Technics SU-V6 amplifier

With this amplifier, you can obtain the best of both worlds. Technics' "New Class A" amplifier circuit combines class A output with stable load condition on all stages. Also, the undistorted sound quality of class-A and the efficient. High output power of class-B are available within a single amplifier. You don't have to trade efficiency and price for sound quality, or switching distortion for high output. The SU-V6's facts and figures support these claims: 70 watts per channel, both channels driven into 8 ohms, from 20 Hz to2O kHz with no more than 0,007%total harmonic distortion. The most important fact, though, is that this integrated amplifier's faithfully reproduced sound exhibits the effortless smoothness of true class-A amplification And yet all this is available at a fraction of a conventional class-A amplifier's cost.

 

New Glass A and Straight DC Provide Both Quality and Quantity

Quality of reproduced sound and quantity of output power are the two general aims we were striving to develop in the advanced circuitry incorporated in the SU-V6. To test the success of our circuit designs, we have employed a new method of analysis called 3DA (first used in the development of the SU-8099 integrated amp), which stands for "3-Dimensional Analysis." With the aid of a computer, this system enables us to test performance at 4,000 points and express the results in 3-dimensional graphic form. From our extensive research using 3DA, we have found that performance requirements within the audio spectrum are best satisfied by building amplifiers that exhibit good performance characteristics from 0 Hz (DC) at the bottom of the frequency range, all the way up to nearly 100 kHz in the ultra-high range ( it's undesirable to go much higher than this point, given currently available circuit components). To achieve performance within these considerations, we have used a number of advanced circuit configurations, the two most important of which are "New Class A" and "Straight DC."

 

New Class A with Synchro Bias for Better High Frequency Response

Transistor switching is a major cause of high frequency distortion in class B and class AB amplifier designs. ln class B designs, two output transistors are used for each channel. The "upper" transistor handles the positive  half of the waveform and the "lower" transistor handles the negative half. But problems occur when the signal crosses the zero point; one transistor turns off and the other turns on. During this crossover, "switching distortion" is  generated. This takes the form of brief pulses with very sharp peaks, which produce high-order harmonic distortion. NFB (negative feedback) does not cope with switching distortion effectively, despite its use fulness in combating ordinary forms of distortion. This switching distortion can also result in intermodulation distortion which muddies reproduced sound to a greater  degree than might be expected from a simple examination of an oscilloscope trace. In class A, the same transistor handles the entire waveform, but a large idling current is required to operate the transistor even when there is no audio input signal. Although this prevents any form of switching distortion, it also results in very low efficiency. Large heat sinks must be provided to dissipate the substantial amount of excess heat that is created. Price is corresponding high In our New Class A circuitry, the output transistor bias current is synchronized with the positive and negatives wings of the input signal so that the output transistors are always in an active state. With this remarkable circuitry, switching distortion is eliminated since the transistors are never allowed to switch off. Because of this synchronized operation, e call  his "synchro bias." Besides  preventing  switching  distortion in the output waveform, it also presents linear load conditions to the voltage amplification stage. Pre-driver load fluctuation is also minimized. The result is the virtual elimination of "crossover distortion."

 

"Straight DC" Configuration for Direct Coupling Between DC Power Amp Section and High Level Input Signals

The SU-V6's design takes full advantage of the excellent low-range frequency response, phase linearity, and low distortion inherent in our refined DC power amp design. By increasing the gain of the power amp section, we have made it possible to directly couple high level inputs, such as tuner, tape, and AUX sources, to the power amp input. The resulting improvement in low range fidelity is a good example of what can be achieved with an innovative, yet uncomplicated, approach to integrated amp design. In fact, you could view this configuration as simply a phono equalizer and a DC power amp.

While this characterizes the "simple is best" philosophy. Some additional innovations were necessary to obtain the desired performance goals. First of all, a high-gain amp is required to raise typical "high level" inputs of 150 mV- 200 mV to output levels of 70 W-100 W. Furthermore, any tendency toward  temperature dependent DC drift must be avoided since the amp's gain extends  all the way down to DC in the low range. To obtain high gain, Technics' SU-V6 amp employs a linear cascode, 3-stage Darlington configuration which provides excellent open-loop performance. As a result, only 45 dB  NFB is required to achieve the 0.007% THD rating at 70 W output. To combat DC drift, 1-chip dual FET's are used for the first stage differential amplifier. Since this prevents mutual temperature differences, DC drift is reduced to a mere ± 10 mV from -10°C to +50°C.

