It is a pleasure to introduce the Sutherland Engineering 20/20 phonopreamp. It is AC powered and it is quiet! It starts with separate external AC power modules for each channel, followed by 10 sections of passive RC filtering and finalized with local constant voltage shunt regulation.
First. Everyone wants the advantages of AC power line isolation offered by battery operation. The 20/20 is for the person who wants those advantages, but does not want to mess with batteries. The 20/20 comes as close as possible to offering an equivalence of battery isolation from AC line power.
Second. Two-Mono (definition: bumping it up from dual-mono) construction. The 20/20 is literally two identical mono phono preamplifiers. Each channel is on its own circuit board, has its own shielded compartment, power indicator, its own AC power supply and its own power cord. It is the ultimate in channel separation.