What is stereo?




There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakers are used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.




H.H. Scott '59





Sony APM-33W

 How Sony's APM Technology Works
What are the major design features of Sony's Accurate Pistonic Motion speakers? One key characteristic is the use of flat drivers. Flat diaphragms have a major advantage over traditional cone-shaped drivers.  In cone-shaped drivers, the outputs from opposing surfaces of the speaker cone interfere with each other, causing inaccurate frequency response. This is known as the "cavity effect", and it's an inherent abnormality of the cone shape design. Beacuse flat diaphragms like the APM driver are not prone to this type of distortion, you hear a speaker with more linear frequency response.

Honeycomb Construction with Four-point Drive.
To ensure that these compact drivers won't lose their shape when presented with powerful sonic modulations, Sony APM drivers feature an innovative aluminum honeycomb design permits the APM drivers to resist bending - a major cause of distortion in typical paper drivers. Yet the aluminum honeycomb is light in weight for superb transient response.
For these reasons, several speaker manufactures use aluminum honeycomb construction. However, only Sony uses square diaphragms and four-point drive to further eliminate potential nodes of vibration. In this way, distortion is reduced to the vanishing point.
 With all the impressive technology built into the ES Series, it would be a shame to spoil the final enjoyment of the music by using a loudspeaker incapable of matching the system's sonic performance. Yet, that's exactly what would happen with many of the most popular spaekers on the marked today. Very few of them are designed to handle the extremely wide dynamic range that's an important part of PCM, Compact Disc, and beta Hi-FI sound. And almost none can reproduce the full spectrum of the audio frequencies without severe inaccuracies and distortion. Even something as fundamental as clean, uncolored bass response is beyond the capabilities of most speakers.
That's way Sony includes the APM-33W Accurate Pistonic Mption (AMP) loudspeakers as an integral part of the ES series system. They are uniquely qualified to deliver all the exciting sonic benefits that are a part of Sony's advanced technologies.
 Reproducing the particular Attributes of Digital-quality Audio
The APM-33W speakers combine remarkable efficiency and impressive power handling capacity (up to 160 watts) with extended bass response and linear, transparent frequency characteristics. The result is the ability to match the dynamic range of the PCM disgital recordeer, the Compact Disc player, and Beta HiFi videocasssette deck without distortion or overload.
And the low frequency output of the APM-33W is smooth and powerful. This characteristic is especially surprising when you consider the dimensions and appearance of the speaker enclosures - they're small and attractive enough for almost any installation in almost any room.
 The Final Analysis
What do these adbanced APM speakers sound like? Their response is clean, distortion-free, and highly accurate. Their frequency range is also impressive - it extends from 39 to 20,000 Hz , +4, -8 dB. Just as important, the APM-33W speakers can easily handle the most demanding input from s digital source and reproduce it with all its striking clarity, in short, the APM speakers perfectly match our design criteria - they're clean, uncolored, and highly musical.
Specifications
Drivers: 
50 square inches APM-type woofer;
1 square inch APM-type tweeter
Frequency Response:  39 Hz - 20 kHz +4, -8 dB
Sensitivity:  91 dB SPL  1W/1m
PowerHandling Capacity:  80 watts nominal, 160 watts maximum
Nominal Impedance:  6 Ω
Crossover Frequency:  2,2 kHz
Enclosure Type:  Bass Reflex
Dimensions (W x H x D):  315 x 540 x 320 mm (12-1/2" x 21-1/4" x 12-5/8")

Weight:  14,4 kg (31 lb, 10 oz)

Sony MDR-CD7

 Building full-size equipment capable of properly reproducing Sony's new media is difficult enough. Add the constraints inherent in headphone design, and you'll understand the design challenge of the MDR-CD7 headphones. To be effective with the ES Series' digital-quality sound sources, they had to combine wide, linear response, deep bass output, and full dynamic range. On top of all that, they had to be lightweight and comfortable to wear.