 

Concentrated Power Block (CPB) Prevents Distortion from Electromagnetic Induction

With the strikingly clean high range response obtained from our New Class A synchro bias circuitry, we made sure that nothing would interfere with proper performance under practical signal handling conditions. Our concentrated power block was developed to prevent electromagnetic induction between those portions of the circuitry which handle large amounts of current and those which handle smaller signals. The power supply and output stage were concentrated in one integrated unit to create the shortest possible connections. With the addition of low impedance laminated bus lines, the power supply loop was minimized. Another advantage of CPB is that it virtually eliminates significant  differences in performance between individual units. Consequently you can expect a maximum 0,007% THD for anv individual SU-V6 amp.

 

ICL Phono EQ Circuit Employing Ultra-Low Noise FETs Permits Direct MC Cartridge Connection

The first stage of the phono equalizer is a differential amplifier with ultra-low noise dual FETs. As a result, no input capacitors are necessary. A mere increase in equalizer gain, rather than an additional pre-preamp or step-up transformer, is all that is needed for MC cartridge compatibility. When the amp is in the straight DC mode, the only capacitor in the entire amp circuit, whether the input is MC or MM, is the EQ output capacitor.

 

Heavy Duty Power Supplies

In an audio amplifier the, power supply must be able to meet the changes in impedance presented by the speaker systems Depending on the frequency this figure can  range from below 4 ohms up to as high as 30 ohms for a speaker system rated at 8 ohms. In the SU-V6 independent rectifier and  ripple filter circuits are  provided for the left and  right channels to assure truly stable DC power. Furthermore the power transformer coils float in a special resin  within shielded cases to prevent power supply hum.

 

Independent Recording Selector with 2-Way Dubbing

With this versatile arrangement you can record from  one source while listening to another since the input and recording selectors are separate. Tape inputs are positioned on both the input selector and the recording selector so that you can record while listening to another source (such as a disc) if you wish.

 

Remote Action Switches Eliminate Excess Wiring

Remote action switches are employed on the input selector, recording selector, and phono selector. Therefore, switching takes place at the ideal location within the circuitry. This contributes to sound quality by minimizing the chances of signal degradation due to extensive wiring.

 

Specifications

Continuous Power Output

20 Hz - 20 kHz (both channels driven)

80 W x 2 at 4 Ω

70 W x 2 at 8 Ω

40 Hz - 16 kHz (both channels driven)

80 W x 2 at 4 Ω

70 W x 2 at 8 Ω

1 kHz ( both channels driven}

90 W x 2 at 4 Ω

74 W x 2 at 8 Ω

Total Harmonic Distortion Rated Power

At 20 Hz to 20 kHz

0,02% at 4 Ω

0,007% at 8 Ω

At 40 Hz to 16 kHz

0,02% at 4 Ω

0,007% at 8 Ω

At 1 kHz

0,01% at 4 Ω

0,007% at 8 Ω

Total Harmonic Distortion Half Power

At 20 Hz to 20 kHz : 0,007% at 8 Ω

At 1 kHz 0,003% at 8 Ω

-26 dB power at 1 kHz :  0,05% at 4 Ω

50 mW power at 1 kHz :  0,08% at 4 Ω

Intermodulation Distortion Rated Power

At 250 Hz  : 8 kHz = 4 : 1, 4 Ω  :  0,02%

At 60 Hz : 7 kHz = 4 : 1 SMPTE, 8 Ω  :  0,007%

Poer Bandwidth both channels driven, - 3 dB

T.H.D. 0,03%, 5 Hz - 60 kHz (4 Ω )

T.H.D. 0,02% , 5 Hz - 60 kHz (8 Ω )

Residual Huma and Noise (Straight DC):  0,3 mV

Damping Factor :  30 (4 Ω ); 60 (8 Ω )

Headphones Output Level/Impedance:  560 mV/330 Ω

Load Impedance

Main or Remote :  4 Ω  - 16 Ω

Main and Remote :  8 Ω  - 16 Ω

Input Sensitivity/Impedance

Phono MM :  2,5 mV/ 47 k Ω

Phono MC :  170 µV/47 k Ω

Tuner, Aux :  150 mV/36 k Ω

Tape 1, Rec/Play :  170 mV/39 Ω

Tape 2 :  150 mV/36 k Ω

Phono max. Input Voltage at 1khz (rms, T.H.D. 0,01%)

Mm :  150 mV

MC :  10 mV

Signal-to-Noise Ratio (Rated Power 4 Ω )

Phono MM :  78 dB (86 dB, IHF A)

