Knock Detection reloaded!

Status: Alpha Phase

After a while without significant results I think it is time to have another look at the issue of knock detection.
Aim is to design a stand-alone device which reliably detects knock and deliverers a digital signal for an ECU or similar.

But first we need doing our homework. For recording noise coming from the knock sensor of your own engine you will need a sensor amplifier. Below you find a pretty well working circuit. I abstained designing a PCB because it is easier soldering the few parts to each other inside a metal enclosure. The latter one is absolutely necessary for avoiding any noise from the engine disturbing the sensor signal.
 

Here some pics of the ready made amplifier:

The amplifier is to record the sensor signal only. It is not needed for the final Knock Detector. It is only my tool for engineering the detector circuit!!