Only the Size and Weight are Small.
The solution?  An innovative transducer design. The MDR-CD7 uses a small but very strong Samarium Cobalt magnet for startlingly wide frequency-response. And a high compliance 24K gold ion plated diaphragm exhibits extraordinary amplitude, resulting in an impressive dynamic range of 135 dB.
For comfort, the slightly off-center mounting position of the urethane earpads guarantees proper side pressure distribution and good balance for all wearers. The pads themselves are specially designed to conform to the ear, further increasing comfort, providing 30 dB of isolation from ambient sound and extending bass response.

Paying Careful Attention to Detail
The cord is made of nearly pure copper. More copper means less oxygen content - since oxygen interferes with the transmission of the sound-carrying electrons, that means the MDR-CD7's wire provides clear, open sound.
With a conventional system, all this careful construction and expensive material might seem like overkill. But with Sony's new digital-quality media, even little things make a big difference.
That's why the MDR-CD7 headphones sound so sensational.
Specifications
Headphone Type:  Closed, dynamic
Driver Type:  30 mm diameter; Dome driver (24K gold ion plated)
Sensitivity:  110 dB SPL at 1mW
Frequency Response:  2 Hz - 24,000 Hz
Impedance:  45 Ω
Rated Power:  10 mW
Power Handling Capacity:  50 mW
Cord:  3 m (30 feet) OFC Litz wire
Plug:  Sony Uni-Match design with both stereo miniplug and ¼" phone plug

Weight (without cord):  80 grams (3 ounces)

TEAC CD-5

 Center-Mounted Mechanism
The CD drive mechanism is mounted in the front center of the unit, providing ideal chassis balance and stability. In the CD-5, the large power supply transformer is positioned in the rear center, and the digital and analog blocks are on opposite sides, preventing any interference from degrading sonic purity.

Innovative Vibration-Resistant Foot Design
The CD-5 features an original foot design for increased vibration damping. Each foot is constructed of diecast zinc-alloy, and is specially mounted to the body to minimize vibration. The point of the foot rests on an independent base featuring a hybrid construction of aluminum and rubber damping material that further prevents the transmission of vibration. These feet not only give the CD-5 an exciting high-tech look, they also contribute to higher sound quality.

High-Precision 1-Bit Bitstream D/A Conversion
Bitstream Conversion is the latest advance in 1-bit D/A conversion technology. It converts the original 16-bit music data to a high-speed 1-bit data stream, which is then converted into analog signals by the high-performance 1-bit DAC. This 1-bit processing eliminates the main source of non-linearity and distortion, resulting in exceptionally transparent music reproduction, especially of delicate, low-level signals.
The CD-5 / CD-3 also employ a 20-bit 8-times oversampling digital filter. This  sophisticated filter stage eliminates left and right channel interference and even-order high harmonics while maximizing signal-to-noise ratio for incredibly clear sound reproduction.
 CN Servo
Servo feedback is a possible cause of signal noise, which is why these players are designed to require a minimum of servo correction. To protect against any residual interference, they are equipped with Teac's exclusive CN (Clean Noise) servo system. It uses a low-pass filter to eliminate potentially de-stabilizing elements from the servo signal, and also helps minimize vibrations in the optical assembly.

Track Focus Holding System (T.F.H.S.)
Teac's unique T.F.H.S. prevents tracking slips and increases stability. Even if the disc surface is scratched or dirty, T.F.H.S. will read tracking and focus error signals accurately while the pickup holds those signals directly in front of the dirty or defective area. As soon as it is passed, the laser continues reading the same track. The result is fewer errors for more accurate music reproduction.
 Time Edit
This function is extremely useful when making tape copies of your favorite CDs. Just press the Time Edit button on the remote control and input the total time of the cassette you're using. In seconds, the tracks that will fit on side A will appear on the calendar display. The CD-5 assumes you'll want to record the tracks in order,but if there's extra time it tells you which tracks will fit on the remaining tape and gives you the optionof adding one of them to the programmed sequence. Press Time edit again and the process is repeated for side B. you maximize recording time and never have the frustration of running out of tape in the middle of a selection.

Synchro Dubbing
When the CD-5 is used together with a teac compatible cassette deck, Synchro Dubbing allows you to control both at once. First use Time Edit to select the CD tracks to be recorded onto the cassette, then press the deck's CD Sync button. CD play and cassette recording begin simultaneously, giving you a simple, miss-free recording start every time.

