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

Infinity 2000AXT (1973 - 1978)

With its all new drivers and enclosure, coupled with 5dB added efficiency over the 2000 A, we at Infinity feel that the 2000 AXT is the standard against which all others near the price range will be compared.
While it can be driven, with most of today's receivers (20 -25 watts RMS/channel minimum), it also easily accomodates the super power amplifiers which are becoming more popular in today's market.

The tweeter section.
The wave transmission line tweeter is probabyly Infinity's most stunning achievement. It's not a cone or piston drive, not an electrostatic, not a ribbon and not an ionic device. In fact, it really doesn't appear in any textbooks on acoustics.
This Walsh tweeter, acting as a vertical, pulsating cylinder, is a purely coherent source of sound radiation - directly analagous to the light emitted by a laser beam. It, therefore, is transient perfect - a feat which no other speaker has achieved.
The drive mechanism of the tweeter in this case is a voice coil in a very intense magnetic field. This drive mechanism was selected for its simplicity and inherent reliability, although any other drive system could be used inasmuch as the cone is only plucked at the base.
Sound velocities much higher than the speed of sound in air are propagated up the metallic cone. Sound is emitted on various parts of the cone corresponding to the temporal and spatial scheme of Figure 1. Thus,each bit of audio information fed into the device is emitted intact at the same instant of tome. This is true around the entire device, so that 360° coherent rediation is a reality.
This new WTLT tweeter was developed and manufactured by Infinity under license from Ohm Acoustics, and is a newly engineered extension of the Walsh patent No. 3424873.

The midrange section.
the midrange speaker is a very high efficiency 4,5" cone utilizing a large Alnico V magnet, the cone of which is treated for five times the stiffness to massratio of conventional speakers. The resulting clarity and transparency is startling.
The bass section.
The bass driver is a 12" woofer with a full one inch movement capabillity. Its cone is treated twice - once to increase the stiffness to mass ratio by a factor of five, while the second treatment ensures proper cone damping to complement the added stiffness. The woofer is loaded into the "Infiniy transmission line" enclosure for superb bass transients. it accurately reproduces the very lowest fundamental bass frequencies.

1 x Walsh WTL Tweeter
1 x EMiT Tweeter
1 x 4" Midrange
1x 10" Q-Woofer
Frequency response: 30 Hz to 21 KHz ± 3,5 dB
Crossover frequencies: 500 Hz, 5000 Hz
Nominal impedance: 8 ohms
Maximum amp power: 200 watts channel program
Minimum amp power: 20 watts RMS channel
Dimensions: 27¾ x 20 x 14 Inch (63,5 x 36,8 x 30,5 cm)
Price: 299,00 $

Micro Seiki MR 622

Turntable part

Drive system: Belt drive scheme

Motor: DC servo motor

Rotational frequency: 33 1 / 3 or 45 rpm

Rotational frequency fine-adjustment span: It is ±6% to a convention velocity.

Turntable: he product made from 31 cm aluminum die-casting, 1.5 kg

Rotation unevenness: 0.05% or less

S/N ratio: 55 dB or more

Tonearm part

Form: Static balance type (MA-202)

Effective length: 237 mm

Overhang: 15 mm

Offset angle: 21 degree 50

The maximum tracking error: 1.5 degrees

Conformity cartridge self-weight: 4 g-16 g (At the time of an option sub-wait using: 10 g - 22 g)

Stylus-force variable span: 0 - 3 g

Cartridge part

Form: man-month type (M-7000/5)

Frequency characteristic span: 5 Hz - 40 kHz; 5 Hz - 50 kHz (V-7000/F)

Output balance: ±0.5 dB (1 kHz)

Channel separation: 30 dB(1 kHz)

Output voltage: 3.5 mV (1 kHz, 3.54 cm/s)

Load resistance: 47 kohms - 50 kohm

The optimal stylus force: 1.5 g

Needle point: 0.5 mil diamond needle

Compliance: 30 x 10 to 6 cm/dyne

Self-weight: 5 g

Switching needle: V-7000/5; V-7000/e; V-7000/F)


