SW1X PRE II

The SW1X PRE II is a pure Class A, zero negative feedback line preamplifier with an Output Transformerless (OTL) power valve output stage, a natural extension of the SW1X DAC and LPU phono stage ecosystem, using 6V6GT power tubes to reduce output impedance and add authority, fullness, and dynamic expressiveness to any source connected before it.

Type and Technology

Line preamplifier with optional phono stage, single-ended Class A vacuum tube. OTL (Output Transformerless) topology using 6V6GT power valves in triode connection at the output, sharing its power valve output design with the flagship SW1X PRE IV. Tube complement: 2x 6V6GT output, 1x 6SN7 driver, 1x 5Y3 directly heated rectifier. 5Y3 valve-rectified CLC choke-filtered B+ power supply. Hybrid point-to-point hardwiring for production consistency. SW1X Stepped Attenuator volume control (24-way discrete resistor). Internally wired with SW1X Magnum, Genesis, and Opus conductors. Available with optional integrated LPX phono stage (designated PRE II LPX), an EF86-based MM phono preamplifier with active series-resistor-less RIAA equalization and its own 5Y3 choke-filtered supply. Output impedance: 10 ohms.

Sound Character

The PRE II brings fullness, authority, and enhanced dynamic expressiveness to any source driving power amplifiers, the 6V6GT output stage's low output impedance unlocks the full potential of connected sources, including SW1X DACs and phono stages with their inherently higher output impedance tube output stages. The OTL topology keeps the signal path clear of output transformers while still providing the tonal character and control that power valves deliver.

Build and Finish

150 x 330 x 400mm at 10kg (12kg with LPX phono option). Specifications subject to change as SW1X's ongoing research and development continues.

Best For

SW1X DAC and LPU Phono owners who want a valve preamplifier to complete their system, and those who want the authority and dynamic presence of a power valve output stage in a line preamplifier without the complexity of output transformers.

Specifications