For sale an ex-demo LA4 MK III Pre-Amplifier in excellent condition. Comes with original packaging and manuals and tubes.
A line pre-amp of outstanding quality
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 has two chokes in double Pi
configuration for well conditioned power giving superb smoothing for
velvety inky black silence. The rectifier valve, which makes a
surprising difference, is the excellent 274B. This outstanding Western
Electric design is probably the best sounding power valve available.
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
Very high quality yet affordable line pre-amp. Ideal for virtually any kind of power amplifier.
Specifications and Features
• Comprehensive manual supplied
• Full instructions for valve change included
• All hand wired point to point
• No printed circuit board to ‘colour’ sound
• ALPs Blue motorised volume pot.
• All Triode design
• 3x 6SN7 valves
• 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
• Attractive valve cover available (£50 extra).
• High quality 2w metal film, & wire-wound resistors
• Solen/SCR audio capacitors (Jensen upgrade option)
• Silver PTFE audio cable
• Gold plated Input terminals
• Four line inputs
• Tape monitor circuit and record output
• 220/240volts 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 23/09/14)