The biggest feature of the 9/9 is its ability to create a high-gain distortion with a solid, fast response, and a low end that doesn't get muddy even when heavily distorted. For example, when you play a palm-muted riff, tremendous sound pressure is output from the amp at high speed. The controls are Volume (top left), Gain (top right), Bottom (center), Treble (small knob), and a Mid-Cut inside the enclosure. The Volume and Gain have a wide effective range, while the Bottom controls the low frequencies that affect sound pressure, and the Treble controls a portion of the high frequencies with a subtle range. The 9/9 is highly versatile in terms of tone, and has been loved by players of many genres. The distortion texture is fine-grained and classic, with good responsiveness to guitar volume and touch. The effectiveness of each control is also excellent, and there is a wide variety of sound variations. And it's incredibly low-noise. It doesn't fit into a category like "〜〜-type," but it has a distinct originality unique to its original circuit, and there is no other distortion with this level of versatility.