KENWOOD L-03A
¥ 180,000 (released in 1983)
Commentary
Integrated amplifier with dynamic linear drive circuit.
It is equipped with a unique dynamic linear drive circuit for digital audio.
This circuit has two amplifiers at the output, a low-power amplifier and a high-power amplifier. Most of the signal is processed by an extremely high-quality low-power amplifier with a distortion rate of 0.001% or less. This low-power amplifier can handle up to 50W. It is driven by a huge power supply that can output more than 150W. This reduces the source impedance and provides excellent characteristics that are not affected by the load fluctuation of the speaker.
On the other hand, a high-power amplifier works when an instantaneous large signal is input, maintains a low distortion factor even at full power, generates little heat and has almost no internal loss. The maximum instantaneous output is 340W + 340W at 4 Ω load and 430W + 430W at 2 Ω load, so it can handle large instantaneous signals.
A unique Σ drive system is used to drive the speaker system with signals similar in shape to the input waveform of the amplifier.
In a general amplifier, when the waveform at the input terminal of the speaker is observed, the waveform itself is deformed far beyond the order of the distortion factor in the normal connection method.
In the Σ drive system, this problem has been improved. In addition to the waveform transmission at the input / output terminal of the amplifier, there is no waveform deformation at the input terminal of the speaker system even when a connection cable of several meters is used.
The dual-head equalizer amplifier is used in the equalizer section.
In this system, an FET is used for MM cartridge input, a transistor is used for MC cartridge input, and the differential circuit and NF element of the input section are replaced by taking advantage of the characteristics of the element, so that the performance of each cartridge can be maximized, and low-impedance low-output MC cartridge is also supported.
The volume uses a super-linked volume that expands the dynamic range of the low volume.
In this volume, two volumes are installed in front and back of the flat amplifier, and by linking the two volumes, the S / N ratio when the volume is reduced is greatly improved.
The input volume is set to a high impedance to ensure a high input impedance of the amplifier, and the output volume is set to an extremely low impedance to achieve a high SN ratio and a wide dynamic range with the overall characteristics from the Phono input to the Σ output terminal.
The theory of magnetic distortion presented by Trio has been further developed and applied to circuit technology and practical technology such as copper plating on chassis, and magnetic distortion which is harmful to sound quality is greatly reduced.
Equipped with a fader touch volume.
Uses a gold plated pin jack.
Equipped with NF-CR type tone control with tone off circuit.
Equipped with front and rear AUX jacks with front and rear changeover switches.
Built-in pre-out / main in terminal.
Equipped with a 3-step frequency and 3-step boost volume control.
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Model Rating
| Type | Integrated amplifier | ||
| Overall Characteristics | |||
| Rated Output (Both Channel Operation) | 150W + 150W (8 Ω, 20 Hz to 20 kHz) 200W + 200W (4 ω, 1 khz, 0.003% THD) |
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| Dynamic Power | 230W + 230W (8 Ω) 340W + 340W (4 Ω) |
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| Total harmonic distortion rate (20 Hz to 20 kHz) |
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| Intermodulation distortion factor (60 hz : 7 khz = 4 : 1) | Tuner, Aux, Tape → SP terminal : 0.003% (8 Ω at rated output) | ||
| Frequency characteristic | DC ~ 200 kHz -3dB (Tuner, Aux, Tape → SP terminal) | ||
| SN ratio (IHF-A, at rated output, SP terminal) | Phono MM:88dB Phono MC:71dB Tuner, Aux, Tpae : 110 dB |
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| Subsonic filter | 18 Hz, 6dB/oct. | ||
| Loudness control (Vol-40dB) | 30 Hz, 60 Hz, 90 Hz : + 3 dB / + 6 dB / + 9 dB | ||
| Damping factor (55 Hz, 8 Ω) | 2,000 | ||
| Rise time | 1.7 μ s (Tuner, Aux, Tape → SP terminal) | ||
| Slew rate | ± 100 V / μ s (Tuner, Aux, Tape → SP terminal) | ||
| Input Sensitivity / Impedance (at rated output, SP terminal) |
Phono MM : 2.5mV/47k Ω Phono MC : 0.1mV/100 Ω Tuner, Aux, Tape : 150mV/47k Ω Main in : 1V/100k Ω |
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| <Equalizer amplifier Phono → Tape rec> | |||
| Phono maximum allowable input (1 kHz, 0.003% distortion factor) |
MM:260mV MC:10mV |
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| Phono RIAA deviation | 20 Hz to 20 kHz ± 0.2 dB | ||
| <Others> | |||
| Output Level / Impedance | Tape rec (pin) : 150mV/220 Ω Pre out (maximum output) : 1V/750 Ω |
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| Power supply voltage | 100 VAC, 50Hz/60Hz | ||
| Rated power consumption (Electrical Appliance and Material Control Law) | 370W | ||
| Power outlet | Power switch interlock : 2 systems, 100W Power switch not linked : 1 system, 400W |
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| Maximum external dimensions | Width 440x Height 158x Depth 383 mm | ||
| Weight | 15kg | ||
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