Looking for piezo mic amplifier circuit

[analogoutput]

I see I posted to this thread five and a half years ago, but I never added to that response to say I’d found another page of interest at A 5-channel mixer / preamplifier for piezo disks by Godfried-Willem Raes and that I later used that as a basis for my revised piezo amplifier module described in this thread:

AO Mikrokosmos II

This is an updated version of my first synth module in Kosmo format, Mikrokosmos, inspired by Music Thing Modular’s Mikrophonie. Like that module, Mikrokosmos II has a piezo pickup attached behind the front panel, and the circuit amplifies the piezo signal and sends it to the output. There is a tactile scratch area on the front panel. You can use your fingernail or a guitar pick to scrape across it and generate output. It will also pick up sounds when you tap or thump on the synth case, plug or …