Bose Model 501 speakers

The Bose Model 501 Direct/Reflecting speaker system incorporates a ten-inch woofer and two three-inch tweeters along with a unique Direct Energy Control allowing the speaker system to easily adapt to your listening room.

Utilizing the walls, ceiling, and floor of your listening room to reflect sound, the Model 501 creates a sense of spaciousness with a strong center image. By radiating the high-frequency sound through the side and front grille panels, the 501 simulates the proportion of reflected and direct sound experienced in the larger environment of a live performance.

The ten-inch woofer found in the Model 501 provides outstanding bass performance while providing a portion of the direct sound at middle range frequencies. The extra-long excursion suspension yields powerful low distortion bass reproduction.

The Model 501 Direct Energy Control adjust the percentage of Direct Sound radiated into the listening area. This control primarily affects the spatial distribution of high-frequency energy and can be used to compensate for speaker placement and listener taste.

 

 

Specifications

Spatial Characteristics :  the Model 501 utilizes Asymmetrical Design for optimum stereo reproduction with rear and side wall reflections. The tweeters, angled toward the rear walls, reflect sound energy into the main listening area. A Direct Energy Control provided with the outward-directed tweeter allows control of the spatial characteristics of the speaker system. The Model 501 is designed in mirror-image pairs for optimum stereo reproduction.

Speaker Configuration :

Woofer - One ten-inch acoustic suspension woofer utilizing a long-throw 1,5-inch diameter voice coil with 16-ounce magnet. Linear high-excursion suspension system provides high output capability.

Tweeter - Two three-inch, wide-range tweeters with extended low-frequency response for use with Direct Energy Control Flat Total Power Radiation to over 16 kHz

Enclosure -  A walnut grain vinyl clad, floor-standing loudspeaker with acoustic suspension design and acoustically transparent side panels.

Impedance :  The impedance of the Model 501 speaker system is conservatively rated at 4 Ω , hower, since the impedance of the Model 501 is substantially above 4 Ω  over all but a small portion of the frequency range high quality receivers can operate an additional pair of 8 Ω  speakers or a second pair of 501's (connected in parallel) with no difficulty.

Power handling:  The minimum recommended power - 20 watts rms per channel. Amplifiers rated over 50 watts can be used with the Model 501, however, each channel should be fused.

Dimensions (W x H x D):  14-1/2" x 24" x 14-1/2"

Weight:  42 lbs

Yamaha NS-2000 speakers

Natural Sound Speaker System

Pure Carbon Fiber Woofer Cone

Improved Beryllium Midrange and tweeter Domes

Unique In-line Speaker Configuration and Rounded Baffle

Uncompromising Choice of Materials and Construction Throughout

Superbly Crafted Cabinetry

 

The lead in sound-oriented technology that has grown out of a hundred-year tradition has been purposefully expanded in this loudspeaker system. Although Yamaha sound transducers are "digital-proof" thanks to fast and precise signal processing, the NS-2000 system is a resounding testament to the fact that research has not rested in this area either.

 

Further refinement of the exclusive beryllium and carbon fiber technology, weight reduction of the membranes and unrivalled experience in processing valuable woods create the Yamaha system in a class of its own, with which digital progress can be heard.

 

The baffle with rounded edges reduces diffraction and ensures increased stereo definition. The precision housing was developed on the basis of irrefutable computer calculations, coupled with knowledge of sound. The bass membrane made of pure carbon fiber is super light and ultra-stable with a diameter of 33 cm. New beryllium domes have a drastically reduced weight of 0.028 g for the tweeter and 0.5 g for the midrange. The crossover is equipped with coils made of oxygen-free copper wire and large-dimensioned ferrite cores. Level controls for the tweeter and midrange are a matter of course in this class.

