Hey all..
I'm building my CGS77 serge filter for my best of CGS BOG panel and i have a question in regards to one of the modifications listed on the project page:
"If you wish the filter to self oscillate at high Q settings, the 68k resistor between pins 2 and 6 of the single op-amp (LM748 on the PCB) can be reduced to 27k. This will also drop the output levels significantly. To recover the levels, feed the LP, BP and HP outputs through three of the onboard buffers, with 39k resistors used in positions marked RG."
Now this sounds like something i would like to do as part of my build, the problem I am having is locating these 68k resistor between pins 2 and 6 of the LM748 (substituted for LM071)
There are two 68k resistors surrounding this chip and neither seem to connect to both pins 2 and 6 as seen in the schematic.
I am using the rev 1.1 board as well
I'm building my CGS77 serge filter for my best of CGS BOG panel and i have a question in regards to one of the modifications listed on the project page:
"If you wish the filter to self oscillate at high Q settings, the 68k resistor between pins 2 and 6 of the single op-amp (LM748 on the PCB) can be reduced to 27k. This will also drop the output levels significantly. To recover the levels, feed the LP, BP and HP outputs through three of the onboard buffers, with 39k resistors used in positions marked RG."
Now this sounds like something i would like to do as part of my build, the problem I am having is locating these 68k resistor between pins 2 and 6 of the LM748 (substituted for LM071)
There are two 68k resistors surrounding this chip and neither seem to connect to both pins 2 and 6 as seen in the schematic.
I am using the rev 1.1 board as well