Problem Loop in 104Z

[mousedown]

Hi

I just bought a Moog 104Z and I can't get the Loop in to work

I have connected with the ring modulator as moog recommends in the manual but the sound does not come back in any way, the sound comes out through loop out but does not come in through loop in, any anything that goes into loop in doesn't sound, it doesn't seem to work

Should anything you connect to Loop in be heard?

Thanks