Lo-D HCA-8300
¥ 60,000 (released in 1976)
Commentary
This is a stereo control amplifier developed to be paired with a power amplifier of the dynamic harmony system.
The equalizer circuit section adopts a 3-stage connected 7-chip configuration of first stage FET differential-PNP differential-constant current drive NPN.
The coupling capacitor uses a capacitorless (ICL) system for the input and a non-inductive metallized polyester film capacitor with superior high-frequency characteristics for the output to improve the frequency and phase characteristics.
In addition, low-noise FETs and high-voltage low-noise transistors are used to provide sufficient feedback for stability over a wide band to improve various characteristics.
The tone control circuit adopts a 3-stage direct connection 6-chip configuration of PNP push-pull with a first stage FET differential low-current drive, and realizes low distortion factor by using carefully selected low-noise FETs and high-voltage low-noise transistors.
In addition, the tone volume is lost at the center, and a method is adopted in which the tone quality can be continuously changed without waviness.
In addition, the volume can be adjusted separately on the left and right by the 2-axis volume, and the sound quality can be corrected by changing the turnover frequency or by the tone defeat switch.
The HCA 8300 employs a 32-contact detent volume with a new mask to improve the conventional trimming type detent volume, which has a drawback that the attenuation characteristic deviates from the standard value at every one step.
The attenuation characteristics can be adjusted in 2 dB steps from 0 to -30dB and in 3 dB steps from -30dB to -70dB. In addition, a four string gang volume is adopted to improve S/N when listening at a low volume.
Equipped with low filter circuit.
In addition, it is equipped with a 3-stage gain selector that expands the fine adjustment range.
The level of Phono1 can be finely adjusted.
The headphone amplifier circuit is built-in.
Muting is activated by the reed relay when power is turned on.
The rack handle used in the photo was sold as a separately sold option.
Model Rating
Type | Stereo control amplifier | ||||
Circuit system | Equalizer amplifier : First stage FET differential PNP constant current drive NPN3-stage direct connection ICL Control Amplifier : First stage FET Differential Constant Current Drive PNP Push-pull 3-stage direct connection |
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Input Sensitivity / Impedance | Phono1 : 2 to 6mV/50k Ω Phono2 : 2mV/50k Ω Tuner, Aux1, 2, Tape1, 2 : 100mV/50k Ω |
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Maximum allowable input | Phono1 : 400 mV to 1,200 mV (RMS, 1 kHz) Phono2 : 400 mV (RMS, 1 kHz) Tuner, Aux1, 2, Tape1, 2 : 10 v or more |
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Output Level / Impedance | Tape rec (pin) : 100mV/600 Ω Tape rec (din) : 40mV/80k Ω Pre out : 1V/600 Ω Headphone : 70mV/90 Ω |
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Maximum output level | Pre-out : 7 v or more Rec out:20V |
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Frequency response (RIAA deviation) | Phono1, 2 : 20 Hz to 20 kHz ± 0.2 dB Tuner, Aux1, 2 : 5 Hz to 100 kHz + 0 to 1.5 dB |
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S/N (IHF, A Network) | Phono1, 2 : 75 dB Tuner, Aux1, 2, Tape1, 2 : 100 dB |
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Residual noise | Pre out : 8 μ V Headphone : 40 μ V |
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Distortion Factor (20 Hz to 20 kHz) |
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Tone control |
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Filter | Low : 20 Hz, 12dB/oct. High : 8 kHz, 6dB/oct. |
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Loudness control (Volume -30dB) |
+8dB(100Hz) +4dB(10kHz) |
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Gain selector | -5, -10, -20dB (can add) | ||||
Semiconductor used | Transistor : 26 FET : 8 Diode : 16 pcs IC : 2 |
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Power supply voltage | 100 VAC, 50Hz/60Hz | ||||
AC outlet | Power switch interlock : 2 systems Power switch not linked : 2 systems |
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Rated power consumption | 9.5W (Electrical Appliance and Material Control Law) | ||||
External dimensions | Width 435x Height 152x Depth 308 mm | ||||
Weight | 6.5kg | ||||
Sold Separately | Carrying Handle TA-2 (¥ 3,500) |