2-SB

About the 2-SB

The LKV Research 2-SB is a high-performance phono preamplifier featuring a fully differential balanced signal path with cascaded JFETs and bipolar transistors operating in class-A with zero looped feedback. It uses high-quality polypropylene capacitors in the signal path and dual-mono, four-layer circuit boards. The unit is housed in a powder-coated black aluminum case internally damped with mass-loaded polymer sheets, and it includes an external power supply for improved noise performance. The 2-SB offers multiple gain settings and adjustable resistive cartridge loading from 50 to 47K ohms, supporting both MM and MC cartridges. It provides single-ended (RCA) and balanced (XLR) inputs and outputs. The design emphasizes ultra-low noise, high signal-to-noise ratio (up to 80dB at low gain), excellent channel separation (better than -90dB), and precise RIAA equalization accuracy within ±0.1% from 20 Hz to 50 kHz. The unit has been praised for its natural, detailed, and lifelike sound reproduction with a tonal balance that maintains black backgrounds even with low output cartridges. It is supplied with a printout of measured performance and has been subject to upgrades including Teflon capacitors in the RIAA filter and improved power supply regulation for enhanced sonic performance. The