The BT module is the small one on the left. The amp is on the right. Yeah I think you can get 4 ch ones. I mounted switches to the pushbuttons to control the BT module and used the original volume pot for on/off and volume.
Second pic is after conversion. I left the tuner mech in place and it still moves the needle. If its not powered up nobody would ever know its been messed with.
The amps come in various wattages. I didnt go too big because im running it through a vintage coustic amp and a pair of rockford fosgate 6x9. Cranks really good for what it is.
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arduino audio amplifier | eBay
