YAMAHA CDX-2000 (1987) | 18-Bit DACs and Pure DAC Direct

The Yamaha CDX-2000 arrived in 1987 as a sophisticated evolution of Yamaha’s earlier high-bit CD players, combining advanced digital processing with exceptionally serious mechanical construction. Its 8× oversampling, independent 18-bit DACs, and unusual Pure DAC Direct output made it an intriguing proposition for enthusiasts who wanted to explore the possibilities of digital audio beyond conventional playback. With its titanium-colored front panel, gold-toned controls, substantial chassis, and imposing weight, the CDX-2000 also represented Yamaha’s high-end audio philosophy during the golden age of the compact disc.

Yamaha CDX-2000 – Main Specifications

Model: Yamaha CDX-2000

Year of introduction: 1987

Type: High-end CD player

Digital processing: 18-bit system with 8× oversampling

Digital filter: 18-bit, 8fs digital filter

D/A converters: Independent 18-bit twin DACs, one per channel

Digital outputs: Coaxial and optical

Signal-to-noise ratio: 118 dB (EIAJ)

Dynamic range: 100 dB or more (EIAJ)

Harmonic distortion: 0.002% or less (EIAJ)

Frequency response, Direct output: 2 Hz–20 kHz, ±0.1 dB

Digital volume control: 0.4 dB steps, using 20-bit processing

Wow and flutter: Below the measurement limit

Dimensions: 474 × 121 × 418 mm

Weight: 15.7 kg

Remote control: Yamaha RS-CDX2000, 44-key wireless remote

Original sale price in Germany: 2.700 DM

The CDX-2000’s appeal lies in its combination of digital precision, mechanical stability, and unusual signal-path flexibility. Yamaha did not simply concentrate on the DAC specification. The player was designed as a complete digital source, with separate attention given to filtering, conversion, power supplies, servo control, and vibration suppression. The Yamaha CDX-2000 employs an 18-bit digital filter operating at eight times the standard CD sampling frequency. Rather than processing audio exclusively at 44.1 kHz, the filter increases the sampling frequency to 352.8 kHz through high-precision digital calculations. This moves unwanted sampling-related noise into a higher frequency range, making it easier for the subsequent analog circuitry to handle. Yamaha specified an extremely precise filter response, with out-of-band noise attenuation of at least 100 dB and in-band ripple of no more than ±0.0001 dB. The filter’s complex processing structure was intended to preserve the accuracy of the audio signal while reducing the influence of digital filtering artifacts, including pre-echo and post-echo. The digital-to-analog conversion stage uses separate 18-bit DACs for the left and right channels. The DACs receive the 18-bit output of the digital filter, allowing the player to perform conversion at a resolution substantially beyond the 16-bit format of the original CD data. Yamaha’s design sought to improve the accuracy of low-level signal reproduction, particularly where quantization errors could become more significant. Independent conversion channels also reflect the company’s attention to channel separation and analog signal integrity. Pure DAC Direct: An Unusual Output Option. One of the CDX-2000’s most distinctive features is its Pure DAC Direct Switch. The player provides two types of analog output: Filtered output: The signal passes through the conventional analog low-pass filter. Pure DAC Direct output: The signal is taken directly from the DAC stage without passing through the low-pass filter. The direct output was an unusual feature for its time and offered enthusiasts the opportunity to compare the character of the DAC signal with the sound of the conventional filtered output. It is important to understand that bypassing the analog low-pass filter does not automatically mean a more accurate or universally superior result. The two outputs represent different signal paths, and the direct output may contain high-frequency components associated with the conversion process. The optical pickup mechanism uses a high-speed linear motor designed for rapid track access. Yamaha also paid considerable attention to the mechanical platform supporting the optical assembly. The transport is mounted on a heavyweight BMC base, intended to reduce resonance and limit the transmission of unwanted vibration to the pickup mechanism. The servo system incorporates a two-way computer-controlled design that automatically switches between fast and slow response characteristics. This arrangement was intended to balance rapid access with reliable disc tracking. The CDX-2000 uses a separated internal construction in which the digital servo, audio, and power-supply sections are arranged on independent circuit boards. Yamaha also incorporated a copper-plated VM stabilizer beneath the audio circuit section, designed to improve mechanical stability and suppress vibration. The audio output circuitry uses a two-stage current-based amplifier arrangement, intended to preserve the integrity of the audio signal while reducing the influence of digital noise. For a player introduced in 1987, this attention to internal organization is an important part of its high-end identity. Independent Power Supplies and Class-A Regulation. The power-supply architecture is one of the CDX-2000’s most substantial design features. The digital servo and audio sections are supplied by a large two-transformer power-supply arrangement, with independent shielding intended to reduce interference. The D/A converter and audio sections also employ separate shunt-regulator circuits operating in Class A. These circuits were designed to provide low-noise, low-impedance power delivery to sensitive analog stages. While specifications alone cannot establish how a player sounds, the architecture demonstrates Yamaha’s intention to treat the CDX-2000 as a serious high-end component rather than a conventional mass-market CD player. The CDX-2000’s physical construction is immediately noticeable. Its front, top, and side panels use rigid extruded aluminum, while a heavy bottom plate contributes to the overall structural strength of the cabinet. The player weighs approximately 15.7 kg, an impressive figure for a CD player of this period. The four large insulators combine sintered alloy, rubber vibration isolation, felt, and an aluminum cover.

