Hi dear friends,
As usual, my diy projects are a loooong term battle

Work, family, source the parts... Now I'm taking this a second break... I've bought an Artec APW-3 not working to use the pot and rocker mechanism and go for this project with Johnathan's schematic but: it doesn't have one, it works with a "mag pot". It's a strange solution. They use a 78L05 to deliver steady 5V to an A1301 Hall effect sensor that delivers 2,35 to 4,7V to a voltage divider and then to an LED/LDR group. Rocking the pedal will change the A1301 output from 2,35V (heel) to 4,70V (toe). The APW3 has a range pot that interacts with the LED and the LDR making things a little harder to understand (smd and double face pcb helps to the pain

)
The good thing about taking long to finish my projects is that they get more focused on the goals! Why to insist in a variable gain to overdrive the amp when I already have several boosters and distortions on my board? I'll stay with a unity gain active volume pedal and use Johnathan's schem.
As the A1301 puts out between 2,35 and 4,7 I'll have to build a voltage divider in order to have between 1,4 and 2,8V at the controling input. Therefore a max of 0,7mA for a 2k resistance in series. Could this properly replace A1 and following circuit on Johnathan scheme?