 

Specifications

Type:  Fully enclosed bookshelf type

Speakers:

Low Frequency :  JA3301 Woofer carbon diaphragm 330 mm (13") cone

Mid Frequency :  JA0802A Midrange Beryllium diaphragm 88 mm (3-1/2") dome

High Frequency :  JA0526A Tweeter Beryllium diaphragm 30 mm (1-3/16") dome

Nominal Input Power :  125 W

Music Input Power :  250 W

Impedance:  6 Ω

Sound Pressure Level :  90 dB/W/m

Crossover Frequencies:

Low/mid :  500 Hz (12 dB/oct)

Mid-high :  6 kHz (12 dB/oct)

Level Controls:

Mid :  +3 dB (Continuously variable)

High :  +2 dB (Continuously variable)

Enclosure:  Fully enclosed type

Volume :  80 l

Exterior:  American walnut Urethane open pore finish

Dimensions (W x H x D):  440 x 752 x 404 mm (17-5/8" x 29-5/8" x 15-7/8")with grille attached

Weight:  47 kg (103 lbs 6 oz)

 

Beveridge System 4 loudspeakers

The world acclaimed Beveridge Model 2, introduced in 1975, created new demand for a non-amplified, less expensive version of this exclusive speaker system, thus the creation of the System 3. through exposure to System 3, thousands of music lovers around the world were asking for "The Beveridge Sound".

Unfortunately, trained ears cannot always afford the best in sound or a listening studio to house a system of the size and caliber of the Beveridge System 3. the demand was there,  and once again Beveridge answered the call with System 4.

 

System 4 has the same sonic design philosophy as the other components of the Beveridge family. Mainly, flat frequency response, low distortion and more importantly, superb sound reproduction. The realistic essence of the original sound is so exact that there is virtually no difference between reproduced and original sound.

 

The Beveridgw System 4 is able to create a left to right image as well as a life-like front to back image. This three dimensional imaging is the capability that separates this extraordinary speaker system from ordinary speaker systems.

While retaining the superior live sound reproduction of larger Beveridge Systems, the System 4 is substantially smaller in both size and price. At one-third the cost of the original System 2SW-2, the System 4 uses the same electrostatic transducer with a somewhat different dispersion lens. The new 100° dispersion lens affords the owner flexibility in room placement of the speakers. They are just 63" tall and 17,5" in diameter, finished in an elegant architectural tambour designed to compliment any decor.

 

Features

Three foot high, full range electrostatic transducer covers all frequencies above 200 Hz. Electrostatic will not arc; low impedance design minimizes effects of dust, moisture and humidity.

Beveridge patented lens gives the three foot electrostatic transducer a minimum of 100° horizontal dispersion over its entire frequency range and vertical length,

Two 12" drivers in sealed box enclosures cover frequencies from 33 to 200 Hz. The design places woofer on bottom end of the column and ensures bass uniformity throughout a room.

Three way amplification:

Single amplifier

Biamplification using internal Beveridge Passive crossover provided, and

Biamplification using external crossover preferably the Beveridge RM-3 electronic crossover.

Separate fused protection for woofer section, electrostatic section and polarizing voltage section.

Step-up audio transformer custom designed for high permeability and non-saturating cores.

 

Specifications

Frequency Response:  33 Hz - 20,000 Hz ±3 dB of a flat response function of approx. -2 dB per octave, over a horizontal polar pattern of  100°

Total Harmonic Distortion :  1% at 90 dB SPL at 3,3 meters from two units as measured in an average room of 38 sq. Meters

Sound Pressure Level: 106 dB peaks, measured at 1m in a 13" x 26" room.

Woofer:  Q = 0,7 -3 dB "elbow" - 33 Hz

Crossover:  200 Hz , 18 dB/octave passive crossover. Directly by-passable

Impedance:  8 Ω  (can vary between 4 Ω  and 9 Ω )

Amplification Required:  Minimum 50 watts RSM per channel, maximum 300 watts per channel. A stable amp into variable low impedances is necessary, one capable of driving 4 mld load, as well as possessing a damping factor of 20 or over , at 10 kHz

Includes:  Two electronic line sources with built-in sub-woofer system, all step-up transformers, crossovers and polarizing voltage network.

Dimensions:

Diameter :  17,5"high :  63"

Shipping Weight:  200 lbs

Finishes:  Oak or walnut architectural tambour and black foam grill standard. Brushed silver aluminum, rosewood and unfinished birch optional. Export versions available.

