pas mane compact four keturkanalis, knopkė tik ijungia arba išjungia LP filtra kanalui, dažniai taip išeina kitaip reguliuojasi

"I have attached the connection diagram for Compact Four, this shows the
common connection mode for this amplifier.
The HP filters are adjustable on the front panel, the LP is adjusted by
changing the modules supplied with the amp.
Standard module is Black and gives 100HZ, no module gives 50Hz. Red is 60Hz,
Blue or Yellow will be 75Hz.
I hope this information is helpful."