A friend of mine wants me to build an octave up / octave down pedal with clean blend, so I decided to take a closer look at the Robot circuit.
It uses a TL072 op amp for the input and output stage.
Looks a bit strange to me, as there is no resistor at the input to set the non-inverting gain stage gain.
Same thing at the output stage.
How to calculate them?
Here's my first idea replacing the stock gain stages:
(http://fs2.directupload.net/images/150417/39agfq5x.png) (http://www.directupload.net)