Preamplifier Usher P-307A Giá: Liên hệ P-307 is the control center of today’s high end sound systems. Its two main functions are source selection and volume control. Every effort has been made to keep P-307 as accurate as possible. To avoid unwanted interactions with adjacent source components, P-307 uses high-quality relays and switching designs to ensure that every source is intact. Thus all sources remain separate from one another and from the power amplifier and cables. In the digital age, analog preamplifiers remain the most reliable and neutral-sounding component of controlling volume. P-307 uses a superior attenuator that offers a neutral sonic performance. Since AC power supply generates noise, P-307′s power supply is housed in a separate chassis. Thus P-307′s audio circuits are exposed only to quiet, regulated DC power and the audio signals itself.