ADC QLM33 MKII ()

That crisp, detailed analog snap is probably coming from a tiny elliptical diamond riding in a cult-favorite ADC shell.

Overview

Flip through a pile of used cartridges at a flea market or scroll eBay listings and an ADC turns up sooner or later, often unrecognized. The QLM33 MKII isn't the flashiest name in vintage cartridges. It shows up again and again in decks from the '70s and '80s, especially in systems where someone upgraded from the stock AT95 but didn't want to pay for a Shure V15. ADC, or Audio Dynamics Corporation, built its reputation on two things: moving magnet cartridges, particularly the revered XLM series, and the quirky but effective Sound Shaper equalizers. The QLM33 MKII belongs to the first group. It wasn't a flagship, but it was a solid-tier performer that punched above its weight when new and still holds up if treated right.

Not much is actually known about the QLM33 MKII as a standalone model. Most of what turns up online is about its replacement stylus, specifically the MKIII variant, and that's where most of the current market activity is. Listings routinely bundle the QLM33 MKII and MKIII together as compatible siblings, and sellers focus on the stylus upgrade path. That makes sense. The stylus is the wear item, the part that drags across the records, and when it's worn it can do irreversible damage to a collection. But it leaves the cartridge body, its internal coils, magnet structure, compliance and output undocumented. No frequency response curves. No tracking force specs. No weight or dimensions. It's like knowing the tires on a classic car but never seeing the engine.

Owners who've kept these running swear by them. The reports are consistent: clean midrange, good channel separation (assumed, given ADC's reputation), and a top end that doesn't shout but reveals. The "special elliptical diamond" stylus is highly polished, bonded, and shaped to dig into the groove walls with precision. A replacement stylus marketed for the MKIII claims to deliver "finer detail and harmonically complete sound quality." That reads like marketing copy, but the promise is clarity rather than boom or brightness.

Part of the appeal is nostalgia. The gray or black body, the clean labeling, and the way it mounts in a SME or Grace headshell all help. ADC cartridges were built while moving magnet designs were maturing and brands were refining stylus profiles to get more from vinyl without shredding it. The elliptical tip was a big step up from the conical types that dominated earlier, and it made better contact with the groove modulations. The "special" elliptical here might hint at a proprietary grind or polish, since ADC was known for tight tolerances. Without factory docs, though, the only sources are third-party sellers and old ads.

Nobody picks up a QLM33 MKII today for the specs. It's a known quantity on the used market, it fits a lot of arms, and it comes from the era when cartridges were serviceable rather than disposable. In theory, a owner could swap the stylus, keep it aligned, and run it for decades. In practice, NOS (new old stock) complete units are rare. Most listings are used cartridges with unknown stylus hours, which is a gamble. ADC made replacement styli available back in the day, but today's options are third-party, often rebranded, and vary in quality. It isn't plug-and-play.

Specifications

Manufacturer	ADC (Audio Dynamics Corporation)
Product type	Phono cartridge
Stylus tip shape	special elliptical diamond
Stylus tip finish	highly polished
Stylus type	Original Bonded Diamond Stylus

Collectibility & Value

The ADC QLM33 MKII lives in the shadow of its stylus. Most of what's on the market is replacement styli or used bodies with unknown wear, not complete cartridges. A new replacement stylus, marketed for the MKIII but compatible with the MKII, is $39.95 from LP Gear. That's decent value for maintaining an existing cartridge. It also says this isn't a high-end collector's item commanding hundreds. It's a functional part for people keeping older systems alive.

Complete used cartridges turn up on the secondhand market, especially in Europe and the UK, at £35 to £65 for a unit with stylus. That's a wide spread, and condition decides it. A cartridge with a worn or damaged stylus is essentially scrap, or worse, because a bad tip can ruin records. One eBay listing offered a NOS (new old stock) bundle of QLM30 MKIII stylus, cartridge and headshell for $106.54, which suggests complete, untouched setups exist but are rare and priced accordingly. Another French site lists a new QLM33 MKIII stylus with cartridge for €80, which feels steep unless the goal is restoring a system to factory spec.

The biggest red flag is that nobody discusses failures, repairs or serviceability of the cartridge body itself. Shure and Denon have rebuild guides and suspension replacement tutorials. The ADC QLM33 MKII has nothing once the stylus is off. If the coils go, the magnet weakens, or the cantilever binds, there's no aftermarket support for the internals, no known rebuilders, and no data on expected lifespan. Buying a used unit means betting that the stylus is good and the generator inside hasn't been knocked around.

Scott Nangle Audio puts the risk this way: "A worn stylus can cause serious (Irreversible Damage) to your records, and provide poor sound quality." With an obscure vintage cartridge like this one, the buyer also takes on the checking: tracking force, alignment, and stylus wear under a microscope. Someone unwilling to do that is better off with something more documented.

Similar items on eBay

No exact ADC QLM33 MKII listings are live right now — these searches show current ADC and similar vintage audio gear on eBay:

Search ADC QLM33 MKII on eBay Browse ADC audio gear on eBay

As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.

Service Manuals, Schematics & Catalogs

Catalog (1989) — archive.org
Catalog — archive.org