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





Allison model ONE

 Unlike many other loudspeaker systems of recent years which depart from a conventional box format, the Allison models One through Four are not clever solutions looking in vain for problems to be solved. Instaed they were developed as rational answers to real problems that are important and audible to anyone. Every aspect of their design is functional, and they are uniquely accurate sound reproducers in the only environment that really matters: a room for listening to music.
More than a year of full-time research on the room-loudspeaker interaction has shown that reflected impedance from the room boundaries increases a conventional loudspeaker's power output at very low frequencies, but decreases it significantly in the middle-bass range.

Another unique aspect of all these systems is the nondirectional dispersion of middle and high frequencies from drivers with relativel high output level. This is accomplished witha new type of diaphragm, convex in over-all profile, which is superior to small dome radiators in dispersion, yet equals the efficiency of ordinary cone speakers off comparable size.
 The ALLISON:ONE system is our flagship, combining maximum frequency range, power output capability, and flexibility in placement.  High Fidelity magazine said it is "the kind of highly accurate sound-reproducer that would attract the serious listener who is both musically oriented and technically astute enough to appreciate really fine sound."
An ALLISON:ONE system is to be used with its back close to a room wall (but not in a corner), and with the bottom resting on the floor or close to the ceiling. Full design performance will be maintained if the cabinet is placed within three inches of these two room boundaries (thus allowing for baseboards and recessed radiators) and if the center of the cabinet is more than two feet from a side wall. Because the system is nondirectional in the forward hemisphere there is no requirement that it be "aimed" at listeners. A stereo pair of these systems can be used on the same wall, on a pair of adjacent walls, or even on opposite long walls at the end away from the primary listening area.

In the Allison; Four system this placement is facilitated by location of the woofer in the top panel  of its bookshelf-size cabinet, rather than in the normal front-panel location. The distance to one room boundary (the wall behind the cabinet) is thus held to the absolute minimum, which maximizes the possible rations of distances. The smoothness of bass output in practical use of the  system is significantly better than it is for any conventional bookshelf design. Only the larger Allison systems are better on this respect than the Four.

Specifications
Speaker complement:
Two 10" (254 mm) woofers;
Two 3½" (89 mm) Convex Diaphragm mid-range units;
Two 1" (25 mm) Convex Diaphragm tweeters
Crossover frequencies:  350 and 3,750 Hz
Crossover network:
LC half-section at both crossover frequencies. Air-core chokes and non-polar computer-grade capacitors are used. Three-position control switch (accessible from front) supplied for selection of system acoustic power response, from nominally flat to concert-hall balance slope.
Impedance:  8 Ω nominal (7 Ω minimum at any setting of balance switch)
Efficiency:  better than 0,7% when placed at floor-wall intersection.
Minimum amplifier power:  30 watts per channel to produce 100 dB sound pressure level in most domestic room environments.
Acoustic power output capability:  0,5 acoustic watt minimum , over full frequency range, with 70 watt peak input.
System resonance frequency:  45 Hz, nominal
Effective system Q:  1.0. Low-frequency response -3 dB at 35,5 Hz, -6 dB at 29,5 Hz
Enclosure:  Stabilized Radiation Loading sealed acoustic suspension design.
Outside dimensions:  40" high by 19" wide by 10¾" front to back (1002 cm by 483 mm by 273 mm). Internal volume:  2,550 cubic inches (41,8 liters).
Material:  High density particle board veneered with walnut, oiled finish
Weight:  67 lbs (30,4 kg)
Full Waranty for Five Years

Micro Seiki DQX-500


DQX-500    FEATURES:
350 mm diameter platter with 600 kg×cm² moment of inertia and quartz lock servo PLL DC motor.
The platter used for the DQX-500 features an extremely high moment of inertia of 600 kg×cm², and this helps suppress fluctuations in the pulsive mechanical amplitude caused by the sound grooves on the record. As far as the static characteristics are concerned, the quartz lock servo system guarantees an outstanding control speed stability. However, it cannot be said to control perfectly the rendom transient load generated by the reproduction of the record sound. In particular, turntables rely for the most part on their platter’s moment of inertia to deal with disturbances in the high frequency range components for an overall improvement in the characteristics. Therefore, based on the basic servo control system, the static load fluctuations are absorbed by the quartz lock PLL system, and the dynamic load fluctuations are improved by the moment of inertia.

Stand-by lamp for easy rated speed checks .
The quartz lock servo PLL system provides a rotational speed with no deviation from the rated 33-1/3 rpm and 45 rpm speeds. There is no need for a strobe and so this has been abandoned in favor of a simple design.When the platter with its high moment of inertia reaches the rated speed the stand-by lamp goes off. This  action allows you to check whether or not the platter is revolving at the right speed.

