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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
DUAL DMS 200
Technical data
Stylus: DN201, 0,6 ±0,1 mil spherical diamond stylus for micro-groove and stereo records
Recommended stylus pressure: 2,5 g (2 -3 g)
Frequency range: 20 c.p.s. to 20 k c.p.s.
Output: ≥ 0,7 mV/1cm/sec perchannel at 1 k c.p.s.
Output difference between channels: Max. 2 dB at 1 k c.p.s.
Isolation between channels: Min. 20 dB at 1 k c.p.s.
Compliance: Horizontal 18 x 10-⁶ cm/dyn; Vertical 18 x 10-⁶ cm/dyn
Intermodulation distortion (FIM): At 2,5 g stylus pressure, 8 cm/sec velocity, ≤ 0,7%
Net weight: 7 p
End resistance: 47 kOhm
Impedance: 5,5 kOhm at 1 k c.p.s.
Ohmic resistance: 1,2 kOhm
Inductance: 850 mH
Un registratore con caratteristiche professionali che stabilisce nuovi parametri nella registrazione in cassetta
Questo modell è frutto della grande esperienza e della sorprendente ingegniosità dei progettisti e deitecnici della Akai che hanno saputoriassumere nel GXC-760D a caricamento verticale e di dimensioni molto compatte, le più raffinate e avanzate tecnologie degli anni '80. 3 motori, 2 per il trascinamento del nastro e il nuovo C.P.G. (polo centrale a frequenze generate) equipaggiato di 40 ingranaggi laterali generatori di impulsi che forniscono la rivelazione al compratore elettronico, per l'accuratezza e la stabilità di rotazione dei 2 capstan a circuito chiuso. 3 testine di cui 2 GX (Monocristallo di ferrite) accoppiate e incapsulate in vetro, in un unico monoblocco, per l'eliminazione della deviazione di fase con possibilità di doppio monitoring professionale. Comandi con circuiti logici a relais che consentono il passaggio da una funzione all'altra con una rapidità e dolcezza di funzionamento senza precedenti.
Qualità timbriche e dinamiche eccezionali con valori di fluttuazione paragonabili a quelli di un registratore professionale a bobine. Esclusivo circuito per la lettura diretta sugli strumenti dei segnali di picco. Dispositivi di calibrazione del livello Dolby in rapporto all'equalizzazione del nastro utilizzato. Possibilità di missaggio del suono tra gli ingressi microfonici e di linea. Possibilità di registrazione temporizzata con comando a distanza (opzionale). Filtro Multiplex. Memoria per arresto automatico del nastro. Dispositivo per la regolazione automatica della tensione del nastro quando si inserisce una nuova casetta. 82 transistors, 8 FET, 8 CI, 125 diodi. La risposta in frequenza si estende entro ±3 dB da 30 a 19KHz con Dolby inserito e la fluttuazione è inferiore allo 0,09%. Styling di grande class e pregio.
Specifications:
Manufacturer: Akai, Japan
Tape counter: 3 digits
Drive type: 1 x servo capstan motor, 2 x DC motors
Head assembly: 1 x GX-2-head system for recording and playback, 1 x delete head
Noise reduction circuit: Dolby, calibrated
Tape equalization: "ADR" system
Inputs: Mic: 0.3 mV 4.7 kohms; Line: 100 mV 70 kohms
Outputs: Line: 775 mV; Headphones: 8 ohms
Level meters display: 2 x switchable VU meters as peak value indicator
Frequency response: 30-19000 Hz (FeCr); 30-16000 Hz (CrO)
Wow and flutter: ± 0.15%
Dimensions: 440 x 142 x 306 mm
Weight: 10 kg
STEREO/MONO POWER AMPLIFIER
POWER HEADROOM
Separating what you do want in fine musical reproduction from what you don't want is a job that calls for power-lots of it. Distortion, noise and unwanted tonal coloration must go. That's why every circuit in the BA-5000 is designed with more than enough power headroom to eliminate everything but the music each step of the way along the circuit chain. Abundant power reserve also enables transients, dynamics and range to be preserved without strain and without the slightest hint of coloration oraudible noise. The meaning of power becomes clear asyou enjoy the musical resolution, transparency and definition of the BA-5000. Here are the facts about its construction and design.
INPUT
The differential amplifier at the input stage of the BA-5000 uses a dual-transistor formed on one semiconductor wafer. Since it offers a high input/low output impedancecharacteristic, the circuit operates with unwavering stability at all times, regardless of the input level control settings.
