Relay Switching Board for DIY tube amp builders and modders. Real Eh is targeted at signal and channel switching mods in vacuum tube amplifiers. An on-board regulated 5vdc supply powers the relay from a 6.3vac tube filament supply. Screw terminal block connections are provided for 6.3ac voltage, activation switch (toggle or footswitch jack not included), LED signaling (LED not included) and DPDT relay switching.