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





Aiwa DX-1500

Hassle-free Playback

Just drop in a CD and press the Play button. The front-loading drawer closes automatically and playback begins.

16-track programmable Playback

Up to 16 selections (including repeats) can be easily programmed into the DX-1500 for playback in any order you like.

Advanced 3-beam laser pickup

The DX-1500's advanced 3-beam laser pickup has been designed for positive and precise tracking of the "pit lane" encoded on Compact Discs. The main laser beam is guided by two sub-beams which track on either side, using highly responsive electronic servo circuitry to keep the main laser on course. The pickup assembly is driven by a linear motor for extremaly fast access time.

High performance LSI's Improve Precision and Stability

The servo control, digital, and D/A sections have been engineered onto specially designed LSI's to simplify signal paths and improve the precision and reliability of signal transmission for faithful reproduction of CD. Along with specially chosen high-quality electronic components, they have been integrated onto a single circuit board which is insulated from the main chassis to avoid electromagnetic interference which can degrade sound quality.

Plus:

Forward and back skip with a single touch

3-way music repeat; entire disc/one track/programmed selections

Manual cue and review (with sound); fast cueing (without sound) in both directions possible in the pause mode

Headphone jack with volume control

Specifications

Frequency response: 2 Hz to 20 kHz (± 1 dB)

Dynamic range: more than 90 dB

Signal-to-noise ratio: more than 90 dB (at 1 kHz, 0 dB)

Channel separation: more than 90 dB (at 1 kHz , 0 dB)

THD: less than 0,004% (at 1kHz)

Wow and flutter: Quartz crystal oscillator precision

Sampling frequency: 44,1 kHz

Quantization: 16 bits linear/channel

Error correction: Cross Interleave Reed Solomon Code (CIRC)

Modulation: Eight to Fourteen Modulation (EFM)

Optical stylus: GaAIAs semiconductor laser ( λ = 780 mm)

Output terminal: Pin jack

Line out: max. output level: 2 V (50 kΩ)

Load impedance: 10 kΩ or more

Headphone out: 12 mW (32 Ω)

Power source: 120/ 220/ 240 V, 50/60 Hz

Dimensions (W x H x D): 330 x 74 x 306 mm

Weight: 3,4 kg

Rotel RT-2100 (1978)

QUARTZ LOCK

As obvious as it may seem, a tuner's true worth is determined by the accuracy of its tuning. Both of Rotel's 2000 series tuners ensure absolute precision by using a quartz crystal oscillator lock system.

Rotel's quartz lock system automatically compares the precise 10,7 MHz emaneting from the oscillator with the approximate 10,7 MHz of the intermediate frequency (IF). Should there be a discrepancy a positive or negative signal is accordingly emitted by the phase comparator which passes through the low pass filter (LPF) and serves to lock the local oscillator.

Touching the tuning knob unlocks the quartz control. Releasing one's hand from the tuning knob automatically activates the quartz lock circuit which then maintains the station selected. Once tuned stable reception is quaranteed and drift is eliminated regardless of changes oscillation is locked.

NEW LED INDICATOR TUNING SYSTEM

Touching the tuning knob causes the quartz lock to unlock upon register of induction voltage. This then causes the local oscillator frequency to become linear and when the tuning pointer approaches the desired broadcasting signal or within ±60 kHz of it the side indicator lamp goes on. When the tuning pointer further moves to within ±8 kHz of the desired station (capture range) the center green indicator light goes on. Releasing the tuning knob at this point causes the tuning lights to extinguish and the quartz lock indicator light on the right side to go on signifying that the quartz lock is operating.

FM FRONT END, IF SECTION

Rotel uses a linear-frequency precision 5 gang variable capacitors. The RT-2100 has a 3 Dual-Gate MOS FET stages, (while RT-2000 has one Dual-Gate MOS FET), both employing the best low-noise components, with resultant superior interference reiection capability as well as having a positive effect on cross modulation interference. The intermediate frequency band is divided into 2 stages, WIDE and NARROW, which ensures superior sound quality under varying conditions of reception, and the linear phase filter aids in low distortion and superior stereo separation.

DIGITAL INDICATORS

Tuning is made amazingly simple and accurate by employing a digital station indicator that can be read at a glance in conjunction with the quartz PLL lock. The signal indicator also uses an easy to see yet beautifully designed LED display system.

MULTIPATH INTERFERENCE SUPPRESSION

The multipath phenomenon in FM reception, similar to double images on television , can adversely affect sound fidelity. With the Multipath switch "ON" it is possible to select the optimum position for an antenna. The degree of multipath interference can be checked with the digital signal indicator on the RT-2100 ( and the signal meter on the RT-2000).

