555 negative voltage: your criticism.

[bountyhunter]

It takes exactly 6.2V to get to -10V at the desired 8mA.

Boncuk

That sounds like the right ballpark, but:

did you try it with schottky diodes to reduce the VBE drop loss?

 

[Boncuk]

Using Schottky diodes the voltage gain was minimal. I used Germanium diodes instead.