Happy New Year!
The first stage bias now looks too high at first glance
Maybe I will email you schematics of suggestions
I presume that for your pro design you can use a few more parts and a more respectable rail voltage?
The alternating stage polarities ides to cancel even-order is fun
When I said first stage bias I meant the base voltage of Q1 btw.
Yes, I will hope to get some examples off to you soon.
BTW what does the noise of your 5V power supply look like