ONKYO Integra C-729 (1998) | Precision and Purity

Released around 1998, the ONKYO Integra C-729 (Onkyo DX-7911) was a high-end CD player designed to extract musical information with exceptional precision. Priced at ¥120,000 in Japan, it combined sophisticated digital conversion, carefully engineered power supplies, and a vibration-resistant disc mechanism in a substantial 10.2 kg chassis.

ONKYO Integra C-729 – Main Specifications

Original price: ¥120,000 Japan, 1.800 DM Germany

Frequency response: 5 Hz–20 kHz

Harmonic distortion: 0.0025% or less

Dynamic range: More than 100 dB

Signal-to-noise ratio: 110 dB or more

Channel separation: More than 100 dB

Wow and flutter: Below the measurement limit

Analog output level: 2 Vrms

Laser pickup: 3-beam semiconductor laser

Digital-to-analog conversion: Dual single-bit DACs with fourth-order noise shaping

Dimensions: 445 × 131 × 365 mm (W × H × D)

Weight: 10.2 kg

Included accessory: Wireless remote control

Advanced Digital Technology and Precision Engineering - Sampling Rate Conversion for Improved Digital Filtering. Sampling rate conversion: One of the C-729's distinctive features is its conversion of the CD's original 44.1 kHz sampling frequency to 52 kHz. According to ONKYO's design approach, this conversion makes noise reduction easier by simplifying the digital filter circuit. It also helps avoid the effects of jitter associated with the conversion process, contributing to improved conversion accuracy. Digital-to-analog conversion: The C-729 employs two single-bit DACs, each using fourth-order noise shaping, with independent conversion paths for the left and right channels. Differential operation helps suppress distortion, while the noise-shaping system is designed to reduce in-band noise associated with single-bit conversion. The result is a carefully engineered approach to translating digital audio into an analog signal. Premium components: ONKYO paid particular attention to the circuitry following the DACs, incorporating film capacitors from German manufacturers Raederstein and WIMA. These components form part of the analog output circuitry, where component selection and circuit layout are important considerations in maintaining signal integrity. Disc-reading accuracy: The C-729 features a digital servo system that measures errors caused by disc eccentricity or warping whenever a disc is loaded. It automatically optimizes tracking and focus, including their respective offsets and gain settings. This helps the player compensate for variations in disc condition and mechanism alignment, reducing reading errors. Mechanical precision: The three-beam laser pickup is driven by ONKYO's original linear motor mechanism, designed to provide responsive operation and high-speed track access. A newly developed rubber magnet improves vibration damping in the magnetic circuit. The die-cast aluminum tray, finished with a mat-like coating, further helps control unwanted vibration. Electromagnetic shielding: The complete disc mechanism is enclosed in a steel case to reduce the influence of electromagnetic noise generated by the pickup. Together, these measures reflect the attention given to both mechanical stability and electrical interference. Stable power delivery: The C-729 uses a double-core laser transformer, a type also employed in ONKYO Integra integrated amplifiers. Its design helps reduce unwanted magnetic leakage. The audio circuitry receives power from two 10,000 µF smoothing capacitors. ONKYO also employs two-stage voltage regulation for the analog section and three-stage regulation for the DAC circuitry, aiming to provide stable operating conditions for both sections. Vibration isolation: DuPont Corian insulators provide another element of the player's mechanical design, complementing the damping measures incorporated into the disc mechanism. 

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MB Quart Reference (1985) | Legendary Active Loudspeaker

Some loudspeakers are designed to reproduce music. Others are built to make the listening experience an event in itself. The MB Quart Reference belongs to the latter category, combining imposing physical dimensions, sophisticated active amplification, and an ambitious four-way design to deliver a truly full-scale musical presentation. Celebrated in the German hi-fi press during the 1980s, this remarkable loudspeaker embodied the pursuit of uncompromising sound quality, backed by an impressive set of technical specifications and a prestigious stereoplay test verdict in June 1985.