Resonance-free monocoque frame.
The phonomotor and tonearm feature a sturdy integrated construction together with the metal frame composed of a three-legged configuration. This means that the turntable functions as a mechanical circulation system so that it is hardly affected at all by external vibration.
Micro's engineers got down to the bottom of the resonance modes caused by the conventional box-shaped construction and came up with a crystal-clear reproduced sound. This is design which is compact achieves an excellent weight balance and features absolutely no dead space. The motor shaft bearings are coupled to the frame with the reinforcement and there is plenty of mechanical strength to support the high inertia which accompanies the rotation of this heavyweight platter. All these features make for an extremely distinct sound image.

Outer power transformer power supply for an improvement in the signal-to-noise ratio.

In order to handle the very faint signals which are transmitted through the cartridge turntables have been beset with the problem of induction caused noise from the AC power source. If you use a moving coil cartridge, the flux generated by a power transformer, for instance can sometimes be the cause of hum. This is why the DQX-500 features a separate power transformer. It is designed to accommodate all the controls. You can therefore use the transformer as far away from the cartridge and tonearm as possible.

Specifications
Turntable Section
Drive System:  Direct Drive
Motor:  Quartz Locked PLL DC servo motor
Speeds:  33 and 45 rpm
Turntable Platter:  350 mm (13¾ inch) diameter, aluminum diecast platter
Platter Weight:  2,6 kg (5,72 lbs)
Moment of Inertia:  600 kg/cm²
Wow and Flutter:  less than 0,02%
S/N Ratio:  More than 63 dB (JIS) 75 dB (DIN-B)
Power:  117 V, 60 Hz (USA , Canada); 220 - 240 V, 50 Hz (other areas)
Power Consumption:  5 W
Tonearm Section
Type:  Dynamic balance
Effective Length>:  237 mm (9 inch)
Overhang:  15 mm (19/32 inch)
Maximum tracking error:  Less than 1,5⁰
Usable cartridge weight:  4 - 12 g (0,14 - 0,42 oz)
Range of tracking force adjustment:  0 - 3 g
General
Dimensions (W x H x D):  410 x 139 x 350 mm (16  x 5½ x 13¾ inch)
Weight:  7,0 kg (15,4 lbs)

Micro-Seiki MA-707 tonearm description

SAE 2100L



SAE 2200



SAE 3200



SAE 2800



Allison Model TWO (1976)

 The ALLISON:TWO loudspeakers system has performance identical with that of the ALLISON:ONE system down to 50 Hz. below that frequency its power output is 2 dB less. The cabinet is 30% smaller but has the same shape and similar proportions. The crossover network, mid-range and tweeter units are identical. Thus the same dispersion of high-frequency energy, power-handling capability, and placement flexibility of the larger system are provided at a substantially lower price. two 8-inch woofers are used in the TWO rather than the 10-inch woofers in the ONE. yet the systems are so audibly alike that a small difference can be detected only with music containing the lowest fundamental frequencies, and even then only infequently.
As with all ALLISON loudspeaker systems, the grille panels are formed of sturdy perforated ABS plastic - a cover material which doeas not absorb extremely high-frequency energy, even far off the tweeter axis. It is far more acoustically transparent than cloth or open-cell foam.

