I am trying to make an amplifier with an opamp, using a single supply. I found lots of ressources online. This response was very informative and I tried to simulate this circuit.
Let's say that I have +/-0.5V signal, and I want to amplify to +/-1V. This is what I did:
This seems to work, but why isn't the signal AC-coupled?
After trying different things I found out that adding a 1k resistor to the ground after the last capacitor seems to fix it, but I can't really understant why. Is it the right way to do it? Why 1k?
Also, I heard somewhere that rail-to-rail opamps were preferable for these kinds of designs (single supply amp). I only got TL072, would this work? I assume that it would be a problem if I used a very low power supply (like 5V) for my opamp but should be OK with a 12V supply, am I wrong?