Following the current discussion on AC mains filter I have briefly completed a simplest LC filter AC mains filter sample.
!!Please do not follow to build the example I am showing!! It is dangerous with lethal voltages present. It looks like this
and it is the LC filter, L = 9mH, C = 235 nF
Here is the measured frequency response. Generator output impedance is close to 0 ohm, load impedance is 3 kohm.
Noise and distortion of SS preamp and tube preamp were measured with and without the filter, similar as done by @amirm . No differences were found with the SS preamplifier.
Some slight differences in output noise spectrum of the tube preamplifier were found, as can be seen below.
Please feel free to suggest further measurements.
!!Please do not follow to build the example I am showing!! It is dangerous with lethal voltages present. It looks like this
and it is the LC filter, L = 9mH, C = 235 nF
Here is the measured frequency response. Generator output impedance is close to 0 ohm, load impedance is 3 kohm.
Noise and distortion of SS preamp and tube preamp were measured with and without the filter, similar as done by @amirm . No differences were found with the SS preamplifier.
Some slight differences in output noise spectrum of the tube preamplifier were found, as can be seen below.
Please feel free to suggest further measurements.