CS Kochsystem Koch Studiotone ST20/C112

The Koch Studiotone 20 is a 20-watt combo amplifier featuring a 30.5 cm (12-inch) speaker, designed for guitarists seeking versatile tube amplification in a compact format. This amplifier utilizes two EL84 power tubes in Class A operation, delivering authentic tube amp tones reminiscent of classic British amplifiers from the 1960s. The unit offers three foot-switchable channels: Clean for transparent, articulated sounds, Overdrive for medium gain, and Overdrive+ for higher gain saturation and compression. Tone shaping includes a 2-way midrange switch that adjusts mid frequencies around 800 Hz, and a 3-way Bright switch for treble control. The back provides extensive connectivity options including a serial effects loop, recording output with speaker simulation, two line outputs (unfiltered and low level), and a headphone output for silent practice. Additional features include a built-in power soak function for volume attenuation, speaker on/off switch, and a short-scale spring reverb system with a front panel control. The amplifier cabinet measures approximately 48 cm wide, 42 cm high, and 24 cm deep, weighing around 15 kg. The speaker impedance compatibility includes 4, 8, and 16 ohm configurations for flexible cabinet combinations. Its robust construction with solid plywood housing and newly developed speaker ensures enhanced durability and reliability. This amplifier is suitable for practice sessions, studio recordings, and performances in small to medium venues, providing professional amplification in a portable format.