 The mechanism by which this effect occurs can be understood as follows. Consider a typical box loudspearer system positioned in a room so that its woofer cone is about two feet from each of the three nearest  room surfaces-say, the floor and two intersecting walls. When the speaker is radiating a very low frequency the cone moves relatively slowly and over a relatively long distance. If the readiated frequency is 40 Hz, for example, it takes 1/40 second (25 milliseconds) for the cone to execute one complete forward-and-backward cycle. Each half of the cycle takes 12,5 milliseconds.
As the cone begins a forward movement it generates the start of a compression wave. This impulse travels at the speed of sound (1,130 feet per second) to each of the three room boundaries  and is reflected back toward the woofer cone, arriving there some 3,5 milliseconds after it left, while the woofer is still generating the compression half of the sound cycle. The reflected waves increase the instantaneous pressure seen by the woofer and enable it to radiate more power than it could in free space - a maximum of 9 dB more power at extremely low frequencies, for which the reflected pressure is virtually in perfect phase coincidence with the woofer's motion.
 But as the woofer tries to radiate higher frequencies, it must reverse its motion more quickly. At 140 Hz, for example, the cone reverses direction every 3,5 milliseconds. it begins its inward half-cycle of motion (attempting to create a rarefaction) just as the three compression - wave reflections begin to arrive back from the room boundaries two feet away. In this case the reflected pressure is completely out of phase with the cone motion, decreasing its radiation efficiency some 11 dB below the anechoic output. That is the worst case: a 20-dB variation in power output (from +9 dB to -11 dB), when the woofer is equidistant from the three nearest room surfaces, from a loudspeaker system which measures flat in an anechoic chamber.
Usuallly the boundaries are not equally distant from the woofer and the effect is not as intense. Typically, the variation in power delivered by the speaker to a listening room is 6 to 12 dB within the woofer range. These effects simply do not exist in anechoic chambers, where  loudspeakers are commonly tested, beacuse there are no reflections from the chamber walls. And measurements made in "live" rooms are complicated by the standing-wave resonances. Consequently a room's influence on the actual power output pf a loudspeaker system as a factor separate from other room effects, has not been well understood until recently.
An uncontrolled variation in system response of this magnitude would be considered intolerable if it originated in, say, a phono pickup cartridge or an amplifier. But it is just as audible when it originates in a loudspeaker. If it could be eliminated, or of its severity could at least be reduced appreciably, an improvement should be expected in the accuracy of the reproduced sound field.
 How can this be accomplished?
The most elegant solution is exemplified in the Allison: Three corner loudspeaker system. The cabinet is designed so as to place the woofer as close as possible to three room surfaces (the floor and two intersecting walls), with the result that the reflections arrive back at the woofer in a very short time (about 1 millisecond). The woofer's operating range is restricted by a crossover network to an upper limit of 350 Hz; at that frequency, the woofer spends 1,5 milliseconds on each half-cycle in one direction. Therefore the reflected pressure is essentially in phase with the woofer's motion, and increases its power output, over its entire operating frequency range. Flat power output from the system is thereby made possible. Put another way, the woofer's radiation loding has been stabilized.
An Allison: Three should be in a room corner. if it were to be moved away from the corner along one wall, the missing side wall could be replaced by another Three system placed side-to-side against the first one. the radiated sound pressure from each system would its own reflected pressure from a corner side wall, and the performance of the pair along one wall would be the same as that of a single system in the corner.
The Allison: One loudspeaker system is exactly that: a pair of model Three systems in one cabinet, operating as one system, which can be located anywhere along a room wall except in a corner.
An Allison: Two system is equivalent in concept to a model One. its size and price are smaller, and its power output below 50 Hz is 2 dB less than that of a model One. Otherwise the systems are identical, In practice this compromise is seldom sudible; the Two is very much a full-range loudspeaker system.
A hole in the woofer power output curve caused by out-of-phase reflections is avoided in Allison models One, Two, and Three by placing the frequency at which it occurs above the woofer crossover point. But in order to do this the crossover frequency must be quite low - not above 400 Hz 0r s0 - even with a woofer as close as possible to the room-surfsce intersection. This requires a three-way loudspeaker system design with separate mid-range and tweeter units, because it is not practical to operate ahigh-quality tweeter down to a 400 Hz crossover point. Consequently, in a less expensive two-way system with the woofer operating up to 1 or 2 kHz, the reflections from nearby room surfaces will be out of phase with the woofer motion at some frequencies within its range.  There is no way to avoid this.

 The voice-coil diameter of Allison tweeter's convex is only 1/2 inch; the side of the cone curvesinwardly, and the outside edge is fastened securely, at a diameter of 1-1/16 inch, to a mouting plate. Because ther is no compliant suspension at the outer edge the entire cone surfsce is forced to flex  as the voice coil moves axially. As it does so, each point on the surface of the cone moves with a velocity that has an in-phase component of motion perpendicular to the voice-coil direction as well as a component parallel with it.
The tweeter thus simulates the motion of a pulsating hemisphere to a remarkable degree. there are other tweeters which generate cylindrical wave fronts; they have excellent dispersion in one plane (the horizontal) But no other design even approaches the Allison tweeter's dispersion at all angles, vertical and horizontal, in the forward hemispere.
This uniformity of output in all directions is not merely a technical tour-de-force of no audible signifcance. It provides a convincing illusion of space around a reproduced sound source, without distortion is not merely a technical tour-de-force of no audible significance. It provides a convincing illusion of space around a reproduced sound source, without distortion of its natural size, and it generates a stereo image that is maintained even for listeners located outside the area definied laterally by the speakers. The tweeter is used in all Allisin louspeakers systems and is unique to them alone.


