AC and DC adaptors for guitar effects

[Davidiot]

I was wondering about the AC and DC adaptors for guitar effects and pedals.

Why does some seem to produce unwanted noise?

What requirement should an adaptor fulfill inorder to be good for pedals and other guitar effects?

Thanks for helping

[jaysg]

If you've purchased the official adapter for some pedal and it's adding noise, that's all wrong and it should go back to the store or the manufacturer. A random 9V adapter [from Radio Shack] might not have enough filtering for a particular pedal. For example, I added an adapter socket to my Vox wah, but found none of my 9V adapters were filtered enough. On the high end, you've got the DC Brick and Voodoo Labs Pedal Power II. There must be others.

[Monkey Boy]

Ground loops. If you can, try it on an isolated ground circuit.

[soma_hero]

The majority of the noise you'll experience is from a lack of filtering. Go to geofex.com and read about power supplies and filtering.

Essentially there needs to be a large capacitor on the output of the power supply to ground to smooth out some of the bumps. For most electronics there is no need for a lot of filtering so most companies leave it off. Big caps are expensive. For guitar effects however, much filtering is needed. If you wanted to use a certain adaptor, you could open the pedal you'll power and add a huge cap (470uF) across the power plugin + and -.

[jjman]

"regulated" is a good type of adapter for these. These have a voltage regulator which smooths the hum and keeps the voltage constant regarless of how many pedals you run (within max spec.)

I like the "One Spot." 1700ma max. More than enough.

[Tonegeek]

+1 on big filters. If you really want to do it right u need separate transformer secondaries/regulation for each effect to avoid ground loops. This will help:

http://www.smallbearelec.com/Categories ... ansformers

3rd item down the list has multiple secondaries.

[jurgen]

The cheapest wall warts only have a single diode in them
rather than a bridge rectifier -makes for pretty lumpy DC
If they're skimping on the diodes don't even ask for caps

[angelodp]

I have found the one spot device to be remarkably quiet and it will run a bunch of pedals and has various adapters for varying connections. And affordable.

ange

[angelodp]

double post - oops

[Davidiot]

Thanks for all your help, I feel like I have a bit better grip on the whole thing now.