Pioneer PD-7100 (1989)

Compact Disc Player
8-times oversampling digital filter: Higher resolution and lower noise
The CD format uses a sampling frequency of 44,1 kHz, to provide a frequency bandwidth of from about 0 Hz to 20 kHz. This frequency can result in the generation of "sampling" noise because its "foldover" frequencies are spactrally close to he audible frequency range. These spurious frequencies - known as sampling noise - are normally eliminated by a higher-order analog filter with steep attenuation response. Such filters, though tend to cause aphase lag in frequencies of 10 kHz and highr, making accurate signal reproduction impossible.
Our 8-times oversampling digital filter offers the solution. It samples the input signal at 8 times the normal frequency (that's 352,8 kHz), shifting the spurious frequenciec far out of the audio range. This makes it possible for us to use a low-order analog filter , made from high-quality discrete parts,with mild attenuation response to remove the spurious frequencies. So our 8-times over-sampling digital filter ends due to folder frequencies, whike maintaining accurate phase linearity up to 20 kHz and enabling low distortion output.

Accu-Focus System: For better frequency response in RF output
The laser beam teht reflects off pits on the surface of tehCD holds billions of bits of digital musical information. The beam is detected by a pickup and the signals are passed on to a photodetector where they are converted into electric RF signals. The photodetector is divided into four components to control the focus servo, inevitably causing phase difference between the four signals the detector has received. The accu-Focus System, however, solves this phase-related problem by adding a delay circuit for the first - ariving signals thus dramatically reducing distortionand improving frequency response in the RF out[ut, especially at high frequencies. As a result, boot noise and distortion, are reduced in the audible frequency range.

Linear-envelope D/A conventer system with twin glitch-less Converters
Our linear-envelope D/A converter system is one of the most advanced designs. Conventional converents use 16 current sources to convert 16-bit data into analog; with them even the slightest error in the current sourcs can lead to conversion distortion. With our new linear-envelope converter, however, we've virtuality eliminated the current-source error. Thus ending conversion distortion.
Moreover there are two converters, one for each channelto end inter-channel phase difference and to provide better sound imaging. And each is a glitch-free type for lower noise.


Linear-motor pickup drive: For stable disc tracking and quick track access

Class-A FET buffer amp: For reduced distortion and improved sound quality
Four separate power supplies: Clean sound beacause analog circuits are insulated from digital crcuits
Anti-resonance concept: Honeycomb chassis, magnetic-clamp disc stabilizer, large insulators
To ensure superb disc tracking and great sound, we,ve come up with the Anti-resonance concept. This concept is expressed in our CD players in the following ways.
The chassis of all our CD players have a ribbed honeycomb construction. This design not only increasses rigidity but also protects the pickup and disc drive system inside from vibration generated by speakers and other external influences.

Optical and coaxial digital outputs
Auto program editing
Time fade editing and "Music Window"
Digital level control: For low-noise, precise level adjustment
On touch digital fade
Variable fade: Fade time may be adjusted from 0 to 9 seconds during operation of Music Window, time fade edit or one-touch fade
Full function SR emote control
Random play: To add fun and variety to digital listening
Ready to play 3-inch (8 cm) CD's
Random programmed play of 24 track
Programmable pause
Repeat: 1 track,all tracks, programmed tracks
Auto space and index search
20 tarck music calendar
10 digit fluorescent display
Headphone output with volume control
Timer play (timer optional)
Subcode output

Specifications
System: Compact disc digital audio system
Frequency response: 4 - 20,000 Hz ±0,5 dB
Signal-to -Noise Ratio: 107 dB
Dynamic Range: 97 dB
Channel separation: 100 dB
Wow and Flutter: Unmeasurable (±0,001%, weighted peak)
Distortion: 0,0025%
Output Voltage:2,0V ±0,5 V
Power Requirement: 120 V 60 Hz
Power consumption: 1W
Dimensions: 420 x 123 x 315 mm
Weight: 5,7 kg