My rechargeable amp I use for a particular purpose needs a new power supply.
The input is DC12v  and the adaptor I had was 15v, 1500mA output and says it is an AC adaptor.
I am confused by AC and DC (not the band) - can I use an AC power supply into a DC input. The power supply has to double as a charger and power supply.
Glynn

If on the power input of the device that requires the power IS 12 volts DC  or DC12v, Then only 12 volts DC should be used .AC power to a specified  DC requirement is usually verboten  ( not allowed).
 
(Message edited by sonicus on November 01, 2014)

Wolf if correct
 thing you need to know is the polarity
of the supply such as what the centre pin is either positive or negative.  
You should see a symbol such as below
 
Mixing it up/getting it wrong will damage your equipment in as much it will release the magic smoke from the components in your device.
If you post here what it is you need to power I can research it and advise exactly what you need. Post a couple of pics of the labels.  
slawie

Slawie is absolutely correct, good call as well .

Thanks.  Two images attached.  I wrongly said that the input is 12v but it is the 15vDC (not the cigarette lighter input) The power supply that says AC on it came with the amp but the cable is wearing out. The amp is Harley Benton (Thomann) but not made any more and is a blatant copy of the old Crate Taxi. It is a great little amp and you can still get the batteries so I don't really want to start again. Thoughts please.  The polarity looks OK to me? Glynn

Positive to center, Sir .

Should be good...Tony

Why do you think it says AC adaptor when it is DC input?

Why does it say AC on the adaptor when it is DC input on the amp?

The adapter converts AC to DC.  Your house current is AC.  Your 9V battery is DC.  Adapter = AC In > DC Out.
 
Bill, tgo

Brilliant - all is clear now.  Thanks to all.
Glynn

If you have concerns about it just use a volt meter to determine if the voltage, polarity and type is as stated.  
 
Keith

Many thanks - have ordered the adaptor from Thomann to match the one I had.  (Also gave into temptation and ordered a Mighty Bright Orchestra Music Stand Light - the postage is the same for one as both so can't lose)

That sounds like a good plan friend !