 

Denon PMA-770 amplifier

Zero Dynamic Distortion

A Non-negative feedback amplifier design is ideal for driving speakers properly. Since audio signals are amplified in one direction only, the primary causes of dynamic distortion, such as time delay, are eliminated. Static distortion, which is caused by the non-linear amplification characteristics of amplifying components such as transistors, is reduced to almost theoretical limits by Denon's Distortion Servo Circuit.

Because of Denon's Non-Negative feedback technology and Distortion Servo-Circuit, the dynamic or pulsive music signals (those that change every moment in level and frequency) can be driven at high power through the widest variety of loudspeakers with surprising clarity and resolution.

The circuit is made up of 3 stages of low noise FET differential amplifiers. In the first stage current mirrors operate as the voltage amplification stage. The complementary emitter follower permits low impedance to be obtained; and is separated completely from the current amplification stage. The current amplification stage, a push-pull output configuration uses high quality, high speed power transistors, providing the speed and accuracy required for accurate reproduction of the original signal.

 

High Efficiency "Direct-A"  Power Amplifier

At the output stage, the Denon developed "Zero-Cross Linear Bias Circuit" eliminates switching distortion caused by the turning On and Off of the power transistors. This circuit enables the PMA-770 to combine both the sound quality of Class A with the high efficiency associated with Class B amplification.

 

Clean Layout and Simple Circuit Construction

The basic construction of the PMA-770 circuit has purposely been kept clean and simple as possible. The entire signal route is totally capacitorless. Even when using MC cartridges, the PMA-770 does not place a single capacitor in the main signal route, all the way from the input to the speaker output. This design speeds up while maintaining the purity of the signal and is what Denon describes as totally "DC construction"

The amplification circuit is of the dual FET differential type, resulting in greatly improved Signal-to-Noise Ratio and reduced distortion. Additionally, the employment of Denon's Direct DC Servo Circuit shut out DC drifts and stabilizes the ultra-low frequencies.

 

Specifications

Power Amplifier Section

Circuit Type:  All stage direct DC servo circuit

Rated Output Power (Both Channel Drive)

100 W + 100 W at 20 Hz to 20 kHz 8 0hm load (DIN, U.K. Europe, USA)

150 W + 150 W at 1 kHz , 4 Ω  load (DIN, U.K. USA)

50 W + 50 W at 1 kHz, 4 Ω  Load (IEC)

Total Harmonic Distortion :

0,008% (20 Hz - 20 kHz at -3 dB rated output 8 Ω  Load)

0,02% (20 Hz - 20 kHz at rated output 8 Ω  Load )

Intermodulation DIstortion :  0,002% below 7 kHz/ 60 Hz : 1/4 (at amplitude output equivalent to rated output)

Output Bandwidth:  5 Hz - 100 kHz (IHF T.H.D. 0,035%)

Transmission Characteristics:  1 Hz - 250 kHz +0 dB -3 dB (at 1 W output)

Input Sensitivity:  150 mV

Input Impedance:  47 k Ω

Output Impedance:  0,08 Ω  (1 kHz)

Output Terminals: 

Speaker A and B Load 4 - 16 Ω or A + B Load 8 - 16 Ω

Headphone/Stereo headphone

Equalizer Amplifier Section

Max. Output:  10 V (at 47 k Ω  load)

Rated Output :  150 mV

Total Harmonic Wave Distortion :  below 0,002% (at 1 kHz, 8 V output)

Input Sensitivity/Impedance

Phono MM :   2,5 mV/47 k Ω

Phono MC :  125 µV/100 Ω

Tuner :  150 mV/47 k Ω

Aux, Tape :  150 mV/47 k Ω

RIAA Deviation:

Phono MM :  within ±0,2 dB (20 Hz - 100 kHz)

Phono MC :  within ±0,2 dB (20 Hz - 100 kHz)

Overall Characteristics

Signal-to-Noise Ratio (IHF A network)

Phono MM 1, 2 :  90 dB (input terminals short-circuited for 2,5 mV input)

