ADC XLM MKII (Late 1970s)
A 650-ohm outlier of a moving magnet cartridge that made difficult records sound easy - provided your tonearm was up to the job.
Overview
The ADC XLM MKII arrived in the late 1970s, when ADC's reputation was at its peak. The design follows a clear philosophy: low moving mass, high compliance, and a coil body that broke from the moving magnet orthodoxy of the day. Most MM cartridges of the era sat around 1000-1500 ohms impedance. The XLM MKII ran a 650-ohm coil with 350 mH inductance. That was deliberate. It was meant to reduce high-frequency roll-off and improve transient response with the standard 47 kΩ phono inputs found on most home hi-fi. It was not the flagship of the ADC lineup. That spot belonged to the wideband ZLM series, tuned for CD-4 quadraphonic playback. The XLM MKII sat one rung below, pitched at audiophiles who wanted near-flagship performance without the finicky setup or astronomical price.
ADC was founded by former Shure engineer Peter Pritchard, and it built its reputation on this kind of engineering: low moving mass and high compliance for better groove contact. The XLM MKII put that into practice. It was designed for low-mass tonearms in the 8-12 g range, where the high compliance worked in its favor. Unipivots and low-mass linear trackers suited it well. Mass-market arms of the era had heavier effective mass and less refined bearings, and they often couldn't control it. Owners report mistracking, resonance peaks in the midbass, skating, and in bad cases permanent cantilever damage if the arm's downforce wasn't dialed in perfectly.
When everything lines up, the tone is liquid in a way few moving magnets ever managed. The XLM MKII doesn't shout about detail. Reviewers at the time noted that it projected a stable soundstage without sounding artificially wide, and owners still report that today, provided the stylus is healthy and the arm compliance is properly matched. A bad XLM MKII can sound dull and lifeless.
There is a naming problem. Sources use both "ADC XLM MKII" and "ADC XLM Mkii Improved," and listings describe the Improved variant as a "Gold series" top-line model. Whether these are the same cartridge or two distinct variants is not clearly documented. Buyers should treat any seller-supplied spec on an "Improved" unit as unverified unless it comes with original documentation.
Key Features
The 650-Ohm Coil Body
The 650-ohm coil was the defining engineering choice of the XLM MKII. The lower impedance, combined with 350 mH inductance, was designed to reduce high-frequency roll-off and improve transient response with standard 47 kΩ phono inputs. Recommended load capacitance is listed at 100-200 pF, though the source itself labels this figure as inferred from era standards rather than measured, so treat it as a starting point. The coil assembly was tightly potted to resist microphonics, a common flaw in cheaper moving magnets. The metal body helped dissipate resonance, which contributed to the stable imaging. Bodies are observed in listings as either black or gold-plated metal.
Nude Elliptical Stylus
By the late '70s, some high-end cartridges were already flirting with line-contact profiles. The XLM MKII stuck with a high-quality nude elliptical stylus, and for good reason. "Nude" means the stylus tip wasn't mounted in a metal shoe, which cuts mass and improves high-frequency response. Combined with the cartridge's low effective tip mass, this stylus could track inner grooves on worn records with less distortion than many contemporaries. Replacement styli from specialists describe the tip as a highly polished special elliptical diamond with .0003 x .0007 inch scanning radii, which works out to a 0.3 x 0.7 mil elliptical needle. Genuine styli were colored black. Generic replacements (such as the R-ZD) list a recommended tracking force of 2 g to 4 g, but that range applies to the generic stylus, not necessarily to the original ADC assembly.
High Compliance, High Stakes
The XLM MKII's high compliance is reported qualitatively and not numerically documented. It was both the cartridge's best trait and its weak spot. Designed for low-mass tonearms in the 8-12 g range, it gave a plush, forgiving ride over warped records and surface noise. In heavier arms or those with poor bearing design, that compliance became a liability. Owners report resonance peaks in the midbass, skating, and even permanent cantilever damage if the arm's downforce isn't dialed in perfectly. It is not a cartridge to put on a stock AT-LP120 or a vintage Technics SL-D300 and expect good results.
Historical Context
The early 1970s had seen a boom in moving magnet development, as manufacturers tried to match the detail of moving coils without their cost and fragility. ADC was at the forefront, emphasizing low moving mass and high compliance to improve groove contact. The XLM line sat just below the ZLM series, which was tuned for CD-4 quadraphonic playback with extended high-frequency response and special stylus profiles. The MKII was the more practical choice for stereo enthusiasts, offering 90% of the performance at a more accessible price.
Competitors included the Shure V15 series, ADC's arch-rival in high-end moving magnets, and the Ortofon OM series, which favored a more neutral, less resonant character. Companies like Denon and Shure focused on ruggedness and mass-market appeal, while ADC catered to the tweaker. The cartridge was also used in OEM versions by companies like Integra, which rebadged ADC cartridges for their high-end tuners and turntable systems. By the mid-1980s, as digital audio rose and cartridge R&D slowed, the XLM MKII became a cult favorite among analog diehards.
Period reviews were enthusiastic. Audio (January 1976, p.51) praised the ADC MKII low-mass cartridges for delivering some of the smoothest and cleanest high-end results the reviewers had heard from record reproduction, noting that heavily recorded difficult musical passages were handled with ease and overall musical accuracy was maintained. The same review found tracking ability at low and middle frequencies exceptional, with the high level requiring half the tracking force of most other cartridges. HiFi-Stereo (November 1975, p.111) agreed, calling the XLM MKII one of the best 2-channel stereo cartridges and better than most CD-4 types. A separate Audio (March 1977, p.77) piece cited independent lab tests showing the XLM-MKII caused no perceivable wear until after 60 plays.
Collectibility & Value
Prices vary widely depending on condition and whether a working stylus is included. A body-only unit with an untested or missing stylus typically sells for $50-$100, which makes it a parts donor or project piece. Recent eBay listings bear that out. A cartridge without stylus has moved at $54.99, while examples with original styli have listed around $110. A fully tested cartridge with a known-good or NOS stylus can fetch $150-$300, especially if mounted on a high-quality headshell. The most desirable listings, NOS in original box with tools and documentation, occasionally break $400. These are rare and often snapped up by restorers.
Common failures include dried-out rubber suspension (leading to loss of compliance or channel imbalance), bent or worn cantilevers, and oxidized pins. The stylus is the most vulnerable part. Elliptical tips can wear asymmetrically, and many surviving units have been played far beyond their lifespan. Before buying, insist on continuity testing for both channels, a clear photo of the stylus under magnification, and confirmation of tracking force calibration. Re-stylusing is possible, and specialists like Musonic offer rebuilt assemblies, but a full refurbishment can cost $120-$180. That is a significant investment on top of the purchase price. Replacement styli remain available from specialists, though NOS units command high prices due to demand from collectors and restorers.
For the hands-on owner, the XLM MKII is a rewarding project: balancing the arm, setting VTF to the gram, and listening for the sweet spot where the bass tightens and the soundstage snaps into focus. For the casual listener, it's a minefield. A modern Ortofon 2M or Audio-Technica VM95 might be a safer bet.
eBay Listings
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