kambule said:Rodolf,
Interested to see the active LPF clean up some residuals if the sound card output.
Do you mind to post the schematic of the active filter circuit ??
thanks in advance.
kb
I do not have the original schematic files since it is a very old design (over 15 year back), so attached is a new one on LtSpice and simulation.
The actual circuit measured in the previous post includes a couple of modifications:
1. Devices are 3 parts from a OPA4134, and the spare one is connected as inverting unity gain buffer at (Out).
2. Resistors R1 and R2 are 10 turn 5K potentiometers.
Care should be taken as usual with grounding, power supply decoupling etc.
Rodolfo