Phono MC :  68 dB (68 dB, IHF A, 250 µV input)

Tuner, Aux :  92 dB (106 dB, IHF A)

Signal-to-Noise Ratio (-26 dB Power 4 Ω )

Phono MM :  67 dB

Phono MC :  65 dB

Tuner, Aux :  68 dB

Signal-to-Noise Ratio (50 mW power 4 Ω )

Phono MM :  64 dB

Phono MC :  62 dB

Tuner, Aux :  65 dB

Frequency Response

Phono  :  RIAA standard curve ±0,5 dB (30 Hz - 15 kHz)

Tuner, Aux, Tape (Straight DC) : DC ~150 kHz (-3 dB) +0, -3 dB (20 Hz - 20 kHz)

Tone Controls

Bass :  50 Hz ±10 dB

Treble :  20 kHz ±10 dB

High-Cut Filter :  7 kHz -6 dB/oct

Subsonic Filter :  20 Hz -12 dB/oct

Loudness Control (volume at -30 dB):  50 Hz -9 dB

Output Voltage/Impedance

Rec Out :  150 mV

Rec/Play :  30 mV/82 k Ω

Channel Balance:

AUX, 250 Hz - 6300 Hz :  ±1,0 dB

Channel Separation:

AUX, 1 kHz :  55 dB

General

Power Requirements:  AC 110/120/220/240 V 50/60 Hz

Power Consumption:  760 W

Dimensions (W x H x D):  430 x 153 x 351 mm (16-15/16" x 6-⅓2" x 13-13/16")

Weight:  12,5 kg (27,6 lbs)

 

Technics ST-S7 tuner

A Quartz Synthesizer Tuner That ls a Worthy Source of High Fidelity

The ST-S7 tuner provides listening quality which will convince you that FM broadcasts can, in fact, be sources of superb sound. To achieve this high level performance, we have departed from conventional tuner design in several areas. Two of the most significant design elements are the incorporation of digital signal processing technology and the introduction of DC amplification and detection (which is impossible to achieve through conventional analog designs). Benefits of this design include improved stereo separation especially in the low-bass range, for a faithful reproduction of musical ambience. This is achieved along with a very high selectivity of 85 dB (±400 kHz) indicating no trade off of selectivity vs. Separation as is the case with conventional designs.

We've also taken full advantage of the quartz synthesizer's potential by providing an optional FM antenna tuning control with our remarkably effective SH-F101 compact room antenna. All this is contained in a sleek, slim tuner with a 43.6 mm (1-23/32") high front panel. In appearance as well as performance, the ST-S7 is an excellent match for the recently introduced Technics "New ClassA" amplifiers.

 

DC Amplification, DC Detection, and DC Stereo Decoding for Excellent Sound Quality

DC capability has recently been introduced to amplifiers. Even though tuners are intended to handle the same audio signals as amplifiers, little progress has been made, until now, in DC tuner technology.

The instability of the local oscillator frequency produces this situation. In a superheterodyne dial-type tuner, a drift in local oscillator frequency creates inaccuracy in the IF center frequency. This results in increased distortion, which is caused by DC voltage in the detector. In a conventional analog tuner, this "output without input" can be corrected, but not prevented. Analog tuners employ AFC (Automatic Frequency Control) to correct this problem, but AFC handles all the DC voltages in the detector stage as erroneous signals. This makes it impossible to provide amplification and detection down to DC.

Unlike the conventional analog tuners, a quartz synthesizer tuner's local oscillator frequency is stabilized by the extremely precise quartz oscillator frequency. Since there is no need for AFC, this makes DC amplification (including the RF stage, DC detection, and DC stereo demodulation) possible.

By taking advantage of the inherent potential of the quartz synthesizer approach, we have produced the world's first DC tuner. ln addition to such a significant innovation, we've also added other useful features which imorove performance, like a balance detector output tor connection to the MPX stage.

 

DC Peak Sample and Hold MPX Circuitry Excellent Stereo Separation

The ST-S7 exhibits very high FM selectivity of 85 dB (±400 kHz),a figure that is rarely matched with conventional designs. Normally, tuners with such high selectivity  have sacrificed in the areas of distortion and stereo separation. But in the ST-S7 the employment of DC peak-sampling holding circuitry has removed this design conflict. Wide stereo separation (55 dB at 1 kHz)  is achieved despite the high selectivity of 85 dB and distortion is only 0.15% stereo. The keys to success are DC capability in the detector and MPX stages and the digital sample/hold processing  of the 38 kHz stereo subcarrier, which replaces the conventional switching decoder method. Because of the high sampling rate, additional information is obtained from the stereo channels. Moreover, frequency separation is un affecled by the potential instability of the 19 kHz pilot signal until the point of complete detuning.

