balancing of input coupling capacitor

[VHF man]

Has anyone successfully implemented something similar to the attached schematic.

I've sim'd with the following values:

C1, C2 = 0.5uF
R6, R7 = 18K
R9 = 82K

The response is essentially flat to 10Hz and 6dB down at about 2Hz.

This approach has the potential for stability problems but with careful selection of values it should be possible to make it work.
The advantage is a much smaller inpuT cap as well as partial distortion cancellation.

 

[VHF man]

Here's a plot with more realistic values.

R6, R7 = 1K
R9 = 33K

Response is now 1dB down at 10Hz.

I should add, the objective is to make the coupling cap smaller but a side effect will be some distortion cancellation.

 

[VHF man]

Now with c2 bypassed....

Also, I forgot to add that C1, C2 are now 1uF for the 2 plots,