Charge Pump Power Supply

[Structo]

Has anybody here built the pedal power supply kit from Weber?

https://taweber.powweb.com/store/modkits.htm#eps

The transformer has 8 isolated 11vac @ 300ma.

And one 9vac @ 2A

It comes with four rectifier/ regulator PCB's.
If you heat sink the regulator it says the output is good to 1A.

$30 plus an enclosure and power cord.

I was thinking about building a better power supply than the One Spot I have now.
But, that dang little One Spot has performed flawlessly for about three years powering five pedals so I'm not sure I need this thing anyway.

Can someone comment on the 2 Ohm sag resistor?
Why would you want sag in a pedal power supply?

How would you configure it to be rock steady without sag?

[LeftyStrat]

I've been meaning to get one. The nice thing is it will work with positive ground fx like the fuzz face.

The sag control perhaps mimics a dying battery?

[DonMoose]

The sag control perhaps mimics a dying battery?

Yup.

[Gibsonman63]

I recently updated my pedalboard with a power supply with isolated outputs. It was really a night and day difference over my older power supply.

[xtian]

Interested, Tom. Keep us posted.

[SoundPerf]

Funny thing, I just ordered a WPDLXFMR-1 last week. Still waiting for the shipping notice. I just finished routing all the traces for my own 8 @ 9Vdc isolated supply PCB. I'm going to pull apart the other DIY power supply I made with 2 @ 18 Vdc and put them in the new one for a total of 10 outputs plus the 9Vac.

I like using my own parts. I'm going with 1000uf low ESR lytics and .1uf Y5C ceramic after the rectifier and 10uf low ESR and .1uf Y5C ceramic after the regulator.

I don't really have much use for the adjustable voltage feature.(sag) I may make one output this way. Some distortion/germanium fuzzes can sound better with lower voltage. I find an actual battery does a better job if I'm going to be that picky.

The more common reason people find that a dying battery will make a Ge Fuzzface sound better is becuase they weren't biased optimally in the first place. I find it easer to get the biasing voltage proper for the individual trannies with the right resistors and then always use a good 9V supply.

I found this Mfg for the enclosure I'm going to use. I like the way they look and not such a bad price.
http://www.boxenclosures.com/category/c ... s__id=1073

Edit: I forgot to say that the One Spots are really nice and well made/designed. But whenever you start to daisy chain there's always the chance of running into problems. I like to have transformer isolated individual outputs to make if foolproof.

[Cliff Schecht]

With pedalboards I've found that getting good, clean power to the pedals is the trick. You can't use a transformer based wall-wart and expect low noise performance from your high gain pedals. You need well filtered and regulated voltage. A simple 7809, a trimpot, a few resistors and some big uF caps are really all you need to clean up any 120 Hz ripple. Isolated power is nice but not necessary if you use short patch cables and a daisy-chaining power cable like the one One-Spot or Boss sells.

I run a power supply similar to the one that Weber offers (the one from General Guitar Gadgets, had a decently small layout) that has worked fine for many years (close to 10 years now!). As of now I'm running 9 different pedals/devices off of my power supply and can get very low noise performance even with two distortion pedals cranked up and all sorts of modulation pedals added. If your pedals are decoupled properly then they shouldn't be throwing any noise into the mix.

One exception is if you run a lot of gain with a lot of digital effects. IME the microprocessor/DSP based effects have an inherently higher noise floor and introduce a lot of high end noise into your signal chain. I took both a Digitech Whammy (which uses it's own supply!) and a Boss RC-2 off my board because they were adding in a lot of digital hash when I kicked on distortion pedals.

Also I agree that the 1Spot is an extremely well designed wall adapter. It was designed by R.G. Keen for Visual Sounds and he did a fantastic job of building a small, high current, low noise switching power supply. The little accessories they sell are really convenient too, I can only spend so long making little adapters for all of my various pedals.

[Structo]

Wow, thanks for all the info guys.

Yeah, that little One Spot is hard to beat for convenience.

Actually it is only powering five pedals now.

Some people have had problems with them but I haven't had any for about five years.

My EHX Stereo Memory Man needs it's own supply as it was noisy on the One Spot.

If and when I ever gig again, I would like to have something that looks a little better than Eric Johnson's rig......

I had thought of making a snake to hold the signal cables and pedal DC but the dollars add up quickly when you consider all that goes into one.
I know there is that company that sells a modular system but those are big bucks.

[Structo]

If I didn't want any sag and just wanted 9vdc do I eliminate the 2 ohm resistor?

Also, if I don't need an adjustable voltage, should I just eliminate the pot and install a 9v regulator?

[SoundPerf]

The resistor and pot are both part of the circuit for the adjustable regulator (a LM317L or similar) if you didn't want any adjustability then a 78L09 is sufficient. Some feel (and it's true) that using a LM317L regardless is a better solution because they are considered to have better regulation and design for about the same price. I usually just go with a 7809 and keep parts count down.

[Cliff Schecht]

7809 is fine. I like to use a trimpot to get the voltage dead nuts on at 9V. The 7809 has thermal protection which kicks in if shorted. I accidentally left my 7809 based supply shorted for a few minutes the other day. The IC got nice and toasty but after 10 minutes in the freezer everything was back to normal. I'm still on the same regulator from when I built this pedal.

Also 7809 can only do 1A, the LM317 can do 1.5A. The 317 I think also has both short circuit and thermal protection as well as better over specs for line/load regulation but with enough filtering neither matters.

Also Tom you can leave off the sag resistor no problem. I wouldn't use one either, it's just making a horribly inefficient linear regulator even more inefficient.

[funkmeblue]

I built the weber kit for a friend and I am getting hum from the power supply. Do you think upping the 1000 uf caps to 4700 uf would help?

[ampgeek]

I stuffed two of these into a very compact package and it has performed flawlessly for half a dozen years or so.

http://www.generalguitargadgets.com/pro ... t-isolated

I suspect that it is similar to/same as the one that Cliff mentioned.

It is great for easy changing of the output voltage for any position (use sockets at those points and just drop in a new regulator) and is very quiet. I run 9, 12 and 18 VDC outputs to my various homegrown pedals.

The only disadvantage is the low'ish current capacity (can't remember what the limit is but is discussed at the above link). Not quite enough goose-poop for a couple of my commercially available pedals.

I contemplated the Weber option but couldn't get my head around how to fit the transformer into the space that I had available. The Flatpacs for the GGG scheme were just the ticket.

Cheers,
Dave O.

[ChrisM]

Better cheaper solution would be 8 or so small flat pack transformers. This way you get completely isolated outputs.

Add a bit of perfboard, caps and a regulator and got got a great noise free isolated regulated supply.

Weber stuff is usually cheap crap (not always though). The sag resistor thing is a joke. With most effects only pulling a couple of mA there isn't any sag to be had with any resistor you put in line there.

Here's one I made a few year back
[IMG:160:120]http://img.photobucket.com/albums/v610/ ... CF0468.jpg[/img]

[IMG:160:120]http://img.photobucket.com/albums/v610/ ... CF0470.jpg[/img]