Audio Database


Lo-D HA-410
49,800yen(1975 release)

The Integrated Amplifier which built in the mic mixing circuitry.

The power amplifier part has a pair transistor for Hi-Fi to which the property was equal, and grounded-emitter inverted Darlington OCL composition.
Moreover, the first rank differential-amplification constant current drive system is adopted as the driver stage. The monolithic IC of a differential amplification is driven by a stabilizing supply, and the crossover distortion at the time of a minute output is conjointly reduced with the constant current drive original with a Lo-D.

An inverted darlington circuit not only obtains power gain in the power amplification stage, but is a circuit system with which a voltage gain is obtained, its nakedness gain is large, and a feedback is applied stably.
Furthermore, since the drive voltage of the driver stage is low and ends, it has the distinctive characteristics that a using of the semiconductor excellent in the noise figure is possible.

The linear drive monolithic IC with a first rank differential amplification and built-in three-step hardwired-connection amplifier is used for the equalizer stage.
Since the first rank is a differential amplification, the it1 by power-source on-off does not occur.

The protection network is carried.

Functionalities, such as a mic mixing circuitry, a low filter, a loudness control, are carried.

The wood case was sold as an option option.

Rating of a mode
Form Integrated Amplifier
<Power amplifier part>
Effective output
20Hz - 20kHz, both channel drive : 35W+35W (4ohms)
30W+30W (8ohms)
1kHz, both channel drive : 47W+47W (4ohms)
37W+37W (8ohms)
1kHz, one-side-channel drive : 60W/60W (4ohms)
42W/42W (8ohms)
Dynamic power (IHF) 100W (8ohms)
THD 0.5% (at the time of an effective output)
0.05% (at the time of 1 / 2 effective output 1kHz)
Cross modulation distortion (70Hz:7kHz=4:1) 0.15% (at the time of an effective output)
0.1% (at the time of 1W output)
Output bandwidth (IHF) 10Hz - 80kHz
Output-terminal A, B:4ohms - 16ohms
A+B: 8ohm-16ohm
Headphone jack: 4ohms - 16ohms
Dumping factor 40 (1kHz, 8ohms) or more
<Preamplifier part>
Input sensitivity/impedance Phono1, 2:2.5mV/50kohm
Tuner, Aux:150mV/47kohm
Tape PB.1:150m/55kohm
Tape PB.2:500mV/55kohm
Mic: 4.0mV/4kohm
Phono maximum permissible input Phono1, 2:150mV (RMS, 1kHz)
An Output voltage/impedance Tape rec1:150mV/1kohm
Tape rec2(din): 40mV/80kohm
Frequency characteristic Phono(RIAA deflection): 30Hz-15kHz±0.5dB
Tone control Bass: ±10dB (100Hz)
Treble: ±10dB (10kHz)
Filter Low: 40Hz, 6dB / oct
Loudness control (Volume-30dB) + 8dB (100Hz), +4dB (10kHz)
S/N (IHF, A network, input short-circuit) Phono:75dB
Tuner, Aux, Tape PB: 90dB
The semiconductor used Transistor: 21 pieces
IC: Two pieces
Diode: 17 pieces
Supply voltage AC100V, 50Hz/60Hz
AC outlet Power-switch interlock: One line
Power-switch un-interlocking.: One line
Power dissipation (Electrical Appliance and Material Control Law) 95W
Dimensions Main unit: Width 435x height 144x depth of 353mm
At the time of a wood case using: Width 467x height 179x depth of 400mm
Weight 8.9kg
Option Wood case LA-200 (6,500yen)