The LA4 MkIII is a top-tier valve line preamplifier, created for the most demanding listeners. Its seemingly simple design — a single gain stage with an output buffer — conceals a refined circuit that delivers a clean, noise-free signal with rich dynamics to virtually any power amplifier.
At the heart of the unit are three 6SN7 triodes (12AU7/ECC82 adapters possible) and a GZ34 valve rectifier (alternatively 5AR4 / Western Electric 274B), giving a gentler sound than silicon diodes. The power supply is based on a dual choke in a Pi configuration and DC valve heating, which translates into an exceptionally low noise level.
The whole is hand-assembled, point-to-point, in a solid aluminium-alloy and steel chassis. Inside are audiophile SCR capacitors (optional Mundorf silver/gold), silver-plated PTFE wiring and metal-film and wirewound resistors. The model was named „Product of the Year 2021” by The Absolute Sound magazine in the valve-preamplifier category.
| Valves | 3× 6SN7 (CV181) |
| Rectifier | GZ34 (or 5AR4 / 274B) |
| Gain | 4× (12 dB) |
| Frequency response | 20 Hz – 20 kHz (±0–0.1 dB) |
| Signal-to-noise ratio | −90 dB |
| THD distortion | typically <0.1% |
| Max. input level | 5 V (at 20 V output) |
| Output impedance | 100 Ω |
| Inputs / outputs | 4× line RCA (+ Bluetooth option), record output, tape monitor |
| Power supply | 230 / 117 V, 100 W |
| Dimensions (W × D × H) | 250 × 370 × 230 mm (with 274B cage; 170 mm without) |
| Weight | 12 kg |
Reference-class valve line preamplifier — 6SN7 triodes, valve rectifier, hand-wired assembly. A clean, noise-free signal. Product of the Year 2021 (The Absolute Sound).