Pitch Control Functions
The CD-5's remote control includes a Pitch Control function that lets you fine-tune the music by increasing or decreasing pitch in 1% steps up to 12%
 Other Important CD-5 Features
Multi-function reomte control unit.
High-speed search keys.
20-selection random and delete programming.
4-way repeat function (One/All/Program/A-B Block)
Extra-heavy chassis with dual-plate structure.
Index search.
Auto space.
Program pause.
Remote controllable on/off fluorescent display dimmer.
Numerical display (Total/Playing/Program/Index).
Time display (Each/Total Remaining/Each Remaining)
Memory program calendar.
Front panel Phones jack input
TOS-Link optical digital output.
2 analog outputs
Specifications
Channels:  two
D/A Conventer [Type/Number]:  Bitstream Conversion / 4
Digital Filter [Type/Oversampling]:  20-bit / 8x
Analog Filter [Type/Order]:  Butterworth / 3rd
Frequency Response:  0 Hz - 20 kHz (±0,1 dB)
Signal-to-Noise Ratio:  105 dB (1 kHz)
Dynamic Range:  98 dB (1 kHz)
Harmonic Distortion:  0,002% (1 kHz)
Wow and Flutter:  Unmeasurable (Quartz accuracy)
Channel Separation:  104 dB (1 kHz)
Analog Output:  2,5 Vrms
Digital Output:  -21 - -15 dBm
Dimensions (W x H x D):  481 x 123,5 x 295 mm
Weight:  7,2 kg net

Teac CD-P3400

 Teac CD-P3400
Special Features:
1-bit D/A conventer
8-times oversampling disgital filter
 Other Features:
Center-mounted mechanism
Multi-function 8-digit fluorescent display
Coaxial digital output
Music calandar
Full-function remote controller
Shuffle play
Random memory programming
3-way (One/All/A-B) repeat function
Program edit
Tape record edit
Auto-space function
Headphones jacks
Specifications
Channels:  two
D/A Conventer [Type/Number]:  1-bit/ 1
Digital Filter [Type/Oversampling]:  16-bit / 8x
Analog Filter [Type/Order]:  Butterworth / 3rd
Frequency Response:  20 Hz - 20 kHz (±0,5 dB)
Signal-to-Noise Ratio:  105 dB (1 kHz)
Dynamic Range:  87 dB (1 kHz)
Harmonic Distortion:  0,008% (1 kHz)
Wow and Flutter: unmeasurable (Quartz accuracy)
Channel Separation:  85 dB (1 kHz)
Analog Output:  2,0 Vrms
Digital Output:  1,0 Vp-p / 47 ohms
Dimensions (W x H x D):  435 x 105 x 251 mm

Weight:  4,0 kg net

Teac CD-P3200

 Teac CD-P3200
Features
8-times oversampling disgital filter
Center-mounted mechanism
Multi-function 8-digit fluorescent display
Music calandar
Full-function remote controller
Shuffle play
Random memory programming
3-way (One/All/A-B) repeat function
Program edit
Headphones jacks
Specifications
Channels:  two
D/A Conventer [Type/Number]:  16-bit/ 1
Digital Filter [Type/Oversampling]:  16-bit / 8x
Analog Filter [Type/Order]:  Butterworth / 3rd
Frequency Response:  20 Hz - 20 kHz (±0,5 dB)
Signal-to-Noise Ratio:  100 dB (1 kHz)
Dynamic Range:  90 dB (1 kHz)
Harmonic Distortion:  0,05% (1 kHz)
Wow and Flutter: unmeasurable (Quartz accuracy)
Channel Separation:  87 dB (1 kHz)
Analog Output:  2,0 Vrms
Digital Output:  No
Dimensions (W x H x D):  435 x 105 x 251 mm

