I just bought a pair of Technics 1200 MK-2's and concorn needles. They both work but when I first turn one of them on it won't output to full level so its real soft sounding. I take the RCA jacks out of the phono 3 input and put them in another unused jack (anyone will do) then when i put them back into phono 3 they are back at full volume. It's really weird how it works. Does anyone know what's going on?

this might sound stupid (but i have learned this from experience) but do u have the headshell/cartridge screwed in all the way on the tonearm?