An equalizer for nine ranges using LC circuits

Thanks the LC arrangement, this circuit for a graphic equalizer also works without the use of integrated circuits and with relatively few components.

The main difficulty, however, is the procurement of the coils. They are barely self-producible. Therefore one will rather resort to other solutions. One can f.e. maintain the scheme and replace the coils with gyrators. However, this requires a considerably higher circuit complexity, since the circuit is needed twice for stereo and so a total of 18 gyrators must be constructed. I managed to got matching coils by removing from an old, defective car-equalizer.