When I use my Line6 Toneport UX1 with the Gearbox or PodFarm guitar software...I can use them as standalone amp simulators, and X1 sees the audio import and records the audio track.

I downloaded a free version of Peavey ReValver, and it won't let me have X1 open at the same time as ReValver...they won't share the audio interface (asio).

What's the difference between these two guitar amp programs, and why can't I use ReValver ?

     This is actually a limitation of ASIO, which can, by architecture, only handle one program at a time. The difference between the two programs is simply the fact that Pod Farm or Gearbox are part of UX1's settings as far as in's out's and handling the driver, designed by Line6. I'm not sure how Line 6 incorporated PF or GB like that, but that's how I take it, and it just works. 
     The work around that I used to use a couple years back was to use "ASIO for all" (not sure if it's still around, but bet it is) and this basically allows you to use WDM drivers, yet tricks programs into thinking it's using ASIO for lower latencies. WDM doesn't have a limitation on shared programs like ASIO does. Hope this helps. I have a UX2 that I use for mobile recording and that seemed to be the work around, but this was a couple of years ago that I used that work around too, but hopefully it will still work for you.


NOTE: using ASIO for all or WDM drivers will inherently require you to adjust latency buffers and such, it won't just work like ASIO does for the most part. 

Another option, would be to use ReValver as a plug, but I'm not sure if that's an option as I'm not familiar with ReValver.

 

  

Thanks ! That makes total sense....I appreciate your timely response and experience !

NP, I hope you find something that works for you.