For all you Shiva users....I've noticed that you can get very different tones by cranking the channel volume and leaving the master low, or cranking the master and leaving the channel low, or somewhere in the middle for both. How do you get the most natural and beautiful sound out of the OD channel? I've been doing a lot of tweaking lately, hard to find *the* sweet spot. I'm just looking for any ideas, anything from settings to tubes to speakers etc. Thanks!