Luckily i find sweep picking quite easy. Best tip is, is to start really slow and keep getting faster. It worked for me ! But do try and use the search... you will find lots on sweep picking if it works.
By virtue of their electrical properties, tubes generate a special waveform when they're saturated, which is why tube engineering has tremendous tonal advantages over solid state or DSP solutions, particularly for crunch and lead sounds. Tubes enter the saturation zone gradually or softly, which lends tube-driven tone its trademark yet totally unique character.