Pioneer SX-D5000 (1980)

 It doesn't take much shopping around to make the discovery that most stereo receivers these days look pretty much alike, with the tuning dials dominating the frontface, with knobs and controls often adding to the clutter. Now comes Pioneer to make a major new contribution to the aesthetics of receiver design. And make a break from the concept of the traditional receiver. The SX-D5000 is totally redesigned. All controls Iexcept Volume and Balance) and switches are sliders and pushbuttons, not levers, rockers or rotary knobs. Indications are all digital, even the one for tuned frequency. You don't have to be a stereo expert to see how these new lines and contours add up to a distinctive kind of elegance. To see how the SX-D5000 gives the appearance of a precision transceiver, with all controls neatly grouped into three.

Visually attractive, functional, operationally comfortable - a rare combination of design qualities in a receiver. Would you expect less from Pioneer?

The SX-D5000 is what receivers should be like in the 1980s. Once again, Pioneer makes the first impression.

 Too Hot to Handle

The traditional alternative to the Class-B amp is Class-A. The former amp employs the on-off switching of transistors in order to minimize heat loss. In Class-A, a large amount of bias (or idle current) is applied to keep the transistors ON at all times, whether or not a signal is present for amplification. This avoids switching distortion. However, as much as 75% of the energy consumed is bled off in the form of heat, adding up to waste, potential damage and inefficiency. Attempts to create a hybrid "A/B" and other alternatives have always ended in frustration.

Pioneer Vari-Bias to the Rescue.

Frustration, however, is often the mother ofinvention.Not so long ago our engineers began to work on what they call :a very imple high-speed bias servo" to increase Class-A efficiency. An inspired breakthrough led to the Pioneer Vari-Bias circuit, which constantly monitors the amplitude of incoming signal, then automatically controls the amount of bias fed to the power transistors.

While they "rest" during no-signal periods they get only a trickle - just enough to keep them from switching off. Actually, this circuit isso simple it does not limit the transient response of the transistors in any way .

DC with a Difference

Still another advantage of the SX-D5000's power amp is its special DC or Direct Current configuration. What makes it special is the coupling capacitors we've used at the input of the amp to safeguard the circuits and your speaker systems. If this precaution is not taken, ultra-low-frequency signals which might be picked up, say, from a warped record can  cause annoying "Doppler distortion" in drivers, adversely modulating the audible frequencies. Pioneer's DC (with a Difference) however, removes signal-delaying capacitors from the negative feedback loops to reduce phase distortion. This contributes immensely to sharp and densely-textured sonic imagery in the final reproduction.

Power Amp Highlights

Continuous Power Output is 80 watts per channel, min. At 8 ohms from 20 to 20,000 hertz with no more than 0,005% total harmonic distortion.

Heat Sink - is the "I-Skived" type, which uses thinly-sliced metal fins on a lightweight but solid frame to provide as much as 50% better heat dissipation than in conventional types.

Protection Circuitry - has gold-plated dual-contact relays for fast response and unfailing dependability should power-related mishaps occur. The receiver and your speakers are fully protected; the circuitry mutes power on/off noise, protects power transistors and speakers from abnormal direct-current potentials and overload at the output.

 Accurate Preamp and Versatile Control

Fluroscan power Output Meter

For added accuracy, we've chosen the Pioneer-exclusive Fluroscanmeter instead of the needle-type analog types. For superior readability, the bar-graph sections of each channel have 12 separate fluorescent segments each. They thus achieve a large and clearly-calibrated display that is easier to read than ordinary VU-type meters. Range is 0,01 to 80 watts, referred to an 8- ohm speaker load.

Low-Noise Phono Equalizer

Two low-distortion monolithic Ics are used, one in each channel, in the phono equalizer to provide exceptionally good signal-to-noise ratio (82dB). Given this circuit design with its precise construction, RIAA equalization is achieved accurately within ±0,2dB over the 20 to 20,000 Hz range with never more than 0,005% THD. Phono overload is 200 mV, permitting you to use high-output cartridges if you desire.