 

25 kHz Quartz Reference Frequency

The reference frequency of the ST-S7's quartz synthesizer tuner is 25 kHz; most other quartz tuners use a reference frequency of 5 kHz. This is but one measure of the ST-S7's superior performance. Although it may seem contradictory to find a reference frequency within an audio band, this arose because of the ready availability of an lC that was originally developed for car stereo tuners. When the 5 kHz reference frequency of this lC leak sin to the audio signal path, a low-level whistling sound is produced. Distortion may not be audible in the relatively noisy environment of an automobile; but it is undesirable, to say the least, in a high quality tuner like the ST-S7. Therefore, we developed our own lC specifically for quartz synthesizer tuners. This new lC produces a highly stable reference frequency of 25 kHz, safely above the audio frequency spectrum.

 

Back-to-Back High-Q Varactors and MOSFET Front End to Prevent lM Interference and Provide High Sensitivity

On a crowded FM band, it is particularly  important to eliminate lM interference (which is caused by interference of three nearby broadcast frequencies) in the tuner's RF stage.

In the ST-S7, our back-to-back varactors (equivalent to a four-ganged variable capacitor) control capacitance through an applied DC potential rather than the manually controlled variation in capacitance found in dial type analog tuners. These varactors exhibit a very high Q so that only the desired broadcast frequency is selected, and intermodulation products from nearby stations are effectively avoided. The 4-pole MOS FET RF amp provides superb sensitivity of 20 µV (78 Ω )/46 dB quieting.

 

IF Staqe Ceramic Filters Have Outstanding Group Delay

Characteristics to Provide High Selectivity and Low Distortion Selectivity is extremely important on a crowded FM dial. With conventional tuners, you have two choices: a wide lF band with low distortion or a narrow lF band with higher selectivity and higher distortion. Because of this, some tuner sare provided with switchable wide/narrow lF bands.

In this tuner, we have succeeded in achieving both low distortion and wide selectivity by using three very carefully manufactured and selected 4-element ceramic filters which have very flat group-delay characteristics. Without resorting to lF band switching, we've attained a very high selectivity of 85 dB (± 400 kHz), while distortion is a very low 0,1% (mono); 0,15% (stereo)

 

Extremely Easy and Accurate Tuning with Quartz Synthesizer Preset Buttons for a Total of 16 Stations, 8 AM and 8 FM, Plus Quartz Lock Indicator

Perhaps the greatest advantage of quartz synthesizer tuning is that virtually perfect tunig can be achieved easily and quickly. Moreover, this completely electronic tuning system readily lends itself to preset capability, thereby eliminating the need for signal strength or center tuning meters.

To "manually" tune the ST-S7, you just press the UP or DOWN button. This lets you electronically scan the dial as long as you keep either the UP or DOWN button pressed. When you reach the desired broadcast frequency, the locked indicator lights up, indicating that the station that you have selected is precisely tuned in.

 

Built-in Programmable Timer for On/Off Tuning of Three Programs

The Technics-developed micro processor. Utilized for our quartz-synthesizer tuning, is so powerful that it can also provide a programmable timer function. This allows you to program the tuner to tune in the stations  you want at the times you choose. The programmable timer can be set to turn two programs off and on every day, and an additional program for one particular time and day of the week. So the tuning of three programs can be left entirely to the tuner. The timer also controls the power to the tuner's switched AC outlet so that your amp or tape deck will turn on at the same time as the programs are tuned in.

This tuner is equipped with a 24-hour quartz clock which provides great accuracy (+ 10, -0 seconds per month). In fact, it can serve as a digital clock when the TUNER OFF button is pressed.

To program the timer, simply set the program selector to WRITE and Dress the preset buttons for the times you want. Of course, you can cancel in the middle of a program (CANCEL) or check your setting (READ). While listening to a program, you can check on the preset time by pressing the CLOCK CALL button. The time will be displayed for about five seconds; then the tuned-in station's frequency will reappear on the digital display.

