M121 High Pass Mod
2007-09-16 by ryktnk
Hello After lots of various attempts I have posted a JPG of a mod for the 121 Module. In the files section. It is an easy mod, and if you cut the tracks on the existing switch on the front panel it could easily be made to switch between LPF and HPF. But, because it is easy version there are two minor drawbacks. 1] The output will be inverted [not to much problem unless it is mixed back with original signal] 2] The filter works as 12db [2pole] [i'm no expert but I think this is what happens]. Still trying to work out the 4pole multimode modification but seems very complicated [!]. -R