I have done quite a number of successful digitisations using Audacity in the past, but not recently. Now nothing works, just squealing acoustic feedback and when recording level is reduced no signal at all.
Details: Mac OS X 10.13.1 High Sierra
Audacity 2.1.0
I started using a brand new small Cassette player as the source, joined to iMac by the players own cable terminating in USB plug. When that didn’t work (with symptoms as above) I reverted to my old system of connecting from a high end DENON cassette player, reaching the iMac’s USB socket through a Behringer UCA22 link-up (converts two separate radio plugs to one USB cable.). This was the arrangement I have used many times when digitising LP records. In both cases the cable comes from the pre-amp sockets on the back of the amplifier in the Hi Fi setup I have.
Sadly the result was exactly the same: acoustic feedback, with no signal when recording level was reduced.
What I am I now doing wrong that I wasn’t a year ago?