 

Specifications

FM Tuner Section

Frequency Range:  87,5 - 108,0 MHz

Sensitivity

S/N 30 dB :  0.95 µV  (75 Ω )

S/N 26 dB :  0.85 µV  (75 Ω )

S/N 20 dB :  0.75 µV  (75 Ω )

IHF Usable Sensitivity :  0.95 µV  (IHF '58 )

IHF S/N 46 dB Stereo Quieting Sensitivity:  20 µV  (75 Ω )

Total Harmonic Distortion

MONO :  0,1%

STEREO :  0,15%

Signal-to-Noise Ratio

MONO:  69 dB (77 dB IHF)

STEREO:  65 dB (72 dB IHF)

Frequency Response:

5 Hz - 18,000 Hz (+ 0,2 dB . - 0,5 dB)

5 Hz - l8 kHz (± 1,5 dB)

Alternate Channel Selectivitv: 85 dB (±400 kHZ); 55 dB (±300 kHz)

Capture Ratio:  1,0 dB

lmage Rejection (at 98 MHz): 80 dB

lF Rejection (at 98 MHz): 110 dB

Spurious Response Rejection (at 98 MHz): 95 dB

AM Suppression: 55 dB

Stereo Separation:  55 dB (at 1 kHz); 40 dB (at 10 kHz)

Carrier Leak:

At 19 kHz :  -65 dB (-70 dB, IHF)

At 38 kHz :  -48 dB (-50 dB , IHF)

Channel Balance:  250 Hz - 6300 Hz ±1,0 dB

Limiting Point:  0,7 µV

Bandwidth

iF Amplifier:  180 kHz

FM Demodulator:  1000 kHz

Antenna Terminals:  75 Ω  (unbalanced) F-type coaxial

AM Tuner Section

Frequency Range: 

530 - 1620 kHz (10 kHz step)

522 - 1611 kHz (9 kHz step)

Sensitivity:  30 µV , 250 µV/m

Selectivity:  55 dB

Image Rejection at 1000 kHz:  45 dB

IF Rejection at 1000 kHz:  50 dB

Timer Section

Clock:  Quartz-lock type 24-hour indication

Precision:  Within 0 to =10 sec. Monthly (at 25°C)

Function:  24-hour programmable every day: 2 times; once only: 1 time

Programmable Contenet:  Program source (FM,AM), Power On/Off timing; Designation of preset stations

Setting Intervals:  1 minute - 23 hours, 59 minutes

Priority Order:  Once, everyday 2, everyday 1

Memory "back-up":  about 3 months (without AC power)

General Section

Power Requirements:  AC 110/120/220/240 V 50/60 Hz

Power Consumption:  9,9 W

Batteries:  DC 45 V (3 "AA" size)

Dimensions (W x H x D):  430 x 53 x 310 mm (16-15/16" x 2-3/32" x 12-7/32")

Weight:  4,0 kg (8,8 lbs)

 

Harman/Kardon A-401 amplifier

The budget minded may initially be attracted by price but they'll be surprised by the sound quality. The A-401 may be combined with modest loudspeakers or handle even the most formidable. It is a pleasant paradox, straightforward and unexpansive, yet suitable for demanding music systems. It's no exaggeration to say that the A-401 would be the system of choice for any Citation owner who requires a second music sound system for the bedroom, the country cottage or the dormitory.

Features included are those that are most consistently required in music systems, tape monitoring, multiple speaker systems, contour, and uniquely, connections for two pairs of stereo headphones.

For less than 20 watts- 20 Hz to 20 kHz; Rise Time- less than 5 microseconds; Square Wave Tilt- less than 5 degrees at 20 ha. The knowledgeable audiophile will recognize these achievements are , on a more modest scale, shared only with the most expensive separate power amplifiers. The A-401 is a serious and competent amplifier.

 

Specifications:

Power Output:  20 watts min. RMS per channel both channels driven into 8 Ω  from 20-20,000 Hz, with less than 0,5% T.H.D.

Power bandwidth:  from 10 Hz to 35 kHz at less than 0,5% T.H.D. into 8 Ω , both channels driven simultaneously at 10 watts per channel

Frequency Response:  from 10 Hz to 80 kHz at less than 0,5% T.H.D. into 8 Ω , both channels driven simultaneously at 1 watt per channel

Square Wave Rise Time:  less than 3 microseconds

Square Wave Tilt:  less than 5 degrees at 20 Hz

Total Harmonic Distortion:  less than 0,5% from 250 milliwatts to 20 watts RMS, both channels driven simultaneously into 8 Ω  from 20 Hz - 20 kHz

Intermodulation Distortion:  less than 0,12% rated output

System Hum and Noise:  better than 65 dB below rated output unweighted

Damping Factor:  30

Dimensions (W x H x D):  300 x 275 x 134 mm (13" x 10-3/4" x5-1/4")

