Icon Audio Stereo 40 Mk IV SignatureThe Icon Audio Stereo 40 Mk IV Signature is a beautifully voiced British tube amplifier that blends classic valve warmth with modern refinement and reliability. Hand built in the UK, it uses a quartet of KT88 output tubes to deliver a sound that is rich, dynamic, and effortlessly musical. The presentation is open and inviting, with a full, textured midrange, authoritative bass, and a treble that remains smooth and extended without glare. In its