SUPERIOR MPX SECTION

In order to improve frequency characteristics in the MPX section, Rotel has paid particular attention to the cut off of the pilot signal (19 kHz) and weakening of the carrier signal (38 kHz). By using LC block filters, high frequency range drop is minimized and a wide range is guaranteed, with the result that rich sound reproduction is possible. The PLL IC is employed to assure constant high stereo separation at low distortion for wide dynamic range.

IF BAND SELECTOR

IF (intermediate frequency) is the front end output (unified at 10,7 MHz for FM) resulting from the difference between the broadcasting signal received and the oscillator frequency. Rotel makes it possible to select between two options Wide or Narrow. When reception is weak, use of a narrow IF band can result in superior selection.


DOLBY FM

When receiving a Dolbylized FM broadcast, turning the function selector on the RT-2100 to the Dolby FM position activates the Dolby NR circuitry and enables enjoyment of a clear sound at lower distortion without loss of frequency response.

TAPE RECORDER LEVEL CHECK

Push the REC CHECK button activates a 400 Hz tone signal from the built-in circuitry. Fail-safe recording is ensured if the tape deck recording level is then set (usually 0 dB) on this tone to prevent overloading by the broadcast signal.

HI BLEND SWITCH

Rotel's Hi-Blend switch creates a faithful and easy-to-listen-to reproduction by cutting out unwanted high frequencynoise with minimum loss for stereo separation and frequency response.


SPECIFICATIONS ROTEL RT-2100

Effective selectivity (IHF): narrow: 80 dB

Frequency characteristic: 30 Hz - 15 kHz ±0.2 dB

Stereo separation: 47 dB (1 kHz)

Capture ratio: 1 dB

Image stonewalling ratio: 115 dB

IF stonewalling ratio: 115 dB

Sensitivity (IHF):

stereo: 36 dBf/35 microvolts (S/N 50dB)

mono: 9.3 dBf/1.6 microvolts (S/N 26dB)

S/N ratio (IHF):

stereo : 75 dB

mono : 80 dB

THD wide:

stereo : 0.07%

mono : 0.05%

THD narrow:

stereo : 0.2%

mono : 0.15%

Muting: 5 microvolts

Dimensions (W x H x D): 482 x 143 x 328 mm

Weight: 7,5 kg

Rotel RD-2200 (1978)

SC REC/PB HEAD

Rotel's 2000 series uses the newly developed and superior SC (sendust core) Head for its REC/PB cassette deck head. The Sendust alloy adds silicon and aluminum to pure iron to give the best magnetic characteristics possible in the ideal REC/PB head.

The Sendust Head solves the problems of weakness and headwear in permalloy and the poor magnetic characteristics of ferrite, which is durable but liable to cracking. Excellent magnetic permeability and a high S/N ratio are thereby guaranteed. Moreover, since it provides as accurate a gap as the ferrite head, even very high frequebcy characteristics are improved. IN addition, with a greater maximum flux density then permalloy linearity is improved and less headwear results in superior performance. A magnetic coercity of 1/2 that of ferrite but magnetic properties equivalent to permalloy ensures less need for demagnetization and overall ease of maintenance.

LED BAR CHART PEAK LEVEL INDICATORS

The RD-2200 uses the ultra modern LED BAR CHART PEAK INDICATOR for record and playback. This consists of 13 independent LED each for both right and left channels that register from - 20 dB to +3 dB. Compared to the analogue system of other peak level meters with limited speed of response, the digital system is superior in speed and presentation since it converts information into peak and average levels. By eliminating all mechanical meters and employing electronic circuitry an instant and accurate register of information is ensured. Parallel displays of both right and left channels provide easy visibility and quality recording.

MEMORY FUNCTION

Depressing the Memory button during recording or playback and adjusting the tape counter to "000" means that the tape will automatically stop at "999" when rewound a major assist in listening to the same tape segment more than once.

SEPARATE MPX FILTER SWITCH

Rotel's 2000 series tape deck has a built-in separate MPX filter switch for optimum FM recording. When "ON" it cuts the 19 kHz and 38 kHz pilot/carrier signals from FM tuner to enable ideal recording; when "OFF" there is no high frequency cutout for other recordings (record disc or microphone), thus permitting optimum frequency response available for recording.

3-STAGE TAPE SE;ECTORS

The Bias and Equalizer tape selectors each have three positions and function in tandem with the superb Sendust Tape Head to get the most out of todays' high quality tapes. In addition to the three positions of Normal, Ferri-Chrome and Chrome there is a control knob for bias adjustment when the bias selector is on "NORMAL" for optimum performance with a particular tape.

DOLBY NR SYSTEM

Rotel's Dolby NR system reduces annoying tape hiss without harming frequency characteristics and improves the S/N ratio to a maximum of 10 dB. Use of Dolby IC's in the 2000 series has simplified construction and improved stability with time.

