TRIO KA-4004
¥ 49,800 (around 1972)
Commentary
This is a pre-main amplifier of the Hi-ATC series that has not only characteristics in the audible frequency band but also characteristics in the ultra-low frequency band.
All stages are directly connected + pure complimentary service circuit by ± 2 power supply system.
Metal cancel transistors are used in the first stage circuit and equalizer circuit of the pre-main amplifier.
The first stage circuit, equalizer circuit and tone circuit are made of low-noise type nichrome evaporated metal film resistor to suppress aging.
A block board is directly connected to various switches such as tone control and filter to eliminate unnecessary lead wires, thereby improving inductive hum and signal-to-noise ratio.
We have developed a shield wire that can be wrapped up to the ground part by improving the conventional shield wire to suppress the deterioration of sound quality caused by soldering of extra parts.
Equipped with high / low filter, muting, and tone defeat switch.
Model Rating
Type | Solid-state stereo premain amplifier | |||||||
Power Amplifier Unit | ||||||||
Effective power |
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Music Power (IHF) | 95W (4 Ω) 56W (8 Ω) |
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Total harmonic distortion factor (8 Ω) | 0.5% (at rated output) 0.05% (Rated Output -3dB) |
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Cross modulation distortion factor | 0.5% (at rated output) 0.08% (Rated Output -3dB) |
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Output Bandwidth (IHF) | 10 Hz to 50 kHz | |||||||
SN ratio (closed circuit) | 110dB | |||||||
Residual noise (8 Ω) | 0.3 mV (0.012 μ W) | |||||||
Input Sensitivity / Impedance | 1.0V/50k Ω | |||||||
Optimum load impedance | 4 Ω ~ 16 Ω | |||||||
Damping factor | 32 | |||||||
Output terminal | Speakers and headphones : 4 Ω ~ 16 Ω | |||||||
Preamplifier Section | ||||||||
Input Sensitivity / Impedance | Phono1, 2 : 2.5mV/50k Ω Tuner, AUX : 160mV/60k Ω Tape PlayA, B : 160mV/30k Ω MIC : 1.3mV/10k Ω (Maximum Volume) |
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Signal-to-noise ratio | Phono1, 2 : 65 dB Tuner, AUX, Tape PlayA, B : 75 dB MIC:67dB |
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Maximum Allowable Input (1 kHz) | 330mV(P-P) | |||||||
Output Level / Impedance |
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Frequency characteristic | Tuner, AUX, Tape Play : 20 Hz to 50 kHz ± 1 db Phono1 and 2 : RIAA deviation ± 0.3 dB |
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Tone control | Bass : 100 Hz ± 10 dB Treble : 10 kHz ± 10 dB |
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Filter | Low : 80 Hz, 12dB/oct. High : 7 kHz, 6dB/oct. |
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Loudness control (rated output -30dB) | 100Hz:+8dB 10kHz:+3dB |
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<General> | ||||||||
Power supply voltage | 100 VAC / 117 V, 50Hz/60Hz | |||||||
AC outlet | Power switch interlock : Route 3 Power switch not linked : 1 system |
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Rated power consumption (Electrical Appliance and Material Control Law) | 66W | |||||||
External dimensions | Width 435x Height 153x Depth 300 mm | |||||||
Weight | 9.3kg |