Low-Distortion Tone Control Amp

This is also an IC-built circuit block, employing NFB to lower distortion to 0,005% or less (4V output) over the 20 to 20,000 Hz range. Bass and Treble adjustments are made on the two slider controls - each with 11 click stops - so they never ad audible distortion to your music.

When the controls are centered at the "0" positions, the tone amp is defeated entirely and you get a flat response at the output.

 Attenuator-Type Master Volume Control

We've improved the "feel" of the master volume control by providing it with decibel calibrations from 0 down to -7 dB. You know at a glance how much power your receiver is delivering on the average, which should be reflected on the Fluroscan power metwr. For operating convenience, the control has 41 detents or click stops.

Preamp/Control Highlights

Function Indicators (FM/AM/Aux/Phono) -  Pioneer's "Light Touch" buttons are employed to indicate the selected function. The buttons are lit and glow green when engaged.

Speakers (A/B) - switches with LED indicators

Low (Subsonic) Filter - 18 Hz with -6 dB/octave curve

Tape Monitor& Duplicate - switches for decks 1 and 2; deck-to-deck dubbing is easily accomplished between the two in either direction

Loudness, Balance, Mode (Stereo/Mono) and Muting (-20 dB) controls.

Adaptor - switch to patch in a signal processor unit such as a graphic equalizer, dynamic processor or reverberation unit.

Pre/Power Amp Separation - is possible bia jumpers on blck panel, still another rare receiver feature of the SX-D5000.

 Drift is Banished by Pioneer's Quartz-PLL Synthesizer

Quartz-PLL is a Gem

Two problems you may be familiar with in your own stereo system: Hiss-ridden, distortion-marred reception from your favorite stations. And "drift - along with incidental noise and distortion - that puts a perfectly tuned station out of tune as heat inside a receiver builds up. These are the problems that the design of the SX-D5000, and its Quartz-PLL synthesizer, avoids.

The front end of the SX-D5000 uses a gem-loke quartz crystal as the most accurate and dependable controller  of the local-oscillator frequency yet devised. It's so accurate that it's used in transmitters at broadcasting stations. The steady frequency derived from the quartz crystal is compared with the desired station frequency via a PLL thousands of times per second. Drift simply cannot develop. Tuning is always accurate and precise.

Reliable performance is enhanced by a combination of the superior qualites of quartz with the astonishing capabilites of two microelectric C-MOS LSIs, one to provide frequency synthesis and the other to make possible Autoscan, Memory and "last Call"

Electronic Varicape for Ganged Tuning Capacitor

In the SX-D5000 a team of varicaps for FM and AM is used instaed of the conventional mechanically ganged variable capacitors. Because they work purely electronically, degradation of basic specifications - even over long periods of time - does not occur. Varicaps provide both the desired tuning capacity of conventional capacitors and the extra advantage of being able to control preset fixed voltages commanded by special Ics at will. This means you can preset your favorite stations and tune them in without scanning the entire FM or AM dial - at the touch of a button.

The use of an FET as teh RF amp means still higher sensitivity, better rejection of interference and improved resistance to overload in any area.

 FM IF with Special Filters

The front end signal goes in what's called the IF section for amplification and removal of noise. In this section we've used three special 2-pole ceramic filters with flat group-delay response to assure still lower distortion.

Integrated Circuits Made to Pioneer's Specifications

Two Pioneer-exclusive Ics are employed in the IF and MPX demodulator sections of the SX-D5000 for reliability and dependability. One (PA-3007A) serves as an FM IF amp/detector. It improves the signal-to-noise ratio, lessens distortion and eliminates "TV buzzes". The 82dB signal-to-noise ratio of this unit is rare.

The other IC is called PA-4006A and it contains a PLL stereo demodulator. It makes FM stereo listening cleaner and more accurate.  The PA-4006A also doubles as automatic pilot signal canceller, eliminating the 19 kHz "switching" signal and ensuring that the audio output is never compromised; even if the modulation percentage of the transmitter changes (as it often does when you tune to a relayed, not main, transmission), the canceller tracks the change.