LINE/MIC/REC - MUTE SELECTOR

Rotel's RD-2200 model has a unique but effective REC MUTE position on its selector. Whereas the Pause button stops the tape and recording momentarily, the REC MUTE position merely stops the recording, and not the tape - in other words, it makes it possible to create blanks in the recording. With the addition of this function on a tape deck, editing of cassettes has become far easier.

FULL AUTO STOP

Rotels FAS mechanism operates in all modes including Record, Play, Fast-Forward and Rewind to stop the tape before it reaches the end and returns the respective buttons to their "OFF" positions.

CUE AND REVIEW

Depressing the Cue and Review switch during playback speeds the tape in either direction and normal playback is resumed instantly when the switch is released: an immeasurable aid in locating a particular song ir segment of a recording.

SPECIFICATIONS ROTEL RD-2200

Motor: EG and a DC motor

Head:

Rec play: SC head

Erasure: Double gap ferrite core

Wow and flutter: 0.05% (WRMS)

Frequency characteristic (MPX OFF):

Normal / LH tapes : 30 Hz - 17 kHz ±3 dB

CrO2/Fe Cr tape : 30 Hz - 19 kHz ±3 dB

S/N ratio (Fe Cr tape):

Dolby in: 64 dB (1 kHz, 0VU)

Dolby out: 56 dB (1 kHz, 0VU)

Input sensitivity/impedance:

Mic: 0.4 mV / 20 kohm

Line(RCA): 140 mV / 50 kohm

Line(DIN): 10 mV / 10 kohm

Output voltage: Line(RCA/DIN): 980 mV

Fast forward and a rewind time: 90 seconds (C-60)

Dimensions (W x H x D): 482 x 150 x 260 mm

Weight: 9 kg

Dynavector DV-505 tone-arm

This unconventional tone arm is our answer to to-day's advanced record cutting technplogy. The DV/505 with its biaxial arm, dynamic and electro-magnetic damping systems and spring loaded tracking force, gives 100% cartridge performance. The DV/505 arm will extrat from the Dynavector cartridge the very maximum in quality and enable you to experience tremendous satisfaction from your records. The 1977 CES Design and Engineering Exibition selected and awarded the DV/505 tone arm. Why not treat yourself to this luxury - the experience will be well worth it.

In a radical departure from conventionally accepted ways of tone arm design, Onlife Research introduces its Dynavector DV-505 arm that looks and in many ways behaves like no other tone arm ever before. By its full technical designation it is called a "magnetically damped, inertia controlled, bi-axis massdivided, dual pivot, dynamically balanced tone arm," a lengthy description whose numerous unfamiliar terms already hint at the uniqueness of this innovative design. Details about features and functions are explained on the back page; the validity of the various design innovations will be demonstrated best, however, in a careful comparative listening test i n conjunction with a high fidelity reproduction system of the highest order of professional quality.

The Dynavector DV-505 Raises Tracing Fidelity to A New Level of Accuracy.

A tone arm has to support and guide the phono cartridge in its path along the record groove, permitting it to faithfully follow all groove excursions at a light tracking force, without however vibrating, resonating or in any other way moving itself. Contrary to conventional thinking, this "steadiness" in a tonearm is best achieved by giving the arm a relatively high mechanical mass. Records, however, being mass produced, almost invariably show some small degree of warp which forces the arm up and down when playing. A n arm of large mass would, because of its high inertia, cause rather violent changes in tracking force. Ideally a tone arm should fulfill two conflicting demands: large mass for steadiness in the horizontal plane, low mass for the vertical plane. A tone arm should actually be two tone arms. Impossible?

The Dual-Pivot Dynamic Balance Dynavector Arm.

The Dynavector DV-505 is two arms in one. Its main arm section of large mass, pivoted to move only in the horizontal plane, provides a superb degree of steadiness; its sub section, separately pivoted to move only vertically, is of low mass, and tracking force is applied by a precision calibrated spring mechanism. It thus provides perfect tracking of lateral a n d vertical groove modulations without being affected by record warp.

Dynamic Damping System. Eliminates Arm Resonance

Every tone arm, being a physical mass, tends to resonate at or around a certain frequency, and this arm resonance can seriously affect the cartridge's tracking fidelity — the sound becomes "muddied" and loses all transparency and clarity. Resonances in conventional tone arms have not really been eliminated but only moved down into the subsonic region at around 10 to 20 Hz where they show up as a strong peak — up to 10 dB — in the system frequency response curve.

To solve this problem in the Dynavector DV-505, a subsidiary vibrating mass consisting of a spring bob weight is provided inside the U-shaped main arm, with its mass calculated precisely in such a way that it will resonate at the same frequency — but in exactly opposite phase — as the arm itself. This opposite resonance has the effect of cancelling out any arm resonance.