Phono MC :  73 dB (input terminals short-circuited for 250 mV input)

Tuner, Tape, Aux :  110 dB (input terminals short-circuited)

Tone Control Adjustable Range

Bass :  ±8 dB at 100 Hz

Treble :  ±8 dB at 10 kHz

Subsonics:  18 Hz at 6 dB/oct

Loudness

Low Frequency :  +7 dB at 100 Hz

High Frequency :  +6 dB at 10 kHz

AC Outlet:  switched x 2 100W Total, unswitched x 1 250 W

Power Requirements:  AC 120 V, 200 V, 220 V, 240 V 50/60 Hz

Power Consumption:270 W (USA); 400 W (IEC); 290 W (Hong Kong); 800 W Maximum Output

Dimensions (W x H x D):  434 x 132 x 407 mm

Weight:  12 kg

 

Denon PMA-750 amplifier

Integrated Amplifier Features:

Non-NFB (Non-Negative Feedback) Amplifier, Zero Dynamic Distortion (Patent Pending)

Super Equalizer; Super Wide RIAA Deviation 20 Hz - 100 kHz ±0,2 dB (Patent Pending)

High Power Direct-A Amplifier 80 W + 80 W

Real Drive Circuit: Significantly Reduces Distortion Under Real Operating Conditions - When Driving Speakers

Clean Simple Circuit Design Combined wirh High Quality Construction

Real-Time Tone Control

Dual Speakers Output Terminals (A or B, A+B)

Dual Input/Output Terminals for Interconnection with Two Tape Decks

A Defeatable Subsonic Filter (18 Hz, 6 dB/oct) Eliminates Unneeded Ultra Low Frequency Noise

Direct Coupling Switch Removes Tone Controls from The main Circuit

Mode Switch with Facilities for Stereo Reverse and Monaural Reproduction

Loudness Control Switch

High Speed Protection Circuity

 

Principle of the Non-Negative Feedback Amplifier

The fundamental block diagram is shown as under. At first, input signal e, and inversed output signal e, are mixed at the input of the direct DS. amplifier. Then, the distortion component d is extracted. This d is amplified by the direct DS. amplifier and is inversed and fed into the main amplifier A, with the original signal e, Thus distortion is finally reduced dramatically and static distortion is brought to zero.

 

Specifications

Power Amplifier Section

Circuit Type:  All stage direct DC servo circuit

Rated Output Power (Both Channel Drive)

80 W + 80 W at 20 Hz to 20 kHz 8 0hm load (DIN, U.K. Europe, USA)

100 W + 100 W at 1 kHz , 4 Ω  load (DIN, U.K. USA)

50 W + 50 W at 1 kHz, 4 Ω  Load (IEC)

Total Harmonic Distortion :

0,008% (20 Hz - 20 kHz at -3 dB rated output 8 Ω  Load)

0,02% (20 Hz - 20 kHz at rated output 8 Ω  Load )

Intermodulation DIstortion :  0,002% below 7 kHz/ 60 Hz : 1/4 (at amplitude output equivalent to rated output)

Output Bandwidth:  5 Hz - 100 kHz (IHF T.H.D. 0,035%)

Transmission Characteristics:  1 Hz - 250 kHz =0 dB -3 dB (at 1 W output)

Input Sensitivity:  150 mV

Input Impedance:  47 k Ω

Output Impedance:  0,08 Ω  (1 kHz)

Output Terminals: 

Speaker A and B Load 4 - 16 Ω or A + B Load 8 - 16 Ω

Headphone/Stereo headphone

Equalizer Amplifier Section

Max. Output:  10 V (at 47 k Ω  load)

Rated Output :  150 mV

Total Harmonic Wave Distortion :  below 0,002% (at 1 kHz, 8 V output)

Input Sensitivity/Impedance

Phono MM :   2,5 mV/47 k Ω

Phono MC :  125 µV/100 Ω

Tuner :  150 mV/47 k Ω

Aux, Tape :  150 mV/47 k Ω

RIAA Deviation:

