Pioneer CT-720 (1979)

At 9.2kg, it lands in your rack with the heft of a promise—this was not built to fade.

Overview

The Pioneer CT-720 isn’t one of those forgotten mid-tier decks that slipped through the late '70s unnoticed. Released in 1979 at ¥79,800, it carried serious engineering intent from the start. At nearly 10 kilograms and stretching over 42cm wide, it commands space like a proper component should. This is a stereo cassette deck that assumes its place beside high-end receivers and turntables, not hidden in a stack. Its design philosophy traces back to the CT-920, suggesting it wasn’t a standalone effort but part of a lineage aimed at performance, even if it didn’t inherit every top-tier feature outright.

Sendust heads handle both recording and playback—a material choice that balances high-frequency extension and distortion performance, especially under high input levels. The erasing head uses a special alloy optimized for clean signal wipe, even on metal tapes with their stubborn coercivity. That matters: metal tapes were still exotic in 1979, and few decks handled them with confidence. The CT-720 wasn’t just keeping up; it was reaching ahead. A closed-loop dual capstan system keeps tape speed stable, minimizing modulation noise and tension swings—critical for maintaining head-to-tape contact and reducing wow and flutter, which Pioneer rates at an impressive 0.04% WRMS.

Owners report the transport is robust, driven by two dedicated motors: an electronically controlled DC motor with a built-in generator for precise capstan speed, and a high-torque DC motor for fast winding. The result? A deck that rewinds a C-60 in 85 seconds or less, without sacrificing long-term durability. The ATLC mechanism—Automatic Tape Slack Compensation—tightens the tape the moment the cassette is loaded, reducing slack that can cause mistracking or uneven wear. It’s a subtle but meaningful touch, especially for users running longer sessions or making critical recordings.

The front panel features a wide-range two-color FL level meter, calibrated from -20 to +8 dB, capable of tracking fast musical peaks. A switch lets users toggle between average and peak response, giving real-time feedback tailored to the content. Controls are soft-push direct change buttons, which feel deliberate and mechanical—no flimsy membrane switches here. A monitor switch allows real-time monitoring of the input signal during recording, a necessity for anyone serious about level setting. Bias is adjustable via a dedicated volume-style control, and the tape selector offers four positions: STD, Fe-Cr, CrO2, and METAL, confirming its readiness for all tape types of the era.

It integrates cleanly into a system: mic input with plug-detect priority switching, line in/out on pin jacks, and even a headset output. The cassette compartment includes back illumination, a small luxury that makes nighttime operation actually usable. And while the timer function requires a separately sold unit, the CT-720 supports it via a standby mechanism, enabling unattended recording—an advanced feature for its time.

Specifications

Key Features

Sendust Recording and Playback Heads

The use of Sendust alloy for both recording and playback heads was a calculated decision. Known for low distortion and strong high-frequency response under high input, Sendust offered a sweet spot between cost and performance. Unlike ferrite, it resists saturation better, preserving transient detail. The heads are configured in a combination type layout, which helps prevent degradation from azimuth misalignment—a common issue in multi-deck setups or when swapping cassettes frequently.

Special Alloy Erasing Head for Metal Tape Compatibility

The erasing head isn’t an afterthought. It’s a special alloy unit designed for high erasure efficiency, particularly critical when dealing with metal tapes that have high coercivity. Without a powerful erase field, residual signals linger, muddying new recordings. This head ensures clean slates, even at the highest tape grades, making the CT-720 one of the earlier consumer decks truly ready for the metal tape era.

Closed-Loop Dual Capstan Transport

Few cassette decks outside the flagship tier used a closed-loop dual capstan system. By feeding speed data back via the built-in generator in the DC motor, the CT-720 maintains precise tape velocity. This isn’t open-loop guesswork—it’s active regulation. The result is minimal speed fluctuation and a wow & flutter rating of just 0.04% WRMS, which rivals many higher-end models. Paired with the high-torque reel motor, it delivers smooth, stable operation across all functions.