Constant, Unvarying Tracking Force

Vertical tracking force is applied by a precision made spiral spring device. This "dynamic balance" system maintains unvarying tracking force regardless of record warp.

Tracking force adjustment is done by means of a dial mounted on the sub arm pivot.


Electro-Magnetic Damping System for Perfect Tracking.

An additional measure of damping is effected by the electromagnetic damping system. A curved rod attached to the rear of the arm is embedded in a magnetic field supplied by two permanent magnets. Any minute movement of the rod, due to an undamped arm resonance, causes an eddy current to be induced in the rod, which in turn interacts with the magnetic field to return the system to its rest state. As response graphs show, the arm thus becomes virtually free from any resonance phenomenon and permits perfect tracking of even subsonic frequencies. This highly effective damping also makes the arm impervious to acoustic feedback and vibrations transmitted through the floor and turntable cabinet, to guarantee utmost clarity of sound under all operating conditions.


Free-standing Type

Thanks to its heavy base, the Dynavector arm can be placed freely on any turntable without requiring screw mounting. (Mounting holes are, however, provided.) A template is supplied for correct overhang adjustment.

Specifications

Overall lenght: 335 mm incl. head shell

Effective lenght: 241 mm

Offset angle: 21,5 degrees

Lateral tracking error: 0° at inner grooves, 2,2° at outer grooves

Overhang: 15 mm

Adjustable height range: 38 - 70 mm

Lateral and vertical sensitivity: less than 50 mg

Head shell connection: standard EIA type 4-pole connection

MartinLogan Source

High-Performance Hybrid Electrostatic Loudspeaker

Source is the world's most affordable high-performance hybrid electrostatic loudspeaker. Incorporating ultra-high-resolution AirFrame™ technology (originally developed for MartinLogan's Summit loudspeaker) Source is capable of an exceptionally dynamic and realistic performance. An 8-inch woofer, MiniETC™ (Energy Transfer Coupler) spikes, and high-end crossover engineering further reinforce Source's high-end pedigree. The result? A stellar performer at an exceptional price.

MartinLogan's advanced AirFrame™ technology and MicroPerf Generation 2 diaphragm electrostatic transducer cover the audible acoustic range with unprecedented high-frequency accuracy and low-level sonic detail. A perfectly integrated, MartinLogan engineered high-resolution 8-inch woofer supplies an authoritative bass performance with extreme precision.

State-of-the-art audio transformer and crossover engineering ensure a transparent link from amplifier to electrostatic panel and woofer. Source's crossover employs a proprietary Vojtko™ topology for vanishingly low distortion and seamless driver integration. This precision-tuned network preserves miniscule sonic nuances while handling the full dynamics of any source with unparalleled source, precision, clarity, and openness.

Key Features:

User adjustable base

CLS Generation 2 electrostatic

Ultra rigid AirFrame

MicroPerf Stators

Paper cone woofer

High-Rigidity, High-Excursion Woofer

Precision Vojtko™ crossover

Dipole Sound Radiation

Low-voltage power supply

Custom MiniETC™ spikes

FREQUENCY RESPONSE: 42-22,000 Hz ±3 dB

HORIZONTAL DISPERSION: 30°

VERTICAL DISPERSION: 28” (71 cm) Line Source

HIGH FREQUENCY: Generation 2 CLS™ electrostaic transducer

PANEL DIMENSION : 28” x 8,6” (71,1 x 21,8 cm)

RADIATING AREA : 241 in2 (1,550 cm2)

LOW FREQUENCY TRANSDUCER: 8" (20.3cm) high excursion, high-rigidity paper cone with extended throw drive assembly, non-resonance asymmetrical chamber format; bass reflex

SENSITIVITY: 90 dB/2,83 V/m

IMPEDANCE: 5 Ω, 1.6 at 20 kHz. Compatible with 4, 6, or 8 Ω rated amplifiers.

RECOMMENDED POWER: 20 - 400 Watts per channel

CROSSOVER FREQUENCY: 470 Hz

COMPONENTS: Custom-wound audio transformer, air core coils

INPUTS: Custom 5-way binding posts

FINISH OPTIONS: Black or Dark Cherry

DIMENSIONS: 1300 × 245 × 370 mm (51.2" × 9.7" × 14.6")

WEIGH: 21,4 kg (47 lbs.)

Rotel RA-2040 (1978)

ROTEL RA-2040

Stereo Class AB Integrated DC Amplifier

Rotel's top integrated amplifier, combining the characteristics of the formidable RB-200 and RC-2000

Less than 0.01% total harmonic distortion at an output of 120 watts per channel ( min.RMS both channels driven into 8 ohms from 20 to 20,000 Hz).

