MM Phono preamplifier.
It is a transistor design that has it’s pedigree in Haiku-Audio studio equipment.The system works in A- class only. Each pre-amplifier channel has a separate stabilized power supply. The entire system uses only the highest-quality WIMA and electrolytic-Gold winding capacitors. The front panel of brushed aluminium has a control and there are RCA sockets on the back of the enclosure, as well as a mains socket, a switch and a ground connection. The SOL MC is the same but designed to amplify the signal for MC cartridges