New Air-core Quadrature Disciminator

Pionner's new-type quadrature discriminator is a combination of an air-core micro-inductor and a detection transformer in a single pack. Benefits include a higher signal-to-noise  ratio, wider channel separation,wider frquency response and a more natural tonal quality. These qualites are enhanced by the use of a separate low-pass filter, one in each channel at the output of the PLL stereo demodulator.

 Pushbutton Station Selection and Other Tuning Conveniences

Autoscan for On-Target Tuning at a Touch

Once the FM function button is pressed, simply tiuch the UP (or Down) button and the digital synthesizer begins to scan the FM frequency band in 100 kHz steps at high speed, searching for the nearest station of acceptable strength. Once a strong station signal is located, scanning stops and the station's frequency is "locked". If this is not the station you desire, simply repeat the process until you find it. When scanning reaches either end of the frequency band, it automatically "retraces." All in All, simple on-target tuning, push-button simple.

Naturally, when the AM function is selected, you get the same automatic convenience. Scan intervals are 1 kHz for Am station selection.

Manual Scan for Added Convenience

Manual Scan is another Pioneer feature you'll quickly come to appreciate. Setting the Auto/Manual Tuning switch to Manual gives you two "submodes" - two different speeds depending on the degree of pressure you apply to the Up or Down buttons. The two speeds are:

Step Tuning : A light touch on either button moves you up or down the tuning dial in steps (100 kHz for FM and 1 kHz for AM). This mode is used for sampling each and every scan interval.

Rapid Tuning : As you continue to press one of the buttons, the frequency band is scanned from end to end at high speed. You use this mode to move rapidly from one band area to another.

Memory - An Unforgettable Convenience

Electronic accuracy pays off in yet another feature in the SX-D5000, a handy Memory facility for FM and AM. To preset a station, you simply select it with one of the station call button numbered up to six. And you can repeat the process for up to six programmed stations for both FM and AM. Station recall is at the touch of a button.

You can unplug the SX-D5000 for up to about three days without losing the preset stations. Back-up circuitry, not batteries, makes this possible.

Fluroscan Digital Tuned-Frequency Readout

Whatever FM station you've tuned, its frequency is shown in five digits on the Pioneer Fluroscan display, one of the most accurate frequency readout displays ever developed. One immediately appreciable advantage over conventional needle-type pointers is that Fluroscan is not subject to parallax, the optical illusion that plagues needle-type pointers.

The SX-D5000 features a five-digit display. Resolution extends to 100 kHz for FM

Fluroscan Tuning/Signal Indicators

So that you can find the desired FM station quickly and accurately even during Manual Scan, we have provided easy-to-read tuning/signal indicators on the Fluroscan panel face. Observe the simple Tuning indicator; the blue bar light when you are right on station (±30 kHz).

The Signal Strength meter on the Fluroscan panel just below the Tuning meter works both for FM and AM. It has five separate "steps" and operates from an elaborate circuit using two special Ics.Together, these precision-built aids enhance the SX-D5000's tuning accuracy for both FM and AM.

"Last Call" Tuning Aid

"Last Call" means that the frequency of the last station you tune before you turn the receiver off is kept intact until you re-power the tuner. This is an important feature for persons who make unattended recordings off the air.

Tuner Highlights

AM Stereo output for future adaptor is provided: output is 450 kHz, buffered.

FM/AM Muting; inter-station noise is hardly audible while you tune an FM or AM station. Muting for AM is a feature rare in receivers today.

LED Indicators for station call buttons

Ball-Joint AM Bar Antenna; swivles to almost any degree for better AM reception.

25µS Dolby De-Emphasis Switch; with an appropriate Dolby decoder conected to the SX-D5000, you can enjoy hiss-free Dolbyized broadcasts immediately.

