We recently acquired a few Sumo units. This compact preamp performed quite well in our tests, and it includes a phono stage. There is an internal MC/MM switch for the phono section, it is currently in the MM position. In the MC position the input impedance is 100 ohms set by plug-in resistors at the phono input, and may be adjusted and optimized for any MC cartridge. All switches and potentiometers were cleaned and lubricated using deoxit. It is in perfect working order and physically it is in very good condition, with some small scratches and scuffs on the top of the unit.