Weight:  4,0 kg net

Panasonic Symposium RS-796US

 Superb Dual Capstan 4-Track Stereo Tape Deck with Continuous Automatic Reverse
"Today's Leader in Tommorrow's Look"
This superb stereo tape deck will complete your home entertainment system. Offers many exciting features. Dual capstan drive, 4-track stereo, Continuous automatic reverse. Records and plays in both directions. Also has 4 tape heads, 3-speed operation. Simple lever operation and pause control. And a wealth of additional features. The Symposium is enclosed in a handcraft walnut cabinet with a solar bronze dust cover. Play it vertically or play it horizontally, the quality of performance is the same-superb.
 Advanced Engineering Features
High Fidelity 4-Track Stereo Tape Deck
Whether for electronics or for quality, this 4-track stereo tape deck will perfectly match your present system-providing your system now is of the finest quality.

Dual Capstan Drive Operation and Four Tape Heads
Dual capstan drive and four tape heads permit the tape to operate at a a continuous, doubly constant speed. Give distortion-free sound with true recording fidelity.
 Continuous Automatic Reverse
Tha Symposium automatically records and plays in both directions without flipping over the reels. The tape ends trigger automatic shut-off mechanisms.

Separate Volume Controls for Recording
Separate volume controls can be used while recording for the most precise adjustment.

Solid-State Engineered
The Symposium is solid-state engineered for ultra reliability and superb performance. Every component every assembly operation is subjected to the most rigid quality control standards. Even the walnut cabinet is handcraft.
Specifications
Operation:  Lever
Tape Speeds:  7 ½ , 3 ¾, and 1-7/8 ips
Reel Size:  7" max
Solid State Device:  15 transistors and 10 diodes
Tape Counter:  Push reset 4-digit
Recording System:  AC bias 85 kHz
Program Time:  4 hours stereo at 1-7/8 ips with 7" tape; 8 hours monaural at 1-7/8 ips with 7" tape
Erasing System:  AC erase
Sound-on-Sound: available with connection cord-C
Track System:  4-track stereo
Fast Rorward Time:  180 seconds with 7" tape
Rewind Time:  180 secons with 7" tape
Frequency Response: 
30 - 20,000 Hz at 7 ½ ips
30 - 13,000 Hz at 3 ¾ ips
30 - 6,000 Hz at 1-7/8 ips
Signal-to-Noise Ratio:  more than 50 dB
Wow and Flutter: 
Less tahn 0,10% WRMS at 7 ½ ips
Less than 0,19% WRMS at 3 ¾ ips
Less than 0,29% WRMS at 1-7/8 ips
Jacks:  2 - Microphone input;  2 - Aux input;  2 - Line output; 1 - Stereo headphone output
Power Source:  AC 117 V 60 Hz
Power Consumption:  about 45 watts
Dimensions (W x H x D):  19-3/4" x 14-1/8" x 8-1/2")

Weight:  32 lb

Technics SU-C700

 Stereo Integrated Amplifier SU-C700

JENO Engine (Jitter Elimination and Noise-shaping Optimization)
Just like the R1, the SU-C700 is a fully-digital amplifier and delivers high-resolution digital signals without any distortion being introduced between the input stage and output to the speakers. Technics has developed an original jitter-reduction circuit, avoiding the sound quality degradation due to jitter common to conventional digital amps. It uses a clock generator for the noise-shaping system to reduce jitter in the low-frequency range and a high-precision sample rate converter to suppress jitter in the high-frequency range.

LAPC (Load Adaptive Phase Calibration)
Technics has developed a speaker impedance optimization algorithm, using digital signal processing to flatten both the amplitude and phase-frequency response to make the most of your speakers. The result is a sound with better focus, spaciousness and definition.

High-speed Silent Linear Power Supply
Using a large-current Schottky-barrier diode, a rectifier circuit with electrolytic capacitors, and a stabilized power supply circuit, the SU-C700 ensures ample power supply at all times, even when dynamic music demands high current. 
 Battery Driven Clock Generator
Technics used battery power for low-noise applications in analog amplifiers in the past: here, this same technology is used to improve digital clock precision, enhancing the definition of the sound.

