Grado Platinum 4 MI Cartridge Mono

With the Platinum4, Grado presents the latest generation of its renowned cartridge within the Timbre Series. As the successor to the Platinum3, this model benefits from several technical and design improvements. In addition to a redesigned housing made of Mediterranean olive wood, it features high-quality internal wiring made of OCC-6N copper and an optimized chassis shape that facilitates setup. Each Platinum4 is handcrafted and meticulously tested in the Grado Labs workshops in Brooklyn, New York.

The Flux Bridger principle – an alternative to MM and MC cartridges

Unlike classic moving magnet or moving coil cartridges, the Grado Platinum4 is based on the moving iron technology developed by company founder Joseph Grado. The patented Flux-Bridger principle uses a small, movable iron component connected to the cantilever. This component moves within a magnetic field, while the coils remain fixed in the housing.

Thanks to its low moving mass, the system reacts exceptionally quickly to musical impulses and enables precise signal conversion. At the same time, the stationary coils remain permanently in their optimal position, contributing to consistent signal quality over the long term. The result combines the dynamics and speed of an MC cartridge with the robustness and everyday usability of classic MM designs.

The Platinum4 uses the latest generation of this generator with four coils and a double magnet system.

Case made of Mediterranean olive wood

One of the most striking innovations compared to the previous model is the case made of Mediterranean olive wood. While the Platinum3 used Australian Jarrah wood, Grado is now using the same wood that is also used in the higher-positioned models of the Timbre Series.

The choice of material is not solely for aesthetic purposes. The natural damping properties of olive wood help to reduce unwanted resonances and support the mechanical stability of the generator. At the same time, the material contributes to preserving the characteristic tonal balance of the pickup.

In addition, the housing shape has been redesigned. The new design improves the view of the cantilever, thereby facilitating both the mounting and precise alignment of the cartridge.

Precise groove scanning

The Grado Platinum4 is equipped with an elliptical diamond stylus mounted on an aluminum cantilever. The elliptical shape allows for a larger contact area with the sides of the record groove than spherical styli, thereby improving detail resolution and channel separation.

With a compliance of 20 µm/mN and a recommended tracking force between 1.6 and 1.9 grams, this cartridge is suitable for a wide variety of medium-mass tonearms. The combination of an elliptical diamond stylus and a lightweight aluminum cantilever ensures a balanced blend of precision, musicality, and everyday usability.

OCC-6N copper and cryotherapy

Another significant innovation is the use of OCC-6N copper for internal wiring. This high-purity copper is manufactured using the so-called Ohno-Continuous Casting process, resulting in exceptionally long crystal structures. The reduced number of grain boundaries supports the lowest possible signal transmission.

After manufacturing, each Platinum4 undergoes an additional cryogenic treatment. During this process, the components are exposed to extremely low temperatures to reduce material stresses and optimize the structural stability of the metals used. Additionally, internal damping is employed to minimize micro-vibrations within the generator.

Three versions for different applications

The Grado Platinum4 is available in three versions, allowing it to be optimally adapted to different phono preamplifiers and applications.

The high-output version delivers an output voltage of 4.0 mV and can be operated directly on conventional MM phono inputs.

For more demanding phono preamplifiers, a low-output version with a 1.0 mV output voltage is available. Despite the lower level, it operates with a high input impedance of 10 to 47 kΩ, thus differing from classic MC cartridges.

Grado also offers a mono version for the authentic playback of historical mono records.

All variants share a low sensitivity to capacitive loads, which makes selecting suitable connection cables straightforward.

Sound character

The Platinum4 follows the sonic philosophy typical of Grado wood-tone cartridges. Reproduction is characterized by balanced midrange, natural treble, and precisely controlled bass. Vocals and acoustic instruments benefit from high harmonic density and authentic timbre.

With an average channel separation of 30 dB and an extended frequency response of 10 Hz to 60 kHz, the cartridge produces a stable, clearly structured soundstage with convincing spatiality. The focus is less on analytical sharpness and more on a musical, natural, and enjoyable listening experience.

Technical data

• Type: Moving-iron cartridge
• Case: Mediterranean olive wood
• Diamond: Elliptical
• Cantilever: Aluminum
• Available versions: High Output, Low Output, Mono
• Output voltage (High Output): 4.0 mV
• Output voltage (low output): 1.0 mV
• Inductance High Output: 55 mH
• Low Output Inductance: 6 mH
• Internal resistance high output: 660 ohms
• Internal resistance low output: 70 ohms
• Recommended load: 10 kO to 47 kO
• Tracking force: 1.6 to 1.9 g
• Compliance: 20 µm/mN
• Weight: 9.4 g
• Channel separation: 30 dB
• Frequency response: 10 Hz – 60 kHz
• Handmade at Grado Labs in Brooklyn, New York