I missed this in the OP.Usually run on low watt mode with master anywhere between 7 to 10 and gain around 6-8
Agreed. I run mine on 20w at any volume.You might be fighting a losing battle playing in low power mode though, it's noticeably more mushy and fizzy than the mid/high setting.
At low volume I use the amp boost, up the gain on the SD-1, and give the GE-7 a high/low "V" shape with some boost.
As the volume goes up, I turn the amp boost off, lower the SD-1 gain, and flatten out the GE-7 as the amp gain takes over and opens up.