PLC-B

About the PLC-B

The Sonic Euphoria PLC-B is a passive preamplifier that employs autoformer attenuators for volume control, providing current gain and impedance matching advantages over traditional resistor/pot-based units. It features three front-panel knobs for source selection, volume control, and a half-step switch. The preamp uses a grounding cable to connect the chassis to earth ground, preventing static discharges and ensuring signal integrity. Internally, it is meticulously point-to-point wired with short lengths of copper wire and includes two autoformers in the unbalanced version, with the balanced version having two pairs. The autoformers share primary and secondary windings, offering simplified transformer functionality but without electrical isolation. This design yields excellent channel separation and low distortion, with distortion rising slightly below 300Hz due to transformer core influence. The PLC-B maintains deep bass, openness, texture, and detail consistently across all volume levels, making it sound significantly more expensive than its retail price. It requires careful matching with source components and power amplifiers due to its unique input and output impedance characteristics. The build quality is very high, with a thick anodized aluminum front panel and solid milled aluminum knobs, ensuring durability and tactile precision. The unit is completely passive and noiseless, requiring no power supply, which simplifies setup and reduces potential noise sources.