This is an early mini-booster pedal that I found in storage yesterday when looking through some boxes of pedals.
As you can see, it is a jfet booster driving a modified mini-booster, in order to get more distortion. I’m not sure what I was trying to achieve with the value choices for some of the resistors and capacitors, but it was a useful pedal nonetheless.
I robbed the knobs off it for another project long ago. The volume pot is wired backwards and I labeled it with a Sharpie instead of rewiring it. I was going to try playing it but the jacks and battery snap were too corroded from years of storage, and it was not worth repairing.
I do not suggest that you build a version from this schematic, and I have just posted it here to show how I used the design in the (distant) past.