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





A&R Cambridge T21

The T21 Stereo FM Tuner
The qualities of the A60 amplifier series demand a tuner that is a complete partner. The T21 is that partner, an ideal match in looks, performance and price.

Great care has been taken in the design of the sound circuitry of the T21 to produce an unusually flat frequency response over the critical listening bandwidth. A "birdie" filter, fitted before the stereo decoder, considerably reduces the unpleasant whistles ("birdies") caused by closely positioned stereo broadcasts it also compensates for phase errors in previous stages which would otherwise add to distortion and crosstalk. A highly efficient ,ultiplex filter removes the 19 and 38 kHz high frequency tones produced by the stereo decoder circuitry, preventing damage to loudspeakers and interference with the bias oscillator in a tape recorder.

Overall, our design and production standards have been carefully maintained with the T21 tuner. We beliwve it is the perfect complement to our range of high performance, value-for-money sound equipment.
T21 also included in the tuning window is a single red LED as a stereo beacon. Tuning can be carried out by either the manuall tuning control or one of the five preset push buttons. Full station search with continuously variable tuning is provided by the rotary knob which has a pleasant and useful flywheel action. For the more frequently used stations each of the five buttons can be individually preset with the controls at the rear of the tuner. A mute facility is provided to remove background noise between the stations. To ensure that a station, once selected, remains accuraattely tuned in, an AFC (automatic frequency control) is fitted.

The  T21 can be used with any amplifier including of course, the A60 itself. A level controll knob on the rear of the tuner allows unwelcome variation in the output volume between the tuner and, say, a record deck to be equalised. Thus only minimal adjustment of the amplifier's volume control is ever needed. Both 75 Ω and 300 Ω balanced serial sockets are provided together with tuner matching plugs, allowing easy connection to all standard FM aerial systems.

Specifications:
Tuning Scale:  21 matched red LEDs in steps of 1 MHz, a gradual changeover in light intensity between adjacent LEDs allows frequency readings of typically 0,2 MHz to be achieved.
Tuning Range:  87,5 - 108,5 MHz
Signal Strength Meter:  bargraph scale using 5 LEDs, 2 red and 3 green
Tuning Meter:  3 LEDs, red-green-red
Stereo beacon:  single red LED
Aerial Inputs:
Socket for 75 Ω and 300 Ω antenna
Performance
Sensitivity (IHF):  1,3 µV
-3 dB Limiting Point :  10 µV
Capture Ratio:  1,5 dB
Alternate Channel Selectivity:  better than 60 dB
Repeat Spot Suppression:  better thann 80 dB
IF Rejection:  better than 80 dB
AM Suppression:  better than 50 dB 
(ref. 75 kHz deviation, 30% AM at 400 Hz, aerial signal  10 µV-10 mV)
Signal-to-Noise Ratio (CCIR/ARM weighted):
Mono :  better than 70 dB
Stereo :  better than 68 dB
Pilot Tone Suppression :  better than -50 dB
Subcarrier Suppression:  better than -40 dB
Total Harmonic Distortion (1 kHz):
Mono :  better than 0,15% (typically 0,08%)
Stereo :  better than 0,25% (typically 0,15%)
Channel Separation:  better than 40 dBf
Frequency Response:  20 Hz - 12 kHz  ±0,5 dB ( typically -3 dB at 15 kHz)
Channel balance:  within ±1 dB
Output Level:  continously variable 10 mV- 1 V at full deviation
Output Impedance:  less than 1 k Ω
Recommended Load:  better than 10 k Ω
Power Supply;  200 - 250 V  AC, 6 VA maximum; (or  100 - 120 V AC)
Deimensions (W x H x D):  450 x 60 x 240 mm (17-3/4" x 2-3/8" x 9-1/2")
Weight (net):  3,3 kg (7,3 lb)

TEAC A-X5030


Integrated Stereo Amplifier A-X5030
Features:
High-power drive capability
Switchable subsonic filter
-20 dB muting switch
Loudness compensation switch
Center-detented bass and treble tone controls
Balance control
Dual speaker terminals and independent speaker A/B switches
Heavy-duty binding-post speaker terminals
Large insulator feet.

Another example of TEAC dedication to delivering the finest possible quality in these amplifiers is the fact that each unit is individually calibrated for optimum performance.
In the A-X series amplifiers, the output stage idling current is determined by a precision trimmer rather than the usual fixed resistor. This is adjusted to provide optimum idling current - and therefore an absolute minimum of crossover distortion - during the final testing and inspection stage. You can rest assured that the amplifier you receive is fine-tuned to deliver super sound quality.
All-Mechanical Short-Path Signal Switching
Many modern amplifiers use semiconductor switches to control signal routing. These like any other electronic part, can degrade signal quality. TEAC has used only top-quality mechanical switches ensuring reliable, distortion-free signal routing. Furthermore, switches handling low level signals are positioned as close as possible to the corresponding rear-panel terminals to minimize the signal path length and are remotely controlled via the panel knobs. This means that noise and interference pickup is minimized for extra signal purity.
 Source Direct Switch
When you want an extra margin of signal purity, the Source Direct switch can be engaged to bypass the tone, balance, loudness controls, muting and subsonic filter controls, giving you the shortest, most direct signal path possible for all input sources.
Versatile Input and recording Capability
Independent input and Rec selectors let you monitor one source while simultaneously recording another. The Rec selector also offers tape-to-tape recording capability. The A-X5030 accept of 6 base input sources like; phono, tuner, CD, tape 1/DAT, tape 2, AUX, and additionally features Adapter/Tape 3 terminals that can be used to connect a third tape deck or an external adapter such as a graphic equalizer or surround processor. The A-X5030 also features a high-performance internal MC phono cartridge head amplifier and an MM/MC phono selector switch.
Heavy-Duty Binding-Post Speaker Terminals
Since speaker cables can have a significant effect on the sound, the TEAC amplifiers are equipped with heavy-duty binding-post terminals that will easily accept high-quality speaker cables while providing solid reliable contact.