ATLC Mechanism for Instant Tape Tensioning

The ATLC (Automatic Tape Slack Compensation) system engages the moment a cassette is loaded, pulling out slack before play or record begins. This isn’t just about convenience—it prevents tape flutter, mistracking, and uneven head wear. It’s a mechanical detail that reflects Pioneer’s focus on long-term reliability and consistent performance, especially during repeated use.

Two-Color FL Level Meter with Peak/Average Switching

The -20 to +8 dB two-color fluorescent (FL) level meter isn’t just for show. It responds accurately to rapid musical transients, and the average/peak response switch gives users control over how aggressively the meter reacts. This is essential for setting optimal recording levels without clipping, particularly when working with dynamic source material. The fluorescent display also ages gracefully—unlike LEDs, it doesn’t burn out quickly.

Dolby B and C Noise Reduction with LED Indication

Dolby support is built in, with an LED display confirming activation. With Dolby OFF, the signal-to-noise ratio hits 59 dB; with Dolby ON, it climbs to 69 dB or more above 5 kHz. This wasn’t just marketing—real users report noticeably cleaner highs and reduced tape hiss, especially on chrome and metal tapes. The system works in tandem with the bias adjustment to optimize recording for each tape type.

Tape Selector with Four Positions (STD, Fe-Cr, CrO2, METAL)

The front-panel tape selector offers four distinct settings, allowing precise bias and EQ calibration for each tape formulation. This level of granularity was still uncommon in 1979, especially outside professional gear. Switching to METAL doesn’t just change a label—it adjusts the entire recording circuit’s behavior, ensuring optimal performance across the tape spectrum.

Bias Adjustment Mechanism with Dedicated Control

A physical volume-style knob allows fine-tuning of recording bias, a feature typically reserved for semi-pro or studio decks. This lets users calibrate the deck to specific tape batches or brands, squeezing out the last bit of fidelity. Combined with the tape selector, it turns the CT-720 into a tunable system, not just a fixed-function recorder.

Monitor Switch for Real-Time Input Monitoring

The monitor switch routes the input signal directly to the output, bypassing the tape head. This lets users verify levels and content before committing to tape—critical for broadcast or archival use. It’s a pro-oriented feature that underscores the deck’s serious intent.

Cassette Back Illumination and Timer Standby

The illuminated cassette well is a small but thoughtful addition, making nighttime operation or dim environments far more practical. Combined with the timer standby mechanism—which works with an optional external timer—the CT-720 supports unattended recording, a feature that would appeal to radio tapers or those recording off-air programs.

Historical Context

Introduced in 1979, the Pioneer CT-720 arrived during a pivotal shift in consumer audio. Compact cassettes were no longer just for portability—they were becoming a legitimate high-fidelity medium. The CT-720 was developed with the design philosophy of the CT-920, suggesting it shared engineering priorities with a higher-tier model, even if it didn’t replicate every feature. Built as a Japanese-market deck, it reflects Pioneer’s focus on precision and reliability during this era. Production is believed to have spanned from 1979 to 1981, placing it at the cusp of the metal tape revolution.

Collectibility & Value

Current market prices are not well documented, though one listing in the Philippines noted a sale price of P8,000, likely Philippine Pesos. No broader pricing trends or auction records are available. Owners report the deck performs well when serviced—"it works and sounds great!" according to one Facebook user—but maintenance is often required. Common issues include scratchy controls and degraded belts, typical of age-related wear. A service manual (D-2652) is available online, and third-party repair kits—including belts and grease—are offered on platforms like Etsy and eBay, suggesting parts support exists for basic servicing. A forum thread on Tapeheads.net references a "no sound on L ch recording" issue shared with the CT-7000, indicating a potential circuit-level flaw in some units. While one Audiokarma user called it "apparently quite rare," no production numbers or scarcity metrics are confirmed.

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