Grado Red4 Phono Cartridge

A Prestige Series moving iron cartridge with bonded elliptical diamond, aluminum cantilever, and standard or P-mount options

The Grado Red4 is part of Grado’s Prestige Series, designed as a balanced, high-output cartridge with broad system compatibility. It maintains the core performance principles that define Grado cartridges while offering dependable performance in an accessible cartridge body.

Like all Grado cartridges, the Red4 is built around a moving iron design based on Joseph Grado’s patented flux-bridger principle. This keeps the coil structure fixed while using low moving mass to generate the signal, giving the cartridge a combination of speed, control, and long-term consistency.

The Red4 uses a bonded elliptical diamond mounted to an aluminum cantilever, with an internal signal path made from ultra-high purity 5N OCC copper. Each cartridge also undergoes cryogenic treatment and internal damping to help reduce unwanted resonance and preserve signal integrity.

Standard Mount and P-Mount Options

Red4 is offered in both standard mount and P-mount configurations, making it suitable for a wide range of turntables and tonearms. Its high-output design is intended for compatibility with standard moving magnet phonostages.

Moving Iron Design

Grado’s moving iron architecture is designed to combine the low moving mass often associated with moving coil cartridges with the practical stability of a fixed-coil design. The result is a cartridge intended to deliver clarity, separation, and tonal integrity without requiring a fragile moving coil assembly.

Diamond and Cantilever

The bonded elliptical diamond provides effective groove contact and reliable tracking, while the aluminum cantilever contributes to a stable and controlled presentation. This pairing supports the Red4’s balanced response, smooth top end, and defined low-frequency performance.

Prestige Series Construction

The Red4 uses a die-injection molded housing for consistent construction and dependable performance. The stylus assembly is user-replaceable, and Prestige Series styli are interchangeable for flexible long-term ownership.

Specifications

Generator Type: Moving iron

Cantilever and Stylus: Aluminum cantilever with bonded elliptical diamond

Output: 4 mV @ 5 CMV (45°)

Inductance: 50 mH

Resistance: 660 Ω

Input Load: 10 kΩ–47 kΩ

Tracking Force: 1.6 g–1.9 g

Compliance: 20 µm/mN

Channel Separation: Average 25 dB, 10 Hz–30 kHz

Frequency Response: 10 Hz–55 kHz

Mounting: P-mount or 1/2" screw mount

Weight: 6 g