DRIVER
Next,the pre-driver circuit is a 2-stage differential amplifier using a dual-transistor stage for balanced zero voltage, followed by an active-loaded driver stage for high-gain Class-A amplification. This allows the application of optimum and stable negative feedback to drastically reduce all types of distortion.
OUTPUT
Three Darlington-connected amplifier stages for high current gain are found in the final output stage, terminated by eight large power transistors, for each channel. The power transistors are arranged in an elaborate "four-in-parallel" OCL complementary symmetry push-pull configuration. This means that linearity is maintained throughout to reduce distortionand further extend power headroom. Results: per channels power output of 300 watts, min. RMS, both channels driven into 8 ohms over a 20 to 20,000 Hz bandwith with no more than 0,1% total harmonic distortion. It is here that the proof of the BA-5000's overall integrity is heard - a very wide dymanic range, and a realistic bass reproduction with virtually no distortion at rated output.
POWER STRAPPING
A high-efficiency transformer couples the final stage of the output power circuit to the speaker terminals. This allows the BA-5000 to deliver its rated output at loads of 8 ohms, 4 ohms or 2 ohms in 2-channel operation; in mono the total of 600 watts, min. RMS over a 20 to 20,000 Hz bandwidth, with no more than 0,1% total harmonic distortion, is available across loads of 16 ohms, available for professional studio work or for PA use at live rock concerts, etc.
BANDPASS FILTER
The transformer also functions as a bandpass filter to cut subsonic signals, such as are generated by warper or offcentered records. Speaker cones are thus protected against exessive excursion and resulting breakdowns.
PROTECTION INDICATOR
If temperatures or electrical conditions warrant the triple protection circuit operates and the front panel Power/Protector indicator changes fromgreen to red; the LED lamp will continue to glow red until safe conditions are restored. It also illuminates in red for moments after power-on, then turns green to indicate that power issafely available to speaker terminals.
PROTECTION CIRCUITS
The BA-5000 has three thoroughly dependable protection circuits:
An ASO detection circuit monitors teh current flow in power transistors and limits the current entering the final stage instantly if the latter semiconductors are forced to work beyond thier Area of Safe Operation (ASO);
A self-restoring temperature detection circuit with a thermistor cuts off the incoming signals from the driver stage if heat rises as the result of overloads or other abnormalities;
An overload detection circuit with quick-acting fuses is also included.
METERS
Accurate metering, a touchy point in amplifiers of this size and quality is assured by the use of two very responsive meters calibrated on the logarithmically compresses scale in steps from 0,01 to 300 watts (8 ohms); scales in decibeles are also provided ( -50 to +5 dB). Pulsive inputs are shown accurately and more quickly than in even the best VUs for correct output power indication.
POWER TRANSFORMER
Less magnetic leakage flux. A highly concentrated magnetic field. Less heat generation. Smaller size and improved power regulation. These are some of teh advantages of the special power transformae which add up to improved transient response, allowing the BA-5000 to respond to pulsive musical signals instantaneously regardless of level. Sansui has used toroidal coil windings on a seamless ring and a twin positive/negative dual power supply format with separate windings for left and right channels to prevent potentially harmful channelinteraction. This transformer also has special provisions for eliminating the audible "thump" of power-on switching.
CAPACITORS
The four oversized electrolityc capacitors (each 22,000µF for a total of 88,000µF) regulate power evenly whether input levels are high or low.
SUPPLY
Low-level circuits such as the input and driver stages are fedbalanced negative/positive current fron an independent dual power supply.
CONTROLS,CONNECTIONS AND MOUNTING
Individual left and right input controls on the front panel, and one stereo set of speaker terminals on the rear panel are provided. The solid chassis uses thick 2 mm steel plates; it is sized and designed forprofessional rack mounting. The chassis cover is an attractive vintage claret color, with jet-black alumite face plate and aluminum trim. The top panel carries the block diagram of the amplifier inside for the benefit of engineering-oriented enthusiasts.Voltage outputs of 70V MONO and 25V STEREO areindicated on the rear panel for convenience in professional applications.
