The Linestage I is an active linestage using vacuum tubes as the gain device. Vacuum tubes are also used in the regulation of the power supply. A class A triode circuit is employed in a most straightforward design, with emphasis on keeping the design as simple as possible. This is in accordance to our design philosophy plus the added benefit of very high reliability (the simpler the design equates to fewer parts, equates to less parts to fail). The purity of the signal is kept as intact as possible as it travels through the preamplifier. As the signal enters, it goes to the selector switch, into the gainstage (the vacuum tube), into the attenuator, and out. Quick and short, minimizing the possibility of signal degradation by eliminating one or more stages in the signal path. This is the most straight forward design possible for this purpose.