Line-in level from OpAmp
Imagine two scenarios: an AC signal which has such a high frequency that the 4.7 nF capacitor appears as a short. And a signal whose frequency is so low (or DC) that the 4.7 nF capacitor is open.

Signal that is blocked by the capacitor (i.e. that is in your filter's low pass band) sees a gain of \$-8/3.4\$.

Signal that is shorted to ground by the capacitor sees even less gain, because the inverting stage is a current-to-voltage amplifier, and flow through the capacitor robs the input of current.

So basically your amplifier tops out at a gain of \$-8/3.4\$ gain.

You might be thinking that there is somehow a gain of 80 due to the ratio between the 8K resistor and the 100 ohms. But that's not how it works!  When you consider the input to be at the 100 ohm resistor, then you have to regard the 3.3K on the left as a source impedance. That source impedance matters because it restricts the current that flows to the current-to-voltage amp.  The gain formula for an inverting stage assumes zero source impedance!