Various Inputs
The SU-C700 supports a wide range of inputs, such as SPDIF, Analog and Phono, as well as USB-DAC for connection of a PC. The digital input terminal supports coaxial 192-kHz/24-bit PCM and optical 96-kHz/24-bit. The USB DAC input terminal supports 192-kHz 32-bit PCM and 2.8-MHz/5.6-MHz DSD native playback (analog output) and asynchronous transmission. The SU-C700 converts analog signals to high-precision 192-kHz/24-bit PCM signals using the A/D converter. The full-digital system achieves high-purity reproduction from any content. 
Specifications
Accurate Digital TechnologyJENO Engine
Technics Definitive DesignHigh Rigidity aluminium cabinet  White LED illuminated large level meter  Symmetric structure
Output Power:
45 W + 45 W (1 kHz, T.H.D. 0.3%, 8 Ω, 20 kHz LPF)
70 W + 70 W (1 kHz, T.H.D. 0.5%, 4 Ω, 20 kHz LPF)
Input Sensitivity /Impedance:
Line :  200 mV / 22 kΩ,
Phono (MM) :  2.5 mV/47 kΩ
Frequency Response:
Line :  20 Hz - 80 kHz (-3 dB, 8 Ω),
Phono(MM):  20 Hz - 20 kHz (RIAA DEVIATION ±1 dB, 8 Ω),
Coaxial 1/2/3 :  20 Hz - 90 kHz (-3 dB, 8 Ω)
Load Impedance4-16 Ω
Analog Input Terminal:  1 x Line; 1 x Phono
Digital Input Terminal:  3 x Coaxial Digital, Optical Digital, USB-B
USB-DAC (USB-B):
USB Audio Class SpecificationUSB Audio Class 2.0, Asynchronous mode
Support Codec
DSCYes (2.8224 MHz, 5.6448 MHz)
PCMYes (32, 44.1, 48, 88.2, 96, 176.4, 192 kHz / 16, 24, 32 bit)
Headphone Output:  Yes
System PortSystem Control Input/Output (Φ3.5 mm Jack)
Power SupplyAC 120 /240 V, 50/60 Hz
Power Consumption:  73 W
Dimensions (W x H x D)340 x 132 x 325 mm (13-3/8" x 5-7/32" x 12-13/16")
Weight:  Approx. 8.3 kg (18.3 lbs)

AccessoriesRemote control

Technics SL-C700

 Compact Disc Player SL-C700
Ultra Low Distortion Oversampling Digital Filter
The oversampling digital filter uses Technics' original algorithm to ensure the most accurate conversion of the digital signal.
High Res Re-master
Technics High Res Re-master converts audio signals to up to 176.4 kHz/32 bits before digital to analog conversion, allowing a natural and expressive sound.
High-Precision Master Clock
A clock generated by high-precision crystal operates the CD reading, Audio DSP, and D/A converters to achieve highly precise digital syncronization, resulting in accurate playback. Independent high-precision Burr-Brown PCM1795 (Texas Instruments) digital to analog converters are used for each channel.
 High-quality Analog Circuit
A symmetrical analog layout eliminates interference between the left and right channels, while keeping signal paths as short as possible to prevent signal loss during transmission.
High Rigidity Metal Double Chassis
To reduce vibration and noise that degrade the purity of sound, the Premium Series features a High Rigidity Metal Double Chassis, using inner and outer steel plates.
High-quality Parts
The high-quality electrolytic capacitors and film capacitors used in the power supply and audio circuits were carefully selected through listening tests.
1x playback
To minimize the noise generated by the mechanisms and motors, the disc is played back at 1x speed, minimizing audio-affecting power supply fluctuations.
Specifications
Noiseless Signal Technology:
Ultra Low Distortion Oversampling Digital Filter;
High Res Re-master;
High Precision Clock Synchronization;
L/R Independent High Precision DAC;
High-quality Analog Circuit;
High Rigidity Metal Double Chassis.
Technics Definitive Design:
High Rigidity Aluminium Cabinet;
Touch Switch Control;
Symmetric Structure.
Disc Compatibility:
Audio CD, CD-R/CD-RW (CD-DA/MP3/WMA,
Discs recorded and finalised on recording devices)
Frequency Response:  2 Hz - 20 kHz (-0,5 dB)
Dynamic Range (IHF-A):  100 dB
Signal-to-Noise Ratio (IHF-A):  117 dB
THD+N:   0.0018 % (1 kHz, 0 dB)
Analog Output Terminal:   LINE x 1
Digital Output Terminal:   Coaxial Digital x 1, Optical Digital x 1
System Port:   System Control Input/Output (Φ3.5 mm Jack)
Power Supply:   AC 120 /220 V,50/ 60 Hz
Power Consumption:  10 W
Dimensions (W x H x D):  340 x 78 x 295 mm (13-3/8" x 3-1/16" x 11-5/8")