Specifications:
Continuous Power Output (RMS):
At 8  :  75 W + 75 W (20 - 20,000 Hz, 0,02% THD)
At 4  :  100 W + 100 W (20 - 20,000 Hz , 0,04% THD)
DIN Power Output:
At 8  :  85 W + 85 W (1 kHz)
At 4  :  120 W + 120 W (1 kHz)
Dynamic Power Output:
At 8  :  100 W + 100 W
At 4  :  150 W + 150 W
Total Harmonic Distortion (Continuous Rated Output Power):
At 8  :  0,007% (1 kHz)
At 4  :  0,01 % (1 kHz)
Input Sensitivity/Impedance:
Phono (MM) :  2,5 mV/ 47 k Ω
Phono (MC) :  0,25 mV/100 Ω
CD, Tuner, Aux, Tape :  150 mV/30 k Ω
Signal-to-Noise Ratio (IHF--A):
Phono (MM) :  80 dB (5 mV)
Phono (MC) :  67 dB (0,5 mV)
CD, Tuner, Aux, Tape :  101 dB
Frequency Response:
Phono (RIAA) :  20 - 20,000 Hz ±0,5 dB
CD, Tuner, Aux, Tape :  5 - 100,000 Hz -3 dB
Dimensions (wxhxd):  435 x 155 x 354 mm
Weight:  10,5 kg

NAD 6340

Cassette Deck
Dolby HX-Pro and DYNEQ: 
Dyneq varies the record equalization to prevent over saturatio when strong high frequency transients occur. HX PRO varies the bias supplied to the bias supplied to the tape during recording to maintain optimum high frequency at all times, thus making a much more accurate reproduction of your source. Note:  HX-pro and DYNEQ are compatible for playback with all cassette decks, including car decks.
Car Circuit: 
Boosts quiet passages in the music without altering the loud passages, making a more practical tape for car or portable players. It also adds equalization for the car environment.
Play Trim:
Developed by Dolby laboratories with NAD, Play Trim compensates for high frequency loss before Dolby NR, restoring highs withput increasing noise. Example: Take an old tape with dulled highs and turn the Play Trim knob and note the restored highs.
Dolby B & C
Full Logic Transport

Specifications:
Speed Accuracy:  +1%
Wow and Flutter: 
less than 0,06% JIS wtd RMS
less than 0,1% DIN wtd. Peak
Frequency Response:  30 Hz - 19 kHz +3 dB (MPX filter Off)
MPX Filter Response:  flat within 1 dB to 15 kHz
Harmonic Distortion:  varies with recording level typically less than 0,3% at -10 dB
Total Harmonic Distortion at 0 dB:
Normal Tape :  less than 1,0 %
CrO₂, Metal Tape :  less than 1,5%
Signal-to-Noise Ratio (ref.3% T.H.D. at 333 Hz CC1R/ARM weighting):  57 dB
Dolby off :  75 dB
Dolby B :  67 dB
Dolby C :  77 dB
Channel Separation:  45 dB at 1 kHz (38 dB broadband)
Erasure:  better than 70 dB at 1 kHz
Input Sensitivity /Impedance:  40 mV/10 k Ω
Maximum Input level:  25 V
Output Level at 0 dB:  500 mV
Output Impedance:  1000 Ω
Power Requirement:  120, 220, 240 V AC 50/60 Hz
Power Consumption:  22 W at 120 V AC
Dimensions (W x H x D):  420 x 122 x 270 mm (16,5" x 4,8" x 10,6")
Weight (net):  4,5 kg (9 lb 15 oz)

NAD 5420

 Compact Disc Player
Balanced MASH One-Bit High Resolution Digital to Analogue Converter:
With CD players utilizing MASH or other one bit technologies, our engineers have found that what really makes the difference in their performance is the care taken in power supply design,, PCB layout, grouding, and selection of analog circuit components
Circuit Simplicity:
Many CD players are "over-designed" with unnecessary stages of analog circuitry that sacrifice transparency and subtle detail. NAD players have just three wide-band analog circuits and only one coupling capacitor in the signal path (bypassed by a low loss film capacitor), thus preserving the emotional detail of the original performance.
Other Features:
Plays 3-inch disc without adaptor
16 tracks programmable
Specifications:
Disc Capacity:  Single disc 120 or 80 mm
Programming Capacity:  16 tracks
D/A Conversion:  MASH, 18-bit resolution 32 times oversampled , linear phase with 18 bit coefficients
Analogue Filter:  5 pole active
Frequency Response:  5 Hz - 20 kHz ( 0/-0,5 dB)
De-emphasis Error:  less than +0,3 dB
Total Harmonic Distortion 0,0025% (at 0 dB , 1 kHz)
Dynamic Range:  98 dB
Linearity:  +0,5 dB; 0 to -90 dB
Signal-to-Noise Ratio (A-weighted, measured with all zeroes test disc):  106 dB
Channel Separation: (1 kHz) :  100 dB
Wow and Flutter:  Unmeasurable (quartz accuracy)
Output Impedance:  120 Ω
Output Level at 0 dB:  2,0 V RMS
Digital Error Correction:  CIRC with double error correction in C1 and C2
Noise at Zero Volume:  less than -120 dB
Power Requirements:  120, 220, 240 V AC 50/60 Hz
Power Consumption:  25 W at 120 V AC
Dimensions (W x H x D):  420 x 84 x 260 mm (16,5" x 3,3" x 10,2")
Weight (Net):  4,1 kg (9 lb 1 oz)