SW1X LPU III Balanced Phono Pre-Amplifier

SW1X Audio Design™ LPU III Balanced

Performance Level 3

Signal OPTs de-coupled Phono Pre-Amplifier

The LPU III Balanced is a Signal Output Transfomer (OPT) de-coupled phono pre-amplifier with a pure class-A, zero-negative-feedback, single-ended circuit.

The SW1X LPU III Balanced Phono Preamplifier delivers a listening experience that’s as natural as it is immersive. With an organic sound signature, it brings music to life in a way that feels unforced, smooth, and emotionally engaging. The LPU III’s rich, warm tones, paired with its dynamic clarity and expansive soundstage, ensure every detail is presented with breathtaking authenticity.

Just like with all our Balanced versions, highest Quality Signal Output Transformers further improve transparency & dynamics. The classic RIAA circuit is made of specially selected materials & components out of production and only available in limited quantities.

The EF86

LPU I, LPU II and LPU III family of Phono Pre-Amplifiers share similar tube input stage – a pair of EF86 pentode tubes. Due to their brilliant sound character, the EF86 tubes were commonly used in many radios and RTR tape recorders in the early 60s. The idea of their circuit design was borrowed from the input stage of early Reel to Reel (RTR) tape recorders, which were used in the mastering studios and radio stations. Maybe that is one of the reasons as why most recording from the 60s are sounding at their best, much better than from the 70s and 80s? In a way, the EF86 input tube design closes the loop and makes all our LPU Phono Amps range a timeless classic.

Read Michael Fremer’s Review

SW1X Audio Design™ LPU III Balanced Phono Features:

Specially Selected and Harmonically Matched Component & Material Quality
MM Phono Pre-amplifier is suitable for all moving magnet (MM) or moving coil (MC) in combination with a matching SUT
Classic 2 Gain Stage Pentode Input-RIAA-Triode Output Design
Signal Output Transformer De-coupled, Zero NFB, Triode Valve Output Stage in Pure Class A, (inductive loading & de-coupling) Circuit Topology
SW1X Audio Design™ Custom Designed Signal Output Transformers
Based on 2 x EF86 Pentodes Input and 2 x 6S45P Special Driver Triodes on the Output
Active Series-Resistor-less RIAA Equalization
5U4GB Valve Rectified CLC2RC (choke filtered) B+ Power Supply
47K Input Impedance & < 20 Ohm Output Impedance
Total Gain is approx. 46-52 dB depending on the Choice of Valves
Maximum Input Voltage: 350mV
Orient Grain, M6 EI Core, Copper flux banded, mains Transformer & Choke