At LMC Home Entertainment, our audio expert and professional installer Andrew assembled a brand-new Linn Sondek LP12, upgraded with Linn's new Keel SE sub-chassis and Klimax Radikal power supply — both Klimax-level upgrades. The arrival of these two performance-critical products raises Klimax-spec LP12s to a new reference benchmark.
Keel SE — reference machined-aluminium sub-chassis
Keel SE is the super evolution of Linn's highest-performance LP12 sub-chassis. In 2006, Keel broke new ground with its precision-engineered single-piece design, and it has been intrinsic to the performance of the Klimax LP12 ever since. With Keel SE, Linn comprehensively improved on the original using Finite Element Analysis. Their engineers evaluated the limitations of previous sub-chassis designs and broke free from them, combining virtual prototyping with Linn's enhanced in-house machining. The outcome is a visibly improved machined sub-chassis with superior stiffness, optimised resonant behaviour, and ideal distribution of mass.
Technical details
The intricate bracing structure on Keel SE's underside — designed using a mixture of manual and computer-aided optimisation — achieves Linn's primary goal of increasing sub-chassis stiffness as much as possible.
That 300% increase means vibrations or displacements travelling through Keel SE have their frequencies forced higher and their amplitudes substantially lowered. Problematic acoustic energy across the spectrum is broken up and dissipated better than before, reducing its impact on the delicate music signal generated by the cartridge.
Rigidity and mass have been increased precisely where they are needed, with particular focus on the path between the Karousel mounting point and the tonearm collar. Even the slightest rocking movement of a sub-chassis and armboard modifies the physical relationship between tonearm and platter, affecting how the stylus tracks the record groove. A stiffer path between bearing and arm minimises that change in geometry and reduces tracking distortion.
By extracting material from calculated areas beneath the armboard, a Keel SE fully loaded with platter, arm and cartridge has its centre of mass balanced more evenly on its suspension than Linn's previous designs. That improves weight distribution between the springs and reduces inertia at the sub-chassis extremities, improving the acoustic isolation properties of any LP12.
Klimax Radikal — flagship LP12 motor control and power supply
Klimax Radikal is Linn's reference LP12 power supply. New casework brings it up to date aesthetically, consistent with the rest of the machined Klimax range. Its performance gains come from a bespoke Utopik power supply in an improved chassis with exceptional electrical and mechanical isolation.
The Utopik supply has separate, dedicated output voltage rails for each of Radikal's two specialised tasks: controlling the motor and powering Urika internal phono stages. These rails are separately self-regulating, so sudden draws from the motor or controller don't affect the rails supplying Urika, and vice versa.
Linn's engineers mounted the Utopik supply inside its own self-contained machined enclosure, nestled behind the front face. Thick aluminium walls and distance from the main Radikal board make for superior electrical isolation. Weighing nearly 14 kg, machined from three pieces of solid aluminium and mounted on high-mass stainless steel feet with rubber ring inserts, the casework is robust in the face of external influences.
Watching Andrew carefully assemble the LP12 with its Keel SE and Klimax Radikal upgrades is a good reminder that in high-end audio, every detail counts.