Tube Box S2 is Pro-Ject's very first product to feature a fully discreet circuit design without using any operational amplifiers (OpAmps). It also is the first product to come with replaceable tubes for tube rolling and sound-shaping. This provides the listener many options to pick from and gives them the ability to alter the sound signature to his/her preference. Tube Box S2 will give a full and relaxed laid back sound with lush mids, just like you would expect it from a much bigger high end tube phono pre-amplifier. It offers support for both MM and MC cartridges and comes with many gain settings that can be switched via the front panel. Five variable input impedance settings are available to adjust to any MM cartridge, while the 47k ohms input impedance setting is fixed and suited for high output MC cartridges. The aluminum/metal casing is adapted to the DS2 line in looks and protects against vibrations and electromagnetic interferences for superior sound.A true high end solution in a much smaller package!