SPECIFICATIONS
POWER OUTPUT:
STEREO; Min.RMS both channels driven from 20 -20000 Hz,with no more than 0,1% THD
300 watts per channel into 2, 4, 8 ohms
24,5 volts into 2 ohms
34,6 volts into 4 ohms
49,0 volts into 8 ohms
MONO; Min. RMS from 20 - 20000 Hz,with no more than 0,1% THD
600 watts into 4, 8, 16 ohms
49,0 volts into 4 ohms
69,3 volts into 8 ohms
98,0 volts into 16 ohms
LOAD IMPEDANCE:
STEREO; 2, 4, 8 ohms
MONO; 4, 8, 16 ohms
OUTPUT VOLTAGE: 25 volts stereo; 70 volts mono
POWER BANDWIDTH: 20 - 20000 Hz at or below rated min. RMS power output and THD
TOTAL HARMONIC DISTORTION: less than 0,1% at or below rated min. RMS power output
INTERMODULATION DISTORTION: (70 Hz; 7000 Hz = 4:1 SMPTE method) less than 0,1%
FREQUENCY RESPONSE: 15 - 30000 Hz, +0dB, -2dB (at 1 watt)
DAMPING FACTOR: approx. 10 at 8 ohm load
HUM AND NOISE (IHF): better than 100 dB
INPUT SENSITIVITY AND IMPEDANCE: 700 mV, 50 kohms (1000 Hz for rated output)
AC OUTLET: unswitched total 150 watts
SEMICONDUCTORS: 59 Transistors, 34 Diodes, 5 Zener Diodes, 2 ICs, 1 LED
POWER REQUIREMENTS:
Power Voltage; 100, 120, 220, 240 V, 50/60 Hz
Power Consumption; 490 watts (rated) 1350 watts (max.)
DIMENSIONS: 482 x 222 x 466 mm (19 x 8¾ x 18 inch)
WEIGHT: 49 kg (108,0 lbs) Net.
Maxell UD XL I e UD XL II: per ogni audiofilo che si rispetti non può esserci alternativa.
Il vostro registratore quasi certamente possiede un selettore per cassette del tipo normale e del tipo cromo. la Maxell vi propone due casette radicalmente nuove che offrono la possibilita di ottenere il meglio dal vostro apparecchio secondo quale posizione del selettore vogliate usare; si chiamano UD XL I e UD XL II.
La UD XL I è stata concepita esclusivamente per l'uso con il selettore del nastro sulla posizione "normal" (120µs di equalizzazione). Confrontata con cassette convenzionali, possiesde un livello massimo di uscita superiore di 8 dB sull'intera gamma delle frequenze. Diventa cosi possibile eseguire registrazioni assolutamente prive di distorsioni anche con alti livelli d'entrata ed in registrazioni dal vivo.
La Maxell UD XL II invece è stata concepita per l'uso con selettore di nastro sulla posizione CrO₂ (Crome) (70µs di equalizzazione). Ciò permette di sfruttare la capacità di ridurre il rumore di fondo propria di questo circuito che generalmente riduce i rumori dell alte frequenze fino a 4 - 5 dB, permettendovi registrazioni pulite e trasparenti senza il minimo "soffio" di sottofondo. Ma, fatto ancora più importante, questa cassetta possiede un raporto segnale/disturbo superiore di 5 dB rispetto alle migliori cassette al cromo ed al ferri-cromo, senza presentare i difetti legati al nastro al cromo quali l'usura delle testine e la risposta molto limitata sulle medie frequenze.
Ma non è tutto: la stupefacente fedeltà di queste nuove Maxell è assicurata anche dalla meticolosa lavorazione della cassetta che in ogni sua parte presenta tolleranze comprese entro 1/5 di quelle ammesse dagli standart philips, oltre ad avere incorporato un sistema di guide del nastro ruotante su supporti in acciaio inossidabile per una completa e totale assenza di wow e flutter. Infine, anche queste nuove cassette adottano l'ormai famoso ed esclusivo "leader tape" Maxell a 4 funzioni:
pulisci testine non abrasivo;
5 secondi esatti per "cueing";
frecce che indicano la direzione di rotazione del nastro;
contrassegni A/B per riconoscere il lato che sta per essere adoperato.
Ogni registratore di classe dispone di commutatore per le cassette al biossidio di cromo. Quindi, a ogni registratore con CrO₂ cassette BASF CrO₂ - per ottenere il massimo livello di dinamica a tutte le frequenze, qualità d'ascolto Hi-Fi, bassissimo rumore di fondo nella registrazione.
Tre vantaggi in uno, Cassette BASF CrO₂
Miglioramento della dinamica: cassette BASF al biossido di cromo, massima dinamica a tutte le frequenze, è un nastro speciale che porta le cassette a livello Hi-Fi.
Meccanica Speciale SM: Finalmente scorrimento del nastro senza problemi, Ridottissimo rumore di fondo, niente più bloccaggi o miagolii.
In versione C-BOX: novità esclusiva BASF, una leggera pressione sul tasto roso e la cassetta è pronta per l'uso. C-BOX; l'idea BASF che aspettavate per mettere ordine fra vostre cassette.
