I have been suffering from same problem for a while now and for me using only line 6 pod HD 500 as my main sound card worked
Steps : 1:goto playback devices
2: set line 6 device as default
playback device
3: setup the quality to 24 bit
48000 hz
4:in DAW setup same bit rate, in
my case 96khz worked inside
DAW(ableton).
-Note: do not connect any other audio hardware to your computer's bus.
-buffer sizes I setup are extra small and 128 bits.
- my PC configuration is Lenovo ideapad laptop with i7 quad-core 8 gigs of ram.
Hope it works for you guys. Keep on rockin'.