Do power supplies really matter?

[Benjamin Strange]

It's been a long time since I frequented the Effects forum - I used to be known as the guy with the biggest (and possibly the most expensive) board here. I ran into some trouble with the IRS, and was forced to sell about $8000 worth of pedals (eek!).

Things have changed quite a bit in the pedal world, and I have no idea what's going on these days. I have stumbled into a pretty serious situation playing in an electro hip-hop band, which is being backed by the Black Eyed Peas, and features Fergie as a guest vocalist on the record. There's not really any standard bass tones on the album, and I'm being asked to recreate many of the synthy and fuzzed out bass sounds, which I plan on doing using a mix of pedals and bass synths. Since I'm so out of the loop as to what's going on, I want to make sure I start the whole thing out right, starting with the power supplies.

There's a lot going on out there, and possibly a lot of pseudo science hype regarding pedal power. Are there any real benefits to the Voodoo Lab PP, or similar power sources, or will a One Spot do the exact same job as as something that costs 10x as much? I know some of the pedals I will be getting will be using different voltages (such as a Whammy 4 and AC powered units), which might be an issue with as many pedals as I can forsee needing. Also, there's a good chance a world tour opening for the Black Eyed Peas could be in the works, so I would possibly need to be considering my input voltages in different countries, so any info on that would be very helpful.

(Also, just to head off (or encourage) any potential humourous questions and/or remarks, yes, I'm the only white dude in the band. I come from a background of industrial/ambient metal, and have never played hip-hop before, but that's exactly what they want. We strike quite the amusing picture: super skinny white dude bassist with a mohawk grooving with the giant, fat, black monster drummer (from Lyrics Born). Yes, it's awesome.)

[TOOL460002]

congrats- sweet gig you got going there.

nothing wrong with a 1spot. i have one im happy with- but i dont trust it with anything that requires more than 200ma- but i didnt expect it to- so it works perfectly for me.

that said- since youre looking to power irregular voltages- you need something more. note that the pp2 can do 24v- but itll take up the last 2 (of 8) outputs- and if one of your remaining pedals is 18v- thatll take up another 2.

for lots of strange voltages you cant beat an ac strip. on my smaller board i have a furman pluglock ac strip- mounts underneath pedaltrains quite easily. i have a 1spot on that for 9v- low amperage- and then 4 spots for wall warts. that combo is also a fraction of the cost of a pp2.

as for world travel- i cant tell you. they make the pp2 in a couple voltages- but id imagine youre fine with 110v. id think a tour like youve described would find a way for you to plug in.

-Adam

[bongomania]

IMO there is some BS-type voodoo about different power supplies, but there is also some verifiable truth behind certain claims.

Whenever you see someone posting "get a 1spot, it works perfect for me" all they are saying is they've never tried to power an unusual pedal, or combine different polarities in the one chain, or use a pedal that was sensitive to noise on the ground plane, or any of the many very real problems that can come up when you have a complex combination of different brands and vintages of pedal.

So if you do plan to power any oddball gear together, the Voodoo PPII or similar device with all isolated outputs is worth its weight in gold.

If it happens that the pedals you buy are all happy sharing a common ground, then the 1spot (or similar) is fine.

Where the BS-type voodoo comes in is in the realm of power conditioners. I wouldn't believe more than 10% of the claims made in that category of device.

For me, using an assembly of unusual pedals, a PPII and a regular power strip is the perfect practical solution.

[Benjamin Strange]

Originally Posted by bongomania

Where the BS-type voodoo comes in is in the realm of power conditioners. I wouldn't believe more than 10% of the claims made in that category of device.
.

This is what I'm curious about - what are these BS arguments, how are they disproven, etc., etc.?

[niftydog]

In terms of mains or "line" filters, the simple debunk is that practically all electronic circuits use DC power, which in good gear is already highly filtered and regulated. Filtering and regulating the mains supply does very little, if anything, to improve the performance of the DC power supplies.

The mains voltage usually terminates at the primary of the transformer or, in the case of a switch mode supply, at some rectifier diodes and doesn't go anywhere else in the circuit. Good gear also filters the incoming mains with a few caps and is designed to cope with fluctuations in mains voltage without detriment.

If you're into belts and braces stuff, get a line filter. If you buy and trust your quality equipment, there's really no need.


As for DC power supplies, the isolated outputs are a definite benefit IMO. Ground loops can be intermittent, but when you get them they can be really disruptive. A good supply with isolated outputs all but eliminates the possibility of your pedalboard causing ground loops. Well filtered supplies are a must or else the mains hum gets injected into everything connected to the supply.