Specifications
Speaker complement:
Two 8" (203 mm) woofers;
Two 3½" (89 mm) Convex Diaphragm mid-range units;
Two 1" (25 mm) Convex Diaphragm tweeters
Crossover frequencies:  350 and 3,750 Hz
Crossover network:
LC half-section at both crossover frequencies. Air-core chokes and non-polar computer-grade capacitors are used. Three-position control switch (accessible from front) supplied for selection of system acoustic power response, from nominally flat to concert-hall balance slope.
Impedance:  8 Ω nominal (7 Ω minimum at any setting of balance switch)
Efficiency:  better than 0,7% when placed at floor-wall intersection.
Minimum amplifier power:  30 watts per channel to produce 100 dB sound pressure level in most domestic room environments.
Acoustic power output capability:  0,5 acoustic watt minimum , over full frequency range, with 70 watt peak input.
System resonance frequency:  52 Hz, nominal
Effective system Q:  1.0. Low-frequency response -3 dB at 41 Hz, -6 dB at 34,5 Hz
Enclosure:  Stabilized Radiation Loading sealed acoustic suspension design.
Outside dimensions:  36" high by 16" wide by 9" front to back (914 mm by 406 mm by 238 mm). Internal volume:  1,775 cubic inches (29,1 liters).
Material:  High density particle board veneered with walnut, oiled finish
Weight:  57 lbs (25,8 kg)
Full Waranty for Five Years

Yamaha CX-1 / CX-2 (1993/1994)

 CX-1 CX-2 Pre-amplifier
ToP-ART™  Total Purity Audio Reproduction Technology
The fundamental reason behind the high performance of Yamaha audio components is a comprehensive design philosophy that we call ToP-ART. It dictates that every factor that could affect performance is analyzed and optimized. From circuit design to individual internal parts to feet and knobs, nothing is left to chance. With the result that each component attains its full potential, so you enjoy the music the way the artist meant it to be heard.

The Direct Path to Optimum Signal Purity
The photo below of the CX-1's interior shows a conspicuous application of the ToP-ART concept. The path the audio signal traveles is straight and direct, so from beginning to end, it encounters the last possible amount of interference.  The entire interior layout is symmetrical and logical, resulting in extremely high 85 dB channel separation and ultra-low distortion of 0,002%. And for the ultimate in signal purity, you can engage the Pure Direct Switch, causing the signal to bypass teh tone control circuitry.


 High Quality Parts and Materials
In the upper reaches of audio component performance, small details and even materials take on increasing importance. Because gold is an excellent conductor and not susceptible to corrosion, these components have gold plated input terminals and headphone jacks. The CX-1 goes a step further, with 2-pin gold-plated solid brass CD and Pre Out terminals for large-size cables. It also uses extremely thick gold-plated wiring for signal routing. The front and side panels as well as knobs, are made of extruded aluminum rather than cheaper materials likely to resonate. Even the nuts and bolts are special types, used only in our separate components. Our commitment to quality was total, and the results are worth hearing.

 Versatile Control Centers
The Cx-1 allows you to select seven different inputs; Cd, tuner, phono, aux, tape 1, 2, 3. It also has a Rec Out Selector for direct selection of the source to be recorded and three-way tape copying. This means you can listen to one source while recording another.
The CX-2 has inputs for two tape decks and for two VCRs, as well.It also provides a Rec Out Selector.
Both components come with a special Power Link cable for connecting them to the MX-1 or MX-2, so the power amp will turn on and off with the preamp.

 Other Notable Features
Low-noise precision 4-gang Master volume control
High accuracy Twin-element phono EQ amplifiers
Switchable phono subsonic filter eliminates the rumble which some turntables may produce.
Center defeat Bass and Treble controls
Remote Controllable, Motor-driven Volume Control and Input Selector eliminate the noise and distortion inherent in electronic switching systems.
20 dB Volume Control Amplifier Using Pure Capacitive Negative Feedback Circuitry (CX-1)
Continuously Variable Loudness Control maintains natural tonality at all listening levels (CX-2)
Extra-Large, Anti-Vibration (XL-AV) Feet specially designed to ensure that external vibrations cannot affect amplifier performance.
30-key Remote Control (CX-1)
63-Key learning-Capable remote Control (CX-2)
Yamaha System Remote Control Capability; allows you to control the major function of other Yamaha system components from the amplifier's remote unit.
 CX-1 Specifications
Input Sensitivity/Impedance
Phono MC : 100 μV/1 k, 220 ohms
Phono MM : 2,5 mV/ 47 kohms
CD, Aux, Tuner, Tape : 150 mV/47 kohms
Phono Maximum Inout Level MM/MC:  7/180 mV (1kHz, 0,05% THD)
Output Level/Impedance
Rec Out : 150 mV/2,5 kohms
pre Out : 1,5 V/47 ohms
Maximum Output Voltage:  10 V (20 - 20,000 Hz, 1% THD)
Headphone Rated Output:  4,5 V/68 ohms (RL=100 ohms)
Frequency Response:  20 - 20,000 Hz,  ±0,2 dB
RIAA Equalization Deviation (Phono MC/MM):  ±0,2 dB/±0,2 dB
Total Harmonic Distortion (20 to 20,000 Hz)
Phono MC to RecOut (3V) : 0,003%
Phono MM to RecOut (3V) : 0,002%
CD, etc to Pre Out (3V) : 0,002%
Signal-to-Noise ratio (IHF-A-Network)
Phono MC (500 μV Input Shortrd) : 90 dB
Phono MM (5 mV Input Shorted) : 95 dB
CD (Shorted) : 110 dB
Residual Noise (IHF-A-Network):  1,0 μV
Channel Separation (vol. -30 dB)
Phono (Input Shorted, 1 kHz/10 khz) : 80/70 dB
CD etc (Input 5,1 kohms terminaled, 1 kHz/10kHz): 85/65 dB
Filter Characteristics (Subsonic):  15 kHz (-18 dB/oct)
Audio Muting:  -20 dB
Gain Tracking Error (0 to -60 dB):  2 dB
Dimensions (w x H x D):  438 x 86 x 405 mm (17-1.4 x 3-3/8 x 15-15/16 inch)
Weight:  8,8 kg (19 lbs, 6 oz)

