Pure valve line Pre-Amplifier – LA4 MkIII

SKU LA4 MkIII Kategoria
Opis produktu

A line pre-amp of outstanding quality

Now with optional Bluetooth connection

Pure Valve
All Triode
Valve Rectified
Remote Control
Four Inputs
Record Loop
Low Gain
Twin Choke PSU
12AU7/ECC82 option also.
Valve and capacitor upgrades available, please enquire with us.

Summary:

Very simple high quality line pre-amp. Ideal for virtually any kind of power amplifier.

Building on the success of the earlier marques, the LA4 MKIII has improved cosmetics and an upgraded circuit. Now with lower feedback and lower gain the macro dynamics and sound stage are enhanced.

A deceptively simple high quality single stage design followed by an output buffer. But what makes the LA4 III special is the power supply and our “finely tuned” design. A high end pre amplifier must have the best power supply. The LA4 MK III uses a large choke in Pi configuration for well conditioned power giving superb smoothing for velvety inky black silence. The rectifier valve, which makes a small but valid difference may be either the Mullard designed GZ34 (pictured) or the venerable WE designed 274B. 

The three audio valves we use are the 6SN7 double triodes. This 1940 vintage valve has all the best characteristics for the job, and its larger size means long life and good stability. Also the sound is more musical as we feel these have a more fluid sound. You can experiment with both vintage and modern types.

Built to last

Like all our equipment the LA4 III is very solidly made. It has a heavy alloy and steel chassis. The internal wiring is all “point to point”, “hand wired”, this is essential for valve amplifiers, and allows for upgrading to larger capacitors, and makes future servicing very simple.

Szczegóły techniczne

Specifications and Features

  • Comprehensive manual supplied
  • All hand wired point to point without PCBs
  • ALPs motorised volume pot.
  • Remote control volume and mute
  • All Triode design
  • 3x 6SN7 valves (CV181)
  • Adaptors available for 12AU7/ECC82
  • GZ34 Valve rectifier (also 5AR4/274B)
  • Double Choke HT supply
  • DC heater supply
  • Signal to noise level -90db
  • Freq response 20hz-20khz +0 – 0.1db
  • Total harmonic distortion typically less than 0.1%
  • Gain x4, 12db
  • Max input level 5v for 20v output#
  • Very low output impedance of 100Ω
  • Suitable for power amps 100mv-5v sensitivity
  • High quality 2w metal film, & wire-wound resistors
  • SCR audio capacitors (Mundorf silver/gold option)
  • Silver PTFE audio cable
  • Gold plated Input terminals
  • Four line inputs plus optional Bluetooth
  • Tape monitor circuit and record output
  • Optional valve cover available
  • 230/117volts 100watts
  • C E compliant
  • 25cmW, 37D, 23H (with 274B and cover), or 17H with GZ34 (no cover) 12kg packed

(Specifications subject to change, errors & omissions excepted 30/09/21)