Way back in 1961, VOX rolled out the AC4 amplifier. Over fifty years later, VOX is continues the AC4 legacy â the all-tube practice amp with remarkable self-control - now in blue and includes the AC30 characteristic top-boost! Description The AC30's Top Boost sound has fascinated guitarists around the world for over fifty years. Capable of massive crunch or the clean, classic “chime,” this Top Boost tone is the essence of VOX's identity. The AC4C1-BL now delivers this unbeatable sound in a portable, compact body. Gain control, Bass and Treble tone controls, and a Master Volume allow any player to easily recreate this historic sound. Remarkable not only for its authentic VOX sound, the AC4C1-BL is also captivating in its appearance. The rich, blue vinyl and Tygon fret cloth date back to 1963. Completing this vintage ensemble is an “old-school” Bakelite handle. Boasting the highest levels of design sensibilities, the long-awaited VOX AC4C1-BL offers an easy way for anyone to achieve the legendary AC30 Top Boost tone.