The Skreddy Pedals™ BC239 FUZZ is a throwback to the late "rams head" era. The BC239 transistor will tend to render less bass, resulting in a more biting and articulate muff tone. Add to that the fact that the later rams heads employed plastic film capacitors instead of the softer, grittier tone of ceramic discs used in the triangle knobs and earlier rams heads, and you get a clear, cutting top end. You'll hear every detail of its velvety distortion. I'm preserving articulation by keeping the gain in check just enough and not letting it get too mushy or syrupy.
Nice and hot with ample harmonics and of course great sustain. Rather than a round, fluty tone, you'll get a meaty grind even in your high notes.