This low pass filter has attenuation of 5.5 dB and the frequencies depend on the values of the components in the case 1 kHz.
This circuit is from a Popular Electronics from the 80's. The components used are not common...
This circuit for 6 lamps was found in old American documentation. The supply is of high voltage...
The circuit is from the 1994 National Semiconductor Linear Applications Handbook but can be...