Linn Klimax Radikal | LP12 Motor Control & PSU

The Klimax Radikal is Linn's reference motor controller and power supply for the LP12 Sondek — the component specified as standard on the Linn Klimax LP12, and the definitive statement of what Linn's motor control and power supply engineering currently achieves at the absolute ceiling of the platform. At £11,500, it is not merely the most powerful Radikal variant. It is a component whose engineering ambition is expressed in a nearly 14 kg machined aluminium chassis, a bespoke Utopik power supply with fully independent dedicated voltage rails, and an auto-calibration routine that adapts to the physical state of the deck on every single power-up — a combination whose collective effect on the LP12's speed stability, noise floor, and musical performance is not marginal refinement but a transformation of the mechanical and electrical foundation on which every other component in the deck depends.

The Klimax Radikal is the correct and necessary power supply for a reference LP12 build — paired with the Linn Keel SE Sub-Chassis, the Linn Karousel Bearing Kit, and the Linn Krane Tonearm or Linn Arko Tonearm, it is the component that brings the LP12's motor control to a standard commensurate with everything around it. At that specification level, the Klimax Radikal's contributions — cleaner motor supply, isolated Urika power rail, every-power-up auto-calibration, and the mechanical silence of a 14 kg chassis — are not marginal improvements audible only on the finest recordings. They are fundamental to the performance of the system as a whole.

The Utopik Power Supply — Two Rails, Completely Independent

The defining distinction between the Klimax Radikal and the standard Radikal is not the motor control circuit, which both variants share. It is the quality and architecture of the power delivery that feeds it. The standard Radikal uses a single regulated supply — excellent in its class, and entirely sufficient for LP12 builds at Selekt specification. The Klimax Radikal uses a bespoke Utopik power supply with entirely separate, dedicated voltage rails: one for the motor control system, one for the Urika or Urika II internal phono stage. These rails are fully independent — they share no transformer, no rectification stage, and no component in the supply chain between mains input and output. What the motor control circuit draws from its rail has no influence whatsoever on what the Urika receives from its own.

The consequence is a dramatic reduction in power supply noise reaching both circuits. The motor runs on a cleaner, more tightly regulated supply, and the active digital speed management operates with correspondingly greater precision. The Urika draws from a supply completely isolated from any motor-related electrical noise — a supply whose cleanliness directly lowers the phono stage noise floor and whose effect on low-level resolution and the retrieval of fine musical detail from the groove is immediately audible. For LP12 owners running Urika II, the dedicated Urika rail is a performance improvement that no other modification to the deck achieves as directly.

Auto-Calibration — Optimised on Every Power-Up

The Klimax Radikal recalibrates its speed management on every power-up — measuring and compensating for the actual physical state of the deck at that moment: bearing friction as the oil stands at its current temperature and viscosity, stylus tracking force from the fitted cartridge, and the environmental conditions of the room. The standard Radikal operates from a fixed calibration established at installation — correct for the conditions under which it was set up, but static thereafter as those conditions inevitably change with temperature, season, and bearing wear.

The Klimax Radikal's auto-calibration means its active digital speed management is always optimised for today's deck — not for the deck as it was when the system was last serviced. Over the years, as bearing friction evolves and seasonal temperature variations shift the viscosity of the bearing oil, the Klimax Radikal adapts silently and completely, without manual intervention. The standard Radikal does not. This single distinction — continuous, automatic, every-cycle optimisation against a static calibration that drifts — is one of the most significant performance differences between the two variants, and one whose value compounds over the lifetime of the deck.

Active Digital Speed Management — The Technology Behind Both Radikal Variants

Both the Klimax and standard Radikal share the same active digital speed management architecture: the LP12's brushed DC motor is monitored and corrected on every rotation of the platter, maintaining 33⅓ and 45 rpm with a precision that no passive or mains-synchronous motor control system approaches. Electronic speed switching between 33⅓ and 45 rpm is standard on both. On the Klimax Radikal, this technology operates from the Utopik supply's cleaner, more tightly regulated output, and with the benefit of every-power-up auto-calibration. The improvement in speed stability over the standard Radikal is measurable and audible: pitch holds with greater consistency, transients are more precisely resolved, and the LP12's characteristic pace, rhythm, and timing — its defining musical identity — is expressed more completely and more confidently.

The Chassis — 14 kg of Machined Aluminium

The Klimax Radikal's chassis is three pieces of solid aluminium, precision-machined and assembled into a structure approaching 14 kg — more than the mass of many complete turntables. High-mass stainless steel feet with rubber ring inserts decouple the chassis from its support surface; the aluminium structure above them provides the inertia that ensures no vibration from the motor assembly, no resonance from the supply electronics, and no structure-borne energy from the shelf reaches the circuits within. The Utopik power supply sits in its own machined aluminium housing within the chassis — thick aluminium walls and physical separation from the main Radikal board providing the electrical isolation that eliminates interference between the supply and the control circuitry it feeds.

The external character of the Klimax Radikal — machined aluminium in black or silver anodised finish, matching the visual language of the Linn Klimax System Hub and the Klimax LP12 — is that of a component whose engineering ambition is expressed entirely in material, precision, and mass.

Technical Specifications

Who Is It For?

The Klimax Radikal is for LP12 owners at, or building towards, Klimax specification — running a Linn Keel SE Sub-Chassis, Linn Karousel Bearing Kit, Linn Bedrok Plinth, and a reference tonearm, where the Klimax Radikal's contributions to speed stability, Urika power isolation, and auto-calibration are fully audible and fully justified by the system around them. It is also the natural answer for any owner running Urika II who wants to realise the phono stage's full potential through the cleanest, most isolated power supply Linn has ever produced for the LP12. For LP12 owners at Selekt specification, the standard Radikal remains the correct and entirely sufficient choice — and the cost difference is better directed at other components. The Klimax Radikal is a future conversation for when the specification around it has reached the level at which it can be properly heard and properly justified.

Buying from Martins Hi-Fi

Martins Hi-Fi has been in Norwich since 1968. Elizabeth Gould runs the business today, and we stock only brands we have heard properly and stand behind.

Fitting the Klimax Radikal involves motor replacement, internal wiring, and a complete LP12 suspension rebalancing — professional installation is essential, and we carry out the complete process as part of our LP12 servicing work. If the Klimax Radikal is part of a complete Klimax LP12 build — alongside a Linn Keel SE Sub-Chassis, Linn Bedrok Plinth, and a reference tonearm and cartridge — we will plan and execute the complete specification with you from a single conversation, ensuring every component is fitted in the correct sequence and the deck leaves our workshop performing as Linn intends.

When you get in touch, you'll be speaking with Dave, Chris and Tim — experienced specialists who can advise on this product and your whole system.

Contact us at info@martinshifi.co.uk, call 01603 627010, or WhatsApp on 07554 687137. You can read more about how we work on our Why Martins Hi-Fi page. We are at 85–91 Ber Street, Norwich, NR1 3EY.