Icon Audio LA4 Mk2 line pre amplifier
A line pre-amp of outstanding quality
With the introduction of our new range of amplifiers we have redesigned our LA4 pre amp to match the cosmetics of our new range. Whilst using the same tried and tested circuit, we have made two important changes:
Firstly we now include the excellent 274B rectifier. This outstanding Western Electric design is probably the best sounding power valve available.
Secondly by providing adjustable gain, this will enable the widest range of sources to get optimum coupling to almost any power amplifier, whilst keeping the noise level to an absolute minimum. With high output CD players the gain of many pre-amps is too high. The LA4 MK II is capable of up to eight times gain, to below unity without attenuating the output.
Completely unspoiled by progress!
What we have not changed is the circuit that gave us the excellent review in Hi Fi News. We still use the brilliant 6SN7 double triode as we feel these have a more fluid sound, and a reputation for a very long life. Probably the best sounding pre-amp valve ever! This venerable 1941 vintage valve both looks and sounds the part, very robust and extremely reliable. It is widely available in both “new old stock” and new production types.
Built to last
We like solidly made equipment. The LA4 Mk II features a heavy alloy and steel chassis. The internal wiring is all “point to point”, “hard wiring” without printed circuit boards, this is essential for valve
amplifiers, and allows for oversize components, easy service and future upgrading. A pre requisite for any pre-amp is an excellent power supply. The LA4 MK II has two chokes in double Pi configuration for well conditioned power giving superb smoothing for velvety inky black silence.
After years of testing we believe that pre amplifiers always sound better with a valve rectifier, and 274B is the best! The LA4 MK II is compatible with virtually any power- amp from past or present. We use only top quality oversized components for the best sonic quality and a long life.
With four inputs and a record loop the LA4 MKII is very versatile.
Anyone thinking of buying a pre-amp should read the independent lab report on the LA4 in Hi Fi News July 2006. This includes ...
“The LA4 offers a ruler flat response to 20 kHz and is only -0.5dB down at 100 kHz...distortion hits an all time low of 0.0009%...the low 100 ohm output impedance ensures it will drive both solid state and valve power amps with ease.”
Paul Miller Hi Fi News
Valve versus Transistor?
It is well accepted that introducing valves into an amplifier is beneficial to the sound. The versatility of the LA4 MK II makes it an ideal pre-amplifier to any solid state power amplifier. You can expect a more vivid, intimate interpretation, and being very easy listen to. It is an ideal partner to digital sources.
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 • 274B Valve rectifier • 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 high x8 (output low x 1.33) • Gain low x4 (output low x 0.66) • Max input level 5v for 40v output • Very low output impedance of 100Ω • Suitable for power amps 100mv-5v sensitivity • Japanese steel transformers with low oxygen copper • Attractive valve cover available (£50 extra). • High quality 2w metal film, & wire-wound resistors • Blue LED mains indicator • Audiophile polypropylene audio capacitors • Silver TEFLON audio cable • Ceramic valve holders for minimum leakage • Gold plated Input terminals • Four line inputs • Tape monitor circuit • 220/240volts 100watts 1A anti-surge fuse • C E compliant • 250W, 370D, 230H (with 274B and cover), or 175H with
GZ34 (no cover) 12kg packed (Specifications subject to change, errors & omissions excepted 16/07/10)
Optional perspex cover available at £100