ADC QLN-II ()

Name: ADC QLN-II
Brand: ADC

That bright, chiseled high end cuts through like a freshly sharpened needle—beautiful when it’s right, brittle when it’s not.

Overview

The ADC QLN-II is a moving magnet phono cartridge that shows up quietly in collections and service trays, often mistaken for its siblings but carrying its own distinct flavor. It’s not flashy, but if you’ve spent time swapping styli between old ADC bodies, you know the subtle differences matter—sometimes in ways that make or break a listening session. This one uses what’s referred to as a "Mk I" body, an early iteration in ADC’s lineup before they tweaked the inductance and voicing across later revisions. That matters because it means parts aren’t always interchangeable, even when they look identical. And yes, someone on Vinyl Engine was kind enough to confirm what many tinkerers have suspected: the QLN-II is functionally the same as the QLM-36. Same guts, same performance specs, same footprint on your tonearm. But don’t go swapping styli blindly—especially not a QLM-36 Mk III stylus onto a QLN-II body—because the mismatch can lead to real-world issues like lower output and a top end that’s just plain harsh.

It’s the kind of cartridge you’d find mounted on a Technics SL-1200 or a Dual turntable in the late '70s or early '80s, assuming it hasn’t been replaced or retired. No one’s writing love letters about its midrange bloom or bass authority, but that elliptical diamond tip with its precise 8 × 18 µm radii was engineered to track detail, not coddle your ears. It delivers, just not gently. And while ADC eventually refined their designs—increasing inductance and adjusting stylus voicing over time—the QLN-II sits earlier in that evolution, with the electrical characteristics to prove it: 300 mH inductance, 375 ohms resistance, and a load recommendation of 47k ohms. It wants to see a standard MM input, nothing exotic, nothing high-capacitance. Keep the cable runs short and the capacitance under 275 pf, and it’ll behave.

But here’s the thing owners learn the hard way: fitment isn’t guaranteed. Even within the same brand and model line, every once in a while, a stylus won’t seat snugly on the body. It looks right, clicks in place, but you get noise—crackles, dropouts, grounding issues—because the connection isn’t solid. It’s not common, but it’s known. And when it happens, it’s maddening. You start questioning your setup, your cleaning routine, your sanity—until you realize it’s just an old ADC quirk. That’s the trade-off: a cartridge with solid specs and decent tracking force range (0.75 to 1.5 grams), but one that demands attention to detail and a bit of luck in the parts bin.

Specifications

Manufacturer	ADC
Output voltage @ 5cm/sec	5.5 mV
Tracking force	0.75-1.5 grams
Frequency response	15-20,000 Hz ± 3 db
Channel separation	26 dB
Channel balance	± 2 db
Stylus tip dimensions	.0003 x .0007 inch Elliptical
Inductance	300 mH ± 10%
Resistance	375 Ohms
Cartridge body color	Black/Gold
Stylus color	Light blue
Max. recommended capacitance	275 pf
Load resistance	47,000 Ohms
Cartridge weight	5.75 grams

Key Features

Special Elliptical Diamond Stylus

The QLN-II rides on a highly polished special elliptical diamond stylus, designed to maximize contact with the groove walls for improved high-frequency retrieval and extended record life. At 8 × 18 µm (or .0003 × .0007 inch), it’s a tight fit for complex modulations, especially in the upper mids and treble. LP Gear’s replacement version touts “harmonically rich sound quality,” but real-world use suggests that richness depends heavily on alignment and system synergy. When matched correctly, it resolves detail cleanly; when mismatched—like with a later-generation QLM-36 Mk III stylus—owners report a noticeable drop in output and a top end that turns aggressive, almost fatiguing. That’s not the stylus failing—it’s the system being asked to perform outside its design window.

Mk I Body Construction

The QLN-II uses what enthusiasts now call a "Mk I" body, the earliest version in ADC’s cartridge housing evolution. This matters because ADC later increased the inductance of their bodies and adjusted the voicing of their styli, meaning newer replacement parts may not electrically or mechanically align with this older platform. The 300 mH inductance and 375 ohm resistance are specific to this generation, and while they fall within standard MM cartridge norms, they interact differently with preamp stages than later models. If you’re rebuilding or maintaining one, stick to period-correct or explicitly compatible parts. The black/gold body with its light blue stylus tip is more than cosmetic—it’s a fingerprint of a particular moment in ADC’s production run.

Electrical Compatibility

With a recommended load resistance of 47,000 ohms and a max capacitance of 275 pf, the QLN-II plays by the book when it comes to MM preamp integration. No exotic loading tricks needed, no impedance-matching dance—just plug it into a standard phono stage and set tracking force between 0.75 and 1.5 grams. Its 5.5 mV output sits comfortably in the middle of the MM range, so gain shouldn’t be an issue on most receivers or dedicated preamps. But that wide tracking force window is both a blessing and a warning: too light and you risk mistracking; too heavy and you’ll wear down both stylus and records faster than necessary. Dial it in carefully, ideally with a digital scale, because this cartridge doesn’t forgive sloppiness.

Collectibility & Value

Replacement styli for the ADC QLN-II are available, with one current market listing at $29.99. That’s for a new stylus only—not the full cartridge. A complete New Old Stock QLN-II, still in its original packaging, once listed for $99.99, suggesting that while not rare, it holds modest value among collectors who prioritize originality or need a matched body/stylus pair. However, one user reported paying $47.95 for a QLM-36 Mk III stylus package, indicating that pricing varies significantly depending on seller, condition, and whether the part is NOS or aftermarket. The biggest caveat isn’t price—it’s compatibility. As noted in user reports, a stylus that doesn’t fit snugly on the body can introduce noise and grounding issues, so buyers should test thoroughly. There’s no data on original pricing or production years, and no professional reviews to benchmark performance, so value remains driven by utility and parts scarcity rather than critical acclaim.