Phono MM :  within ±0,2 dB (20 Hz - 100 kHz)

Phono MC :  within ±0,2 dB (20 Hz - 100 kHz)

Overall Characteristics

Signal-to-Noise Ratio (IHF A network)

Phono MM :  88 dB (input terminals short-circuited for 2,5 mV input)

Phono MC :  72 dB (input terminals short-circuited for 250 mV input)

Tuner, Tape, Aux :  110 dB (input terminals short-circuited)

Tone Control Adjustable Range

Bass :  ±8 dB at 100 Hz

Treble :  ±8 dB at 10 kHz

Subsonics:  18 Hz at 6 dB/oct

Loudness

Low Frequency :  +7 dB at 100 Hz

High Frequency :  +6 dB at 10 kHz

AC Outlet:  switched x 2 100W Total, unswitched x 1 250 W

Power Requirements:  AC 120 V, 200 V, 220 V, 240 V 50/60 Hz

Power Consumption:230 W (USA); 400 W (IEC); 200 W (Hong Kong); 680 W Maximum Output

Dimensions (W x H x D):  434 x 132 x 407 mm

Weight:  12 kg

 

SAE Mark XVII equalizer

Solid State Stereo Octave Equalizer

Control - for many years the need to tailor program material to meet individual tastes has been apparent. Highly sophisticated multi-control systems have been available to meet these needs in the recording studio, on the rock stage and at the concert hall (places where you would find the 2700B). However, the need to control sound in the home has never fully been realized, due to limitations in present consumer designs. There were numerous requests for a modestly priced, quality equalizer to improve old or worn records, and to compensate for speaker performance and room conditions without degradation of sound. The Mark XVII is the answer to these requests, incorporating many of the same unique performance and convenience features as our professional half-octave equalizer,, the 2700B. For example, we use the same long throw oil-damped graphic potentiometers as the 2700B. We feel this offers better accuracy for spectral control and smoother operation. We also incorporate our famous L-C-R network which result in the best balance of performance, low noise, and reliability. The toroid inductors are precision wound at our factory and then hand picked for each model to offer the ultimate in performance.

Finally, the latest in output design is incorporated to ensure that the Mark XVII would affect the sound in no other way than that for which it was intended - the control of frequency response. The Mark XVII can deliver over 11V into a 10 k Ω  or greater load, assuring undistorted performance with any program material. SAE's unequalled talents show through in measurements too-both T.H.D. and Intermodulation Distortion are less than 0,03% and the noise is 90 dB below rated output. We feel that such a level of performance in an equalizer of this size and flexibilty is a true innovation in the audio industry.

 

Features

Octave Control

Twenty precision L-C-R band-pass filters offer octave control for each channel. Precision-wound toroid inductors, low-loss capacitors, and precision-tracking potentiometers result in low noise, low phase shift, and low distortion.

Dual Range

The individual frequency controls operate over a range of +8 dB for program equalization or +16 dB for more drastic modification to room or speaker response. These two ranges are front panel selectable.

Individual EQ Defeat

Front panel selection is available for the individual defeat of the equalization on either channel. This offers A-B comparison between speakers and between equalized and non-equalized program material. You may also simply defeat the equalizer for some program sources.

Output Drive

The high output voltage circuitry delivers over 11 Volts RMS into a 10 k Ω  or greater load. This allows the Mark XVII to be terminated into any unique load configuration without an incrase in distortion or current limiting.

 

Specifications

Frequency Response:  20 Hz - 20,000 Hz ±0,25 dB

Bandwidth:  3 dB down at 6 Hz and 80 kHz

Total Harmonic Distortion (at any level to rated output from 20 Hz to 20 kHz):  less than 0,03%

Intermodulation Distortion (at any level of rated output with any 2 mixed frequencies between 20 Hz and 20 kHz at 4/1 voltage ratio):  less than 0,03%

Signal-to-Noise Ratio :  greater than 90 dB below rated output

Rated Output:  2,5 Volts RMS

Output at Clipping:  greater than 10 Volts into 100 k Ω ; greater than 9 Volts into 10 k Ω