Weight:  6,2 kg (13,5 lbs)

 

Coral CX-7 speakers

Model CX-7A

 

Model CX-7 MkII

 

3-Way, 3-Speaker System

Specifications

Type:  Air Tight

Speakers

300 mm (12") woofer

One soft dome squawker

One hard dome super tweeter

Impedance:  8 Ω

Program Source Input:  80 W

Frequency Response:  35 - 40,000 Hz

Output Sound Pressure Level:  93 dB

Crossover Frequency:  1,500 Hz ; 8,000 Hz

Dimensions (W x H x D):  350 x 580 x 314 mm (13-13/16" x 22-13/16" x 12-6/16")

Weight:  17 kg (37,4 lbs)

Finish

CX-7A :  rose wood

CX-& MkII :  walnut or black

 

Coral CX-77 loudspeakers

12-inch 3-way 3-speaker system

Symmetric Paired Cabinet Systems - Enclosure

The higher the performance of the speakers, the more important the quality of their enclosure becomes. The CX-77 system uses a bass-reflex enclosure, which features a highly condensed multi-layer particle board, eliminating unwanted vibration. The side, baffle and back boards are strongly reinforced. Ester wool, Tetoron wool and soft felt, all with excellent sound properties, are used as acoustic material. The speakers are symmetrically mounted to achieve optimum directivity. Beautifully finished with UVD coating, the CX-77 system enclosure symbolizes the perfection of the system.

 

Woofer

The light, tough cone paper ensures optimal linearity.

Proper balance among tweeter, squawker, and woofer is crucial when assembling a good speaker system. Cone paper, the heart of the woofer, must possess high Young's modulus and be fully flexible. The woofer in the CX-77 speaker system features Coral's own specially developed micro-crystal cone paper, the surface of which is coated with fine hollow crystal grains 0,1 mm in diameter and with a specific gravity of 0,3. thus partial vibration has been greatly enhanced, refining the transient characteristics of the lower and bass ranges. The rest of it, too - the free edge with full linearity, diecasting frame absolutely without resonance, powerful magnetic circuit help - all contribute to some of the richest, most listenable low frequency sounds available.

 

Squawker

Titanium dome ideally shaped to overcome molding difficulties.

Coral, having developed its own exclusive method for loading highly rigid titanium speaker domes, is now able to provide the audiophile with the most superb mid-range speakers ever. The voice coil in these speakers features CCAW winding and flawlessly maintains optimum balance of mass, extending the high range limit ans largely improving transient characteristics. The aluminum bobbin boasts large input resistivity, and a spacious back cavity easily expands the Frequency Response of the lower range to efficiently cover everything from 700 Hz to 7,000 Hz. Clear, faithful sound.

 

Tweeter

A super-tweeter with a super-high limit - 40,000 Hz

The ultimate limit of high-frequency sound reproduction, plus the elimination of distortion and the optimum in transient characteristics. The attainment of these goals is what audio engineers are continually stribing toward - to build a tweeter which will flawlessly reproduce the delicate high-range sound properties of every musical instrument. Coral's is a hard dome-type super-tweeter that uses a diaphragm of 18-micron-thick ultra-thin Super Duralmin having a crossover frequency of 7,000 Hz. The expanded high-range frequency response of 40,000 Hz easily reproduces everything within the normal audible frequency of 20,000 Hz with outstanding directivity. The sound quality is amazing.

 

Level Controller

An attenuator that enables continuous variation of the mid- and high-frequency ranges independently. The levels may be easily regulated simply by removing the front Saran cloth net.

 

Dividing Network

Low-loss design employing a Mylar film capacitor and a coil featuring a high permeability reluctance ferrite core, which refuses to cause linear distortion even under large input. The design brings out the maximum transient characteristics of each speaker, the result being thoroughly well-balanced sounds.

 

Specifications

Enclosure:  Bass-reflex type

Speakers

1 x 300 mm Woofer

1 x 50 mm titanium dome squawker

1 x 20 mm hard dome tweeter

Frequency Response:  30 - 40,000 Hz

Crossover Frequency:  700 Hz ; 7,000 Hz

Output Sound Pressure Level:  94 dB

Program Source Input:  80 W

Impedance:  8 Ω

Dimensions (W x H x D):  390 x 650 x 320 mm

Weight:  22 kg

 

JVC KD-95 cassette tape deck

The best of JVC's new lineup of high-performance cassette decks, the KD-95 features nearly all the JVC exclusives introduced on preceding pages. Its electronics and mechanism are truly sophisticated and provide the widest dynamic range, lowest distortion and least noise yet achieved in a stereo cassette configuration. Its outstanding specifications are ample evidence of a JVC engineering triumph.