Power source: AC 100 V, 50/60 Hz

Power consumption: 13 W

Dimensions: (Width x height x depth) 500 x 170 x 383 mm

The Fisher TA-600 (1960)

The Fisher Model 600 is a complete stereophonic FM-AM tuner, stereo audio control and dual-channel power amplifier - all in one integrated chassis. Only the speaker need be added to permit the 600 to function as a high-fidelity sound system for the reception of standard FM or AM programs or for FM-AM stereo broadcasts.
In addition to playing Fm and AM radio programs, the Model 600 can be used as the stereo control center and stereo amplifier for the reproduction of phonograph records and tapes. Any type of record changer or player, tape deck or tape recorder may be operated with the Model 600 receiver, either monophonically or stereophonically . Provision is also made for plugging a multiplex adaptor into the Model 600 for receiving FM multiplex stereo broadcasts.

The world's only Stereo Receiver for the discriminating Audio enthusiast
 For  those who want the convenience of an  all-in-one instrument ... versatility at the heart of their hi-fi installation ... as well as the quality of performance and dependability that have typified all FISHER high fidelity products for over twenty-one years - THE FISHER TA-600 is the only possible choice.
Rated Power:  20 watts per channel
Frequency Response:  25 to 20.000 cps ±1 dB
Dimensions  (W x D x H):  17 x 14-1/2 x 4-13/16 inch
Weight:  33,5 lbs netto (40 lbs ship)

1.Forty watts of power from dual twenty-watt amplifiers (seventy watts peakpower)
2.Cascode RF stage on FM for extreme sensitivity
3.Bridge-type, low-noise triode mixer on FM
4.Input and output jakcs for MULTIPLEX reception
5.Two MicroRay tuning indicators to help you tune in the weakest signal as casily as the strongest
6.Connections for four, eight and sixteen ohm speakers (rear)
7.Rotalable, ferrite loop antenna for maximum signal power and minimum interference (rear)
8.Two-position bandwidth on AM (a must for stereo)
9.Ten kilocycle whistle filter to eliminate interference from adjacent stations
10.DC filament supply to reduce hum to complete inaudibility
11.Dual bass and treble tone controls
12.Five-position input selector
13.Five-position stereo-monomonophonic switch
14.Dual balance control
15.Master volume control
16.Tape monitor switch
17.High and low frequency filters
18.Loudness contour switch
19.Five input level adjustments (rear)
20.Phase-reversing switch to compensate for any improperly phased tape recordings or speakers (rear)
21.Tape recorder output jacks (rear)
22.Special input jack arrangement to permit using an external FM tuner with the TA-600 for the reception of FM-FM stereo broadcasts (rear)
23.Auxiliary AC outlets for plugging in associated equipment (rear)

Monrio STO-O1 Multifunction Music Server

The STO Music Server offers a silent playback system when playing from the built-in HD or CD Drive. It is a high performance audio playback system designed as a true audiophile unit.
We've incorporated all the functionality you need into the STO Music Server and eliminated the need for a PC. Now you can store your music, manage your collection and even burn CDs. All that in high performance audio fidelity.
Extend your musical repertoire and enjoy thousands of free internet radio stations, delivered directly to your stereo system. On the STO Display, get detailed information about the artist, album and track that is currently playing.
Unlike listening to your music on a computer, iPod or MP3 music players, the STO Music Server combines a high-resolution DAC, Tube Output stage, CD quality digital sound, ultra-quiet hard drives and passive cooling to eliminate fan noise to deliver the best possible hi-fi audio quality.


- 1x front SD Card interface

- 1x rear USB 2.0 Host interface.

- 1x RJ45 10/100M Base-T Ethernet interface.

- 1x HDMI 1.3 HD video/audio integrated interface.

- 1x AV/Stereo OUT combination interface.

- 1x Component(Y/Pb/Pr ) video out interface.

- 1x Stereo Audio Analogue out interface

- 1x Coaxial SPDIF digital audio out interface.

- 1x Optical SPDIF digital audio out interface.

