This tube has the deepest, tightest low end of any 6L6. The mids are full of complex harmonics. The highs are sweet and down right lush. This Slovakian tube has colorful lows, loose/easygoing mid body, and a brightly shining chime for the highs. In overdrive, it offers a tight and focused bite with crisp, bright, and well-defined articulation. When over driven the JJ’s get very rich and thick. They don’t squash down and they have excellent definition and detail.