This is a hidden gem of a booster. Just switch it on without a second thought, and it transforms your sound into something juicy, deep, and full of flavor. It's already discontinued, making it a valuable piece of gear. The Simble Predriver is more than just a preamp. It combines the functions of a preamp, booster, compressor, and high-frequency harmonic enhancer. This musical tone can be freely adjusted with your picking attack and the guitar's volume pot. The boost amount varies depending on the input signal level and the position of the HOT/COOL switch. It provides a maximum boost of approximately +10dB and an average of approximately +6dB in the low frequencies. The Simble Predriver's special circuit uses low-noise transistors with a high input impedance (over 2MΩ), allowing it to boost the sound of piezo pickups without compromising the tone. The output impedance is 50KΩ, so it can also be used before a fuzz pedal. Power consumption is very low, and if you unplug the input jack when not playing, a 9V battery can last for several years. • Power: 9V DC (negative terminal at DC-jack tip) • Current Draw: 2.5 mA when pedal is on / 0.1 mA when pedal is off • Input Impedance: > 2Mohm • Output Impedance: < 50 kohm • The battery is disconnected from the circuit when using the DC power jack. #tgakki Tsukamoto Gakki