Robert
Reverse Engineer
This reminds me of when I realized my tail wasn’t normal…
Dime the Volume, use the Gain control to control volume, you basically have the Power Boost.
Use the Volume / Gain like an overdrive, you have the Overdriver.
You can pull the charge pump and run it at 9V if you'd prefer as well.
I just wanted to make both options available... Some purists would prefer to not have the Master volume, other folks would prefer it.