- 1x Stereo Audio Analogue in interface

- 1x AV/Stereo IN combination interface.

- 2x internal SATA I/II interfaces

- 1x 100 ~ 240V AC power interface.

- 1x Full function remote controller.

- One CD/DVD Drive

- Two SATA HDD or 5.25' Pull-type HDD rack installable (Option).

- Support USB 802.11n/b/g WIFI dongle, Up to 300Mbps transmission speed.

- Size: 430 x 330 x 50mm (W x D x H) .

Storage Supported:

- Two internal 1TB Hard Disks (one used as backup)

- One internal CD/DVD drive

- External USB Hard Disks

- External USB media card readers

- USB disks / USB sticks

- iPod external dock station

- WAV / WMA / MP3/ FAT file systems supported


- 24bit/192kHz Digital-to-Analog Converter

- Tube Analog Audio Output Stage (tube complement 1 x 12AU7)

- In-built CD/DVD Drive, Internet Radio, SD Card MP3 Player, Aux Input

- Touch screen display

- iPod, iPhone application – iPod and iPhone touch becomes a touchscreen remote

- Record, Store & Play from HDD, DISC or Analog Audio Input

- Record to Internal hard disk

- Timer Recording

- Time Shift

- EPG Program Schedule Recording

- Web Remote Schedule Recording

- Audio Streaming

- Wired & Wireless Network

- Expand more storage with USB2.0

- UPnP Media Streaming

Storage Supported:

- Two internal 1TB Hard Disks (one used as backup)

- One internal CD/DVD drive

- External USB Hard Disks

- External USB media card readers

- USB disks / USB sticks

- iPod external dock station

- WAV / WMA / MP3/ FAT file systems supported

Acoustic Research AR 10 π (1977)

The Acoustic Research 10π is a new speaker system from Acoustic Research that addresses itself to these considerations. Under actual listening conditions, the AR-10π delivers as flat an energy response as the state of the art permits. And it is able to maintain this response characteristic under a great variety of conditions of use. The result is a further significant improvement in the degree of realism with which music can be heard in the home.

The AR-10π - is designed to reproduce music in the home as accurately as the state of the art permits. Its ability in this respect represents a number of significant evolutionary improvements over previous designs. Further the AR-10π - is intended to offer an unprecedented degree of flexibility without any sacrifice in accuracy. The combination of these characteristic, we believe, represents a significant step forward in loudspeaker design.

 The AR 10π is a no-compromise 3 way speaker system with excellent dispersion and even energy output all across the audible spectrum. A pair of 3 position switches allows the owner to adjust the mid and high-range drivers to the "liveliness" of the room while the 3-position woofer environmental control allows the owner to adjust the low-end response to speaker placement. This allows the owner to place the speakers on the center of the wall, on the floor against the wall or away from the wall.

Drive units:
Low-Frequency:  300 mm (12 in.) acoustic suspension woofer,
Mid-Frequency:  38 mm (1-1/2 in.) hemispherical dome midrange,
High-Frequency:  19 mm (3/4 in.) hemispherical dome highrange.
Crossover Frequencies:  525 Hz, 5000 Hz
Frequency Range:  27 Hz-30 kHz
Impedance:  4 - 8
Sensitivity:  9 watts
Three 3-position switches for woofer environmental control and for midrange and highrange level control
4 to 8 nominal, depending on switch positions, highest impedance in π and -6 dB switch positions, lowest in 4π and 0db
1 watt will produce 86 dB SPL on axis at 1 meter.
Amplifier Power Requirement:
25 watts (into one speaker only) will produce 100 dB SPL in a 3000 cu π room of average reflectivity (energy absorption coefficient of 0,15), 50 watts (25 watts per channel) will produce 103 dB SPL in the same room.
Power Handling Ability:
May be used with amplifiers capable of delivering up to 150 watts continuous power per channel being driven to clipping 10 % of the time, on normal music material source
Nominal Power Handing: 100 watts (max, 250)
Crossover Network:
Half-section LC network on each driver using air-core chokes and computer grade bi-polar electrolytic capacitors. acoustic output of midrange and highrange drivers as well as the normalizing of woofer output for the three basic environments accomplished via an autotransformer and individual switching networks
Driver Resonance Frequencies:
Woofer 18 Hz (free air), midrange 400 Hz, highrange 400 Hz
System Resonance Frequency:  42 Hz
System Low Frequency Response:  -3 db at 35 Hz
Effective System Q:  0.75
Flux Density:  Woofer 9800 gauss, midrange 13000 gauss, highrange 14000
Volume of Enclosure:  41.9 liters (1.48 cu. ft.)
Cabinet Dimensions:  354 x635 x 273 mm deep (13-15/16 x 25 x 10-3/4 in.)
Weight:  unpacked 24.9 kg (55 lb.)