The best IMO is a custom built supply. The voodoo labs are great, but a bit limited in their output current and kinda pricey. Several pre-built power supply 'modules' can be mounted in an enclosure pretty cheaply, and you can customise the configuration.

[JanusZarate]

[cracks his fingers as he begins a LONG post]

AC powered units AND world touring? Hmm... here's a useful overview of a few popular power supplies, to give you an idea of your options.

The Voodoo Lab Pedal Power 2+ is very versatile because of its isolated outputs. Here are its general specs:

(6) 9VDC outputs @ 100mA max. each
- (2) of the (6) are adjustable outputs with variable voltage dials (4-9VDC)
- (4) of the (6) have switches to change the voltage to 12VDC
(2) 9VDC outputs @ 250mA max. each
- Switches for both outputs to provide the necessary voltage for Line 6 Modeler pedals (I forget the spec...)
(1) Courtesy AC Outlet

You can use a special Y-cable to create 18VDC and 24VDC sources for pedals that need it.

But those few DC pedals that need more than 250mA, as well as AC pedals, are out of the picture. However, it has a courtesy AC outlet on the back which you could plug a wall wart into. I used it for my old Whammy IV, and I use it frequently in live situations to power our rhythm guitarist's board so he doesn't need to use an extension cord.

The other problem with the Voodoo Lab is that the U.S. version only works on 110/120VAC. You'd need to order the proper version (i.e., 220VAC and others) for foreign countries from Voodoo Lab, if you wanted to use one abroad.

Voodoo Lab is coming out with the Pedal Power Versa sometime soon (although it's been delayed for a while, and final specs are pending). It's a combination of their PPAC 9 (which only powers AC pedals like the Whammy) and PP2+. It has less outputs overall, but it'll cover 9VAC (for the Whammy).

Meanwhile, switch-mode power supplies like the Visual Sound 1 Spot and Godlyke Powerall can work worldwide without a transformer (100V-240VDC) - they simply need the right connector. They can provide 9VDC, up to 1700mA, via a daisy-chain setup. With special "voltage pump" adapters, you can increase the voltage on a single barrel in the chain up to 18VDC or 24VDC, at the cost of spare current. It's cheap, efficient, and covers a typical pedalboard rather easily. But daisy chains are the bane of positive-ground pedals and others that require isolation.

The Dunlop DC Brick also operates on a "daisy-chain" principle (in other words, no isolated outputs), but you need the proper 18VDC wall wart for the country you're in to run it. It provides up to 325mA total for (7) 9VDC pedals, and up to 675mA total for (3) 18VDC pedals.

T-Rex offers some useful power supplies as well. Two are isolated, and one (the regular Fuel Tank model) is not. The FuelTank Junior is one of the tiniest and most inexpensive isolated-output supplies out there. It has (5) isolated 9VDC outputs @ 120mA each, and you could link two outputs together (as with any isolated-output supply) to get an 18VDC output with the proper cable. The FuelTank Juicy Lucy, meanwhile has (5) isolated 12VDC outputs @ 300mA each, and it's probably a generally useless supply to the bulk of us (except T-Rex fanatics). There is also the FuelTank Classic, which is an unsual one. It sports (8) non-isolated 9VDC outputs with a shared total of 500mA, (1) isolated 12VDC output @ 500mA, and (1) isolated 12VA output @ 500mA.

And here's some real food for thought, although it's technically not out until January '09 (supposedly... it's been delayed for a long time...): the CAE/MXR MC-403 Power Supply. It's a bit large, very flexible, and on the pricey side ($200). These are the specs I know of, based on my research:

INPUT: 100VAC, 120VAC @47-63Hz. 220VAC, 240VAC @ 47-63Hz (Europe)

OUTPUTS: 17 total, all isolated
(8) 9VDC outputs @ 80mA max. each
(2) Adjustable outputs with range selection switches and variable voltage dials (6 - 15VDC) @ 200mA max. each
(4) 18VDC outputs @ 125mA max. each
(2) 9VAC outputs @ 800mA max. each
(1) Courtesy AC Outlet

Now THAT might be the one-stop solution for your Whammy and world tour needs, minus any high-current DC pedals you might have (aren't you glad it has a courtesy AC outlet? ). I'm curious to see how they're doing the international voltages thing, though. The low current on the DC outputs is disappointing, though. Fortunately, it is generally not a problem.

If you have any questions about anything I posted, feel free to bug me via PM or reply here.

[Nikoubis]

Originally Posted by MysticBoo

[cracks his fingers as he begins a LONG post]

...

Nice post Boo.

Any word on the BBE Supacharger? I think it has isolated outputs as well, no?

