If I have an old fuzz box that needs battery power, or a newer one that has a center-positive jack and can't share power with other center-negative pedals...
Is it safe to use one of these? Will it do the trick?
Cool, thanks. I have been looking at the GigRig VB-BC "virtual battery" and can't figure out why it would be worth $40 instead of using one of these clips.
GigRig is a isolated and voltage regulated adapter where the other is a plain simple cable with a battery adapter soldered on. 2 completely different devices. As to which would be better for your application you'll have to decide.
From Analogmans page on GigRig VB.....
"Do you rely on batteries to power any of your pedals? Due to the design of some pedals like our germanium Sunface, they need an isolated source to operate properly. If you try to power them from a non isolated source such as a daisy chain they can be noisy, and in some cases can even damage your precious pedals. How would you like all the benefits of batteries with none of the drawbacks?"
Dave makes a good point. When I used the adapter on my phase 100, I was hooking it up to an Eventide PowerFactor or an MXR MC403, since I have those in my rack.
You could technically plug it into a daisy chain type of PSU but, you have to account for the issues Dave described.