DC amplification

Class AB operations

Pure complimentary amplifier configuration

High overload capacity and precision RIAA equalization - the optimum design in am integrated amplifier

DC CIRCUITRY

The RA-2040 uses DC amplifiers with excellent response at very low frequencies and makes maximum use of its DC circuitry design. As is becoming standard in precision equipment, Rotel's DC amps have eliminated all capacitors ( which give unwanted time constant) from the signal path and the negative feedback loop, stabilized the DC range and greatly improved transmission characteristics, enabling superior low frequency performance.

On the other hand, negative aspects of DC circuitry such as DC drift due to fluctuations in input and in power supply have been eliminated in the 2000 series by stabilizing the differential's mid-point electric potential, using circuit technology to achieve a DC balance, and securing an adeguate CMRR (Common Mode Rejection Ratio) value. As a result, the audio enthusiast is even free to enjoy the full dynamic range of organ music, with all its low frequency signals.

CLASS AB OPERATION

In general the biggest drawback to Class A amplifiers, which have no switching and crossover distortion is their low efficiency. Rotel, however, employs a new system that maximizes the superior sound quality of Class A amps while at the same time ensuring maximum output. Class A operation which is amazingly distortion free and provides excellent sound quality when listening to regular music, automatically switches over to Class B operation when more power is required by a large signal. By adopting this ideal system, where Class A operation handles average music signals and Class B ensures a broad dynamic range during peak signals, the 2000 series Class AB philosophy proves its true worth distortion is held below 0,01% even during maximum output (Class A operation below 5 watts as previously mentioned are remarkably distortion free).

LARGE SCALE TOROIDAL CORE TRANSFORMER

Smaller and lighter than conventional transformers, toroidal core transformers are remarkably effective for large power output. The RA-2040 use toroidal transformers which give superior regulation and little leakage flux leading to excellent high power output and low hum.

SOPHISTICATED PROTECTION CIRCUITRY AND OVERLOAD INDICATOR

The 2000 series uses 3 sets of protection circuitry to protect both the amp itself and the speakers from possible overload damage. One is electronically controlled ASA (area of Safe Operation) detecting circuitry that employs a relay to protect the output transistors and the speakers in case of accidental overload. The second is a DC feedback power limiting circuitry taht serves to protect the transistors when impedence load falls below 4 ohms. The Overload Indicator light located on the front panel of the amplifiers informs the user when the above circuitry goes into operation. The third is the separate relay which overcomes the problems of loud pop-noise and abnormal in-rush current when turning the power switch on.

MC HEAD AMPLIFIER

The MC head amplifier built into the RA-2040 use DC circuitry without capacitors in the input stage. The entry for signals from the MC (moving coil) cartridge is a FET differential with perfect symmetry to both negative and positive input signals. The output stage uses a pure complimentary push-pull circuit. This results in an input sensitivity/impedance value of 0,1 mV/33 ohms.

WIth a built-in MC head amp it becomes possible to enjoy music without having to use an external headamp or booster transformer even with a high performance MC type cartridge.

PHONO EQUALIZER

Rotel's RC-2000, RA-2040 and RA 2030 use a 2-stage DC connected differential input circuit with low noise FET. With a push-pull output stage, this results in excellent S/N high overload capacity and accurate input impedance.

OPTIMUM PHONO IMPEDANCE AND LOAD CAPACITANCE SWITCH (FOR MM CARTRIDGES)

2 switches are attached tothe above Rotel models which make it possible to create the optimum load conditions for MM (moving magnet) cartridges. These permit choise of three impedance loads (35 kohms, 50 kohms, and 70 kohms) and 3 additional capacitance positions (0, 100, 200 pF) onthe Phono1.

RECORD SELECTOR FUNCTION

A separate recording selector switch is attached tothe above models which makes it possible to choose the signal desired for recording regardless of the source input one may by listening to. For examplr this makes it possible to record from a record disc while listening to FM.

2-WAY TAPE DUBBING

Since the tape monitor switch and the recording selector function independent of each other, dubbing between 2 tape decks is possible irregardless of what is being played through the amplifier. Simple operation of the switch permits dubbing between 2 tape recorders in either direction.

TONE CONTROL

Use of a DC amp style tone control that eliminates coupling capacitors from the NF loop guarantees accurate reproduction even at low frequencies. Because of this circuitry design placing the Tone Defeat switch "ON" allows operation as a totally flat buffer amp.

Turnover frequencies forboth Bass and Treble are switchable between 2 options, allowing for wide variation in possibilities. Control range is -10 dB +10 dB.The RA-2040 use a calibrated attenuator-type tone control system and RC-2000 uses independent controls for both left and right channels, permitting precise function.