Pathos Acoustics TWIN TOWERS RR

The first appearance of Pathos on the hi-fi scene did not go unnoticed: a short time after its debut, the T.T. has achieved a solid position among those very few components which contribute to writing the history of High-Fidelity. International audio reviews welcomed the first product from Pathos with front page covers, highly enthusiastic comments and numerous prestigious awards.

When listening to music reproduced through a T.T. amplifier, everyone can experience the honest difference in terms of musicality, transparency, tonal colour and absence of listening fatigue. The reason why this difference can be consistently and immediately appreciated is because the T.T. is different. This difference is named INPOL®, the exclusive worldwide patented pure Class A  feedback-free circuitry which has been claimed to represent the most important innovation in musical amplification of the last years.

Highly selected components, pure silver Pathos signal wiring, and craftsmanship of the highest level are the most appropriate compliments to the T.T. reference sound. Through the years, the TT has been constantly perfected and updated in order to keep this living legend alive. Today the TT is available in its original volume configuration - a purely resistive 24-step manual volume control - and also in a remote controlled version - an optical device which drives a battery of read relays (vacuum packed, thorium contacts), which in turn drive a network of precision resistors (1% metal layer) in 1dB steps.

The Pathos Twin Tower is available in three versions:
Classic (C): manual 24 step resistive volume
Reference Remote : (RR): remote resistive volume in 1dB steps
Anniversary : like the TT RR with balanced input

Main Specifications:
Type:  integrated amplifier operating in pure class A according to INPOL® circuitry
Power Output:  2 x 35 W at 8 Ω
Feedback:  absent
Frequency Response:  13 Hz ÷ 78 kHz  ±0,5 dB
Total Harmonic Distortion:  0, 5% up to the maximum power
Signal-to-Noise Ratio:  90 dB
Slew Rate:  38 volt/µs
Input Impedance:  100 k
Absorption at Rest:  240 W
Dimension (W x H x D): 470 x 240 x 450 mm
Weight:  42 kg

Sonus Faber Guarneri Memento

When, in 1994, Sonus Faber introduced the limited-edition Guarneri Homage loudspeaker to celebrate the 250th anniversary of the death of master violin maker Giuseppe Guarneri, the company embraced the musical-instrument analogy in the process of designing the speaker. Even the design of the enclosure relied more on techniques used to build musical instruments in the 18th century than on science-based, 21st-century loudspeaker technology.

The Guarneri's cabinet consists of 21 staves of thick, solid, hand-selected maple, separated by thin wooden strips, dyed aniline black, that are aged for two years before being kiln-dried. The wood is then shaped, assembled by hand, and glued, using heat and pressure techniques similar to those used for centuries in the making of violins. The cabinet's inner walls are lined as needed with copper sheeting (lead used to be in there as well, but use of the toxic heavy metal is no longer permitted), to distribute and damp resonances and produce cabinet-to-cabinet uniformity.

The cabinet's nonparallel walls are said to inhibit the generation of unwanted standing waves, and to help "guide" the backwave to the port. More important, the original Guarneri Homage, fitted with a custom-designed 6" Scan-Speak woofer and custom Dynaudio Esotar tweeter, received rave reviews across the board for both its measured and its musical performance.

