Zesto Audio has developed a new power supply system called the ESP Power Supply and implemented it in three tube models: the Andros II and Andros Deluxe II phono preamps, and the Leto Ultra II preamp. According to the company’s president and developer, George Counnas, the new power supplies “predict the energy of music” and “unleash the full potential of the circuit, making it easy to operate without having to strain” – resulting in more natural music.
The main difference between the new power supply is in the transformer: instead of the W-shaped one, a toroidal one is used, which generates less noise. The power supply circuitry now uses fewer components, but they are more massive, resulting in increased reliability and power. The thoughtful design is said to protect the circuit from power surges. As a result, the high voltage supply in the new unit increased by 20% from 250V to 300V, increasing the headroom of the dynamic range. The dynamic range itself has grown from 90 dBV to 122 dBV. The noise level in the phono stage has decreased by 5 dBV.
Devices with updated power supplies are already in production. The Andros II phono preamp will cost $5,200, the Andros Deluxe II $7,500, and the Leto Ultra II preamp $10,900.