Specifications

Continuous Power Output:  80 watts per channel, min. At 8 ohms from 20 to 20,000 Hz with no more than 0,005% THD

Total Harmonic Distortion: 

No more than 0,005% (continuous rated power output)

No more than 0,004% (40 watts per channel power output)

Intermodulation Distortion (50 Hz : 7,000 kHz = 4:1): 

No more than 0,005% (continuous rated power output)

No more than 0,004% (40 watts per channel power output)

Frequency Response:  3 to 450,000 Hz +0 dB, -3 dB

Input Sensitivity/Impedance:  1V/50 kΩ (Power amp In)

Output:

Speaker : A, B, A +B, OFF

Headphones : Low impedance

Damping Factor:  60 (20 to 20,000 Hz, 8Ω)

Hum and Noise (short circuited, A network):  115 dB

Pre-amp Section

Input Sensitivity/Impedance

Phono : 2,5 mV/50 kΩ

Aux, Tape 1 & 2, Adaptor In:  150 mV/50 kΩ

Phono Overload Level:  200 mV(1 kHz, THD 0,005%)

Output level/Impedance:

Tape Rec 1 & 2, Adaptor Out:  150 mV

Pre Output: 1V/1kΩ

Total Harmonic Distortion:  No more than 0,005% (20 to 20,000Hz, 4V output)

Frequency Response

Phono (RIAA Equalization):  20 to 20,000 Hz,  ±0,2 dB

Aux, Tape 1 &2, Adaptor:  5 to 100,000 Hz,  +1,0 dB, -3,0 dB

Tone Control

Bass : ±8 dB (100 Hz)

Treble : ±8 dB (10 kHz)

Filter

Low (Subsonic) : 18 Hz (6 dB/oct)

Loudness Contour (volume control set  at -40dB) : +6 dB (100 Hz), +3 dB (10 kHz)

Hum and Noises (Short-circuitedm A network)

Phono : 82 dB

Tuner, Aux, Tape 1 & 2, Adaptor:  100 dB

Muting : -20 dB

FM Tuner Section

Usable Sensitivity:  10,2 dBf (1,8 µV); (Mono)

50 dB Quieting Sensitivity:

Mono : 15,7 dBf (3,2 µV)

Stereo : 34,2 dBf (28,2 µV)

Signal-to-Noise Ratio (at 85 dBf): 

Mono : 82 dB

Stereo : 78 dB

Distortion (at 65 dB)

100 Hz : 0,1% (mono); 0,2% (stereo)

1 kHz : 0,07% (mono); 0,1% (stereo)

6 kHz : 0,1% (mono); 0,2% (stereo)

Frequency Response: 30 to 15,000 Hz ±0,5 dB

Capture Ratio:  1,0 dB

Alternate Channel Selectivity: 80 dB (400 kHz)

Spurious Response Ratio:  80 dB

Image Response Ratio:  80 dB

IF Response Ratio:  90 dB

AM Suppression Ratio:  60 dB

Muting Threshold:  35,7 dBf (32 µV)

Stereo Separation:  50 dB (1 kHz), 35 dB (30 Hz to 15 kHz)

Subcarrier Ratio:  65 dB

SCA Rejection Ratio:  65 dB

Antenna Input:  300 Ω balanced; 75 Ω unbalanced

AM Tuner Section

Sensitivity:  300 µV/m (IHF, ferrite antenna);  15 µV (IHF, external antenna)

Selectivity: 30 dB

Signal-to-Noise ratio:  45 dB

Image Response Ratio:  30 dB

IF Response Ratio:  60 dB

Antenna:  Ferriote loopstick antenna

Semiconductors:  11 FETs; 24 ICs; 98 transistors; 100 Diodes

General

Power Requirement:  120 V, 60 Hz ;  220 V, 50/60 Hz

Power Consumption:  250 W

Dimensions (W x H x D):  499 x 173 x 460 mm (19-5/8" x 6-13/16" x 18-1/8")

Weight:  16,2 kg (35 lbs) without package