I have currently moved my entire pc to Linux only and have an irritating issue with my usb sound card. Before going any further I have to admit that I have disabled Pulseaudio in YAST as my main audio card M-Audio 2496 is not correctly configured with it (it sees only the digital output from the card and not the analogue that I require). My main audio use is to play flac files through an Audiophile system and so M-audio working is paramount. However in the evenings I sometimes want to listen to BBC iplayer and thus use the Fiio usb headphone amp; or have been in windows. Now I’m a little stuck.
A major feature of pulse audio is to provide superior and easier to use functionality for multiple sound devices. It provides multiple device functionality that was either difficult to do, or not possible with only alsa. Sometimes ‘jack’ will provide functionality that the basic alsa lacks.
In any event to configure either alsa alone, or to configure jack, to perform some of the simple pulse multidevice functions is not trivial and is difficult.
My suspicion is if what you wish to do is feasible, you may need to write a custom .asoundrc file to assist, and for sure that is not something I can help with. Possibly ( not sure ) there may be no one on our forum with the prerequisite knowledge. As noted, this may not be trivial. Possibly focus your learning/education efforts on .asoundrc to do this.
Thank you for that pointer oldcpu. I thought this may be something quite obscure and in depth, but I am willing to roll my sleeves up and have a go. You never know if I succeed I may be of help to others in the future.