[amsat-bb] Virtual Audio Cable

All, I am in the process of setting up my station to receive telemetry from AO-85 and then AO-73. I have come across a number of references to a “Virtual Audio Cable” being used to connect the RTL-SDR dongle to the telemetry software. A Google search returns a number of hits for such a cable. Some free, some not. Does anyone have any experience using any of these products in the application I want to? If so, is there one you would recommend? Stay away from? Hints, pitfalls? Any insight would be appreciated. I just hate downloading product after product for evaluation without any prior knowledge. Reminds me of the old BBS systems and shareware! Thx -Steve