Grado Reference4 Phono Cartridge A Timbre Series moving iron cartridge with American Osage wood body, nude Shibata diamond, and machined boron cantilever The Grado Reference4 is part of Grado’s Timbre Series, positioned as a refined wood-body cartridge designed for resolution, control, and musicality. It uses an American Osage wood body chosen to help control resonance, with a reshaped housing that improves cantilever visibility during setup. Like all Grado cartridges, the Reference4 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 Reference4 uses a nude Shibata diamond mounted to a machined boron cantilever, with an internal signal path made from ultra-high purity 6N OCC copper. Each cartridge also undergoes cryogenic treatment and internal damping to help reduce unwanted resonance and preserve signal integrity. High-Output, Low-Output, and Mono Builds Reference4 is available in high-output and low-output stereo versions, allowing compatibility with a wide range of phonostages. Mono high-output and mono low-output versions are also available as special-order builds. 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 nude Shibata diamond provides excellent groove contact and detail retrieval, while the machined boron cantilever is chosen for low mass and responsive behavior. This pairing supports the Reference4’s clarity, speed, and stability across the frequency range. Wood Body Construction The American Osage wood body gives the Reference4 its distinctive appearance while helping manage resonance. The revised housing shape also improves visibility during alignment, making setup easier across a wide range of tonearms. Specifications Body: American Osage wood Generator Type: Moving iron Cantilever and Stylus: Machined boron cantilever with nude Shibata diamond Output (High, Low): 4 mV, 1 mV Inductance (High, Low): 55 mH, 6 mH Resistance (High, Low): 660 Ω, 70 Ω Input Load: 10 kΩ–47 kΩ Tracking Force: 1.6 g–1.9 g Compliance: 20 µm/mN Channel Separation: Average 30 dB, 10 Hz–30 kHz Controlled Frequency Response: 10 Hz–60 kHz Capacitive Load: Non-sensitive to capacitive load Builds: High Output, Low Output, Mono Weight: 9.6 g
