L 'H2A is a headphone amplifier, built with vacuum tube technology.
The circuit uses four double triodes (ECC82/12AU7): the first triode is used as a voltage amplifier, the second triode is utillizato as a phase inverter and driver of the final stage. The last two triodes are current amplifiers and work with a negative voltage grid "fixed", in securing the class dell'amplifictore that in this case work in pure class A. The structure has three processors: the first is the power, the other two are output. The transformers are manufactured completely in place with copper wire of first choice. They are used all selected components, such as metal film resistors al'1% of toll.
The assembly of each electronic component is wired in the air completely by hand.