Swapping one wall wart for another is pretty easy - just make sure the replacement has the same
- plug size
- plug polarity
- output type (AC or DC)
- wattage (it's OK to have more wattage than the one you're replacing)
"Switching type" wall warts tend to be more efficient, although they're seldom marked as such. One way to get an idea is to plug a 'wart into a kill-a-watt with no load - it should register zero. Another way is simply the weight (switching 'warts tend to be a lot lighter for the same wattage).
There are three variables in plug size:
- inner diameter
- outer diameter
The easiest way to get a match is to head down to your local radio shack - they usually have an assortment of "dummy plugs" (look for a hanging keyring-like-thing near where their replacement warts and plugs are sold). Yes, RS personnel can sometimes be offensive in their urge to sell you as much as they can. Remember that they are salespeople not techies, so often very basic technical questions can drive them to the other end of the store (or as I like to joke about their slogan : "You have questions - we have deer-in-the-headlights"). Ask enough questions and they will sidle away when you come into the store (stuff like "are these resistors 5% or 10%?").
Anyway, bring the piece of gear the wart is going to be plugged into with you and try all the plugs until you find a fit. That'll be marked outer dia/inner dia/depth. Write that down.
Then (via the web) head over to some surplus electronics places - like American Science and Surplus
- or try a froogle search for "AC adapter"
. It does take a bit of looking.
Note that if the piece of gear you're going to run is 12VDC or 5VDC and only needs to be on when your PC is on (and can be located near your PC) you can just run it from your PC's power (you do
have high-efficiency PC PSs, right?). There are power pass-through brackets (I got mine at NexFan.com - but they're obscurely-enough listed that I can't find 'em now).
Finally - audio amplifiers do tend to work better with the old non-switching power supplies. The new "Super T" amps seem to be OK with switchers, but otherwise I wouldn't make this swap for an amp.
Hoping some of this helps...