Weight:  Approx. 5.2 kg (11.5 lbs)

Technics SE-R1

 Stereo Power Amplifier SE-R1
Sets a new high performance standard for digital amplifiers by employing state-of-the-art components and innovative technologies.

JENO Engine (Jitter Elimination and Noise-shaping Optimization)
Jitter is a major cause of distortion in digital systems, and is caused by mis-timing in the master clocks used in digital-to-analog conversion. To eliminate the degradation of sound caused by jitter, Technics has developed an original jitter reduction circuit, comprising a clock generator in the noise-shaping system to reduce jitter in the low-frequency range and a high-precision sample rate converter for suppressing jitter in the high-frequency range. Thus it reduces jitter in an ideal way over the entire frequency range.
This works with a newly-developed and original high-precision PWM (Pulse Width Modulation) conversion circuit, optimizing the noise-shaping speed, the degree and requantization number, and the PWM gradation, in order to convert high-resolution signals to PWM without causing any damage to the dynamic range. These new technologies enable new Technics digital amplifier designs to reproduce the natural and delicate nuances of music.
GaN-FET Driver (High-speed and Low-impedance Power Devices)
In the speaker-driving section of the amplifier, Technics has employed a high-speed GaN (gallium nitride) FET driver device with super-low resistance. This enables the construction of a high-power amp using a single push-pull configuration, allowing the length of the large current carrying signal path to be shortened, and resulting in outstanding linearity regardless of the sound level.
 LAPC (Load Adaptive Phase Calibration)
The impedance of a speaker is not constant: it varies according to frequency, thus altering the loading on an amplifier and therefore potentially the sound. Technics is able to measure an amplifier's frequency amplitude-phase characteristics with speakers connected, and has developed a speaker impedance adaptive optimization algorithm using digital signal processing to achieve ideal impulse response. Correction processing based on the new algorithm achieves a flat frequency response for both amplitude and phase, not possible in conventional amps, and delivering a sound with rich spatial expression.
Technics Digital Link (Original Digital Signal Transmission)
Some systems use a digital link between source component and pre-amplifier, keeping the digital signal pure as long as possible: Technics Digital Link goes further. It has eliminated the volume control function from the pre-amplifier, and instead transmits the volume control information, together with the audio signal, directly to the power amplifier in digital form. The power amp's jitter reduction circuit reduces any effect of jitter in signal transmission, then performs the volume control immediately before the PWM converter. This new sound transmission interface, Technics Digital Link, supports audio signals and also eradicates inter-channel effects by transmitting the left and right channel signals separately. Technics Digital Link has achieved an ideal amplifier configuration, minimizing any degradation between the pre-amplifier and the power amp, and resulting in superb stereo separation and reproduction of even the most subtle signals. The result is a more detailed and dynamic sound.

High-speed Silent Linear Power Supply
The accurate reproduction of everything from dynamic and powerful sounds to the low-level signals expressing delicate nuances requires a special power supply in an amplifier. It needs to be both powerful and low-noise, as well as capable of responding instantly to a continuously changing audio signal without any voltage fluctuation. The power supply circuit of an ordinary amp consists of a large-capacity power transformer and a rectifier circuit: after examining ways to achieve ideal voltage and current waveforms, Technics decided to use a choke-input rectification, plus a discrete stabilized power supply circuit. These technologies incorporated in the power supply circuit enable the amp to drive the speakers powerfully under any conditions.

