As an owner of Jadis amplifiers, I also obviously feel they offer beautiful, glorious sound.
In addition to your power cord experience, I've found they show as much sensitivity to tube rolling as any amplifiers I've come across. It amazes me how far you can push the sound in whatever direction you want to head. Driver and output tubes more so than the input, and I recommend starting with them, though the input tubes also definitely need attention. As time passes, you should experiment. You can REALLY improve things from where the factory starts
In addition to your power cord experience, I've found they show as much sensitivity to tube rolling as any amplifiers I've come across. It amazes me how far you can push the sound in whatever direction you want to head. Driver and output tubes more so than the input, and I recommend starting with them, though the input tubes also definitely need attention. As time passes, you should experiment. You can REALLY improve things from where the factory starts