These substantial feet were inherited from the design approach associated with Yamaha’s prestigious 10000 Series. The titanium-colored front panel and gold-toned operating controls further distinguish the CDX-2000 from more conventional Yamaha models. Features for Everyday Use. Although its engineering is the main attraction, the CDX-2000 was also equipped with an extensive collection of operating functions. Digital Volume Control. The player includes a variable digital volume control with adjustments in 0.4 dB steps. Yamaha specified a 120 dB dynamic range for the 20-bit volume-control processing system. The variable output could be useful in systems where the CD player was connected directly to a power amplifier or another component without a conventional volume control. However, digital attenuation can reduce effective resolution at lower listening levels, so many enthusiasts may still prefer to use a dedicated analog preamplifier. Search, Programming, and Display Functions. The CDX-2000 offers a comprehensive range of playback controls, including: Two-speed monitor search, Index search, Direct track selection, Manual - delete - and random programming modes, Single-track, all-track, program, and A/B repeat. Approximately three-second space insertion between tracks. 24-track music calendar. External timer compatibility. Independent track, index, and elapsed-time displays. Optical pickup position display. Output-level indication. The supplied 44-key RS-CDX2000 remote control provides access to nearly all major functions, including tray operation, programming, track selection, and volume adjustment.

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Sony CFS-D7 (1979)

The Sony CFS-D7 belongs to an interesting period in Sony’s portable audio history, when the humble radio cassette recorder was becoming far more sophisticated than its utilitarian origins suggested. Large, beautifully engineered and packed with features, the CFS-D7 reflects Sony’s philosophy of bringing genuine recording and tuning capability into a format that could still be taken on the road. SIR-III ... Discover More...

KENWOOD HD-1000X (1993) | High-Density Hi-Fi Concept

The Kenwood HD-1000X is one of those early-1990s systems that becomes more interesting the longer you look at it. Built around compact 27 cm-wide components, the HD series combined serious construction, discrete circuitry and an unusually complete selection of sources in a format that was considerably smaller than conventional hi-fi separates. The HD-1000X captures a fascinating moment when Kenwood was trying to redefine what a sophisticated component system could look like.

