I was looking at a TDA2003 datasheet. Under absolute maximums it lists DC Supply at 28V and then it lists operating voltage at 18V. What do they mean by the DC supply? Can I run this amp off a 24V battery?
I think the problem is, but not sure how accurate it is. That with supply voltages higher than 18 volt will cause problems with power dissipation. The chip will easy overheat. So you will be needing a quite large heatsink. At 24 volt. I would have used some other amplifier IC.
I agree, it is not suitable for a 24v lead-acid battery use.
You can probably find an amp chip that will run from dual supply +18v/-18v etc, that can be made to run ok from a 24v battery, you just need two big filter caps.
I attach the schematics of the Amplifier and Power supply of an Electone. The B+ for the 2003 was taken before IC503 (+12V regulator) and the voltage is not stated. I guess it should be +15 to +18V the most or else the +12V regulator would overheat.
The output drives a 8" speaker plus 2 smaller speakers. I think it is configured as BTL to get higher output.