CX-2 Specifications
Input Sensitivity/Impedance
Phono MC : 100 μV/100 ohms
Phono MM : 2,5 mV/ 47 kohms
CD, Aux, Tuner, Tape : 150 mV/47 kohms
Phono Maximum Inout Level MM/MC:  6/180 mV (1kHz, 0,05% THD)
Output Level/Impedance
Rec Out : 150 mV/2,5 kohms
pre Out : 1,5 V/47 ohms
Maximum Output Voltage:  10 V (20 - 20,000 Hz, 1% THD)
Headphone Rated Output:  4,0 V/68 ohms (RL=100 ohms)
Frequency Response:  20 - 20,000 Hz,  ±0,2 dB
RIAA Equalization Deviation (Phono MC/MM):  ±0,3 dB/±0,2 dB
Total Harmonic Distortion (20 to 20,000 Hz)
Phono MC to RecOut (3V) : 0,004%
Phono MM to RecOut (3V) : 0,002%
CD, etc to Pre Out (1,5V) : 0,002%
Signal-to-Noise ratio (IHF-A-Network)
Phono MC (500 μV Input Shortrd) : 82 dB
Phono MM (5 mV Input Shorted) : 94 dB
CD (Shorted) : 110 dB
Residual Noise (IHF-A-Network):  1,0 μV
Channel Separation (vol. -30 dB)
Phono (Input Shorted, 1 kHz/10 khz) : 75/65 dB
CD etc (Input 5,1 kohms terminaled, 1 kHz/10kHz): 75/60 dB
Filter Characteristics (Subsonic):  15 kHz (-18 dB/oct)
Audio Muting:  -20 dB
Gain Tracking Error (0 to -60 dB):  2 dB
Video Input Sensitivity/Impedance:  1 Vp-p/75 ohms
Video Output Level/Impedance:  1 Vp-p/75 ohms
Dimensions (w x H x D):  438 x 86 x 319 mm (17-1.4 x 3-3/8 x 12 inch)
Weight:  5,4 kg (11 lbs, 14 oz)

Yamaha MX-1 / MX-2 (1993/1994)

 MX-1 Mx-2 Power Amplifier
Top-ART Ensures Top Quality
Like the preamplifiers the MX-1 and MX-2 benefit from Yamaha's ToP-ART design policy. Every single part was carefully considered during their development, so you can be sure you're purchasing a component with the finest quality throughout. A number of these parts are particulary noteworthy. They use twin massive power transformers and twin heavy-duty extruded aluminum heat sinks. Their block capacitors are extremely large (MX-1 : 36,000 μFx2 and 33,000 μFx2), and all PC board wiring is extra-thick and gold-plated. To support these heavy components and prevent vibration, they have a special ART base inside the chassis. It has a double panel structure, each 1,6 mm thick, and the MX-1 adds extra damping material between the two panels. If these two amps sound weighty, they are; try picking one up. But remember, those heavy parts are where the power comes from.
 Huge Power Output and Low-Impedance Drive Capability
The MX-1 delivers 200 watts per channel of RMS power at 8 ohms, and 250 W at 2 ohms. MX-2 output is 150 W at 8 ohms and 250 W at 2 ohms. Note that both of these amplifiers are rated for continuous output power all the way down to 2 ohms - impossibile for most amplifiers because lower impedances cause much higher amounts of distortion. This means that these amps can be used with low impedance speakers and will function flawlessly even under fluctuating loads caused by variations in the music signal.
Dynamic power levels, or the ability to deliver momentary power levels beyond the RMS power rating, are also exceptionally high. 280/610 W (8/2 ohms) for the MX-1 and 190/400 W (8/2 ohms) for the MX-2. This ability is especially important when playing CDs, which have a very wide dynamic range.