MB Quart Reference: Main Specifications

Type: Four-way active loudspeaker system

Frequency response: 16–32,000 Hz

Total available amplifier power: 500 watts

Amplifier performance

Bass amplifier signal-to-noise ratio: Greater than 80 dB, typically 85 dB

Midrange/high-frequency amplifier signal-to-noise ratio: Greater than 90 dB, typically 98 dB

Automatic activation: Selectable switch-on thresholds

Automatic standby: Approximately four-minute switch-off delay, with a tolerance of ±1 minute

Loudspeaker drivers

Tweeter: 25 mm MCD titanium dome

Midrange: 50 mm MCD dome

Mid-bass: 245 mm cone driver

Woofer: 380 mm cone driver with cast chassis

Cabinet finish: Real mahogany wood, with other finishes available at additional cost

Grille: Removable textile grille

Dimensions (W × H × D): 53 × 187 × 53 cm

Weight: 134 kg per loudspeaker

The Technology Behind the MB Quart Reference - Four-Way Active Design. Active loudspeaker architecture is one of the defining characteristics of the MB Quart Reference. Rather than relying on a single external amplifier and a conventional passive crossover network, this system incorporates its own amplification, with separate amplification arrangements specified for the bass and midrange/high-frequency sections. The advantage of this approach is greater control over the different frequency ranges. It also allows the loudspeaker system to be designed as an integrated whole, with its drivers and amplifiers working together toward a common performance objective. With a claimed total available power of 500 watts, the Reference was clearly intended for listeners who wanted more than a compact, living-room hi-fi experience. A Four-Driver Array Covering the Entire Audible Spectrum. Specialized drivers handle different portions of the music, from deep bass to the highest treble. The substantial 380 mm woofer provides the physical foundation for low-frequency reproduction, while the 245 mm mid-bass driver handles the next section of the spectrum. Above them, the 50 mm MCD dome takes care of the midrange, where vocals and many of the instruments that define a recording's character reside. A 25 mm titanium-dome tweeter completes the arrangement, extending the system's claimed frequency response to 32 kHz. The result is a sophisticated driver configuration designed to combine scale, bandwidth, and detailed musical reproduction. MCD Dome Technology and Titanium High Frequencies. Dome-driver engineering is another notable feature of the MB Quart Reference. Both the midrange and tweeter use dome diaphragms, with the tweeter specifically identified as a titanium design. The midrange dome is intended to reproduce the critical frequencies responsible for vocal presence, instrumental texture, and much of the perceived naturalness of a recording. The titanium tweeter extends the response into the upper frequencies, helping complete the system's wide stated bandwidth. The original brochure identifies the midrange and tweeter as MCD dome units but does not fully explain the MCD abbreviation. It is therefore best to preserve the manufacturer's terminology rather than speculate about the exact material or construction involved. Amplifier specifications reveal how seriously MB Quart approached system integration. The published total harmonic distortion figure is below 0.006% at rated power, accompanied by an intermodulation distortion figure below 0.04%. The adjustable RCA inputs accommodate a range of source-output levels, with specified settings extending from 500 mV to 16 V. This flexibility would have helped the system integrate with different preamplifiers and other compatible audio sources. A selectable bass-level switch offers adjustments from +2 dB down to −8 dB, referenced to 30 Hz. This provides a degree of control over the low-frequency balance to suit the room and listening preferences. Automatic Operation for Everyday Convenience. Automatic power management makes this imposing loudspeaker more practical to operate. The Reference features selectable signal thresholds for automatic activation, allowing the system to respond to an incoming audio signal. If no further signal is detected, the loudspeaker switches off after approximately four minutes, with a stated tolerance of one minute either way. A Cabinet Designed to Make a Statement. Real mahogany construction gives the MB Quart Reference a suitably luxurious appearance. Measuring 187 cm tall, with a footprint of 53 × 53 cm, each loudspeaker has a presence that few contemporary domestic hi-fi speakers can match. At 134 kg per cabinet, these are exceptionally substantial pieces of equipment. The removable textile grille offers a more traditional furniture-like appearance, while the exposed driver arrangement presents a distinctly technical aesthetic when the grille is removed.

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SANSUI MH9 (1999) | Micro High-End Hi-Fi System

Imagine a complete micro Hi-Fi audio system that takes up barely more space than a CD case. The SANSUI MH9 micro Hi-Fi component system combines CD playback, MiniDisc recording, radio reception and compact bookshelf speakers in an elegant, space-saving design. With its platinum-gold aluminum front panels, sophisticated editing functions and optional cassette deck, the MH9 brings serious versatility to the world of miniature Hi-Fi.

