HPF Tech HPF-Pre Series 3

[sparella]

There is a new version of the HPF-Pre which uses opamps instead of transistors. It looks like a handy little utility box to have around: buffer + phase inverter + 12db HPF @ 35Hz + 12db variable HPF 35-140Hz + volume trim.



Complete info at:
https://sites.google.com/site/hpftechllc/home/technical-diy-stuff/hpf-pre-series-3-technical-info

[Neil mcNasty]

Try this...
NOTE: I have not had the opportunity to build or verify this yet...
It might be a good idea to check for errors that might have slipped me by.
Let me know if you see something wrong!