Input Impedance:  100 k Ω

Output Source Impedance:  400 Ω

Output Load Impedance:  10 k Ω  minimum

Insertion Loss:  less than 1 dB with controls centered

Equalizer Range:  ±16 dB or ±8 dB at : 40 Hz,  80 Hz, 160 Hz, 320 Hz, 640 Hz, 1280 Hz, 2500 Hz, 5000 Hz, 10 kHz, 15 kHz

Power Requirements:  110, 125 V AC , 50 or 60 Hz

Power Consumption:  10 watts

Dimensions (W x H x D): 432 x 146 x 178 mm (17" x 5,75" x 7")

Weight:  20 lbs (shipping)

 

Akai CR-80 SS cartridge tape recorder

8-Track, 4/2-Channel Cartridge Recording /Playback

Model CR-80 SS is equipped with a built-in 4-channel power amplifier and 4 Speaker Jacks for Instant 4-channel or 2-channel operation. This compact unit makes 4-channel stereo recording a "cinch" even where space is a factor. The same Akai robust mechanism for top rate performance and endurance. One Micron Gap Rec/Playback Head for amazing frequency response to 16,000 Hz

 

1-Micron Gap Head

Just what is a one-micron gap head? It's a head with a width of only one astounding micron. Until now two or four micron gap heads have been the standards for comparing tape recorders. However, Akai has pushed ahead and narrowed the head gap; thus narrowing the difference between tape recording results and actual sound.

The Akai perfected one-micron gap head has these distinctive advantages over heads with wider gaps:

A - Excellent Frequency Response even at low tape speed

B - Clear, high pitched sound can be regenerated as a frequency tone and recorded smoothly with a minimum of distortion.

Motor

The motor of model CR-80 SS is a condenser starting two-speed induction motor. The winding characteristics of this 2-8 pole motor provides tape-speed stability and minimizes distortion

 

 

Other features:

Public Address System - this unit can easily be converted into a P.A. System

Automatic Stop/Continuous Play

4/2 Channel Stereo Selector

Inputa and Phone Selector

Program Indicator Lamp

 

Specifications

Track System:  8-track, 4-channel /2-channel compatible stereo

Tape Speed:  3-3/4 ips

Wow and Flutter:  less than 0,25% rms

Equalization:  Correct equalization for playback of tapes recorded to NAB curve

Frequency Response:  30 to 16,000 Hz (±3 dB)

Distortion:  less than 2% (1000 Hz "0" VU)

Output Power:

Total Music Power :  40 W (10 W each channel) at 8 Ω

Continuous Power :  28 W (7 W each channel) at 8 Ω

Signal-to-Noise Ratio:  better than 47 dB

Erase Ratio:  better than 60 dB

Bias Frequency:  60 kHz

Heads:

Rec/Playback :  8-track, 4-channel stereo head

Erase :  8-track, 4-channel erase head

Motor:  2-speed induction motor

Fast Forward Time:  4-channel stereo, 230 seconds using a 300 ft cartridge tape (approx. 15 ips)

Recording Capacity:  30/60 min. 4-ch/2-ch stereo using a 300 ft cartridge tape

Output Jacks

Line (4) :  1,23 V("0" VU) / 100 Ω

Speaker (4) :  10 W / 8 Ω 

Phone (1) :  30 mV / 8 Ω

Input Jacks:

Mic (4) :  0,5 mV/5 k Ω

Line (4) :  50 mV/150 k Ω

DIN Jacks:  2 Input/Output DIN jacks:  0,4 V/10 mV (front/rear channels)

Semiconductors:  19 Transistors; 19 Diodes

Integrated Circuits:  4 Linear IC; 4 Power IC

Power Requirements:  120 V 60 Hz

Power Consumption:  75 W

Dimensions (W x H x D):  485 x 138 x 280 mm (19,4" x 5,5" x 11,2")

Weight:  12 kg (26 lbs)

 

Akai GXC-710D cassette deck

The GXC 710D is another front-load model , and very sophisticated it is, too.

