ADC 660E

A rare vintage phono cartridge that quietly turned heads in HiFi circles - when you can even find one

Overview

The ADC 660E never got fanfare or five-figure auction results. It gets mentioned in passing on forums, turns up once in a blue moon on eBay, and gets described in listings as “pretty rare.” It is a moving magnet stereo phono cartridge, not a household name and not a trophy piece, but it has a quiet reputation among people who know it. ADC made it - the audio electronics brand, not the medical company - in the 1960s analog high-fidelity movement, for listeners who valued precision over prestige. It belongs to the 600-series family of cartridges, which ADC positioned as reliable, serviceable units with replaceable styli. That was a practical advantage when stylus life was measured in mere tens of hours.

The 660E differs from its siblings in its elliptical diamond stylus, a step up from the spherical tips common in budget and mid-tier cartridges of the time. According to the Catalogue of High Fidelity Equipment & Accessories 1965, the 660E is “As 660 but with elliptical diamond stylus,” which makes it a higher-resolution variant of the standard ADC 660. That upgrade would have meant better high-frequency detail and reduced record wear, assuming proper alignment and tracking. The cartridge works on the moving magnet (MM) principle, also called “inductive magnetic” (IM) in period literature. A tiny magnet moves within fixed coils to generate the signal. The stylus can be replaced without rewiring or recalibration, which was a real convenience for users and technicians.

The 660E remains obscure. No service manuals, schematics, or detailed reviews have surfaced in the digital archive. Most of what exists is secondhand anecdotes and catalog entries. Even the name appears inconsistently - sometimes “ADC 660E,” sometimes “A.D.C. 660E” - which fits the patchy documentation typical of niche audio gear from this period. It was never a mass-market product. Its scarcity today suggests limited production or perhaps being overshadowed by more aggressively marketed competitors like Shure or Pickering.

Elliptical Diamond Stylus with 15° Tracking Angle

The elliptical diamond stylus is the defining feature of the ADC 660E. This geometry traces the record groove more accurately than spherical tips by making better contact with the vertical modulations in the groove wall. It was becoming standard in mid-to-high-end cartridges by the mid-1960s, and ADC’s adoption of it in the 660E positioned the model for audiophiles who wanted more detail without stepping into exotic territory. The Catalogue of High Fidelity Equipment & Accessories 1965 confirms the stylus type and notes that the 660E shares its core specifications with the ADC 660, differing only in this upgrade.

Vertical tracking angle is specified at 15°, a standard value for the era, compatible with the majority of tonearms designed for monophonic and early stereo records. This angle ensures optimal alignment between stylus and groove, minimizing distortion and wear. Tracking force is listed for the base 660 model as “4 to l grams.” The character “l” is likely a typeset substitution for “1,” which suggests a recommended range of 0.4 to 1.0 grams. That light tracking force would have required a well-balanced tonearm and careful anti-skating adjustment. It also meant reduced record wear, which matters for collectors playing valuable pressings.

Moving Magnet Generator with Replaceable Stylus

The 660E is a moving magnet (MM) cartridge, also labeled “IM” (inductive magnetic) in some documentation. It uses a fixed coil system with moving magnets attached to the stylus cantilever. This layout was favored for its stability and serviceability. Moving coil designs required delicate internal wiring and were often non-serviceable. MM cartridges like the 660E let users replace the stylus assembly without sending the unit in for factory recalibration. That was a major selling point for technicians and home users alike, particularly in markets where access to specialized repair services was limited.

The replaceable-stylus design was a hallmark of ADC’s 600-series, and the 660E fits that approach. No official service manual has surfaced for the 660E. There is a compatible stylus for the ADC R-660/R660, listed at $29 as of May 3, 2024. Forum users on Audiokarma have noted that “they very rarely appear but instead a adc r6e stylus meant for a adc 660e,” which suggests replacement parts may still circulate under related model numbers, even if the cartridge itself is scarce.

Historical Context

The ADC 660E appears in the Catalogue of High Fidelity Equipment & Accessories 1965 with an original price of £13 18 6 (A), including tax. That put it in the upper-mid tier of phono cartridges at the time - less expensive than flagship models from established brands but not a budget option either. Its place in ADC’s lineup alongside other 600-series models suggests a deliberate strategy of tiered performance options on a unified, serviceable platform. The company, known for practical and reliable cartridges, didn’t chase the high-end spotlight and focused on consistent performance for serious listeners and technicians.

Advertisements and catalog entries confirm the 660E was available by 1965 and likely stayed in circulation into the late 1960s, though no definitive end date has been documented. It was part of a broader wave of stereo phono cartridge development that followed the adoption of the 45/45 cutting system and the rise of stereo LPs. It never reached the fame of contemporaries like the Shure V15 or the Pickering XV-15, but informed circles recognized it. HiFi-Stereo (July 1965, p.50) noted that the 660/E “bore a close family resemblance” to other ADC induced-magnet cartridges tested, which suggests a consistent sonic signature across the line - one characterized by “small overshoot and no perceptible ringing.”

Collectibility & Value

On March 1, 2025, a used ADC 660E appeared on eBay with a listing price of $199, described as a vintage elliptical stereo phono cartridge. Market data from completed eBay sales between January and April 2026 shows a wide spread: high sale at $558, median at $150, low at $30, with a current trend trending upward and a latest sale at $194. Volume averages around 15 units per month, indicating steady but niche interest.

Collectors are drawn to its rarity and to a well-engineered, serviceable cartridge from a respected but under-documented brand. Ownership comes with caveats. No service manuals or schematics have surfaced, and compatibility with replacement styli remains uncertain. The ADC R-660/R660 stylus is sometimes cited as a potential match, but no official cross-reference confirms this. As one Audiokarma user put it: “I can not find a lot of information on the vintage ADC 660E but both professionals/turntable guru's have told me that ADC made a great Cartridge.”

Market Value

┌──────────────────────────────────────────────────────────────────────────┐
│ ADC 660E                                                        Aug 2026 │
├──────────────────────────────────────────────────────────────────────────┤
│ High      $817                                    Latest            $108 │
│ Median    $155                                    Trend           ▼ Down │
│ Low       $30                                     Volume           ~8/mo │
├──────────────────────────────────────────────────────────────────────────┤
│   $900 ┤                                                                 │
│        │                     .                                           │
│        │                                                                 │
│   $514 ┤       .                        .                                │
│        │                          .       .                              │
│        │       .        . .. ....                                        │
│        │.  .   .  .  ....  . .....                                       │
│     $0 ┤  .  .   .    ...  . ....                   .     .         .   .│
│        ├─────────────────────────────────────────────────────────────────│
│    vol │▁ ▁▁ ▁ ▄ ▁▁  ▁▄▂█ ▁▄ █▅▄▆▂▂     ▂ ▁         ▁     ▁         ▁   ▁│
│        └─────────────────────────────────────────────────────────────────│
│         2026-01                      2026-05                      2026-08│
└──────────────────────────────────────────────────────────────────────────┘