This Pedal is currently available.
Clean Boost
This pedal is a guitar preamp capable of sweeping from +5db up to +40db of clean gain. Its maximum undistorted output level is +16dBu and it is intended for use with a tube amp.
The MORE uses a standard 9V center negative adapter. Power consumption with no signal is 45mA and at max OP (+16dBu) is 52mA.
http://www.uniontone.com/shop/union-tube-transistor-more-clean-boost