 Hyperbolic Conversion Amplification (HCA)
High performance amplifiers generally use Class A amplification, but the Yamaha-developed HCA circuit goes a step beyond conventional Class A. In a Class A amplifier, when output exceeds a limit determined by the idling current, operation degrades to Class AB, resulting in increased crossover and switching distortion. HCA eliminates this problem by obtaining its output form hyperbolic conversion. So there's less distortion, a wider range of linear operation, and less heat generation.

 Advanced Power Supply (APS)
An amplifer's power supply circuitry is one of the critical determinants of its overall performance. If it does not provide a constant voltage the power transistors will not be able to perform properly. At low power levels, ordinary power supplies are adequate, but at middle and high levels, especially at low impedances, voltage irregularities called ripple are likely to occur. Yamaha's APS circuitry prevents ripple, maintaining  precisely constant voltage at all power levels.

 New Linear Damping Circuit
The damping factor of an ampilfier is its ability to stop the speaker cone from vibrating when it shouldn't, that is when the signal stops. level variations due to high amp impedance tend to reduce the damping factor, and frequency variations cause it to fluctuate. This new circuit cancels the effect of these variations, maintaining an extremely high, stable damping factor (350 at 8 ohms, 20 -20,000 Hz). The result is superior articulation of all sounds and significantly improved frequebcy response.

Other Notable Features
L/R level Controls (on rear panel)
Gold-plated Input Jacks (MX-1 Jack are Solid Brass)
Extra-Large, Anti-Vibration Feet
2-Way Binding Speaker Terminals (Banana Plug Compatible)

 MX-1  Specification
Minimum RMS Output Power per Channel:
200 W (8 Ω) from 20 to 20,000 Hz at no more than 0,008% THD
260 W (4 Ω) from 20 to 20,000 Hz at no more than 0,03% THD
320 W (2 Ω) from 20 to 20,000 Hz at no more than 0,09% THD
Dynamic Power per Channel (by IHF Dynamic headroom Measuring Method):
280 W at 8 ohms
460 W at 6 ohms
630 W at 2 ohms
Dynamic Headroom :
1,46 dB at 8 ohms
2,48 dB at 6 ohms
2,94 dB at 2 ohms
Power Bandwidth (8Ω, 0,03%  THD, half Rated Power):  10 to 60,000 Hz
Damping Factor
(SPA, 8Ω, 20 - 20,000 Hz) : 350
(8Ω, 1 kHz) : 250
Input Sensitivity/Impedance (Main IN):  1,46 V/20 kΩ
Frequency Response (Main In):  20 to 20,000 Hz, ±0,5 dB
Signal-to-Noise Ratio (IHF-A-Network):  125 dB (Main In, Shorted)
Residual Noise (IHF-A-Network):  20 μV
Channel Separation (Vol -30 dB, Main In, Input 5,1 kΩ terminaled)
1 kHz/10 kHz : 80 dB/ 60 dB
Dimensions (W x H x D):  438 x 116 x 486 mm (17-1/4 x 4-9/16 x 19-1/8 inch)
Weight: 24,kg (52 lbs, 14 oz)

MX-2  Specification
Minimum RMS Output Power per Channel:
150 W (8 Ω) from 20 to 20,000 Hz at no more than 0,008% THD
190 W (4 Ω) from 20 to 20,000 Hz at no more than 0,03% THD
230 W (2 Ω) from 20 to 20,000 Hz at no more than 0,09% THD
Dynamic Power per Channel (by IHF Dynamic headroom Measuring Method):
190 W at 8 ohms
310 W at 6 ohms
410 W at 2 ohms
Dynamic Headroom :
1,03 dB at 8 ohms
2,12 dB at 6 ohms
2,51 dB at 2 ohms
Power Bandwidth (8Ω, 0,03%  THD, half Rated Power):  10 to 60,000 Hz
Damping Factor
(SPA, 8Ω, 20 - 20,000 Hz) : 350
(8Ω, 1 kHz) : 250
Input Sensitivity/Impedance (Main IN):  1,26 V/20 kΩ
Frequency Response (Main In):  20 to 20,000 Hz, ±0,5 dB
Signal-to-Noise Ratio (IHF-A-Network):  123 dB (Main In, Shorted)
Residual Noise (IHF-A-Network):  20 μV
Channel Separation (Vol -30 dB, Main In, Input 5,1 kΩ terminaled)
1 kHz/10 kHz : 80 dB/ 60 dB
Dimensions (W x H x D):  438 x 116 x 486 mm (17-1/4 x 4-9/16 x 19-1/8 inch)
Weight: 19,5kg (43 lbs)