[JanusZarate]

Originally Posted by Nikoubis

Nice post Boo.

Any word on the BBE Supacharger? I think it has isolated outputs as well, no?

Oh yeah, I forgot that one.

It's pretty much a PP2+, without the voltage sag features. I forget what else is different... available current, I think.

[Toasted]

I think my board sounds better when I'm using my Pedal Power two than when I'm using my Onespot. Fo' real.

Less noise, better harmonics on the dirt, cleaner sweep on the phase.

[Benjamin Strange]

Originally Posted by Toasted

I think my board sounds better when I'm using my Pedal Power two than when I'm using my Onespot. Fo' real.

Less noise, better harmonics on the dirt, cleaner sweep on the phase.

This is something I wonder about - is this just pseudo-science and smoke and mirrors, or is there some actual principle at work here?

[bongomania]

I'm not solid on the actual principles, and it seems to me that a lot of other tech heads are equally confused. But I can say that there are some pedals I've used where I could hear the difference between a transformer supply and a switch-mode supply. The DHA pedals are a prime example- I received both xfo and switching supplies, and two of their pedals, and in both cases I heard a bit of background buzz/whine when using the switchmode supply- but only when in conjunction with certain other sensitive gear. IOW for most people playing through a typical bass rig there is probably no audible difference; and it is plausible that some devices may be designed to minimize or eliminate audible artifacts from the power supply; but for some sensitive hi-fi gear the switchmode is audible and annoying.

As far as it affecting harmonics, phase sweep, etc., I am not so sure how that would work. I'm on the fence about that one.

[megadan]

Originally Posted by Benjamin Strange

This is something I wonder about - is this just pseudo-science and smoke and mirrors, or is there some actual principle at work here?

It's definitely possible - isolated outputs instead of daisy chaining can mean fewer ground loops, which create hum.

[JanusZarate]

Originally Posted by megadan

It's definitely possible - isolated outputs instead of daisy chaining can mean fewer ground loops, which create hum.

+1, but a ground loop creates a seriously large amount of hum. The major advantage of an isolated-output supply is preventing ground loops and other ground-related issues (i.e., with positive-ground pedals) altogether by isolating the grounds.

In general, I've found that using an isolated power supply allows me to dodge the RF interference a daisy-chain setup might amplify. Having had some RF-sensitive pedals before, I can attest to this.

However, I honestly don't think it'll make your pedals sound better otherwise. I haven't personally heard any difference between my old 1 Spot, my old DC Brick, and my current PP2+ (aside from RF noise). Of course, given that I have had (and currently still use) some oddly-powered pedals (18V, 24V, positive-ground 9V, and the like), I wouldn't leave home without my PP2+.

[AndyLES]

Originally Posted by bongomania

As far as it affecting harmonics, phase sweep, etc., I am not so sure how that would work. I'm on the fence about that one.

I think if there IS an audible difference, it's because the pedals are finally operating at their optimum voltage, with plenty of juice to feed their milliamp draw.

[David Wilson]

Originally Posted by bongomania

Whenever you see someone posting "get a 1spot, it works perfect for me" all they are saying is they've never tried to power an unusual pedal, or combine different polarities in the one chain, or use a pedal that was sensitive to noise on the ground plane, or any of the many very real problems that can come up when you have a complex combination of different brands and vintages of pedal.

So if you do plan to power any oddball gear together, the Voodoo PPII or similar device with all isolated outputs is worth its weight in gold.

agreed. My MI Audio Neo Fuzz can't be used with other regular pos tipped pedals on a onespot chain because it reverses the polarity, so I can only use it on my pedalboard with dedicated adapter or isolated output adapter like PP II.
I'd never claim in a million years it sounds better than using a OneSpot

[niftydog]

Originally Posted by bongomania

...I could hear the difference between a transformer supply and a switch-mode supply.

The obvious difference is that switch modes are just high-powered squarewave generators! The frequency of switching will vary from brand to brand - some operate at the upper end of the audible spectrum (20khz-ish), whereas others operate way up at 400khz. Most of them will tend to "fizz" if you put your ears right up close - especially under light load.

Switchmodes require much more attention paid to their filtering a shielding, which is often lacking in the ubiquitous cheap supplies. They are very electrically noisy devices but the noise is "the opposite" of the low frequency hum like you'd expect from a linear supply. The much larger filter caps and the concept of "transformer regulation" make linear supplies behave very differently to their switching cousins. It's kind of like the tortoise and the hare - linear supplies stash power away in the filter caps for a "rainy day" - switch modes supply only what's needed, but they run very fast when it starts to rain!