The ET7-S2 enhance triode line-stage preamplifier has been designed to incorporate the advances made with the Series 2 upgrade to our flagship GAT into a more affordable model. The circuitry of the ET7-S2 follows closely that of the GAT Series 2. The audio circuit is elegant in its simplicity. An audio amplifier stage consisting of a single-ended triode amplifier provides the voltage gain. This amplifier stage is connected to the preamplifier outputs through a high-current MOSFET buffer, which achieves a very low output impedance, making the ET7-S2 extremely flexible in the choice of interconnect cables and amplifiers. DC voltage is supplied to the circuit by the revised discrete voltage regulator developed for the GAT Series 2. It isolates the audio circuit from the power line by maintaining negligible impedance across the audio frequency band. Infra-sonic noise is minimized by operating the tube filaments (heaters) on a dc voltage supplied by a separate regulated power supply.