SUbSONIC AND SUPERSONIC FILTERS

Rotel 2000 series comes equipped with two filters - subsonic and supersonic - that eliminate unwanted components from the very high or very low frequency ranges inaudible to the human ear can have a negative effect on the audible range due to intermodulation and excessive base speaker cone excursions. The Rotel filters eliminate these at 12 dB/oct slope to provide perfect reproduction of the original sound.

Power amplifier part

Output power (both channel drive):

140 W/ch (4 Ω, 1 kHz)

120 W/ch (8 Ω, 20 Hz - 20 kHz)

THD: 0.01% (at the time of an output power 20 Hz - 20 kHz)

Cross modulation distortion: 0.015% (at the time of an output power 8Ω)

Frequency characteristic (1 W/ch; 8 Ω):

DC in : DC -100 kHz +0 -1 dB

AC in: 5 Hz - 100 kHz +0 -1 dB

Input sensitivity/impedance: 1V/50kΩ

Dumping factor: 100 (1 kHz)

S/N ratio (IHF-A network short-circuit): 110 dB

Crosstalk (10 kHz): 65 dB

Equalizer part

THD:

Phono MAG : 0.005%

Phono MC : 0.006%

RIAA deflection (20 Hz - 20 kHz): ±0.3 dB

Input sensitivity/impedance:

Phono1 MAG : 2 mV/35, 50, 70 kΩ/0, 100 or 200 pF

Phono2 MAG : 2 mV/50 kΩ

Phono3 MC : 100 mV/33 Ω

Maximum permissible input (1 kHz, THD 0.5%):

Phono MAG : 400 mV

Phono MC : 15 mV

Preamplifier part

THD: 0.008% (at the time of an output power 20 Hz - 20 kHz)

Frequency characteristic: 4 Hz - 160 kHz

S/N ratio (IHF-A network):

Tuner, Aux : 95 dB

Tape monitor : 95 dB

Remains noise (at the time of a volume min): 6 mV; 100 dB

Input sensitivity/impedance:

Tuner, Aux : 150 mV/ 50 kΩ

Tape monitor : 150 mV/50 kΩ

Maximum permissible input (1 kHz, THD 0.5%): 15 V

Slew rate: 40 V/muS

Square wave rise time: 2 microS

Subsonic Filter: 15 Hz, 12dB/oct

Supersonic filter: 24 kHz, 12 dB/oct

Control width:

Bass : ±5 / ±10 dB

Treble : ±5 / ±10 dB

Max. power consumption: 900 W

Dimensions (W x H x D): 482 x 143 x 408 mm

Weight: 22 kg

Rotel RA-2030 (1978)

ROTEL RA-2030

Stereo Class AB Integrated DC Amplifier

less than 0.01% total harmonic distortion at a rated output

Class AB

DC configuration

INcorporates the same MC head amp as The RA-2040 into its own top level functions - an integrated amplifier incorporating the maximumfunctions of its class

Avery clean amplifier

DC CIRCUITRY

The RA-2030 uses DC amplifiers with excellent response at very low frequencies and makes maximum use of its DC circuitry design. As is becoming standard in precision equipment, Rotel's DC amps have eliminated all capacitors ( which give unwanted time constant) from the signal path and the negative feedback loop, stabilized the DC range and greatly improved transmission characteristics, enabling superior low frequency performance.

On the other hand, negative aspects of DC circuitry such as DC drift due to fluctuations in input and in power supply have been eliminated in the 2000 series by stabilizing the differential's mid-point electric potential, using circuit technology to achieve a DC balance, and securing an adeguate CMRR (Common Mode Rejection Ratio) value. As a result, the audio enthusiast is even free to enjoy the full dynamic range of organ music, with all its low frequency signals.

CLASS AB OPERATION

In general the biggest drawback to Class A amplifiers, which have no switching and crossover distortion is their low efficiency. Rotel, however, employs a new system that maximizes the superior sound quality of Class A amps while at the same time ensuring maximum output. Class A operation which is amazingly distortion free and provides excellent sound quality when listening to regular music, automatically switches over to Class B operation when more power is required by a large signal. By adopting this ideal system, where Class A operation handles average music signals and Class B ensures a broad dynamic range during peak signals, the 2000 series Class AB philosophy proves its true worth distortion is held below 0,01% even during maximum output (Class A operation below 5 watts as previously mentioned are remarkably distortion free).

