Ortofon SPU CLASSIC N E

The SPU CLASSIC N E continues the tradition of Ortofon SPU cartridges, first introduced in 1958 to meet the demands of stereophonic reproduction. This moving coil cartridge uses a nude elliptical diamond, which improves groove tracking compared to spherical diamond models. Sold without the usual integrated SPU headshell, it allows for more flexible installation on modern tonearms while preserving the distinctive sound characteristics of the series.

Detailed Technical Specifications

The construction of the SPU CLASSIC N E is based on a proven moving coil architecture with high-purity copper (OFC) coils that ensure faithful signal transmission. The nude elliptical diamond features a curvature radius r/R of 8/18 µm, allowing for precise tracking of the finest groove modulations. This elliptical geometry reduces the contact area with the vinyl compared to a spherical diamond, minimizing record wear while increasing playback resolution.

The cartridge body, weighing 13 grams, sports a matte black finish that reflects Ortofon’s understated, professional aesthetic. This relatively high mass contributes to playback stability and pairs perfectly with medium to high-mass tonearms. The lateral dynamic compliance of 8 µm/mN classifies this cartridge as a moderate compliance system, requiring a tonearm with suitable effective mass to optimize system resonance.

Audio Performance and Sound Quality

The SPU CLASSIC N E delivers an output voltage of 0.2 mV, typical of high-end moving coil cartridges. This relatively low output absolutely requires a step-up transformer or a quality MC phono preamp to fully reveal the cartridge’s potential. The internal resistance of 2 ohms calls for a load impedance above 10 ohms for optimal operation.

The frequency response ranges from 20 Hz to 20 kHz with a tolerance of +3/-2 dB, ensuring balanced reproduction across the entire audible spectrum. Channel separation exceeds 20 dB at 1 kHz and remains above 10 dB at 15 kHz, guaranteeing a precise and stable stereo image. This cartridge faithfully reproduces the sonic properties of the SPU Classic GM E series, renowned for its warm musical character and ability to reveal the nuances of vinyl recordings.

Compatibility and Mounting Solutions

The SPU CLASSIC N E stands out from traditional SPUs by lacking an integrated headshell, requiring the use of the supplied SPU N adapter for mounting on standard headshells. This solution allows installation on most modern tonearms while preserving the specific SPU tracking geometry. Owners of vintage SPU headshells can mount the cartridge directly to recreate an authentic setup, although these headshells are no longer available for purchase.

The tracking angle of 20° and the recommended tracking force of 40 mN (4 grams) are in line with SPU standards established over decades. This relatively high tracking force ensures optimal tracking of complex modulations and contributes to the characteristic stability of SPU playback. The tracking ability of 60 µm at 315 Hz demonstrates the system’s mechanical robustness and its capacity to reproduce the most dynamic passages without distortion.

Use Cases and Applications

The SPU CLASSIC N E is ideally suited for hi-fi systems that prioritize sonic authenticity and musical character. It excels particularly in reproducing jazz, classical, and rock recordings from the 1960s and 70s, an era when SPUs helped define the industry’s quality standards. Audiophiles seeking the signature SPU sound without the constraints of an integrated headshell will appreciate this modern solution.

This cartridge is perfectly suited for turntables equipped with high effective mass tonearms, where its moderate compliance finds optimal balance. Systems using quality step-up transformers will fully reveal the potential of this cartridge, especially with the ST-7 transformer recommended by Ortofon. Vintage setups will particularly benefit from this cartridge, which modernizes a system while preserving the authentic period sound.

Technical Specifications

General Information

• Moving magnet cartridge: SPU CLASSIC N E
• Nude elliptical diamond
• Coil wire material: high-purity copper (OFC)
• Cartridge color: matte black

Electrical Specifications

• Output voltage at 1,000 Hz, 5 cm/s: 0.2 mV
• Internal impedance, DC resistance: 2.0 Ω
• Recommended load impedance: > 10 Ω

Audio Performance

• Channel balance at 1 kHz: < 1 dB
• Channel separation:
  • at 1 kHz: > 20 dB
  • at 15 kHz: > 10 dB
• Frequency response: 20-20,000 Hz +3/-2 dB

Mechanical Specifications

• Tracking ability at 315 Hz at recommended tracking force: 60 µm
• Lateral dynamic compliance: 8 µm/mN
• Stylus tip radius: r/R 8/18 µm
• Tracking force range: 30-50 mN
• Recommended tracking force: 40 mN
• Tracking angle: 20°
• Cartridge weight: 13 g