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LA 4 MK III
Pure Valve Line Preamplifier Instructions
Previous model shown with front power switch and gloss paint and upgraded CV181 (6SN7) valves
About the LA 4 MK III
Thank you for purchasing one of our amplifiers, a lot
of care has gone into the design, selection of
components and production of this amplifier. We are
sure that you will hear the difference.
To get the best out of the LA4 MK III. Please read the
enclosed notes. We have tried to give you all the
information you need.
We would recommend that
everyone follows the ‘quick set up guide’.
Should
you be uncertain about anything to do with your LA4
MK III please contact your dealer.
The LA4 MK III is a line amplifier designed to
complement high quality valve or transistor power
amplifiers requiring an input voltage of 1volt or
greater. Also an attenuated lower level output can be
provided on request for more sensitive amplifiers like
Leak, or integrated amplifiers that require a lower
signal level.
Our philosophy is to use traditional valve minimalist,
circuitry. The beauty of valve amplifiers is that they
are usually very simple; therefore with the use of
traditional point-to point construction, modern high
performance low tolerance components, it is possible
to achieve very high sonic performance. This
simplicity enables us to avoid the use of printed
circuit boards, which are not ideal for valve amplifiers
despite their common use.
Although technical performance is important, we
never forget that sound quality takes overriding
priority in our design and production. The LA4 MK III
has a massive overload capability and even then
would go into ‘soft clipping’, which is much more
benign and easier on the ear than overloaded
transistors.
The simplicity of the circuit means that there are
much fewer components for the signal to pass
through, fewer connections and switches, again
adding to the purity of sound. This simplicity also
means that we can use higher quality oversized
components, such as 2w resistors.
The use of popular valves, which are still in
production, means that obtaining replacements is
easy and inexpensive when necessary.
In the process of building the LA4 MK III to its high
standard no corners have been cut and we have also
paid close attention to the appearance.
The remote control has its own separate power
supply so the operation will not influence sonic
qualities.
The final result is an amplifier with excellent
characteristics, with an accurate yet smooth and
transparent quality.
The circuit is almost identical to the LA4 MK1, the
changes being variable gain and the excellent GZ34
or 274B rectifier.
Various upgrades are available at the time of
ordering or may be retro fitted. These include
“Mundorf” capacitors and various premium valves
which will enhance the performance of the LA4 MK
III.
IMPORTANT!
THIS MANUAL CONTAINS
ESSENTIAL HEALTH & SAFETY
INFORMATION FOR YOU AND
YOUR AMPLIFIER. PLEASE
READ & KEEP SAFE AND
REFER TO IF NECESSARY
