Pedal board power supply............

[Mickster]

Hey guys....I'm going to do a DIY pedal board for 5 pedals maximum. I hate the cost of those power supply bricks. Have any of you come up with a different way to power the pedals? They're all Boss pedals so I'm sure all the power feeds will be the same polarity. I have no problem with soldering...wiring...etc. What have you guys done for power? Or should I just give in and buy a brick?

 

[mjbphotos]

Godlyke Power with a daisy chain cable. If all you've got are 5 pedals with the same power requirement, that should be the easy solution.

 

[Mickster]

Godlyke Power with a daisy chain cable. If all you've got are 5 pedals with the same power requirement, that should be the easy solution.

Just checked it out and it looks like the way to go. Thanks mjb........much appreciated.

 

[Steenamaroo]

If you DIY something, considering having switches or some other convenient way to flip polarity incase you add a pedal that's positive pin instead of negative, or vice versa.
Also, consider having -9,0,+9 if you think there's ever a chance of mixing positive ground pedals in (rangemaster?).
Those would run on -9 + 0 where positive (0V) is ground.
That way ground is the same to both types of pedal.

 

[Mickster]

If you DIY something, considering having switches or some other convenient way to flip polarity incase you add a pedal that's positive pin instead of negative, or vice versa.
Also, consider having -9,0,+9 if you think there's ever a chance of mixing positive ground pedals in (rangemaster?).
Those would run on -9 + 0 where positive (0V) is ground.
That way ground is the same to both types of pedal.

Good thoughts there Steen. Nothing ever stays the same when it comes to the pedal board right? And never thought about negative vs positive switching.

 

[bouldersoundguy]

Switching polarity is cool, but you could get the PSM-5 pedal and go all-Boss. The PSM-5 also lets you switch an effects chain in and out of the signal path.

 

[mjbphotos]

The Godlyke kit linked to above includes a polarity reversal jumper cable!

 

[Mickster]

Yup....already placed the order for the Godlyke kit. Thanks again for that tip MJB.

 

[ashcat_lt]

The Godlyke kit linked to above includes a polarity reversal jumper cable!

I like this a little bit better than the switch idea. Make sure that cable is blatantly obviously different from the others so that it never gets used in a normal pedal. I didn't click the link, but usually they'll be a different color. When you get a pedal that needs it, either just keep that cable in that pedal or pain around the power jack the same color as the cable or do something else that makes you stop and think before you (or anyone else) plugs it in.

A much better idea IMNSHO is to re-wire the pedal to conform with the majority. It's usually pretty easy to do, but it'll probably void your warranty and may affect resale value unless its easily reversible. But then you just don't have to worry about it. I have a couple Moogerfoogers that are apparently too cool to use the negative tip standard, but my dad forbid me to re-wire them and for some reason I've respected his wishes so far even though he'd never know the damn difference.

Reverse polarity kills pedals pretty quick. Many of them feature "protection" circuits which can help for about long enough to figure out the battery ain't going on the snap that way, but usually not long enough to go "why won't it turn on? [stomp] [stomp] [wiggle cable] Oops wrong power!" Then the protection diode explodes and unless you get real lucky and it takes out some of the PCB traces around it, the rest of the pedal is now completely defenseless. An AC adapter in a DC hole does the same thing!

 

[ecc83]

Like so many things electronic to do with guitars, some very bad design decisions were made in the early days and now we are stuck with them!

The barely adequate 9 volt supply was too convenient to pass I suppose but when external power became practical they COULD have standardized on 12volts and included SERIES diode protection in the pedal (with a nice meaty res' cap).

And, I wince every time I read "daisy chain"! MIDI is a daisy chain but multiple pedal power is a PARALLEL system.

Dave.

 

[mjbphotos]

Likebut multiple pedal power is a PARALLEL system.

Dave.

the description is not how the electrics are hooked up, it's how the wires are done - one pedal to the next , to the next ... instead of one wire from the supply to each pedal, so you'd have 5+ wires all stretching out along the way, getting tangled.

I wish they'd offer a cheap supply with multiple voltage options on different jacks (9 and 12 seem to be it). My Radial pedal takes 15 volts, no bricks offer that at all.

 

[ecc83]

the description is not how the electrics are hooked up, it's how the wires are done - one pedal to the next , to the next ... instead of one wire from the supply to each pedal, so you'd have 5+ wires all stretching out along the way, getting tangled.

