What are S4GB tubes?

S4GB stands for selected for Guitar and Basses. These tubes are intended for amplification in guitar, bass and effects devices, as well as all musical instrument amplifiers. Unlike S4A tubes, they are not selected for low distortion, but for good dynamic playability, openness of sound, with different levels for different amps and sound directions in the 12AX7 range, and robustness in mobile use. All tubes are hand-selected at BTB Elektronik for low microphonics, low noise and low hum, so that the amp works quietly on stage, at home or in the studio. For preamp tubes, we offer the matched / balanced option. This is particularly advantageous for the phase inverter stage and clean operation. This option can also be beneficial when used in the studio, for example in a compressor, or in multi-channel effects devices.