Blackstar S1-200 Series One 200-Watt Tube Guitar Amp Head
Four selected KT88 power valves form the backbone of this 200W high gain power house and provide unbelievable dynamics and head-room. The DPR control allows the power to be reduced down to 20W for beautiful power amp distortion at a much lower volume level. Setting new standards in tonal flexibility, the deceptively simple preamp section has four world-beating channels (6 modes) which are further augmented by dual ISF controls.

ISF CONTROL
The ISF control works in conjunction with the Tone control. It allows you to choose the exact tone signature you prefer. Fully CCW is a more American characteristic with a tight bottom end and more aggressive middle, and fully CW is a British characteristic which is more woody and less aggressive.