IMic settings for the MacMini

Question

I have an older version of the Griffin iMic. I am getting very variable results in using this with my MacMini. I am transferring cassettes to iTunes and am using a Sony Stereo Cassette Deck TC-WE475. I make the connection with the Line Out and connect it to the Line In (Loudspeaker icon on the old iMic). The simple iMic instruction leaflet says if I do this I should slide the little switch towards the Loudspeaker symbol. However if I do this the recordings are very buzzy. If I go contrary to Griffin's instructions and slide the little switch towards the Microphone icon (on the old iMic)
Sometimes I get a quite adequate result using Griffin's recommended setting and sometimes a buzzy result. At other times I get much better results by going contrary to Griffin's recommendations and sometimes a buzzy result!!
I would like to understand what is happening here. Can anyone help?

Answer 1

I believe the imic switch is a simple gain boost. So if the signal is to low it will bring it to a acceptable level. So if the level is already at a good level boosting it can cause clipping (buzzing).
So turn monitoring on and listen for clipping or too low a level and switch accordingly.
One more thing the loud speaker icon is usually a output not a input but if it works as input I guess it's a input.