Wiring for barrel connectors

[crowsmith8]

This is probably a very simple question, but I'm just learning this stuff so bear with me.  I just bought a used Voodoo Labs Power Pedal, but it didn't come with any connectors, so I'm going to wire my own.  I was just wondering how to go about wiring them.  Do I go tip to tip, or tip to center?  Can anyone give me any advice?  Thanks in advance.

[Dave_B]

I'd guess it's tip-to-tip, sleeve-to-sleeve, but it's worth checking with a meter just to be safe.  Do you have a way to do that?  By the way, here's a manual for a similar model. 

[crowsmith8]

I just got a meter, but I haven't used it yet.  Any recommendations on how to use it?

[Dave_B]

Assuming your effects are "negative center", your goal is to measure +9vdc when you put the black probe in the center hole and touch the red probe on the sleeve of your homemade cable.  Depending on your probes, it's probably not a good idea to measure the jacks directly, since you run the risk of shorting them out. 

[crowsmith8]

Cool thanks.  Now what if the effect has a "positive center" will I need to wire the connector any differently?  And for measuring I would assume then I would want to put the red probe in the center hole and touch the black probe to the sleeve and then get a +9vdc measurement.

[Dave_B]

That's correct.  You should probably start by looking at your effects and seeing what power connections they need.  Odds are they're mostly 9vdc neg centers with a 9vac thrown in to complicate things. 

Some of the larger Line 6 and Digitech stuff is 9vac.

[crowsmith8]

So I know that I have both 9vdc and 9vac pedals, so would I want to wire the 9vdc connector so that it goes tip to tip and sleeve to sleeve, and then for the 9vac wire the connector so it goes tip to sleeve and sleeve to tip?  I'm starting to confuse myself, so anything to help me clear this up would be great.  Thanks so much for all your help so far.  Last question,  if I were to wire these wrong would it damage any of my pedals?

[Dave_B]

So I know that I have both 9vdc and 9vac pedals, so would I want to wire the 9vdc connector so that it goes tip to tip and sleeve to sleeve...

That depends on two things: What pedals are you using and what's coming out of the Voodoo box.  I don't want to discourage you from doing this yourself, but it might be worth dropping a line to Voodoo to see what they charge for the ready-made cables.  I only say that because I've built things that ended up being available cheaper and better made than my efforts. 

If you want to roll your own (and that's fine, by the way), lets back up a little and list the pedals you want to use.  That should help eliminate some of the confusion.  Then we can go back and answer some of the other questions.  This isn't hard to do, we're just getting things out of order.

Thanks so much for all your help so far.

No problem. 

[crowsmith8]

Okay, so hear are the pedals I want to power:
Analogman Bi-Comp
MXR Phase 100
Teese RMC3
Ibanez TS9
Klon Centaur
Boss RC-20
And two pedals I made from BYOC
I believe that all of them take 2.1mm x 5.5mm barrel 9vDC adaptor "negative center" except the Klon which has a 3mm "positive center"
And the Voodoo lab pedal power that I have has 8 9v regulated DC outputs.

[Paul Perry (Frostwave)]

Here's what *I* do wrong: use a meter to get the socket connections, but forget that you have to do this when a cable is pluged in!!! if it is a switched socket. OK it was years ago but I am still  .

[Dave_B]

Here's what *I* do wrong: use a meter to get the socket connections, but forget that you have to do this when a cable is pluged in!!! if it is a switched socket. OK it was years ago but I am still  .

Did I mention how I smoked my Obsidian because I tried to get clever with the positive grounding.  Oh well, wrong thread.   

Crowsmith, I haven't looked up all those pedals, but assuming you're correct, it sounds like it will work for most of them.  The RC-20 is a 200ma effect.  I think the original Voodoo PP2 is rated at 100ma for all the jacks. 

I admit there are a crapload of steps here, but most of them go pretty quick. 

By the way, I checked this a few times, but if someone notices a problem or disagrees with my methods, please feel free to say so.   

• Cut a piece of cable to whatever length you need.
  
• Strip the ends of the cable and tin the wires (apply a little solder to each one). 
  In my experience, tinning the wires helps with barrel connectors since it reduces the amount of heat they're subjected to.  I've melted a couple over the years.
  
• Solder a barrel connector to one end of the cable.
  If the cable has an indicator on one side (a white line for example), solder that wire to the center pin.  Otherwise don't worry about it.  Solder the other wire to the longer piece on the connector. 
  
• Using diagonal cutters, clip the excess wire as close to the solder joints as possible.  There shouldn't be any exposed wire when you're done.
  
• Set your meter to "Ohms" and measure the resistance between the two wires. 
  This is to make sure you didn't short anything.  The meter should read 'infinite'.   
  
• For the moment, don't screw the "shell" of the connector on.
  
• Keeping the wires separate, plug your new cable into the Voodoo supply.
  
• Set you meter to "DC Volts" and make sure it's above the 10v range.
  
• Turn the supply on and measure the voltage across the two wires.
  If the meter reads +9vdc (or thereabouts) the black probe is touching the negative wire.  If it reads -9vdc, the red probe is touching the negative wire. 
  
• Mark the negative wire so you can keep track of it later.
  
• Turn off the supply.
  
• (Optional)Trace the negative wire back to the supply to verify if the supply pins are negative or positive.  This way you'll know in the future.
  
• Remove the new cable, crimp the wires as best you can and screw the shell on.  Check it again for continuity. 
  Sometimes the shell can make the wires touch together if you're not careful soldering.  This is just a precaution. 
  
• Slide the other shell onto the cable and solder the other connector on. 
  Make sure you connect the negative wire to the shorter center pin. 
  
• Clip the excess, crimp, and screw on the shell as before. 
  
• Measure for continuity one last time to make sure you didn't short anything.
  
• Turn on the power.
  
• Plug in the cable.
  
• Measure the voltage on the plug to make sure you have wired it "negative" center.
  Put the black probe in the center hole.  Touch the red probe on the outer part.  It should read +9vdc, not -9vdc.
  
• Plug it into your pedal and rock on.
  

When you get to the 3mm cable, everything is the same except you need to switch the leads on the 3mm connector to make it a positive ground.  By that time you'll be an expert.  Just make sure you get +9vdc when you put the red probe in the center and touch the black probe on the outer part.

[crowsmith8]

Looks pretty straight forward, I'll give it a try and let you know how it turns out.  Hopefully I'll get to it tonight.  Again, thanks so much for all your help.  I've definately learned a lot.

[crowsmith8]

Thanks for all your help.  I was able to make all the cables I needed.  Not to metion, I learned a good amount of useful info.

[Dave_B]

Excellent.  Congratulations, crowsmith!  Oh, and you're welcome.