Custom Voodoo Labs Pedal Power 2 Plus

[induction]

That resistor is part of a low pass filter that's not really needed. No harm will come from simply replacing it with a jumper (assuming no build errors or user errors), and it will still be quiet. (The regulator and filter caps do an excellent job of cleaning up the power ripple.) Likewise, no harm will come from replacing the resistor with another one with a higher power rating. Neither option will move the problem down the line unless there is a build problem or user error (reversed supply voltage, accidentally plugging supply voltage into one of the outputs, etc.). The problem is the resistor itself. It is simply seeing too much current for its power rating.*

Notice that the Medusa is almost exactly the same circuit as the original circuit this thread is about. Other than the charge pump, the only major difference is that the Medusa is more compact. In a circuit that generates heat, more compact is not necessarily an improvement.




* Power = current squared times resistance. A 100 ohm resistor dissipates 1/4 watt at 50 mA, a 1/2 watt resistor can handle up to 70 mA, and a 1 watt resistor can handle 100 mA. So even a 1 watt resistor can't come close to handling all of the current the regulators are capable of providing. I'd just replace it with a jumper. That said, the current consumption of an unloaded regulator is only a few mA. So if you're burning up resistors with no load, there's probably an error in your build.

[Beaker]

Thanks Induction!

[luca.metal]

Can I bulid this with a switching 12v pover supply? Or it's a bad idea?
I want to make it fit in a 125B so the switching power supply will fit nicely as it takes less space than a tranformer.

[induction]

Assuming your supply is 12V DC, then yes, you can. That's what it's designed for. Part of the beauty of this design is that it turns cheap, noisy (aka switching) adapter power into quiet, regulated power. I use a 12V switching supply to run mine. It works great.

In any case, the supply is not part of this layout. Where you get your 12V DC from is entirely up to you. You can use any 12V DC wallwart you have laying around, or one you find at the Goodwill for $4 (like I do), just make sure it has enough current capability to run all of your pedals (plus a little extra for heat loss).

Also, the 12V supply is not intended to go inside the case, and no transformer is included in this design. You can use an external adapter just like you would with a regular pedal. Mine fits in a 250B, which is smaller than a 125B. Here's what it looks like, in case it helps.

[Pavlos]

just wondering if there is a version of Rocket88's original layout that would have more +9v (Perhaps 10 in total) but omit the 18v and -9v outputs? And I know it might be a crazy thought but how easy would it be to have a modular layout that covers any (Sensible) number of outputs? say an input module, an output module and insert as many individual / pairs of outputs between the two until the desired size is achieved. Was just thinking that some of us are using fairly modest boards with only two or three pedals on it, while others prefer to have a variety of dirt boxes, mods, delays etc at our toes at all times. So why have a large number of outlets when only a few are needed and vice versa. Many thanks in advance for any replies and also many thanks to all who contribute to the site, In a little under a year I've gone from being capable (With care and clear instructions) of re-wiring a guitar to having the confidence to try my hand at even some of the larger more complex/sensitive builds such as delays, phasers, chorus etc, which with a lot of careful reading of posts and taking good advice (Not to mention plenty of fine toothed comb fault finding) have been mostly successful so far I think my trying to play with this would likely result in a pile of ash where I once lived though

[mug]

I build this over the weekend and tested it with a 12V laptop PSU and it works fantastic! I changed the layout to 8x 9V and omitted the -9V and +18V. It is quite repetitive - much like Pavlos said it would be easy to cut off/add "stages".



Since the L7809s are rated +35V max do you guys think a 20V PSU would be ok as well?

[Ciaran Haslett]

20V will be fine however the harder the regulators must work...the more energy they waste as heat.  So it's probably worth heat sinking them just to be on the safe side.

[mug]

I'll install some washers as heat sink and probably will drill some vent holes in the box as well just to make sure.
Thanks Ciarian!

[Chris60601]

This is outstanding!!! I am opting to go the 8 x +9v ports with a 1032L enclosure with a 12v power adapter (as mentioned in the original post).

So, here are my questions:

There is room inside for another vero board that I can install that would give me outlets along the backside. For example, I could add a few more +9s, a few -9s and a few 18s to the backside.

1. Could I use the current 12v adapter to power both vero boards, if so, is the 12v enough?
2. If the above is true, what's the best way to go about it?
3. Could both boards be merged into one larger vero board and still use the same 12v adapter?
4. Would it be better to just separate both vero boards and use separate 12v adapters?


Here are some picks to give you an idea so far:

[rocket88]

I'm actually doing something similar, but with a 1590BB. I'm gonna have 2 boards just like the original layout in there with each board powered by its own +12V adapter. The jacks are gonna be stacked so 2 rows top and bottom. I'm also cutting a some venting in the side to prevent too much heat build up.

Only reason I'm using a 1590BB is to keep the footprint down, but originally planned on the same enclosure you're working with.

[Chris60601]

Sweet! GMTA! I actually have heatsinks for my build. This is a little higher than I would like but I suspect this should fit snuggly into my soon-to-be-delivered Blackbird 1530 pedal board and I suspect my white builds will go nicely with the black board.

[Travis]

Chris what are the inner dimensions on that box? I'm looking to build a power supply but I want to use the Weber transformer. Haven't picked a box yet but I think it will need a bit more height than most boxes provide

[Chris60601]

I picked up my unpainted box at Mammoth (2.65" x 9.75" x 2.0 - outer dims)
Maybe 1/8" off for inner?

[radeeshan]

Hi,

I made the first version of this,



then i removed the +18 part and added another separate board for 5 more 9v outputs, 11 in total I was powering this with an +12v 1A power supply. but after i made it 11 outs some pedals didnt work. so i upgraded the power supply to a +12v 2A power supply. now it's working fine. no humms or noises. totaly happy with this built.

[Teddeeh]

With this build, can i use 33uf or 47uf caps or do i need specifically 22uf caps?

[induction]

You can go higher with no problem. I'd avoid going lower, though. I chose 22u tantalum because they are physically small and I had a lot of them. Electrolytics are fine also.

[Teddeeh]

Thank you man, one more wuestion, could i use a 1n540x in place of D1 to increase the 1A limit posed by the 1n400x/1?

[induction]

That would work. Multiple diodes in parallel works too.

[Teddeeh]

I have heard from people thet the 1n5401 would work but diodes in parallel wouldnt, as the max current would be limited to whatever the diode could handle.
Thats what ive read. Dont know if its true but i trust the peeps who said it.

[induction]

That's not accurate. Current divides itself among multiple pathways according to the resistance of each pathway. Two identical diodes in parallel can pass twice as much current as one alone.

Think of them like water hoses. Assuming the source has enough pressure, 6 hoses in parallel will spray 6 times as much water as one hose by itself.

Or, if you prefer, think of how much traffic can fit on a two-lane highway vs a one-lane highway, etc.