I have received a video demo from the person selling one of these. I know for a fact this tape machine has three heads. One things is unclear to me. In the video they are engang the record function and I notice that after they press stop while the red button is engaged you can hear the input source until they disengage the red button. I tried looking up through the manual and on the device itself (from photos), but I can't seem to find a switch between tape and source. Given it has three heads, am I right to assume the third head is related to the built in echo mode? Here is the video in question
https://www.youtube.com/watch?v=7aAXiafmkgw