25 mm ultra dynamic linearity ring radiator
driver, with dual toroidal wave-guide.
150 mm ultra dynamic linearity driver.
CCAW/Kapton “eddy current free” voice
coil. Dynamically linear magnetic field
motor incorporating Kellog and Faraday
rings. All moving elements optimally ventilated
for “resonance free” response.
Designed along the philosophy of the least
interference with the musical path.
The conceptually minimalist implementation
uses 6 db/octave slopes and components
of the highest quality and coherence.
A unique structured Silver-Palladium alloy
conductors used, totally coherent on the
entire signal path. Cross-over point 2.500 Hz.
39 Hz - 30.000 Hz, tuning port included.
88 dB SPL (2,83 V/1 m).
4 ohm.
30W - 200W, without clipping.
2 way vented box loudspeaker.
Lute shape design, constrained-mode
damping, enclosure formed using 21
pieces of hand selected solid maple wood.
Graphite or red violin piano gloss.
DIMENSIONS (with stand):
1230 x 300 x 480 mm (HxWxD).
WEIGHT (*with stand):
87,4* Kg per pair - net weight / 113,5 Kg per pair shipping weight.

Pioneer TX 608 (1979)

Usable Sensitivity MONO: 10,8 dBf (1,9 μV)
50 dB Quieting Sensitivity: MONO: 15 dBf; STEREO: 38dBf
Signal-to-Noise Ratio at 65 dBf: MONO: 80dB; STEREO: 74 dB
Distortion at 65 dBf MONO:
100 Hz: 0.1%
1 kHz: 0.1%
6 kHz: 0.15%
Distortion at 65 dBf STEREO:
100 Hz: 0.2%
1 kHz: 0.2%
6 kHz: 0.25%
Capture Ratio: 1.0 dB
Alternate Channel Selectivity: 60 dB
Stereo Separetion: 1 kHz: 40 dB; 30 Hz to 15 kHz: 35 dB
Frequency Response: 20 Hz to 15 kHz (-1.0/+0.5 dB)
Spurious Response Ratio: 70 dB
Image Response Ratio: 60 dB
IF Response Ratio: 80 dB
AM Suppression Ratio: 55 dB
Subcarrier Product Ratio: 50 dB
Multing Threshold: 17.2 dBf (4.0 μV)
De-Emphasis Switch (Switchable): 25 μs - 75 μs
Antenna Input: 300 ohms balanced; 75 ohms unbalanced

IHF, ferrite antenna: 300μV/m
IHF, external antenna: 15μ
Selectivity: 35 dB
Signal-to-Noise Ratio: 50 dB
Image Response Ratio: 40 dB
IF Response Ratio: 70 dB
Antenna: Built in Ferrite Antenna

Output Level: 650 mV/ 4,3 kΩ (FM 100% MOD:)
ICs: 3
FET: 1
Transistors: 8
Diodes: 15
Power Requirements: 110 - 220 V, 50/60 Hz
Power Consumption: 14 W
Dimensions (W x H xD): 430 x 151 x 284 mm, (17¾ x 5¹⁵/₁₆ x 11³/₁₆)
Weight (Without Package): 5,3 kg, (11 lb 11 oz)

AKAI AT-2400 (1975)

Frequency Range: 88MHz to 108 MHz
Sensitivity (IHF): 1,8 μV
Capture ratio: 1,0 dB
Selectivity (IHF): More than 80 dB
Image Rejection: More than 90 dB (98 MHz)
IF Rejection: More than 100 dB (98 MHz)
Spurious Rejection: More than 100 dB (98MHz)
AM Suppression: 55 dB
Signal to Noise Ratio: 75 dB
Harmonic Distortion Mono: less than 0,2% (100% modulation)
Stereo: Less than 0,3% (100% modulation)
Tuning Indicator: Signal Strength meter and Center Tuning meter
Muting: level Control (5μV to 100μV) / Switchable to ON-OFF
Stereo Separation: More than 42 dB (1 kHz)
Sub Carrier Suppression: More than 65 dB
Output Voltage Variable: From 0 mV to 1,6V
Fixed: 0,77V (100% modulation)
Antenna Input Impedance: 300 ohms balanced, 75 ohms unbalanced