SANSUI MH9 – Main Specifications

CD receiver: CD-9MH, with integrated amplifier, CD player and FM/AM tuner

MiniDisc deck: MD-9MH, featuring recording, playback and editing functions

Speakers: S-9MH, two-way bass-reflex bookshelf design

Optional cassette deck: D-9MH, featuring auto-reverse and Dolby B noise reduction

Optional rack: GX-9MH, designed specifically for the MH9 system

Amplifier output: 20W + 20W at 4 ohms (EIAJ practical maximum)

Speaker configuration: Two 10cm cone woofers and one 5cm cone tweeter per speaker

Speaker enclosure: All-wood cabinet with bass-reflex loading

Maximum speaker input: 30W (EIAJ)

Dimensions and weight:

CD receiver CD-9MH: 140 × 129 × 274mm; approximately 2.0kg

MD deck MD-9MH: 140 × 129 × 259mm; approximately 3.2kg

Each S-9MH speaker: 155 × 258 × 237mm; approximately 2.8kg

The optional D-9MH cassette deck measures 140 × 129 × 259mm and weighs approximately 2.0kg. 

The GX-9MH dedicated rack measures up to 340 × 174 × 222mm and weighs approximately 1.5kg.

The Technology Behind the SANSUI MH9. CD-9MH: CD Playback, Amplification and Radio in One Unit. Integrated functionality: The CD-9MH is the heart of the MH9 system, combining a CD player, stereo amplifier and FM/AM tuner in a remarkably compact enclosure. Its amplifier delivers a practical maximum output of 20 watts per channel into 4-ohm speakers. A Super Bass function adds extra low-frequency emphasis, while electronically controlled tone adjustment allows the sound to be tailored using the supplied wireless remote control. Digital playback: The CD player employs a 1-bit D/A converter and offers a comprehensive selection of playback modes. Its 15-track music calendar provides a quick overview of the disc, while programming allows up to 20 tracks to be selected in a preferred sequence. Repeat playback is available for a single track, the entire disc or a programmed selection. Random playback adds another way to enjoy a familiar CD collection. Radio reception: The integrated wideband FM/AM tuner covers a broad range of frequencies. An area guide function simplifies station selection, while both automatic and manual tuning are provided. The tuner also supports manual preset memory, allowing up to 15 FM stations and 15 AM stations to be stored. MD-9MH: A Fully Featured MiniDisc Recording and Editing Deck. Beyond simple recording: The MD-9MH transforms the MH9 from a compact playback system into a capable digital recording station. It supports CD-synchronized recording, making it possible to record music from a compatible CD source with minimal intervention. The deck also provides a 20-track music calendar, 20-track program selection, repeat modes and random playback. MiniDisc editing: One of MiniDisc's greatest advantages was the ability to manipulate recorded material without physically cutting tape. S-9MH: Wooden Speakers with a Double-Drive Bass System. Each cabinet contains two 10cm cone woofers for low-frequency reproduction and a 5cm cone tweeter for high frequencies. The two woofers employ a double-drive system intended to reinforce bass performance within the limitations of a small enclosure. Bass-reflex loading: The speakers use a bass-reflex design to extend low-frequency output beyond what a sealed enclosure of similar size might achieve. 

Their all-wood cabinets provide a more traditional speaker construction than the plastic enclosures often associated with compact mini systems. The result is a bookshelf design intended to complement the MH9's miniature electronics without sacrificing the character of a conventional Hi-Fi setup. D-9MH: Optional Auto-Reverse Cassette Playback and Recording. The cassette deck features auto-reverse operation, Dolby B noise reduction and synchronized recording with compatible CD and MiniDisc sources. It is important to note that the D-9MH was sold separately. It is not part of the standard three-component MH9 configuration, and the system's alarm/recording timer cannot be used to make timer recordings on this cassette deck. Elegant Styling and Everyday Convenience. Platinum-gold finish: The MH9's aluminum front panels give the system a distinctive appearance, setting it apart from more conventional black or silver mini systems. The backlit display adds visual clarity, while the supplied wireless remote control makes it easier to manage playback, tuning and electronic tone adjustments from a listening position. Alarm and recording timer: Another useful feature is the programmable timer, which allows users to set start and end times, select a source and specify the volume level. Depending on the selected source and operating mode, this provides convenient scheduled playback or recording. Last but not least this micro Hi-Fi is actually a rebranded Victor UX-MD1...

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Victor original