Audio Database

The

ROTEL RA-2040
148,000yen( at the 1970 in-the-late time(?))

Description
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The Integrated Amplifier which integrated the performance of rc-2000 and returns-to-biases-2000.

DC scheme which removed the capacitor from the input unit is adopted as a main-amplifier part, an equalizer amplifier, MC amplifier, and flat amplifier.
Dual FET to which the property was equal is adopted as the first rank of DC power amplifier part, and the pure complimentary OCL circuitry and the conjointly excellent tone quality are realized. Moreover, about the drift of the middle point potential which poses a problem with DC amplifier, a power supply variation is suppressed in each stage, a pair property is raised, and the stability is improved.

Taking advantage of the merit of the tone quality of Class-A amplifier, AB class operation method which can acquire the Oide power is adopted.
Usually, it is a Class-A operation at the time, and it changes to B class operation automatically at the time of the Taishin number which needs big power.

The low distortion is realized by investigating thoroughly until it results in the design of the printed circuit board, or a placement of a shielding code including a material or component partses.

It excelled in the high efficiency at the regulation, and the large-sized toroidalcore type transformer with little leakage flux is adopted as a power-source part.

As a protection network, the electro carry control ASO (area of safe operation) circuitry and DC feedback power limit circuitry are carried. The electro carry control ASO circuitry has protected the transistor and speaker of amplifier by relay operation. Moreover, the DC feedback power limit circuitry operated quickly to the overload, and has protected the transistor.
Furthermore, in RA-2040, a relay for exclusive use and an in rushes absorber are prepared also to the in rushes electric current at the time of the power activation which poses a problem with the Oide power amplifier, and the security and the robustness are improved.

The peek indicator by light emitting diode is carried. 13 light emitting diodes per channel were adopted, power was transposed to digital one, and the quick window is realized.
Since the sensitivity switching (-20dB) organization and the off-switchpoint are equipped, it reads easily also at the time of a small sound volume, and the indicator window can also erase an indicator, when unnecessary.

MC head amplifier is carried.
The head amplifier adopted as RA-2040 serves as DC scheme which banished the capacitor from the input circuit.
The differential-amplification circuitry which used the super-low-noise transistor is adopted as a first rank circuitry, and the pure complimentary push-pull circuit is adopted as an output stage.

The two-step DC difference input circuitry by low-noise FET is adopted as an equalizer-amplifier part, and the property which was excellent with the stream composition which made the output stage the push pull has been acquired in it.

The switchpoint of each control of the phone selector, the recording selector, and the function selector is installed in the rear panel, and has stopped leading about of a shielding code to the minimum. The operation serves as a scheme with which the rod of the shape of a plate extended from the thumb of the front panel drives the switchpoint of a rear panel.

A load impedance can also adjust three steps and three steps of additional capacitance, and man-month cartridge can do nine kinds of combination in total.

The recording selector is carried and the output signal to a tape deck can be chosen regardless of the sound which comes out from a speaker.

DC amplifier scheme is adopted as a tone control circuit. Moreover, it is possible to cancel a tone circuitry and to also make it operate as flat buffer amplifier with a tone-defeat switchpoint.
RA-2040 -- a turnover frequency -- Bass/Treble -- a two-step coordination can be performed, respectively.

The Subsonic Filter and the supersonic filter are carried.

The termination by which the gilding treatment was carried out is adopted.

The front panel serves as EIJ specification rack-mounted type.


Rating of a mode
Form Integrated Amplifier
<Power amplifier part>
Output power (both channel drive) 140 W/ch (4 ohm, 1kHz)
120 W/ch (8 ohm, 20Hz - 20kHz)
THD 0.01% (at the time of an Output power 20Hz - 20kHz)
Cross modulation distortion 0.015% (at the time of an Output power 8ohm)
Frequency characteristic (1 W/ch, 8ohm) DC in:DC-100kHz+0 -1dB
AC in: 5Hz-100kHz+0 -1dB
Input sensitivity/impedance 1.5V/50kohm
Dumping factor (8ohm) 65 (20Hz - 20kHz)
100(1kHz)
S/N ratio (IHF-A network short-circuit) 110dB
Crosstalk (10kHz) 65dB
<Equalizer part>
THD Phono MAG:0.005%
Phono MC:0.006%
RIAA deflection (20Hz - 20kHz) }0.3dB
Input sensitivity/impedance Phono1 MAG: 2mV / 35, 50, 70kohm/0, 100 or 200pF
Phono2 MAG: 2mV / 50kohm
Phono3 MC: 100 microvolts/33 ohm
Maximum permissible input (1kHz, THD0.5%) Phono MAG:400mV
Phono MC:15mV
<Preamplifier part>
THD 0.008% (at the time of an Output power 20Hz - 20kHz)
Frequency characteristic 4Hz - 160kHz
S/N ratio (IHF-A network) Tuner, Aux: 95dB
Tape monitor:95dB
remains noise (at the time of a volume min) 6 microvolts, 100dB
Input sensitivity/impedance Tuner, Aux:150mV /, 50kohm
Tape monitor: 150mV / 50kohm
Maximum permissible input (1kHz, THD0.5%) Tuner, Aux:15V
Tape monitor:15V
Slew rate 40V/muS
Square wave rise time 2microS
<Control property>
Turnover frequency Bass:150Hz/400Hz
Treble:7kHz/2.5kHz
Control width Bass: }5dB / }10dB
Treble: }5dB / }10dB
Supersonic filter 24kHz, 12dB / oct
Subsonic Filter 15Hz, 12dB / oct
<Synthesis>
Maximum electric power consumption 900W
Dimensions Width 482x height 143x depth of 408mm
Weight 22kg