SOPHISTICATED PROTECTION CIRCUITRY AND OVERLOAD INDICATOR

The 2000 series uses 3 sets of protection circuitry to protect both the amp itself and the speakers from possible overload damage. One is electronically controlled ASA (area of Safe Operation) detecting circuitry that employs a relay to protect the output transistors and the speakers in case of accidental overload. The second is a DC feedback power limiting circuitry taht serves to protect the transistors when impedence load falls below 4 ohms. The Overload Indicator light located on the front panel of the amplifiers informs the user when the above circuitry goes into operation. The third is the separate relay which overcomes the problems of loud pop-noise and abnormal in-rush current when turning the power switch on.

MC HEAD AMPLIFIER

The RA-2030 both use a low noise FET differential amplifier for the input stage and a 3-stage parallel-coupled circuit for the output stage. WIth a built-in MC head amp it becomes possible to enjoy music without having to use an external headamp or booster transformer even with a high performance MC type cartridge.

PHONO EQUALIZER

Rotel's RA 2030 use a 2-stage DC connected differential input circuit with low noise FET. With a push-pull output stage, this results in excellent S/N high overload capacity and accurate input impedance.

OPTIMUM PHONO IMPEDANCE AND LOAD CAPACITANCE SWITCH (FOR MM CARTRIDGES)

2 switches are attached tothe above Rotel models which make it possible to create the optimum load conditions for MM (moving magnet) cartridges. These permit choise of three impedance loads (35 kohms, 50 kohms, and 70 kohms) and 3 additional capacitance positions (0, 100, 200 pF) onthe Phono1.

2-WAY TAPE DUBBING

Since the tape monitor switch and the recording selector function independent of each other, dubbing between 2 tape decks is possible irregardless of what is being played through the amplifier. Simple operation of the switch permits dubbing between 2 tape recorders in either direction.

TONE CONTROL

Use of a DC amp style tone control that eliminates coupling capacitors from the NF loop guarantees accurate reproduction even at low frequencies. Because of this circuitry design placing the Tone Defeat switch "ON" allows operation as a totally flat buffer amp. Control range is -10 dB +10 dB.

SUBSONIC AND SUPERSONIC FILTERS

Rotel 2000 series comes equipped with two filters - subsonic and supersonic - that eliminate unwanted components from the very high or very low frequency ranges inaudible to the human ear can have a negative effect on the audible range due to intermodulation and excessive base speaker cone excursions. The Rotel filters eliminate these at 12 dB/oct slope to provide perfect reproduction of the original sound.

Power amplifier part

Output power (both channel drive):

100 W/ch (4 Ω, 1 kHz)

80 W/ch (8 Ω, 20 Hz - 20 kHz)

THD: 0.01% (at the time of an output power 20 Hz - 20 kHz)

Cross modulation distortion: 0.015% (at the time of an output power 8Ω)

Frequency characteristic (1 W/ch; 8 Ω): 2 Hz - 200 kHz; +0 -3 dB

Input sensitivity/impedance: 1V/50kΩ

Dumping factor: 90 (1 kHz)

S/N ratio (IHF-A network short-circuit): 105 dB

Crosstalk (10 kHz): 60 dB

Equalizer part

THD:

Phono MAG : 0.005%

Phono MC : 0.006%

RIAA deflection (20 Hz - 20 kHz): ±0.3 dB

Input sensitivity/impedance:

Phono1 MAG : 2 mV/35, 50, 70 kΩ/0, 100 or 200 pF

Phono2 MAG : 2 mV/50 kΩ

Phono3 MC : 200 mV/150 Ω

Maximum permissible input (1 kHz, THD 0.5%):

Phono MAG : 300 mV

Phono MC : 10 mV

Preamplifier part

THD: 0.008% (at the time of an output power 20 Hz - 20 kHz)

Frequency characteristic: 4 Hz - 160 kHz

S/N ratio (IHF-A network):

Tuner, Aux : 95 dB

Tape monitor : 95 dB

Remains noise (at the time of a volume min): 6 mV; 100 dB

Input sensitivity/impedance:

Tuner, Aux : 150 mV/ 50 kΩ

Tape monitor : 150 mV/50 kΩ

Maximum permissible input (1 kHz, THD 0.5%): 15 V

Slew rate: 30 V/muS

Square wave rise time: 3 microS

Subsonic Filter: 15 Hz, 12dB/oct

Supersonic filter: 24 kHz, 12 dB/oct

Control width:

Bass: ±10 dB (100 Hz)

Treble: ±10 dB (10 kHz)

Max. power consumption: 500 W

Dimensions (W x H x D): 482 x 143 x 408 mm

Weight: 18 kg

Rotel RA-2020 (1978)

ROTEL RA-2020

Stereo INtegrated DC Amplifier

The integrated amplifier that has comprehensive refinements essential to excellent sound quality with ease of operation.

Less than 0.02% THD at max output of 60 watts per channel ( min.RMS both channels driven into 8 ohms from 20 to 20,000 Hz) - the component to match all others, with DC amplification, MC head amp, and no compromises on the quality inherent in Rotel's 2000 series.

