to get + AND - 9 volts off one power supply? and another dumb ?

[pinkjimiphoton]

i know, newb alert, but i tried searching and now my eyeballs are drippin' down my cheeks...

i built this a while ago...

http://www.diystompboxes.com/smfforum/index.php?topic=90228.msg766412#msg766412

here's a better pic, pdf...exact same device.

http://experimentalistsanonymous.com/diy/Schematics/Fuzz%20and%20Fuzzy%20Noisemakers/ETI%20Octave%20Fuzz.pdf

i thought it ran on 18 volts, but r.g. said it was a 9 volt bipolar supply with a solid ground, or something to that effect.

i really wanna add this to my pedalboard, i can replace my bobtavia and big muff both with just this one pedal...but i need to somehow be able to run it off a standard kinda power supply, if possible...is there any way to do that, easily, efficiently, and in a small enough way to make it fit in the box? i'll have some room to work with if i ditch the batteries.

or should i just bite the bullet and run it with batts?

also, right now, i have two footswitches wired up, the first one is a standard in/out bypass with led , the second switches fuzz 1/fuzz 2 , also with led's to show which fuzz is on at the time.

my really dumb newbe question is, how can i make it so that the fuzz selection led only lights when the effect is not in  bypass? right now, one or the other of the fuzz led's is ALWAYS on from the moment i power the beast up.

is there any way to fix that, looking at the schematic? sorry for my ignorance, but i'm kinda stumped on how to do this correctly!! my way works, but i have a feeling there's more to it than i seem to understand as far as doing it correctly/efficiently.

thanks once again!!

[Govmnt_Lacky]

Hey Jimi,

First of all... very interesting work you have been doing on the Ludwig project    Looks like you guys are almost there!! 

Now, unless I am wrong, why can't you get your +9V and -9V out of a regular charge pump circuit?

You could just get the +9V from your input. Then, you can run a parallel input into the charge pump to convert it into -9V VIOLA!!!!!!

Hope this helps 

[Renegadrian]

yeah you should check the MAXIM ICs

[pinkjimiphoton]

hi guys, i've heard the term charge pump a bunch of times, but what is it? is there one that would be better for my application than another?

got any link or anything that i can learn enough about it to make a realistic decision? i really know nothing about this stuff!!!

[frequencycentral]

http://www.geofex.com/circuits/+9_to_-9.htm

[R.G.]

Technology has moved on. I'd use the LT1054 today for the same app.

I *gotta* get time to rewrite stuff on GEO!   

[Govmnt_Lacky]

Technology has moved on. I'd use the LT1054 today for the same app.

Good call RG.

I recently had to do some research on the LT1054 to see exactly how much current it could handle. Since the MAXIM 1044 can only top out at around 50mA I was curious.

I got info directly from the manufacturer that the LT1054 can handle up to 100mA 

I proved this by using it in a MXR M117 clone that I built and I have yet to see it fail as I measured it pulling between 75-85mA

Definitely recommend the LT1054 

[pinkjimiphoton]

ok, i'll try one of those instead...but...which one? and do i basically wire it the same as in R.G.'s illustrations still?

they have a bunch of different ones at mouser,

http://www.mouser.com/Semiconductors/Power-Management-ICs/Charge-Pumps/_/N-41dte?Keyword=LT1054&FS=True

some say Charge Pumps BiPolar Regulated, some say Charge Pumps Switched-Capacitor Voltage Converter

and i am clueless! does it matter which is used?

i'll order one tonite, i love mouser...it'll be here by tuesday....but which? i'm imagining (in my limited newbe way) that i'm looking for the charge pump bipolar regulator, right?

either
595-LT1054CP
http://www.mouser.com/ProductDetail/Texas-Instruments/LT1054CP/?qs=sGAEpiMZZMuCocSLMfZw%2fyGSoHZPoTgByzTJiBAZ4hc%3d

or 595-LT1054IDW

http://www.mouser.com/ProductDetail/Texas-Instruments/LT1054IDW/?qs=sGAEpiMZZMuCocSLMfZw%2f6sUt7kx7cy2kG1M5wKajsQ%3d

does it matter? or should i get the capacitor voltage convertor one?

[R.G.]

Be sure you get the "CP" version. It's in a DIP package. The other one is surface mount.

[pinkjimiphoton]

thanks bro!! done!!

[markeebee]

Mad Bean has a nice prefabbed board, and a layout if you want to make your own:

http://www.madbeanpedals.com/projects/RoadRage/docs/RoadRage_ver.3.pdf

[pinkjimiphoton]

thanks mark, looks good! i'll see if i can whip up a vero version later. thanks again!

[digi2t]

This will give you + and - 9 vdc. The same principle is used in Taylors Gristleizer pedal, it works well.

http://gaussmarkov.net/wordpress/circuits/bipolar-9v-power-supply/

You put +9 in, you get + and - 9 out. You'll just have to be carefull about current though.

Cheers bro!

[pinkjimiphoton]

awesome bro, thanks!!

that looks like the easiest route to go with so far. i like the big caps idea...nice and clean and quiet. i ordered the charge pump last nite, should be here tomorrow.

figured out my switching dillemma too...was so obvious i coulda smacked my self!!  just changed it so the b+ went to the center lug on the bypass switch, and ran a jumper from the led cathode spot on the switch to the center lug on the other switch. easy, easy...works great~!

[digi2t]

figured out my switching dillemma too...was so obvious i coulda smacked my self!!

Often times, the best thing is to walk away, and go do something completely different. Game of stickball, have a beer, take a crap, whatever. Then, when you decide to come back, the solution unveils itself to you.

Just life's little way of telling you, "Hey, asshole... take a break!"

[pinkjimiphoton]

[MikeH]

Theres also a +/-9v project at Tonepad using the MAX1044.  I've used it a few times; it works great.

[pinkjimiphoton]

yah,  i saw that...but gonna go with r.g.'s suggestion, chip should be here tomorrow, and then i'll see what's what!

thanks tho bro!