Lo-D HA-410
¥ 49,800 (released in 1975)
Commentary
Pre-main amplifier with built-in microphone mixing circuit.
The power amplifier section consists of a pair transistor for Hi-Fi with uniform characteristics and a grounded emitter inverted Darlington OCL circuit.
In addition, the driver stage employs a low-distortion and stable first stage differential-amplified constant-current drive system, which drives differential-amplified monolithic ICs with a stabilized power supply. Combined with Lordi's unique constant-current drive system, it realizes sound with little crossover distortion at the time of very small output.
The inverted Darlington circuit is a circuit system in which not only power gain but also voltage gain can be obtained at the power amplifier stage. The naked gain is large and feedback can be stably applied.
In addition, since the drive voltage of the driver stage is low, excellent semiconductors can be used as noise figures.
The equalizer stage of the preamp section has differential amplification on the first stage and uses a linear drive monolithic IC with a built-in 3-stage direct-coupled amplifier.
Since the first stage is a differential amplifier, a click does not occur due to power on / off.
Equipped with a protection circuit.
It is equipped with functions such as microphone mixing circuit, low filter and loudness control.
The wood case was sold separately as an option.
Model Rating
Type | Pre-main amplifier | ||||||
Power Amplifier Unit | |||||||
Effective power |
|
||||||
Dynamic Power (IHF) | 100W (8 Ω) | ||||||
Total harmonic distortion factor | 0.5% (Effective Output) 0.05% (1 kHz at 1/2 Effective Output) |
||||||
Intermodulation distortion factor (70 hz : 7 khz = 4 : 1) | 0.15% (at effective output) 0.1% (at 1W output) |
||||||
Output Bandwidth (IHF) | 10 Hz to 80 kHz | ||||||
Output terminal | A, B : 4 Ω ~ 16 Ω A + B : 8 Ω ~ 16 Ω Headphone terminal : 4 Ω ~ 16 Ω |
||||||
Damping factor | 40 or More (1 kHz, 8 Ω) | ||||||
Preamplifier Section | |||||||
Input Sensitivity / Impedance | Phono1, 2 : 2.5mV/50k Ω Tuner, Aux : 150mV/47k Ω Tape PB. 1 : 150m/55k Ω Tape PB. 2 : 500mV/55k Ω Mic : 4.0mV/4k Ω |
||||||
Phono maximum allowable input | Phono1, 2 : 150 mV (RMS, 1 kHz) | ||||||
Output Level / Impedance | Tape rec1 : 150mV/1k Ω Tape rec2 (din) : 40mV/80k Ω |
||||||
Frequency characteristic | Phono (RIAA deviation) : 30 Hz to 15 kHz ± 0.5 dB | ||||||
Tone control | Bass : ± 10 dB (100 Hz) Treble : ± 10 dB (10 kHz) |
||||||
Filter | Low : 40 Hz, 6dB/oct. | ||||||
Loudness control (Volume -30dB) | + 8 dB (100 Hz), + 4 dB (10 kHz) | ||||||
S/N (IHF, A-Network, input short) | Phono:75dB Tuner, Aux, Tape PB : 90 dB |
||||||
<General> | |||||||
Semiconductor used | Transistor : 21 IC : 2 Diode : 17 pcs |
||||||
Power supply voltage | 100 VAC, 50Hz/60Hz | ||||||
AC outlet | Power switch interlock : 1 system Power switch not linked : 1 system |
||||||
Rated power consumption (Electrical Appliance and Material Control Law) | 95W | ||||||
External dimensions | Body : Width 435x Height 144x Depth 353 mm Wood Case : Width 467x Height 179x Depth 400 mm |
||||||
Weight | 8.9kg | ||||||
Sold Separately | Wood Case LA-200 (¥ 6,500) |