DC CIRCUITRY

The RA-2020 uses DC amplifiers with excellent response at very low frequencies and makes maximum use of its DC circuitry design. As is becoming standard in precision equipment, Rotel's DC amps have eliminated all capacitors ( which give unwanted time constant) from the signal path and the negative feedback loop, stabilized the DC range and greatly improved transmission characteristics, enabling superior low frequency performance.

On the other hand, negative aspects of DC circuitry such as DC drift due to fluctuations in input and in power supply have been eliminated in the 2000 series by stabilizing the differential's mid-point electric potential, using circuit technology to achieve a DC balance, and securing an adeguate CMRR (Common Mode Rejection Ratio) value. As a result, the audio enthusiast is even free to enjoy the full dynamic range of organ music, with all its low frequency signals.

MC HEAD AMPLIFIER

The MC head amplifier built into the RC-2000 and RA-2040 use DC circuitry without capacitors in the input stage. The entry for signals from the MC (moving coil) cartridge is a FET differential with perfect symmetry to both negative and positive input signals. The output stage uses a pure complimentary push-pull circuit. This results in an input sensitivity/impedance value of 0,1 mV/33 ohms.

The RA-2020 both use a low noise FET differential amplifier for the input stage and a 3-stage parallel-coupled circuit for the output stage.

WIth a built-in MC head amp it becomes possible to enjoy music without having to use an external headamp or booster transformer even with a high performance MC type cartridge.

PHONO EQUALIZER

The RA-2020 uses a Class A differential amplifier in the first stage and push-pull IC circuitry in the output stage, ensuring ample phono overload capacity.

2-WAY TAPE DUBBING

Since the tape monitor switch and the recording selector function independent of each other, except for the RA-2020, dubbing between 2 tape decks is possible irregardless of what is being played through the amplifier (for the RA-2020, only either of tape decks can be played). Simple operation of the switch permits dubbing between 2 tape recorders in either direction.

TONE CONTROL

Use of a DC amp style tone control that eliminates coupling capacitors from the NF loop guarantees accurate reproduction even at low frequencies. Because of this circuitry design placing the Tone Defeat switch "ON" allows operation as a totally flat buffer amp. Control range is -10 dB +10 dB.

SUBSONIC AND SUPERSONIC FILTERS

Rotel 2000 series comes equipped with two filters - subsonic and supersonic - that eliminate unwanted components from the very high or very low frequency ranges inaudible to the human ear can have a negative effect on the audible range due to intermodulation and excessive base speaker cone excursions. The Rotel filters eliminate these at 12 dB/oct slope to provide perfect reproduction of the original sound.

Power amplifier part

Output power (both channel drive):

85 W/ch (4 Ω, 1 kHz)

60 W/ch (8 Ω, 20 Hz - 20 kHz)

THD: 0.02% (at the time of an output power 20 Hz - 20 kHz)

Cross modulation distortion: 0.02% (at the time of an output power 8Ω)

Frequency characteristic (1 W/ch; 8 Ω): 2 Hz - 160 kHz; +0 -3 dB

Input sensitivity/impedance: 1V/50kΩ

Dumping factor: 80 (1 kHz)

S/N ratio (IHF-A network short-circuit): 100 dB

Crosstalk (10 kHz): 57 dB

Equalizer part

THD:

Phono MAG : 0.006%

Phono MC : 0.008%

RIAA deflection (20 Hz - 20 kHz): ±0.5 dB

Input sensitivity/impedance:

Phono1 MAG : 2 mV/50 kΩ

Phono2 MC : 200 mV/150 Ω

Maximum permissible input (1 kHz, THD 0.5%):

Phono MAG : 200 mV

Phono MC : 5 mV

Preamplifier part

THD: 0.01% (at the time of an output power 20 Hz - 20 kHz)

Frequency characteristic: 5 Hz - 120 kHz

S/N ratio (IHF-A network):

Tuner, Aux : 92 dB

Tape monitor : 92 dB

Remains noise (at the time of a volume min): 8 mV; 100 dB

Input sensitivity/impedance:

Tuner, Aux : 150 mV/ 50 kΩ

Tape monitor : 150 mV/50 kΩ

Maximum permissible input (1 kHz, THD 0.5%): 15 V

Slew rate: 30 V/muS

Square wave rise time: 3 microS

Subsonic Filter: 15 Hz, 12dB/oct

Supersonic filter: 24 kHz, 12 dB/oct

Control width:

Bass: ±10 dB (100 Hz)

Treble: ±10 dB (10 kHz)

Max. power consumption: 450 W

Dimensions (W x H x D): 482 x 143 x 328 mm

Weight: 13 kg