Sorry, the other post I made about this has the wrong video link and I think I am passed the time I can edit it.
Boss Katana 100 Review - Slow Gear Plus Delay Settings (Amazing)!
In this video, I do an Boss Katana 100 review and demo. Specifically, I show how adding the effect "Slow Gear" as a module and adding delay with a delay speed of 350 makes the guitar sound how Eddie Van Halen uses the volume effect to create the swell effect. It also sounds like Jimi Page on the Songs Remains the Same when he is doing the solo including part with the violin stick. Enjoy.
Can the Line 6 Spider V do this without any pedals?