RE: ac adapter question

["samba -" <sambacomet@hotmail.com>]

  My understanding is that you have to match the miliamps as well as the 
voltage. some devices can handle deviations better than others but large 
variations are to be avoided. Often if one tests actual output with a 
meter,it's not precisely as marked. Also the polarity of the connector has 
to match,some have the outer ring positve ,some negative,this is usually 
marked. I  discovered this when I had one that fit the specs but didn't 
work 
,when I noticeds the  reversed polarity  I cut off the connector, switched 
it around,and reconnected-worked fine.
It's easy to find lots of wallwarts at thrift stores for cheap,you can 
take 
the device with you to test if they work.