Trouble understanding audio amplifier schematic

I have been looking at audio amplifier circuits online to use in a small-ish speaker system I am working on. I found the circuit in the image which is a pretty straight forward circuit and has cheap/easy to find parts. My only question is where exactly do I hook the audio input. I am guessing I connect to the .1uf capacitor on the left chip and to the ground, but I don't know. Thanks for your time.

the circuit is also here:
bp2.blogger.com/_ztWtnthp5tk/RkW7cyJceRI/AAAAAAAAAK0/7-Gi_-bt-ro/s1600-h/circuit-TDA2003+Amplifier+BCL+%28bridge+amplifier%29+18W+for+CAR.jpg


lemonie8 years ago
The circle on the left I believe

L
Jayefuu8 years ago
Your guess is correct :D Between the left hand side of the capacitor (the circle, as lemonie said) and ground.