THIEL Audio approaches speaker system design with the intention of providing the discriminating listener with musically accurate loudspeakers that incorporate a broad range of important performance characteristics. Our emphasis on total performance requires attention not only to musical qualities, but also to such characteristics as high efficiency, rellabillity and cost-effectiveness. The Thiel model 02 loudspeaker is a two way ported design that provides smooth, natural reproduction and good bass response in an efficient bookshelf system.
PERFORMANCE FEATURES
Smoothness and balance are the most critical factors for natural sounding reproduction of music. The Model 02 has a smooth response and is accurately balanced, resulting in very detailed and natural sound. Accurate bass response is an important musical characteristic that is often not achieved in speakers in this price class. The bass response of the Model 02 is clean and tight, extending flat to 45 Hz without boom or distortion.
Efficiency,although not directly audible, is very important for realistic reproduction of the dynamic range of music. Dynamic range capability without amplifier overload is facilitated by the high efficiency of the Model 02. The combination of natural reproduction, good bass response and high efficiency distinguishes the Model 02 as an exceptional value in its price class.
TECHNIQUES
Relatively small diameter drivers are employed for excellent transient response, very broad dispersion and uniform power response. The woofer is a 6½ inch unit for accurate reproduction of midrange musical detail. A high crossover is thus permitted, which is above the ear's most critical range. The bass frequencies are produced by a ported system with a fourth order Butterworth tuning to 45 Hz. The extended bass response is the result of the small woofer with a long throw voice coil in conjunction with the port loading. The tweeter is a one inch cloth dome exhibiting excellent transient and dispersion characteristic extending to 20,000 Hz.
The cabinet is hand-crafted with geniune hardwood venners with a natural, lacquered finish. This finish is designed to show off the inherent beauty of the specially selected cabined woods; Black Walnut, Brazilian Rosewood or White Oak.
Quality is carefully maintained throughout manufacture. Each driver and crossover is individually tested before final installation. After completion the system is carefully inspected and again tested to asure that it is performing to specifications. The confidence that we have in its quality and dependability is reflected in our 5 year warranty.
SPECIFICATIONS
Frequency response: flat ± 2dB 45 - 20,000 Hz
Sensitivity: 90 dB/watt-meter
Crossover frequency: 60 Hz accoustical, 2000 Hz
Recommended power: 10 - 100 watts
Enclosure type: tuned port
Size: 19 x 11 9,5 inches
Weight: 22 pounds
Cabinet options: Walnut, Rosewood, Oak
Grille: black doubleknit polyester
Warranty: 5 year limited
Specifications
DESIGN:
2-driver, 2-way bass reflex, quasi-3rd order resistive port.
CROSSOVER:
2an order electro/acoustic at 1,8 kHz
HIGH FREQUENCY DRIVER:
25 mm (1") TTD™ treated textile dome with aluminum former, ferro-fluid cooled and damped.
BASS/ MIDRANGE DRIVER:
165 mm (6½") with diecast chassis, polypropylene cone and Apical™ former.
PERFORMANCE
LOW FREQUENCY EXTENSION:
40 Hz (DIN)
FREQUENCY RESPONSE;
> On Axis (0⁰): ±2 dB from 70 Hz - 20 kHz
> Off Axis (30⁰): ±2 dB from 70 Hz - 15 kHz
SENSITIVITY-ROOM/ANECHOIC:
89 dB/86 dB
SUITABLE AMPLIFIER POWER RANGE:
15 - 100 watts
MAX INPUT POWER:
80 watts
NOMINAL/MIN IMPEDANCE:
8 ohms / 4 ohms
PHYSICAL:
INTERNAL VOLUME: 11,1 litres (0,39 cuf)
HEIGHT: 33 cm (13 in)
WIDTH: 21 cm (8 in)
DEPTH: 28 cm (11 in)
WEIGHT: 14 kg (31 lbs)
FINISHES: Black Oak, Oak
Drive Units
1 x 26mm high-frequency with aluminium dome, 26mm coil on aluminium former, wound with polymide resin and heat cured
2 x 200mm bass/midrange with composite short fibre cone, 26mm coil on high temperature former, wound with polymide resin and heat cured
Frequency Response:
50Hz – 20kHz ± 2.5dB on reference axis
Sensitivity:
91dB spl(2.83V 1m)
Nominal Impedance:
8 ohms
Power Handling:
10W – 150W into 8 ohms on unclipped programme
Dimensions:
Height: 886mm, Width: 236mm, Depth: 407mm
Finish:
Black ash or walnut vinyl