I wish they'd offer a cheap supply with multiple voltage options on different jacks (9 and 12 seem to be it). My Radial pedal takes 15 volts, no bricks offer that at all.

Right........I wonder why? I have a chunky PSU that can drive 4 cameras plus a hard drive CCTV recorder and that has a one in, 5 out "fan" adaptor cable. Since pedals are usually seen in a line such a cable seems eminently suited?

But then, as I said, guitar electronics has ever been of half arsed design.

Dave.

 

[ashcat_lt]

The "daisy chain" model makes some sense if the power supply is at one end of the pedalboard, but I don't like them for a couple of reasons:

1) The barrels of the plugs are positive voltage. If you only have a few pedals plugged in, leave a couple unplugged, and they end up touching just about anything else (other pedals' chassis, cable plugs, sometimes even the floor) then the entire fucking power supply shorts! Hopefully it protects itself from burning to death, but even then you spend a while scratching your head and swapping cables and then it works for a little while but then mysteriously cuts out again... Some come with covers, but they get lost quick. I found that a little section of a normal drinking straw does a pretty good job, but of course like condoms they only protect you if you can be bothered to stop and put them on.

B) They are not individually filtered, so if one pedal is doing something funky and causing the power supply to wiggle around, all of the other pedals are going to feel it and the noise propagates through the system. One would hope that the pedals themselves are individually filtered, but that's not always good enough.

III) Almost as important is the fact that the power supply's ground is five times further (in wire length and resistance) from the last pedal in the chain than it is from the first. That's not exactly best practice, especially considering that there's a ground loop built into these the pedal chain by default. Star grounding is much better in theory and at least a little better in practice.

A "fan" of parallel cables is a little better for the grounding aspect, but doesn't really adress either of the other problems. I very much prefer individual holes with their own caps across them.

I don't bother with the commercial supplies, and generally don't really worry about regulation even. I just buy the jacks and stick them in a box. The most classic version I call the tuna can (even though it was actually crab), and I often just built them into pedals or other boxes that will be used near pedals. The one I use now is inside my (otherwise passive) TB feedback looper. My bassist powers all of his pedals (except the Bass Whammy, which runs on the dreaded AC) from the distortion pedal I built him. Two others are different types of kill switches on top of being individually filtered, polarity protected power supplies. I power them from 9V DC adapters with 800-1500ma capacity that I've picked up along the line. If that wallwart is the wrong polarity, I hack the end off and fix it.

 

[ecc83]

I have often wondered Ash' if a single BM supply with individual "go and send" diodes per output (with 1000mfd at the final output) would fix the earth loop issues? Just one of scores of ideas I would have liked to investigate had my git electronics career not happened very late and was cut short by health problems!

Re the dangly sparkers, the CCTV fan is an inline socket to 5 inline sockets so you just use the appropriate length of plug to plug for each device. Seems bloody obvious to me!

I would also like to see EU regs making sockets mandatory on power lumps. I bet 90% of failures are cracked cables at the lump exit point and the PSUs are welded up and MUST not be taken apart (well, I do!) EU already bans very low power mains frequency AC to AC supplies on efficiency grounds.

Dave.

 

[mjbphotos]

The One Spot, and Godlyke power supplies (and any ohte rpedal supply except a brick) don't even have ground pins, they are 2-conductor plugs. That eliminates the ground loop problem! (and the need to bring one of those old 3-2 adapters when the mains has a ground problem).

 

[ecc83]

The One Spot, and Godlyke power supplies (and any ohte rpedal supply except a brick) don't even have ground pins, they are 2-conductor plugs. That eliminates the ground loop problem! (and the need to bring one of those old 3-2 adapters when the mains has a ground problem).

Ah! I was thinking more of pedal to pedal loops, heard of instabilities? In any even I would always assume the PSU would be earth free? What we call "class 2" insulation.

Deliberately removing a mains earth is a BIG no-no here with our growed up voltage!

Dave.

 

[ashcat_lt]

Ah! I was thinking more of pedal to pedal loops...

That's what I was talking about. Redundant ground connections between pedals.

Deliberately removing a mains earth is a BIG no-no here with our growed up voltage!

It's pretty stupid here, too, but we insist on the right to kill ourselves via ignorance.

Those 3>2 prong adapters are NOT meant to lift the safety ground connection! They all have a little metal loop which is supposed to connect to the (grounded!) screw on the outlet, but you can also run a wire from there to a known good earth ground point.