 

Mechanical Accuracy

The JVC KD-95 employs two motors - a precision frequency-generator (FG) servomotor for capstan drive and a DC motor for reel drive, all operations are undertaken electronically by the JVC developed TTL (Transistor-Transistor Logic) IC which activates three electromagnetic plungers; a light touch of any control button allows you to move from one mode to another without having to go through Stop. Also, the deck's large flywheel - 80 mm in diameter - is coupled to the capstan to help reduce wow and flutter. And finally, a professional touch has been added to the KD-95; its head assembly has screws which allow the user to adjust the head azimuth, height and tilt.

 

Sophisticated Electronics

We used the best of JVC electronics technology in designing our top-of-the-line KD-95. first, its recording amp is formed of the 2-stage direct-coupled NPN configuration featuring high linearity. Second, its equalized circuit is of the DC feedback type for excellent transient characteristics and unmuddiet lows. Third, convenient Recording Equalizer and 400 Hz Signal Oscillator circuits are included.

 

Recording Conveniences

Inn JVC's "Real Time" pause mechanism, the heads are in contact with the tape even in the pause mode. The Timer Standby facility inside the KD-95 permits repeated, interrupted record and play - a feature rarely found on cassette decks. Also offered are two recording circuits, one for Mic/DIN input and the other for Line input, which allow you to mix microphone sounds with other sources. Plus a pair of rack-mounting brackets, which is a standard accessory in every KD-95.

 

Specifications

Type:  Stereo cassette deck

Track System:  4-track, 2-channel

Cassettes:  C-30; C-60; C-90

Frequency Response:

Chrome Tape

Nominal :  20 - 18,000 Hz

Typical :  30 - 16,000 Hz

SF Tape

Nominal :  20 - 17,000 Hz

Typical :  30 - 15,000 Hz

Signal-to-Noise Ratio:  56 dB (from peak level, weighted)

The Signal-to-Noise Ratio is improved by 5 dB at 1 kHz and by 10 dB above 5 kHz with ANRS On

Effect of ANRS (Normal Tape)

Improvement of SN :  the same with ANRS

Improvement of Frequency Response :  6 dB at 10 kHz (0VU recording); 12 dB at 10 kHz (+5VU recording)

Improvement of Distortion : 3% at 10 kHz (0VU recording)

Wow and Flutter:  0,05% (WRMS); ±0,2% (DIN 45500)

Crosstalk:  65 dB

Harmonic Distortion:  1,2 %

Bias:  AC bias (95 kHz)

Erasure:  AC erasure (95 kHz)

Heads:

Recording/Playback :  Sen-Alloy head

Erasure :  Double gap, Ferrite head

Motors:

1 x FG servo DC motor

1 x DC motor

Tape Speed:  4,8 cm/sec

Fast Forward and Rewind Time:  90 sec. With C-60 cassette

Playback Equalizer Time Constant

Normal/SF Tape :  3180 µs/ 120 µs

CrO₂ Tape :  3180 µs/ 70 µs

Semiconductors:  8 ICs; 88 Transistors;  71 Diodes

Input Terminals

Mic Jack (sensitivity/Impedance):  0,2 mV/600 Ω  - 10 k Ω

Input Jack (level/impedance) :  78 mV/100 k Ω

Output Terminals

Output Jack (level/Impedance) :  0 - 0,5 V / 2 - 7 k Ω

Matching Load Impedance :  50 k Ω  or more

Headphone Jack (level/impedance) :  0,6 mW/ 8 Ω  - 1 k Ω

DIN Socket

Min. Input Level :  0,1 mV /k Ω

Input Impedance :  11 k Ω

Output Level :  0 - 0,5 V

Output Impedance :  2 - 7 k Ω

Matching Load Impedance :  50 k Ω  or more

Power Requirements:  AC 100, 120, 220, 240 V 50/60 Hz

Power Consumption:  35 W

Dimensions (W x H x D):  420 x 211 x 321 mm (16-1/2" x 8-1/4" x 12-5/8")

Weight:  11 kg (24,2 lbs)

 

Nakamichi Dragon cassette deck

The ultimate innovation in cassette technology - precise, fully automatic playback head azimuth adjustment. Optimum reproduction quality in both forward and reverse playback modes.

