I had to many old speakers at home and would like to convert them in a compact mobile phone amplifier.
For this project you need :
_ Two old speakers free
_ AC/DC 12V 3A 6$
_ PAM8610 amplifier 6$
_ Jack cable 2$
_ main cable reused free
So all of it for less than 15$ and a bit of time.
Step 1: Amplifier
I used the PAM8610 board for amplifier.
It is a 12V 2x10W Amplifier and not 15W as said on the seller website.
10W @ 10%THD/Channel Output into a 8Ω Load at 13V
Low Noise: -90dB
Over 90% Efficiency
With Shutdown/Mute/Fade Function
Over Current , Thermal and Short-Circuit Protection
Pop Noise Suppression
To improve it I add a 4700uF cap on the 12Vdc input, and you can change the cap output to MKP instead of X7R.
Step 2: AC/DC 12V
To supply the amplifier I used a 12V 3A output AC/DC converter.
12V * 3A = 30W so it will be ok for the 2 * 10W output of PAM8610.
I never used the AC/DC at full power to avoid pushing it to much.
On top of that you can add a main 220V filter to protect it.
Step 3: Assembly
I removed the old speaker from the first cabinet and add it to the other one.
I drill too holes on the right face of the cabinet, one for the tweeter and one for the subwoofer.
I solder a switch between the AC/DC converter and the main cable 220V, and connect the 12V AD/DC output to the PAM8610 12V input. I connect both speakers Right and Left to the amplifier, and finaly a jack input.
I add a loud noise from the amplifier so i connect the earth(not neutral) to the ground amplifier, and noise desappear.