For the schematic, there is a trace on the web which was posted in this thread, about 1/3 the way down page 11 I put up links to all the Kubicki designs. https://www.freestompboxes.org/viewtopic.php?t=3818&hilit=fodera&start=200 The schematic is here, https://elektrotanya.com/files/forum/20...

tonyharker wrote: ↑01 Nov 2021, 16:07 The circuit around the second op amp is just a Baxandal feedback tone control and is correct.

Thank you. I looked that up and learned a lot.
I am sure I have seen a Baxandall circuit before but I did not bring it together.
Now I will remember. Hopefully

I am the proud owner of what is called a cowpoke bass. This is a bit of an odd Fender bass having 22 frets and an active preamp. It has been produced in Mexico for only about two years (94/95). Some belive the preamp was designed by Mr. Kubicki as this was the time Fender had a collaboration with hi...

Back on topic. Maybe this Post can be spit? At least it started with this: Hello. Below Variable HPF filter 20Hz...200Hz, tested, working very good. Fit in a 1590A. PCB ready for termotransfer : http://efekty-diy.pl/pdf/HPF%20PCB.pdf Schematic and BOM: http://efekty-diy.pl/pdf/high%20pass%20filter%2...