ADC SS-110 Mark II (1979–1980s)

Name: ADC SS-110 Mark II
Brand: ADC

A 10-band graphic equalizer with a spectrum analyzer that dances like a disco heartbeat. Tone shaping as theater.

Overview

Turn it on and the first thing you notice is the light show, not the sound. Twin vertical banks of neon-like LEDs pulse in real time with the music. The ADC SS-110 Mark II is an equalizer, but it is also a living room centerpiece and a conversation starter, a relic from the moment when audio gear stopped hiding behind brushed aluminum and started performing. Ten sliders per channel sit under your hands. Some vintage EQs feel clinical. This one plays the mood-setter, a tool for exaggeration as much as correction.

Production dates are murky, but listings and unit date codes point to a 1979 origin with runs into the mid-80s, so call it late 1970s or early 1980s. The SS-110 Mark II sits in the middle of ADC's Sound Shaper line, a tier above basic tone controls but not in the realm of studio-grade parametric units. It's consumer-prosumer, the kind of unit you'd find in a high-end home stereo stack next to a Technics turntable and a Nakamichi cassette deck. The "Mark II" name suggests refinement over an earlier version, though evidence of a true Mk I is slim. Some collectors suspect the SS-100SL is a rebranded sibling, differing only in faceplate text and minor trim. Either way, the Mark II is the version people remember, thanks largely to that analyzer.

It's a stereo 10-band graphic EQ. Each slider gives ±12dB of cut or boost at ISO-standard frequencies: 31Hz, 63Hz, 125Hz, 250Hz, 500Hz, 1kHz, 2kHz, 4kHz, 8kHz, and 16kHz. That top octave was still relatively novel in consumer gear at the time. It gave tweeter fans a way to add airiness, or, more often, to overdo it and fry their ears. The circuit is solid-state and all-analog, with no digital tricks or presets. No memory, no MIDI recall, no remote. Just knobs, sliders, and lights. Later units in the 1990s might have added those features, but this one is hands-on and immediate.

Despite the visual flair, the SS-110 Mark II doesn't scream "professional." It lacks the ruggedness of a Drawmer and the surgical precision of a dbx unit. It wasn't meant for tracking vocals or mastering tapes. It was built for the living room, for turning up the bass on Parliament records and smoothing out the harshness of early digital CDs. In that role it works well, not because it's transparent but because it's expressive. The EQ curve is broad, almost forgiving, so you can push sliders around without fear of phase collapse or unnatural artifacts. It won't fix a bad recording, but it will make a decent one feel bigger and bolder.

Specifications

Manufacturer	ADC (Audio Dynamics Corporation)
Production Years	1979–mid 1980s
Model	SS-110 Mark II
Type	Stereo 10-band graphic equalizer with spectrum analyzer
Frequency Bands	31Hz, 63Hz, 125Hz, 250Hz, 500Hz, 1kHz, 2kHz, 4kHz, 8kHz, 16kHz
Boost/Cut Range	±12dB per band
Inputs	2 x RCA (stereo)
Outputs	2 x RCA (stereo)
Signal-to-Noise Ratio	Not specified in research
Total Harmonic Distortion	Not specified in research
Frequency Response	20Hz–20kHz (typical, based on band range)
Power Supply	110V AC, 60Hz (Taiwan-manufactured units)
Power Consumption	110 W
Dimensions	15" W × 7.75" H × 6" D
Weight	Approx. 15 lbs (7 kg)
Display	Dual-channel LED spectrum analyzer (10-segment per channel)
Construction	Steel chassis, plastic faceplate, aluminum trim
Country of Manufacture	Taiwan

Key Features

The Spectrum Analyzer: More Than a Light Show

Yes, it's flashy, and yes, it's nostalgic. But the dual-column LED display on the SS-110 Mark II is also functional feedback. Each vertical bar corresponds to one of the ten EQ bands and lights up in real time to show relative signal strength. Unlike later digital analyzers that sample and reconstruct, this one is analog and immediate, reacting with a slight lag that gives it a warm, almost organic feel. It won't show you exact dB levels, but it will tell you if your 125Hz slider is doing too much, or if your highs are fizzling out. For tinkerers, it turns EQ adjustments into a visual game. Tweak the bass and the bottom lights surge. Pull down the treble and the top row dims.