Battery Driven Clock Generator
The best power supply for delicate circuitry such as the clock generator in the new amplifiers is one entirely isolated from any noise or fluctuations in the mains supply. Technics has extensive experience in circuits using battery isolation, having used them to create ultra-low-noise pre-amplifier stages in past analog amplifiers.
Construction

Dual Mono Construction
The main amplifier layout separates the left and right channel signal paths completely, all the way back to the secondary winding on the power transformer, to prevent mutual interference and also achieve an ideal weight balance. This design gives optimal stereo separation, and also allows the two channels to be laid out in ‘mirror image’, giving equal signal-path lengths for each channel. 
 Signal Path Minimization
The length of the signal path is kept as short as possible to improve the signal to noise ratio, reduce potential sources of distortion and interference, and give the most direct communication of the music.

High Rigidity Metal Double Chassis
To support heavy parts and components and lower the center of gravity for improved stability, the inner chassis of the SE-R1 is made of 3-mm-thick plate, but the amplifier uses a huge, and very heavy, mains transformer: to support this better and reduce vibration, columns of die-cast aluminium are arranged at appropriate intervals between the bottom inner chassis and outer chassis. The external casing is made of a 7-mm-thick aluminium plate to resist the effect of electromagnetic noise.

High-quality Parts
Large, newly designed speaker terminals enable the connection of thick cables, and even the screws are high precision to ensure they remain tight, giving a firm and reliable cable connection. The insulators are cast iron for high rigidity and an excellent damping effect: this reduces both susceptibility to vibration, and the transmission of any vibration to external devices.
Specifications:
Accurate Digital Technology:
JENO Engine,
GaN-FET Driver,
LAPC (Load Adaptive Phase Calibration),
Technics Digital Link,
High-speed Silent Linear Power Supply,
Battery Driven Clock Generator,
Dual Mono Construction,
High Rigidity Metal Double Chassis.
Technics Definitive Design: 
Aluminium plain miter joint,
White LED illuminated large level meter,
Symmetric structure.
Output Power:
150 W + 150 W (1 kHz, T.H.D. 0.5%, 8 Ω, 20 kHz LPF)
300 W + 300 W (1 kHz, T.H.D. 0.5%, 4 Ω, 20 kHz LPF)
Input Sensitivity and Impedance:
Unbalanced 1.2 V / 47 kΩ,
Balanced 1.2 V / 47 kΩ.
Frequency Response:  1 Hz - 90 kHz (-3 dB, 8 Ω)
THD + N:  0.05% (1 kHz, 75 W, 8 Ω, 20 kHz LPF)
Load Impedance:  A or B, Bi-wiring: 4-16 Ω, A + B: 8-16 Ω
Analog Input Terminal: Unbalanced x 1, Balanced x 1
Digital Input Terminal:  Technics Digital Link x 1
Power Supply:   AC  120 / 220 V, 50/60 Hz
Power consumption:  250 W
Dimensions (W x H x D):  480 x 241 x 567 mm (18-7/8" x 9-15/32" x 22-11/32")

Weight:   Approx. 54 kg (119 lbs )

Garrard SP25 Mk II

 Designed to meet the demand for a high-quality single record playing unit at moderate cost, this unit incorporates a number of special features including a cue and pause control, calibrated fine  stylus force adjustment, pickup arm bias compensation and a large turntable. On completion of playing a record the pickup arm automatically rises, returns to its rest and the motor switches off.
 The Garrard SP25 MkII is a 4-speed single record playing unit incorporating an improved tubular aluminium pickup arm with a resiliently mounted counterbalance weight and a calibrated dial to set stylus force easily. It is elegantly styled, and has many features associated with more costly equipment, such as a cueing device to lower and raise the pickup gently, a patented pickup arm bias compensator and a lightweight plug-in pickup shell which will accommodate a wide range of cartridges. In addition it has a large, loaded turntable driven by a magnetically screened resiliently mounted Garrard Laboratory Series electro motor, through a retractible rubber wheel. The pickup returns to its rest automatically after playing a record and unit switches off.