The Double Action" eject and tape loading safety feature is completely foolproof. When you press the Eject button, the cassette envelope moves out from the front panel just like a drawer. The upper part is carefully positioned for easy tape loading and levers at either side of the cassette holder make sure the cassette can't be inserted upside down. It's easy it's simple. And it's safe.

The combination once again of Akai's GX head plus Dolby Noise reduction plus Akai's ADR system plus a new drive system gives the highest of hi-fi performance. Tape speed is perfectly stabilised. Wow/flutter is as low as 0,08% rms. What's more, with the switchable Multiplex Filter circuit to cut out the 19 kHz pilot signal during stereo broadcast recording through an FM receiver, you get a clear and undistorted frequency response range to 17,000 Hz.

The rest of the features you can almost tale for granted. But let's just remind you of them to make sure you know exactly how much the GXC 710D has to offer you.. Memory Rewind Peak Level Indicator. Tape Selector Switches (low noise, CrO₂, ferrichrome) Direct Function Change Controls . Mic/Line Input Selector for improved Signal-to-Noise Ratio . Automatic Stop with tape release. Pause Control Line Output Level Control.

The GXC 710D is, as we said a very sophisticated machine- in its styling , in its features and in its outstanding performance.

 

Specifications

Track System:  4-trak, 2-channel stereo

Tape Speed:  4,8 cm/s (1-7/8 ips

Wow and Flutter:  less than 0,08% WRMS

Frequency Response: 

Low Noise Tape :  30 to 14,000 Hz (±3 dB)

CrO₂ Tape :  30 to 16,000 Hz (±3 dB)

Fe-Cr  Tape :  30 - 17,000 Hz (±3 dB)

Distortion:  less than 1,5 % (1,000 Hz 0 VU)

Signal-to-Noise Ratio:  better than 50 dB (with Dolby; up to 60 dB , above 5 kHz)

Bias Frequency:  100 kHz

Erase Ratio:  better than 70 dB

Heads:  GX recording/playback head and erase head

Motor:  4-pole hysteresis synchronous outer-rotor motor

Fast Forward and Rewind Time:  80 sec C-60 cassette tape

Output Jack: 

Line :  0,775 V (0 VU) required load impedance; more than 10 k Ω

Phone :  30 mV/8 Ω

Input Jack:

Microphone :  0,3 mV/5 k Ω

Line :  70 mV/100 k Ω

DIN Jack : 

Output :  0,55 V

Input :  3 mV

Dimensions (W x H x D):  440 x 142 x 304 mm (17,3" x 5,6" x 12")

Weight:  8,8 kg (19,4 lbs)

 

Akai GXC-310D cassette deck

The GXC-310D takes great pride in its performance. For example, it has a closed loop double capstan drive system - a feature usually found only in very expensive cassette models. With this system, the recording/playback heads is positioned in the centre between two capstans and pinch rollers. This not only gives better head-to-tape contact but also maintains constant tape tension.

An integral part of this system is an anti-vibration hysteresis synchronous motor. The net result of this combination is outstanding tape travel stability, constant tape tension and speed, and an excellent wow/flutter specification of 0,07% RMS.

Like all Akai cassette machines, the GXC-310D features the Dolby NR system to reduce tape hiss to a virtually inaudible level, give a bigger frequency response and a better Signal-to-Noise Ratio. But it also features Akai's ADR (Automatic Distortion Reduction) system which varies the equalisation at high input levels to cut distortion and extend the dynamic range at high frequencies.

Its amny other features include a Peak Level indicator, Automatic Stop, Limiter switch, Mic/Line Input Selector for a wider dynamic margin and less noise, Pause Control, Output Level Control for perfect matching with any amplifier input, Tape Run indicator, Memory Rewind and Index Counter, direct function change controls and a bias and equalisation switch for low noise, CrO₂ or ferrichrome tape. Again, there's a specially designed perspex dust cover as an optional extra.

