The MXR MC-401 Custom Audio Electronics Boost / Line Driver pedal is a great clean boost for your pedalboard. The CAE Boost is great for boosting signal on long cable runs too. Check out the The MXR MC-401 CAE Boost / Line Driver.
Mr. Black’s Boost Tiger delivers 20 decibels of clean preamp gain to boost your amp to the top of the food chain. Unity gain gives you color and clarity, push it a bit for transparent overdrive, or put it in your effects loop for a lead boost that roars.
The Electro Harmonix Analogizer is great for warming up a sterile guitar tone. With 26dB of boost and musical tone shaping controls, the Electro Harmonix Analogizer may be just the thing you need to spice up a dull guitar sound.
The Devi Ever Punch Love is a clean/dirty boost pedal designed to push your signal to the limit be it through a bunch of pedals or hitting the input of your tube amp like a fist. The Devi Ever Punch Love features switchable clean boost/dirty boost for added grit when needed.