1 Spot 9V DC Power Adapter

[jeremylangford]

I have a 1 Spot power adapter and a daisy chain to power all my pedals. How come the power adapter doesn't have a prong for ground?



I am in the process of making a pedal board and I need to buy an extension chord to run from the board to an outlet. I was looking at different extension chords at Wal-Mart and figured I need to get one with a ground input and ground output so my pedal powering doesn't cause any buzzing but then I realized that the 1 Spot adapter doesn't have a ground plug.

[ChrisK]

The power adapter doesn't have a prong for SAFETY ground as it doesn't need one. Being double insulated and galvanically isolated, a safety ground is superfluous and not required by U.L. since a single (internal) component failure will not result in a user shock hazard AND the adapter is supposed to be directly plugged into an outlet.

I am in the process of making a pedal board and I need to buy an extension chord to run from the board to an outlet.

I would use a quality power strip and not an extension cord. If you must use an extension cord, use a quality one with a safety ground wire (three prong).

While you're at it, buy an outlet tester and test every outlet that you'll use before you use it (including any in your home).

I was looking at different extension chords at Wal-Mart and figured I need to get one with a ground input and ground output so my pedal powering doesn't cause any buzzing.

The safety ground wire in any mains cord is not a shield for noise reduction. It shares the cord with at least one wire that has 120 VAC on it (coupling is). The proper reference place for noise shielding ground connections is the amp input.

[jeremylangford]

Dec 23, 2008 18:05:19 GMT -5 ChrisK said:

I would use a quality power strip and not an extension cord. If you must use an extension cord, use a quality one with a safety ground wire (three prong).

I was gonna get a power strip to go under my pedal board but now that I'm using the 1 spot adapter, I only need one outlet to plug into. Why would I need a power strip? The only problem is that the 1 spot won't reach from my pedals to the outlet on the stage I play on. Thats why I figured I needed an extension chord.

Also, I was wondering how much better a brick power supply would be than the daisy chain method I am using? What would be better if I started using a power brick with no daisy chain?

[ChrisK]

Why would I need a power strip?

They have those pesky little detail things inside like a circuit breaker and transient/over voltage protectors.

Also, I was wondering how much better a brick power supply would be than the daisy chain method I am using? What would be better if I started using a power brick with no daisy chain?

What does "a brick power supply" mean? Is the "brick method" a star topology (I know what a daisy chain topology is)?

[jeremylangford]

Dec 23, 2008 19:48:53 GMT -5 ChrisK said:

What does "a brick power supply" mean? Is the "brick method" a star topology (I know what a daisy chain topology is)?

[ChrisK]

In this case, this pic is worth two words; "star topology" it is.


The reason that I asked about the brick power supply is because in the electronics industry, these are what are known as brick power supplies;
www.coselusa.com/

[jeremylangford]

So would something like the Voodoo Lab be a lot better than my daisy chain? What would I see a difference in?

Also, I was looking at Walmart to decide what power strip to put under my board. There are a lot. Could you tell me what I need to make sure it has?

[ashcatlt]

Dec 31, 2008 13:16:38 GMT -5 jeremylangford said:

So would something like the Voodoo Lab be a lot better than my daisy chain? What would I see a difference in?

The biggest difference is better isolation between pedals. Some pedals can dump all kinds of nasty noise onto the power supply, which will come through as noise of one sort or another in other pedals connected via daisy chain to that same supply. Some of the cheap "brick" type pedal power supplies aren't much more than a daisy chain in a box, but the Voodoo Labs and similar have individually regulated outputs. Here's a pretty good thread on the subject.

There's also an issue of ground loops in the daisy chain. The top part of this article gives some info on that.

All of this, though, is talking about potential problems which may never impact your situation.

Also, I was looking at Walmart to decide what power strip to put under my board. There are a lot. Could you tell me what I need to make sure it has?

You don't need much for this application. Enough holes for whatever you want to plug in is nice. A cable long enough to reach where you need it is nice. I like the ones that have extra clearance around each outlet to allow for multiple wallwarts.

[jeremylangford]

What would be bad about using an extension cord?

[newey]

ChrisK said:

They have those pesky little detail things inside like a circuit breaker and transient/over voltage protectors.

Extension cords do not have those pesky little things. Now, if you want to plug in a lamp, an extension cord is fine. If you're plugging in electronic equipment, some protection is a nice thing to have.

Now, mind you, these things come in 2 classes. What are often sold as "Power strips" are often just a glorified extension cord with several outlets. Chris is talking about the kind with a circuit breaker, often sold as "surge protectors" for use with a PC. These are a few dollars more.

Now, you've only got a single little wart to plug in. But, once you have all the extra outlets on an extension cord or strip, the tendency is to use them. And most people don't calculate the loads they're running.

This is not (well, probably not) a noise issue, it's a safety issue. But I have a strip with a breaker with my amp and pedalboard plugged into it, I figure if I'm going to spend the extra few bucks to protect my PC, then my amp deserves no less.