ADC RQ-4 (–)

Name: ADC RQ-4
Brand: ADC

A tiny diamond tip that kept the music spinning—simple, durable, and built to trace grooves without fuss

Overview

If you’ve ever flipped over a turntable cartridge and squinted at the needle, wondering what miracle keeps your records from turning to noise, the ADC RQ-4 is one of those quiet heroes. It’s not flashy, not a flagship, just a replacement stylus—the kind you’d order when the old one finally gave up after years of faithful service. Designed specifically for the ADC Q-4 (or Q4) phono cartridge, the RQ-4 was never meant to steal the spotlight. But in its modest role, it delivered. Owners report good rendition of voice and music, which, for a conical diamond tip in its class, is no small praise. This wasn’t a hyper-precise elliptical stylus chasing audiophile accolades—it was a workhorse, built for reliability and longevity.

And longevity it had: the RQ-4 is described as having a long playing life, a selling point that mattered when replacing a stylus meant recalibrating tracking force and alignment, not just snapping in a new one. At a time when many entry-level cartridges came with steel or sapphire tips that wore down records (and themselves) quickly, a diamond stylus—even a conical one—was a meaningful upgrade. The tip is highly polished, which likely helped reduce groove wear and maintain consistent contact as it traced decades of vinyl. While we don’t have original specs on tracking force or compliance, the fact that replacements are still available today speaks to its footprint in the ecosystem of vintage audio. It’s the kind of part you didn’t think about—until you needed it.

Specifications

Manufacturer	ADC
Product type	Replacement needle/stylus for phono cartridge
Stylus tip shape	Conical
Stylus tip material	Diamond
Stylus tip finish	Highly polished

Collectibility & Value

The ADC RQ-4 isn’t collected so much as it’s used—kept on shelves by turntable owners who know the pain of a dead stylus and a pressing to play. As of current listings, a replacement RQ-4 sells for $26.95 USD, a price that reflects its status as a functional spare part rather than a vintage artifact. There’s no data on original pricing or production years, and no known common failures or maintenance quirks documented—likely because it was never complex enough to fail in interesting ways. Its value lies purely in utility. If you own an ADC Q-4 cartridge, finding an RQ-4 stylus means your setup stays alive. That’s the quiet dignity of this little diamond: it’s not rare, not legendary, but still, somehow, available.