 

Specifications

Track System:  4-trak, 2-channel stereo

Tape Speed:  4,8 cm/s (1-7/8 ips

Wow and Flutter:  less than 0,07% WRMS

Frequency Response: 

Low Noise Tape :  30 to 14,000 Hz (±3 dB)

CrO₂ Tape :  30 to 16,000 Hz (±3 dB)

Fe-Cr Tape :  30 - 17,000 Hz (±3 dB)

Distortion:  less than 1,5 % (1,000 Hz 0 VU)

Signal-to-Noise Ratio:  better than 50 dB (with Dolby; up to 60 dB , above 5 kHz)

Bias Frequency:  100 kHz

Erase Ratio:  better than 70 dB

Heads:  GX recording/playback head and erase head

Motor:  4-pole hysteresis synchronous outer-rotor motor

Fast Forward and Rewind Time:  75 sec C-60 cassette tape

Output Jack: 

Line :  0,775 V (0 VU) required load impedance; more than 10 k Ω

Phone :  30 mV/8 Ω

Input Jack:

Microphone :  0,3 mV/5 k Ω

Line :  60 mV/100 k Ω

DIN Jack : 

Output :  0,4 V

Input :  2 mV

Dimensions (W x H x D):  440 x 142 x 300 mm (17,3" x 5,6" x 11,8")

Weight:  8,6 kg (18,9 lbs)

 

Nakamichi 580 cassette tape deck

The Crystalloy SuperHead

The 580 uses the record/play SuperHead, originally introduced on the 600 II Cassette Console. The latest version of this head boasts an incredibly narrow 0,9 micron gap. This is narrower than most playback-only heads in three-head designs, and it assures distortion-free playback of the highest frequencies. Yet, during record, the amazing SuperHead magnetizes the tape as if it has a much wider gap, thanks to proprietary manufacturing techniques that virtually eliminate head core saturation. The prof. Is in the 580's remarkable frequency response, there are many three-head cassette decks on the market that cannot come close to matching this performance. The magnetic properties of Crystalloy, furthermore, are far closer to ideal than anything else currently available, including sendust to none, which means distortion is very low. And thanks to special surface "cutouts", the SuperHead lasts a long time. 

 

 

The Direct Flux Erase Head

Mast manufacturers would be very satisfied indeed with a unique device lke the record/play SuperHead. But Nakamichi's in-depth research has shown that even the best of record/play heads can be further improved by providing more complete erasure than normally available. Any noise left on the tape before it reaches the record head can be detrimental to sound quality. The noise is "modulated" by the record head signal, and the recording is thus robbed of clarity. This has been a much neglected area because most designers assume that all an erase head needs do is bring the previously recorded signal down to the level of tape hiss. But in our tests, we found that recordings made on "virgin" or bulk-erased tape sounded better and had less modulation noise than a recording made on normally erased tape. The implication was clear; an erase head should ideally do the same thing as a powerful bulk-eraser.

 

Specifications

Tape Speed:  4,8 cm/s (1-7/8 ips) ±1%

Wow and Flutter:  less than 0,1% WTD Peak 0,05% WTD rms

Frequency Response:  20 - 20,000 Hz ±3 dB (SX, EXII Tapes, -20 dB Rec. Level)

Signal-to-Noise Ratio:  better than 60 dB at 400 Hz, 0 dB, IHF-A WTD rms (Dolby  NR In. SX Tape) better than 63 dB at 400 Hz, 0 dB (SX, EXII Tapes

Total Harmonic Distortion :  less than 1,5% at 400 Hz, 0 dB (SX, EXII Tapes)

Erasure:  better than 60 dB below saturation level at 1 kHz

Separation:  better than 37 dB at 1 kHz, 0 dB

Crosstalk:  better than 60 dB at 1 kHz, 0 dB

Bias Frequency:  105 kHz

Input Sensitivity/Impedance:  50 mV/50 k Ω

Output Level/Impedance:  1 V (400 Hz, 0 dB, (at Max.)/3,3 k Ω

Headphone:  45 mW

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

Power Consumption:  20 W max.

Dimensions (W x H x D):  500 x 130 x 350 mm (19-11/16" x 5-1/8" x 13-25/32")

Weight:  8,3 kg (18 lb 5 oz)