Tannoy Canterbury 12

 The Canterbury 12 is a truly special loudspeaker made only to order with certification and personalised nemeplate. Both the Canterbury 12 and the larger Canterbury 15 use the classic Alcomax 3 high-energy magnet versions of the famous Tannoy Dual Concentric driver in either 12-inch or 15-inch chassis.
Alcomax 3 is an unusually high energy permanent magnet. The special iron/nickel alloy is doped with cobalt, aluminium and other rare metals to produce a magnetic material with very special properties. Alcomax 3 has a high remanent magnetism and energy product. In other worlds, it magnetises to a  high level and retains that unusual degree of magnetisation. Alcomax 3 is also an electrical conductor. These properties give the Dual Concentric drive unit using an Alcomax 3 magnet an exceptionally clean transient response and increased sensitivity.
 The Canterbury 12 employs a high performance 12-inch Dual Concentric driver in a braced birch-ply cabinet. Burr walnut veneers and solid walnut mouldings are used to enhance both structure and beauty on the cabinet.
Van den Hul bi-wiring is used through out. High frequency energy can be tailored through high current gold-plated switch blocks with controls for both treble energy and roll-off. Low frequency adjustment is through the Tannoy Variable Distributed Port System (VDPS)

Specifications
Power Rating:  110 watt RMS (450 watt peak)
Recommended Amplifier Power:  50 - 200 watt/channel
Sensitivity ( 2,83 V at 1 m):  94 dB
Maximum SPL:  114 dB at 1m for 110 watt RMS (121 dB at 1m for 450 watt peak)
Nominal Impedance:  8 ohm
Minimum Impedance:  5,5 ohm
Frequency Response:  33 Hz - 22 kHz , ±3 dB
Crossover Frequencies:  1,6 kHz
Crossover Control:
 ±3 dB over 2,5 kHz to 22 kHz shelving;
+3 dB to -6 dB per octave over 3,7 kHz to 22 kHz slope
Crossover Type:  Bi-wired, hard-wired, passive, low-loss, time and impedance compensated Type 1090
Driver Type:  12-inch Dual Concentric High Compliance Type 3179
Enclosure Type:  Variable Distributed Port
Enclosure Volume:  140 litre
Dimensions (H x W x D):  900 x 580 x 480 mm; (990 x 680 x 540 mm packed)
Weight:  47 kg complete (52 kg packed)
Enclosure Material:  Solid walnut with birch ply

Tannoy Canterbury 15

 The Canterbury 15, like its smaller brother, employs an Alcomax 3 version of the classic Tannoy Dual Concentric driver. For this drive unit a substantial high pressure die-cast 15-inch chassis is used.
This high-performance drive unit is installed in a cabinet where "attention to detail" is the byword. Birch ply, from Finland, is used for both the carcass construction and its substantial bracing. The cabinet is then finished in selected burr walnut wood veneers and completed with rich mouldings in solid walnut.
Gold-plated terminals are employed and give the option of bi-wiring. Van den Hul cable is used throughout the loudspeaker. 
 Along with the hard-wired crossover network and acoustic source aligning system this top-quality cable ensures minimal signal loss. Both treble level and roll-off can be adjusted by means of high-current switch blocks. Low frequency output can be tuned to suit any room and personal taste using Tannoy's unique Variable Distributed Port System.
The Canterbury 12 and Canterbury 15 loudspeakers are made to special order only. They are supplied with a certificate of ownership and a polished brass nameplate engraved with the name of your choice. Both are destined to become true heilrooms.

Specifications
Power Rating:  125 watt RMS (550 watt peak)
Recommended Amplifier Power:  50 - 250 watt/channel
Sensitivity ( 2,83 V at 1 m):  96 dB
Maximum SPL:  117 dB at 1m for 125 watt RMS (124 dB at 1m for 550 watt peak)
Nominal Impedance:  8 ohm
Minimum Impedance:  5,5 ohm
Frequency Response:  28 Hz - 22 kHz , ±3 dB
Crossover Frequencies:  1,1 kHz
Crossover Control:
 ±3 dB over 2,3 kHz to 22 kHz shelving;
+3 dB to -6 dB per octave over 3,4 kHz to 22 kHz slope
Crossover Type:  Bi-wired, hard-wired, passive, low-loss, time and impedance compensated Type 1091
Driver Type:  15-inch Dual Concentric High Compliance Type 3889
Enclosure Type:  Variable Distributed Port
Enclosure Volume:  235 litre
Dimensions (H x W x D):  1100 x 680 x 480 mm; (1180 x 680 x 600 mm packed)
Weight:  63 kg complete (70 kg packed)
Enclosure Material:  Solid walnut with birch ply

