Hi all, thanks to everyone's help, especially administrators answers the opamp circuit work. Now the problem is it's not outputting 20w : I'm trying it on a 5w 4ohm woofer and also tried to power it with 24v using lead acid batteries, still same. Please note that the 1uF cap at Vin is replaced by a polarized capacitor. I'm thinking of removing the 2200uF cap at out. What do you think ?

 

Hello,

The 24 volts is way to low for 20 Watts.
At 24 volts you might expect about 5 Watts, as you are using single supply.
The 2200 μF capacitor is a must for a single supply amplfier.
Without it the speaker will have a high DC of about 1/2 the supply voltage.

Bertus

 

So you mean this is normal. Ok so I should be using a 50v transformer in that case. Thank you

 

From the datasheet:


Using a single supply that means 50V or 60V.
Note that the capacitors have to be rated to handle these voltages.
You will get about 1.4 times the transformer voltage after the rectifier (assuming a full wave bridge) and smoothing capacitors so the transformer should be 35V to 42V.

 

Is it designed to handle 50V Vcc?

{ed}
So it seems it can handle 50V.
Beware if you are using 4Ω Speaker.

 

Is it designed to handle 50V Vcc?

The IC is and the circuit will handle such voltages if the capacitors are suitably rated.

 

If you want more power from a 24V supply then you would need to use an audio amp with bridge type output, as that doubles the voltage across the speaker load for a given supply voltage.