Kenwood HD-1000X – Main Specifications

A-1001 Integrated Amplifier

Output: 2 × 45 W DIN at 1 kHz into 8 ohms

Power supply: Toroidal transformer with generously sized electrolytic capacitors

Amplification: Discrete L.A.P.T. driver and power-stage circuitry

Circuit layout: Logical Flow Construction with short signal paths

Features: CD Direct, dynamic active bass, high-precision volume control

Remote control: IR control for the HD system

Construction: 1.6 mm steel chassis and 5 mm aluminum front panel

Terminals: Large speaker terminals compatible with laboratory-type connectors

DP-1001 CD Player

D/A converter: Kenwood DAC 7 bit-stream converter

Digital processing: 8× oversampling and third-order noise shaping

Analog stage: Discrete low-impedance push-pull output circuit

Digital output: Optical

Programming: 20-track memory

Functions: Repeat, shuffle, priority and multi-edit

Construction: 1.6 mm steel chassis and 5 mm aluminum front panel

T-1001L Tuner

Reception: FM, AM and LW

Tuning: Quartz PLL

RDS: PS, PTY, AF and CT

Presets: 20 stations

Features: Automatic station search, last-station recall and remote control

Construction: 1.6 mm steel chassis and 5 mm aluminum front panel

X-1001 Cassette Deck

Mechanism: Horizontal front-loading cassette tray

Transport: Centrally positioned drive

Control: Full-logic

Search: DPSS title search

Noise reduction: Dolby B/C

Recording: Dolby HX Pro, Auto Bias, CCRS and CRLS

Other features: Timer operation and switchable MPX filter

Construction: 1.6 mm steel chassis and 5 mm aluminum front panel

DM-1001 MiniDisc Recorder

Recording system: ATRAC

Digital connections: Optical input and output

Copy protection: SCMS

Mechanism: Front-loading

Display: 38-character text display

Editing: TOC editing and track reordering

Control: IR remote

GE-1001 Parametric Equalizer

Bands: Three parametric bands

Frequency selection: 33 center frequencies

Slope: Seven selectable settings

Adjustment: ±10 dB

Features: Recording equalization and tape monitoring

LS-300G Loudspeakers

Tweeter: 28 mm soft dome

Woofer: 150 mm aluminum-frame driver

Crossover: 1.5 kHz, 6 dB/octave

Cabinet: MDF, approximately 20–41 mm panel thickness

Terminals: Gold-plated

Shielding: Magnetic shielding for placement near televisions

SRM-1001 components stand, SR-300G speaker stand

Original sale price in Germany: approx. 6.700 DM

With the HD-1000X Kenwood Takes a Different Route. The "HD" designation stood for High Density, referring to the compact dimensions and densely engineered construction of the series. At approximately 27 cm wide, these components were considerably narrower than the familiar full-size separates that dominated serious Japanese hi-fi at the time. But Kenwood clearly did not want the HD series to be perceived simply as a mini system. The physical construction tells a different story. The components use 1.6 mm steel chassis and substantial 5 mm aluminum front panels, giving them an unusually dense and purposeful appearance. 

The A-1001 amplifier is perhaps the best expression of the HD philosophy. Its rated 45 watts per channel isn't particularly remarkable by early-1990s standards, but Kenwood concentrated on the architecture surrounding those watts. The amplifier uses a toroidal transformer, generously sized electrolytic capacitors and discrete L.A.P.T. circuitry. Kenwood's L.A.P.T. — Linear Power Amplitude Transistors — approach was intended to provide highly linear transistor operation while reducing reliance on heavy negative feedback. Logical Flow Construction was another part of the design philosophy, with the signal path kept short and direct. There is also a dedicated CD Direct function, reflecting the growing importance of CD as the primary source at the time.

DP-1001: A CD Player from the Bit-Stream Era. The DP-1001 is equally revealing of its period. Kenwood's DAC 7 used bit-stream/PDM conversion together with 8× oversampling and third-order noise shaping. This was part of the broader movement during the late 1980s and early 1990s toward alternative approaches to conventional multi-bit DAC architectures. The analog section is particularly noteworthy. Kenwood used a discrete, low-impedance push-pull output stage rather than treating the analog output as an afterthought. The result is a CD player that fits the HD philosophy surprisingly well: compact dimensions, substantial construction and a relatively elaborate internal architecture.

X-1001: When the Cassette Deck Was Still Serious Business. The X-1001 is one of the most appealing pieces for cassette collectors. By 1994, the compact cassette was no longer the unquestioned future of consumer recording, but manufacturers were still producing technically ambitious decks. Kenwood equipped the X-1001 with Dolby B/C, Dolby HX Pro and Auto Bias. It also offered CCRS automatic recording from CD, along with CRLS for analog sources. The horizontal loading arrangement gives the deck much of its visual identity. The centrally positioned transport was intended to help suppress vibration, while full-logic operation and DPSS search provided the kind of automation expected from a sophisticated deck of the period. 

T-1001L: The Tuner at the End of an Era. The T-1001L represents another transitional component. Traditional quartz-locked FM/AM/LW tuning is combined with RDS functions including station identification, program type, alternative frequencies and time information. That makes it particularly representative of the early-1990s broadcast environment. The tuner isn't simply there to complete the visual stack. It reflects the period's attempt to modernize a fundamentally traditional analog source with digital information and sophisticated control electronics. 

DM-1001: Kenwood Embraces MiniDisc. The DM-1001 shows where the HD concept was heading. MiniDisc had arrived as a new digital recording format, and Kenwood incorporated it into the HD family through the DM-1001. ATRAC compression, optical digital I/O, SCMS, TOC editing and a 38-character display place the machine firmly in the early MiniDisc era. For collectors, this is particularly interesting because it shows that the HD concept was not frozen around CD and cassette.

GE-1001: The GE-1001 is an unusual addition to the system. Rather than using a conventional graphic equalizer, Kenwood provided three parametric bands with 33 selectable frequencies and seven slope settings. That gives the unit considerably more control than the typical consumer equalizer of the period.  Its presence also reveals something about Kenwood's concept of the HD system. The company wasn't merely selling a stack of source components. It was offering a complete, configurable listening system.

LS-300G: The Matching Loudspeaker. The LS-300G completes the original HD concept. The two-way design combines a 28 mm soft-dome tweeter with a 150 mm woofer and a relatively gentle 6 dB/octave crossover at 1.5 kHz. The cabinet construction is particularly interesting for such a compact system. MDF panels range from approximately 20 to 41 mm in thickness, while the speakers also feature magnetic shielding for placement near a television.

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