Pickup Arm Facilities
Stylus Force Adjustment
Integral Stylus Force Calibration
Bias Compensator
Cue and pause
 Cabinet Installation
The SP25 MkII requires minimum cabinet space 15-3/8" long by 13-1/8" wide with clearance for the pickup arm counterbalance weight to overhang 1-1/8" max. Behind the unit plate and 1-13/16" max. to the side of the unit plate, according to the weight of the pickup cartridge fitted.  The unit requires 3-1/2" space above and 2-7/8" below the top of the motor board.
 Voltage and Frequency
The Garrard SP25 MkII has a low voltage range motor suitable for 100/130 volts AC or a dual voltage range motor , suitable for either 100/130 or 200/250 volts AC.  These units are suitable for various power supply frequencies depending on the motor pulley fitted. The pulleys are coloured for easy indentification: Nickel for 50 Hz and Brass for 60 Hz.
Specifications
Type: Single record player
Motor:  4-pole induction
Speeds:  Four speeds 78, 45, 33-1/3 and  16-2/3
Plater:  267 mm (10 ½")
Pickup Arm:
Material:  Tubular Aluminium
Design:  Weight counterbalanced; Slide or Plug-in Pickup Head
Voltage Range:  High and Low
Finish:  Polychromatic Dark Green and Silver

Dimensions:  383 mm (15-1/16") wide by 317 mm (12-1/2") front to rear by 73 mm (2-7/8") above and 70 mm (2-3/4") below lower edge of unit plate.

Mission PCM II

 The PCMII was designed utilizing the Cyrus digital and analogue know-how and was built to the same exacting standards as all Mission-Cyrus products.  Of paramount consideration in the design and manufacture of a compact disc player is the integrity and sufficiency of the power supply section as well as the accuracy and consistency of the digital to analogue convertors (DACs).  Exceptional power supplies were designed for every stage of the PCMII.
The four separate power supplies give substantial power reserves and stability, ensuring that the different signals are not compromised in any way and that the sensitive digital and analogue circuitry, the laser/servo system and the control sections do not interact.
 Highly consistent pre-selected DACs ensure superior linearity and purity of the output signals, resulting in true fidelity in the reproduction of the recorded program material.  To further enhance the PCMII’s superior sonic Performance, the system contains a variety of pioneering facilities.  These include remotely controlled; display “shutdown” to minimize digital traffic, absolute “phase-invert” for optimum extraction of the recorded information and an exceptionally transparent electronic volume control for ultimate ergonomics of the system.
For the more demanding audiophiles, the PCMII can also be upgraded by the addition of a Cyrus PSX external power supply unit.  Connection of the PSX to the PCMII feeds dedicated clean power to the analogue section, resulting in availability of more power reserves for other sections of the machine.  The enormous reservoir of pure power available to the analogue section of the PCMII makes for increased refinement of the system.
Specifications
Frequency Response:  20Hz to 20KHz
Signal-to-Noise Ratio (20Hz-20KHz):  96 dB
Total Harmonic Distortion:   0.003% at 0 dB;  0.008% at -10 DB
Intermodulation Distortion:  0,002% at 0dB, (19KHz/20KHz);0,003% at  -10dB, (19KHz/20KHz)
Volume Control:  +4 dB to -59 dB (1dB steps)
Track Access Time:  lesss than 2 sec. mean
Error Correction:  900 um
Channel Balance:  ±0.2 dB
Remote Control:  30 function
Dimensions (W x D x H):  430 x 300 x 85 mm

Net Weight:  6.5 kg

Grundig HiFi Box 501

 A timeless design - the round shape - highlights the Grundig spherical speakers from all conventional forms very effectively. Grundig ball boxes can be leave free or hang in the room.
Two-way system with 1 woofer and 1 dome tweeters with 50 watts maximum music power .

Specifications Hifi Box 501
System:  2-way system with 1 woofer and 1 dome tweeter concentrically placed
Type:  Bookshelf placed on an small base or hanged up to the ceiling
Crossover:  2500 Hz
Imput Power:  35/50 Wmax
Frequency:  48 - 26000 Hz
Impedance:  4 Ω
Volume Box:  5,5 l (approx)
Finish: Aluminum silver with black grille
Dimensions (diameter):  250 mm

Weight:  3,3 kg