Sound Redirector is a simple portable application to redirect Wave In to Wave Out.
Any Wave In source and any Wave Out output can be selected. The most evident scenario to use the program is to connect an analog set to line-in (e.g. old walkman). Mute the line-in playing source, and enable the line-in recording source then start the program and choose line-in for input. Then you can use equalizer, noise filter and other effects your sound cards provides on wave out but most likely not on analog line-in. From version 2.0 you can also use VST plugins.
A bonus feature is the change phase processing that helps on old cassettes where the phase is not right. You can only notice this error if you have a subwoofer for bass (the bass is very weak). Classic 2 speaker setups not affected since the left and right channels are separated fully.
Windows Server 2008