Frequency Range: 520 kHz to 1,605 kHz
Sensitivity (IHF): 180μV/m (bar antenna), 15μV (external antenna)
Selectivity (IHF): More than 30 dB
Image Rejection: More than 55 dB (1,000 kHz)
IF Rejection: More than 45 dB
Signal to Noise Ratio: More than 50 dB
Output Voltage Variable: From 0mV to 550 mV
Fixed: 250 mV (30% modulation)
Antenna: Built-in ferrite bar antenna

Semi-Conductors: Transistors: 12, Diodes: 9, FETs: 1, ICs: 4
Power Requirements: 110/220/240 V, 50 -60 Hz Switchable
Dimensions: 440 x 141 x 336 mm; (17,3 x 5,6 x 13,2 inches) (W x H x D)
Weight: 6,6 kg (14,5 lbs)

Kenwood KT-313 (1979)

AM/FM Stereo Tuner

Kenwood's well-balanced design ensures interference rejection and exceptional reception

at a moderate price point. Dual meter tuning for razor-sharp accuracy.

Outstanding Usable Sensitivity in its class: 10,8 dBf (1,9μV).

Excellent signal-to-noise ratio: Mono 77 dB, Stereo 72 dB.

Low harmonic distortion of 0,15% and high alternate channel selectivity of 60 dB (stereo at 1kHz).

PLL in MPX section for improved stereo separation.

Signal strength meter and center-of-channel tuning meter ensure tuning accuracy.

FM Mode Auto bar automatically adapts for stereo or mono operation according to broadcast conditions.

MPX filter blends high frequencies of stereo broadcasts during noisy reception conditions.

Unique internal rotating AM bar antenna for better tonal quality.

FM Section

Sensitivity 30 dB Quieting: 10,8 dBf (1,9μV)

Sensitivity 50 dB Quieting: Mono: 17,2 dBf (4,0μV); Stereo: 38,3 dBf (45μV)

Signal-to-noise Ratio at 65 dBf

Mono: 77 dB

Stereo: 72 dB

Total Harmonic Distortion at 1 kHz

Mono: 0,1%

Stereo: 0,15%

Capture Ratio: 1,0 dB

Alternate channel Selectivity: 60 dB

Stereo Separation

at 1kHz: 45 dB

50 - 10 kHz: 35 dB

AM Section

Usable Sensitivity: 16μV

Signal-to-noise Ratio: 50 dB

Selectivity: 25 dB

Dimensions: 400 x 140 x 275 mm

Weight: 4,4 kg

Kenwood KT-413 (1979)

AM/FM Stereo Automatic Seequential Tuner

Automatic location and fine tuning of all stations with only a light touch to the tuning bars.

All LED operation and preselect of up to 5 FM and AM stations.

Left and Right tuning bars automatically locate the stations.

Fine tuning is accomplished by the automatic Servo Lock system.

Stop Level switch in High position limits selection only to strong broadcasts. In low position, all stations come through.

Convenient Preset switch for preselection of up to 5 stations for FM, 5 for AM.

Fast-acting Light Emiting Diode (LED) signal strenght display.

FM Mode Auto switch automatically adapts for stereo or mono operation according to broadcast conditions

FM Section

Sensitivity 30 dB Quieting: 10,8 dBf (1,9μV)

Sensitivity 50 dB Quieting: Mono: 17,2 dBf (4,0μV); Stereo: 37,2 dBf (40μV)

Signal-to-noise Ratio at 65 dBf

Mono: 77 dB

Stereo: 72 dB

Total Harmonic Distortion at 1 kHz

Mono: 0,1%

Stereo: 0,15%

Capture Ratio: 1,0 dB

Alternate channel Selectivity: 60 dB

Stereo Separation

at 1kHz: 50 dB

50 - 10 kHz: 40 dB

AM Section

Usable Sensitivity: 20μV

Signal-to-noise Ratio: 50 dB

Selectivity: 25 dB

Dimensions: 400 x 140 x 275 mm

Weight: 4,4 kg