In a slightly different genere than the luxurious 1000ZXL, the Dragon is undoubtedly the finest cassette deck available. It represents the culmination of Nakamichi's vast technical resources and experience, retaining the basic uncompromising Nakamichi standards of performance through use of such innovations as an Asymmetrical, Dual-Capstan Double-Direct-Drive Transport, a Discrete Three-Head configuration, very high quality record/playback amplifier circuitry and, of particular interest to perfectionists, our unique NAAC (Nakamichi Auto Azimuth Correction) for the ultimate in playback performance from both sides on any tape.

 

Proper azimuth alignment is one of the most important factors in achieving the best possible cassette reproduction quality. For this reason, several Nakamichi cassette decks offer either automatic or manual adjustment of record head azimuth. Ideally, however, playback head azimuth should be adjustable so that even tapes recorded on other decks will be reproduced with the recorded frequency response and sound quality fully intact. Commercially available music tape, tapes borrowed from a friend, tapes in which the shell has warped slightly (a common occurrence) - all actually require some degree of playback head azimuth alignment to provide the best possible reproduction quality. Further, inaccuracies in cassette shell symmetry result in completely different azimuth alignment requirements in forward and reverse on auto-revers decks, often causing a significant variation in sound quality. All these points and problems LED Nakamichi to the development of the world's first fully automatic playback head azimuth alignment system NAAC, and its incorporation into this fine deck.

The Dragon's unique double direct drive system employs two Nakamichi quartz PLL servo Super Linear Torque DD motors (one for each capstan) so that wow and flutter are essentially eliminated while maintaining perfect transport stability in both forward and reverse directions. Auto reverse operation has been made available only in the playback mode so that the superb performance of the Discrete Three-head System is not compromised. Of course, full provision is made for left and right channel bias and record/playback level adjustment. All the Dragon's performance features also mean that the built-in Dolby C-type noise reduction system operates under ideal conditions for the best performance. Likewise, heads, mechanism and amplifiers are all the best available, as are features such as the microcomputer-controlled, real-time mechanism control system proven in other Nakamichi decks. Convenience features include Auto Rec Pause, where the deck automatically enters the pause mode during recording if a blank interval of 30 seconds or longer is detected in the source, switchable MPX and subsonic filters, easy cueing, and a dual-speed auto fader function, for customized recording with professional fade-in/fade-out results.

 

Specifications

System Configuration:  4-track, 2-channel stereo

Heads:  3; erase head x 1; record head x 1; 4-track, 4-channel playback head x 1

Motors Transport :

 Two Quartz PLL DC brushless, slotless coreless Super Linear  Torque DD Motor for Capstan drive

 one DC Motor for reel drive

Auto Azimuth Correction :  DC Motor

Mechanism :  DC Motor

Tape Speed: 1-7/8 ips (4,8 cm/sec)

Wow and Flutter: less than 0,019% WTD RMS; less than ±0,04%  WTD Peak

Frequency Response:

20 Hz - 22,000 Hz ±3 dB (recording level -20 dB , ZX tape)

20 Hz - 21,000 Hz ±3 dB (recording level -20 dB , SX, EX II tape)

Signal-to-Noise Ratio:

Dolby C-Type NR On [70 µs, ZX tape] :  better than 72 dB (400 Hz, 3% T.H.D., IHF A-WTD RMS)

Dolby B-Type NR On [70 µs, ZX tape] :  better than 66 dB (400 Hz, 3% T.H.D., IHF A-WTD RMS)

Total Harmonic Distortion :  less than 0,8% (400 Hz , 0 dB, ZX tape)

Less than 1% (400 Hz, 0 dB, SX, EX II tape)

Erasure:  better than 60 dB (100 Hz, 0 dB)

Separation:  better than 37 dB (1 kHz, 0 dB)

Crosstalk:  better than 60 dB (1 kHz, 0 dB)

Bias Frequency:  105 kHz

Input Line Sensitivity/Impedance :  50 mV/50 k Ω

Output Level/Impedance

Line  :  1 V (400 Hz, 0 dB, output level control at max.)/ 2,2 k Ω

Headphone :  45 mW (400 Hz, 0 dB, output level control at max.)/ 8 Ω

Black Box Series DC Output:  ±10 V, 125 mA max.

Power Requirements:  100,120, 220, 240 V AC 50/60 Hz

Power Consumption:  45 W max.

Dimensions (W x H x D):  450 x 135 x 300 mm (17-3/4" x 5-5/16" x 11-13/16"

Weight:  9,5 kg (21 lbs)