ADC 10E Mk.IV (1972)
A very light cantilever and a 0.7-gram tracking force. It's a cartridge that makes records disappear, if your tonearm can keep up.
Overview
The ADC 10E Mk.IV is not for a weak tonearm. In a system that can handle it, the payoff is transparency and micro-detail that still impresses decades later. It doesn't shout. The soundstage is layered and stable enough that eccentric pressings or mild warps don't break it up. The highs are smooth, not etched, and open without sounding analytical. Bass is tight and articulate, with speed and control that belie its 1972 origin. Imaging is pinpoint and three-dimensional, and complex music doesn't rattle it.
Inside, the 10E Mk.IV uses ADC's "induced magnet" design, an alternative to traditional moving magnet systems. A moving permanent magnet adds mass and inertia. So the 10E Mk.IV uses a soft iron collar that moves between fixed pole pieces and induces flux without the weight penalty. That makes for a much lighter moving assembly, which is critical for both high compliance (rated at 30 × 10⁻⁶ cm/dyne) and excellent high-frequency tracking. The elliptical stylus has a contact radius of 0.0003 inches and a lateral radius of 0.0007 inches. It digs deep into the groove walls and pulls out detail that spherical tips miss. Output is a healthy 4 mV, so it works with standard MM phono stages without extra gain.
This is no plug-and-play upgrade. The 10E Mk.IV was never meant for budget changers or flimsy arms. The low tracking force and high compliance make it unforgiving of poor setup, inadequate damping, or turntable resonance. Owners report that if the arm isn't up to the task, the stylus can "wobble all over the record," mistracking independently of the tonearm's motion. It isn't a moving coil, but its performance borders on MC territory, provided everything else in the chain is optimized. ADC itself advised against using the 10E Mk.IV on low-quality equipment, which was a rare bit of honesty in an era of inflated marketing claims.
Key Features
Induced Magnet Design with Fixed Internal Magnet
The core change in the 10E Mk.IV is the induced magnet system. It moved the fixed magnet from the stylus assembly into the cartridge body, a significant redesign from earlier 10E models like the Mk.II. Moving mass dropped dramatically, so the soft iron collar can respond faster to groove modulations without the inertia of a moving permanent magnet. The magnet itself stays stationary, shielded within the plastic housing, while the collar oscillates between pole pieces to induce signal in the fixed coils. This avoids the trade-off between output and tracking common in conventional MM cartridges. The 10E Mk.IV delivers high output and excellent transient response without sacrificing detail or speed.
Elliptical Stylus with Micro-Fine Tip Radii
The 10E Mk.IV uses an elliptical stylus with a contact radius of 0.0003 inches and a lateral radius of 0.0007 inches. That shape makes better contact with the high-frequency modulations in the groove wall. It gives better channel separation than most contemporaries: 30 dB from 50 Hz to 12 kHz and still 15 dB at 20 kHz. The stereo image has exceptional depth and definition, with instruments in distinct positions and not bleeding into one another. That level of separation was rare in mass-market cartridges of the early 1970s, and it contributed to the 10E Mk.IV's reputation for disappearing during playback.
Optimized for High-Compliance, Low-Mass Arms
The 10E Mk.IV has a compliance of 30 × 10⁻⁶ cm/dyne and a tracking force of 0.7 grams. It was designed for arms with moderate to high effective mass, such as the SME 3009 or AR XA. The recommended load impedance is 47,000 ohms nominal, with 145 pF of capacitance (accounting for a 5-foot cable), which fits standard MM inputs of the era. Frequency response runs 10 Hz to 20 kHz within ±2 dB. Audio (December 1972, p.69) noted that the 10E Mk.IV "differs in several categories" from earlier ADC models, pointing to its refined mechanical layout and improved signal generation. The vertical tracking angle is set at 15 degrees, a standard value that works with most tonearm geometries.
Historical Context
The 10E Mk.IV was introduced in 1972, during a period of rapid innovation in phono cartridge design. High compliance, low tracking force, and improved channel separation were becoming key differentiators in the high-fidelity market. It was positioned as a direct competitor to the Ortofon V15/III, another low-mass cartridge that demanded precision setup. It was also a transitional model, reportedly the last ADC cartridge with the brand's boxy, rectangular body style before the sleeker designs of the XLM series. The XLM evolved directly from the 10E Mk.IV's platform, with advanced materials and lower distortion. ADC never achieved the mass-market presence of Shure or Stanton, and stayed a favorite among listeners who valued engineering over branding.
Collectibility & Value
Today the 10E Mk.IV has a small but passionate following. NOS (new old stock) units occasionally appear on eBay, typically priced between $150 and $250, though some vendors list them at $359.99 for sealed, untested examples. Condition matters. The rubber suspension in the stylus assembly is prone to drying out over time, leading to mistracking or imbalance even if the stylus looks intact. The lead wires are also fragile, and repairs require specialized tools and expertise. The biggest hurdle is the lack of replacement styli. None are manufactured today, so a damaged tip can render the cartridge unusable unless a donor unit is available. Finding a sealed NOS stylus is considered a rare win among collectors. For those with compatible arms, especially vintage SMEs, AR XAs, or upgraded Lenco L75s, the 10E Mk.IV is capable of outperforming many modern MM cartridges when properly set up.
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Service Manuals, Schematics & Catalogs
- Catalog — archive.org
- Catalog (1989) — archive.org
- Catalog — archive.org