Marantz 2275

 FEATURES
75 Watts Minium RMS per channel, at 8 Ohms, from 20 t0 20,000 HZ, with no more than 0,25% THD
Phase-Lock-Loop FM Multiplex Demodulator
Variable Frequency Tone Control Turnover Points and Mid-Range Tone Control - separate for each channel with eleven detented positions for easily repeatable settings
Direct-Coupled (Full Complementary) Output Amplifiers
Dolby FM (75μS/25μS) De-Emphasis Switch.
Complete facilities for two Tape Recorders with the ability to "dub" from either one to the other
Front panel Tape Dubbing Jacks
Multipath/Signal Strength Meter.
 For over three years the Marantz 2270 was the standard by which all others compared their receivers. Now, its successor, the 2275 carries that comparison one step futher.  The 2275 boasts of a Phase-Lock-Loop FM Multiplex Demodulator to assure maximum separation with  a minimum of distortion. The Multipath Indicator tells you the best position of your FM antenna. The Variable Turnover Tone Controls provide a flexibility for contouring the sound that is far superior to anything previously available. Plus, there's a unique Dolby De-emphasis Switch for use with an external adaptor - to accommodate Dolby FM broadcasts. There are complete facilities for two tape recorders with the ability to "dub" from either one to the other. And the pre-out main-in jacks permit convenient use of any external device such as an equalizer or electronic cross-over. The direct-coupled full complementary amplifier output circuitry assures crystal clear highs and solid lows. The entire package is backed up with a full three year parts, labor and performance guarantee.

 A full Complement of Inputs and Outputs
In addition to the standard phono and auxiliary inputs, two sets of tape inputs and outputs are provided to facilitate copying from one tape deck to another. Front panel dubbing jacks allow you to add a third tape deck without disrupting any rear panel connections.
The preamp-out/main-in jacks on the rear panel enable you to use the preamplifier and amplifier sections independently. You get simplified connection of external components such as noise reduction systems, equalizers and electronic crossovers - and the ability to use the receiver's preamp section to drive a separate power amplifier. Here's another benefit: Connecting the preamp section directly to a tape deck enables you to make specially equalized recordings by using the preamp's flexible tone controls.

SPECIFICATIONS   2275

Rated Power Output:  75 Watts (Minimum Continuous Watts per Channel, Both Channels Driven)
Power Band:  20 Hz to 20 kHz
Total Harmonic Distortion:  0,2%
Load Impedance:  8 ohms
I M Distortion (IHF Method, 60 Hz and 7 kHz mixed 4:1 at Rated Power Output):  0,2%
Damping Factor (at 1 kHz):  60
Main Inputs Sensitivity/Impedance:  1,0 V/75 kΩ
Frequency Response (at 1W Output, 20 Hz to 20 kHz):  ±20 dB
Pre-Amplifier Section
Phono
Dynamic Range (Ratio of Input Overload to Equivalent Input Noise):  96 dB
Equivalent Input Noise (RMS, 20 Hz to 20 kHz):  1,5 μV
Input Sensitivity and Impedance:  1,8 mV/47 kΩ
Frequency Response (re. RIAA, 20 Hz to 20 kHz):  ±0.75 dB
High Level Inputs (Aux and Tape)
Input Sensitivity and Impedance:  180 mV/85 kΩ
Output Impedance
Tape record:  200
Pre-Out:  900
Tone Controls
Bass:  ±12 dB (50 Hz)
Mid:  ±6 dB (700 Hz)
Treble:  ±12 dB (15 kHz)
AM/FM SPECIFICATIONS
Quieting Slope (Mono) 30 dB Quieting:  1,9 μV (10,8 dBf)
5 μV (19,2 dBf) : 55 dB
10 μV (25,2 dBf) : 60 dB
50 μV (39,2 dBf) : 70 dB
1000 μV (65,2 dBf) : 72 dB
Distortion at 1000 μV (65 ,2 dBf, Mono)
100 Hz : 0,3%
1000 Hz : 0,25%
6000 Hz : 0,35%
Distortion at 1000 μV 965,2 dBF, Stereo)
100 Hz : 0,4%
1000 Hz : 0,35%
6000 Hz : 0,55%
Distortion at 50 dB Quieting (Mono and Stereo)
1000 hz : 0,6%
Hum and Ni=oise at 1000 μV (65,2 dBf)
Mono : 70 dB
Stereo : 60 dB
Frequency Response 30 Hz to 15 kHz
Mono : ±1,0 dB
Stereo : ±1,5 dB
Capture Ratio
at 100 μV (45,2 dBf) : 1,8 dB
at 1000 μV (65,2 dBf) :  1,5 dB
Alternate Channel  Selectivity:  80 dB
Spurious Response Rejection:  100 dB
Image Response Rejection:  100 dB
IF Rejection (Balanced):  100 dB
AM Suppression at 100 μV (45,2 dBf):  62 dB
Stereo Separation
100 Hz : 35 dB
1000 hz : 42 dB
10 kHz : 30 dB
Pilot (19 kHz) Rejection:  65 dB
AM usable Sensitivity:  20 μV
Dimensions (W x H x D):  17-5/16 x 5-3/8 x 14-3/8 inch
Weight:  37,9 Pounds