Build and Layout: Form Meets (Mostly) Function

The layout is straightforward: two columns of sliders, one for left and one for right, flanking the analyzer. The sliders are smooth but not silky. There's a slight resistance that keeps them from drifting, but they're not as precise as high-end Alps faders. The faceplate is black plastic with silver lettering. It looks sleek in photos, but real-world units often show wear around the slider bases and logo. The aluminum side panels add heft and help dissipate heat from the internal power supply, which draws a hefty 110 watts, unusual for a line-level processor. That power draw hints at a beefy internal transformer, possibly overbuilt for the task, and it also means the unit runs warm. Long listening sessions are fine, but stacking it under a receiver or in a tight rack isn't ideal.

Sound Character: Warm, Broad, and a Little Wild

The SS-110 Mark II doesn't aim for neutrality. It adds a gentle warmth, a slight thickening in the lower mids that can make thin recordings sound fuller. The filters are broad, with Q values likely around 1/3 octave, so boosting 2kHz won't isolate vocals the way a parametric EQ does, but it will lift presence across the mix. That makes it useful for corrective work on bright or boomy systems, and just as good for creative shaping. Crank the 63Hz and 125Hz, drop the 2kHz, and your rock playlist sounds like it's coming from a 1970s car radio: lo-fi and punchy. The 16kHz band adds sparkle, but push it too far and you'll bring in hiss and listener fatigue. Used with restraint, it can liven up dull tapes or early CDs. It's not a stealth processor. You'll know it's in the chain.

Historical Context

The late 1970s were a golden age for the "audio lifestyle." Stereos were furniture and status symbols. Companies like Sony, Pioneer, and Kenwood sold experiences along with components. The ADC SS-110 Mark II arrived right in the middle of this boom, when graphic equalizers were moving from pro-audio curiosities to consumer must-haves. Before this, tone controls were limited to bass and treble. Now average listeners could tweak ten frequencies and watch their music move in light. Competitors like Sony's EQ-60 and Panasonic's EQ-3000 offered similar features, but few matched the ADC's visual drama. Even the name, "Sound Shaper," smacked of futurism.

ADC, or Audio Dynamics Corporation, remains a shadowy figure in audio history. No major corporate footprint, no Wikipedia entry, minimal press coverage. Evidence suggests it was either a boutique brand or a private label operation, possibly tied to BSR (British Sound Reproducers), known for turntable mechanisms. The "ADC / BSR" listing for a replacement power switch hints at a shared supply chain or rebranding deal. Whatever its origins, ADC didn't push innovation in circuit design, since this EQ uses standard state-variable filter topology of the era, but it understood presentation. In a market where looks mattered as much as specs, the SS-110 Mark II stood out.

It also arrived just before the digital revolution. By the mid-1980s, graphic EQs would gain microprocessors, memory presets, and digital displays. The SS-110 Mark II, with its all-analog signal path and lack of smarts, was already a throwback by 1985. It sits between the minimalism of early hi-fi and the excess of the 1980s.

Collectibility & Value

Today, the ADC SS-110 Mark II trades in the sweet spot between affordability and desirability. Units in working condition with full LED function sell for $120 to $220 on eBay and Reverb, depending on cosmetic state and whether they include the original box or manual. Fully restored examples, recapped and cleaned with replaced sliders, can fetch up to $300, but that's near the ceiling. It's not a rare unicorn like a vintage Lexicon reverb, but it's not a dime-a-dozen shelf warmer either. The appeal is that spectrum analyzer: functional, nostalgic, and easy to share on social media.

Ownership comes with caveats. The power supply, drawing 110 watts for a line-level device, is a red flag. No widespread reports of fires exist, but service technicians observe that the internal transformer and filter capacitors are prone to aging. Units that haven't been recapped in decades may hum, distort, or fail to power on. The LED drivers can also degrade, leading to dim or flickering bars. That's sometimes fixable with new transistors and sometimes needs a full panel replacement. Sliders wear out, developing crackle or dead zones, and replacements are not standard. Cleaning with DeoxIT helps, but it's a temporary fix.

When buying, test every slider for smoothness and noise, check that all LED segments light evenly, and listen for hum or distortion at high gains. Avoid units missing the bottom cover plate. It's "unnoticeable" on a shelf, but its absence exposes live circuits and reduces structural rigidity. If the unit smells of burnt electronics, walk away. Recapping and slider refurbishment can cost $100 to $150 at a specialist shop, so factor that into your budget. For that reason, working, tested units are worth the premium.

Despite these quirks, the SS-110 Mark II has aged well visually. Its boxy silhouette and glowing face fit right into modern retro setups, especially paired with wood-cabinet speakers or vintage turntables. It's not essential audio gear, but it's fun gear.