Quote from the Facebook group ....
Easy Way To Do Digital Modes with an SDRplay.
Digital modes are EASY to decode with an SDRplay RSP. Assuming you have an SDRplay with drivers installed , and it is receiving signals, here are the other steps you should take.
1. Download Virtual Audio Cable (trial version has an annoying lady yelling "TRIAL" every few seconds but paid version is very good), OR download VB-Audio which is free.
2. Download Fldigi , Multipsk, DM780, Digipan, Winwarbler or MixW . Fldigi works on Linux or Windows the rest of the aforementioned are Windows. I can't help with Apple iOS. Most folks here use Fldigi or Multipsk.
3. Install VAC or VB-AUDIO. The default install is usually set to install two virtual audio cables. You should view these as virtual version of old fashioned patch cords that you likely used with an audio cable on a sound system. A "cable" audio IN and another one carrying audio OUT. After you have done this, you can almost ignore these programs since they work mostly in the background and rarely need changing beyond the default settings.
4. Install your digital mode software . In each of these applications is a set-up or configuration area . To receive and decode digital modes you only need to be concerned with receiving signals and thus can ignore the more complicated transmit settings. In the set-up/configuration area , look for the sound card options. They are usually labelled INPUT and OUTPUT. Some label it Receive and Transmit.
5. Select the INPUT/Receive option and a drop-down list of all your sound devices is usually listed. Instead of the default soundcard in your PC or laptop, look for one called VAC or Virtual Audio Cable or VB-Audio (depending on what you installed). Usually things will work if you select VAC Input or VB-Input. Some list it as Line 1 or Line 2.
6. Now boot up your preferred software used to run the SDRplay RSP. You will need to change the audio path in this software. For example in SDR-Radio Console V2, within a VFO you click on AUDIO then PLAYBACK DEVICE. In HDSDR, click on SOUNDCARD and then RX INPUT FROM RADIO. Change this to match the setting you selected in your digital mode software.
7. You should now see the received radio signals appearing in the waterfall of the digital mode software. If they don't, trying flipping Line ONE to Line 2 in the digital mode software , it can only be one or the other. You may now be able to SEE signals but may also have lost the ability to actually hear the audio signals through your computer speakers. If that is the case, let us know here. There is an easy solution to this.
8. Now, move your SDRplay to 14070 USB or 7070 USB (USA) . In your digital mode software find the mode selector and select PSK31 , sometimes called BPSK31. Most times of the day on either 20M or 40M you will hear PSK31. Move the cursor on to the waterfall and click right on the vertical line about 31 hz wide that is slowly moving down your waterfall. You should be easily be able to decode a signal above an S1.
9. If you get this far, check back here and we will move on to further questions including decoding other modes. If you got this far and it works, the 80% of the other modes are just as easy. Then next steps are some of the nifty extra things your digital mode software can do. After ensuring you are receiving OK, we can move on to fancy tricks like automatically determining what mode your are seeing, or having the software sound an alarm upon receipt of certain key words, or automatically receiving bulletins and importing in to your web browser.
End of quote...
The above was reproduced from a posting in the facebook group https://www.facebook.com/groups/sdrplay/ which is a great place to ask detailed questions of other users doing what you are trying to do. (plus you don't have to wait for a moderator to approve your post once you become accepted as a friend in the closed and very friendly group.