Audio Database


Lo-D HA-510
59,800yen(1975 release)

The Integrated Amplifier which attained low distortion and high output-ization.

The power amplifier part consists of a pair transistor for Hi-Fi selected carefully, and a grounded-emitter inverted Darlington pure complimentary. Moreover, a stable differential-amplification constant current drive system is taken in in the driver stage, and high-quality sound-ization is attained by suppressing the crossover distortion at the time of a very small output.

The equalizer stage is a three-step stream composition of a first rank difference input-FET-bipolar transistor, and a 280mV dynamic margin has been obtained by driving with ±2 power source.

A flat amplifier part is the two-step hardwired-connection type by the combination of FET-PNP, and low distortion and a stabilization are attained by applying NFB to alternating-current / direct-current concurrent.

22 contact switchpoint type Attenuator is adopted as a volume, and exact volume control is enabled.

A control of loudspeaker B level can adjust to -15dB.
Thereby, level doubling of a loudspeaker is possible in the case of a compare audition.

Functionalities, such as a tone defeat, a low filter, a mode switch, a loudness, and a microphone input plug, are carried.

The wood case was sold as an option option.


Rating of a mode
Form Integrated Amplifier
<Power amplifier part>
Circuit system 1 step of differential whole page hardwired-connection grounded-emitter inverted Darlington
Pure complimentary OCL
Effective output
20Hz - 20kHz, both channel drive : 50W+50W (4ohms)
43W+43W (8ohms)
1kHz, both channel drive : 65W+65W (4ohms)
50W+50W (8ohms)
1kHz, one-side-channel drive : 80W/80W (4ohms)
56W/56W (8ohms)
Dynamic power (IHF) 140W (8ohms)
THD 0.3% (at the time of an effective output)
0.008% (at the time of 1 / 2 effective output 1kHz)
Cross modulation distortion (70Hz:7kHz=4:1) 0.05% (at the time of an effective output)
0.05% (at the time of 1W output)
Output bandwidth (IHF) 8Hz - 45kHz
Frequency characteristic 10Hz-30kHz+0 -1 dB
Input sensitivity/impedance 0.7V/70kohm
Output-terminal A, B:4ohms - 16ohms
A+B: 8ohm-16ohm
Headphone jack: 4ohms - 16ohms
Dumping factor 60 (1kHz, 8ohms) or more
S/N 100dB (IHF, A network, input short-circuit)
<Preamplifier part>
Circuit system Equalizer amplifier: The differential three-step hardwired connection per step, an FET using
Control amplifier: NF form, a first rank FET using
Input sensitivity/impedance Phono1:2mV/50kohm
Phono2:2-5mV/50kohm (Low/High switching)
Tuner, Aux, Tape PB1, 2:100mV/50kohm
Mic: 2mV/25kohm
Phono maximum permissible input Phono1:280mV (RMS, 1kHz)
2:280-750mV (RMS, 1kHz) of Phono(es)
An Output voltage/impedance
Tape rec1, 2 : 100mV/1kohm
Pre out: 0.7V/4.7kohm (rate)
6V/4.7kohm (maxima)
Frequency characteristic Phono(RIAA deflection): 30Hz-15kHz±0.3dB
Tone control Bass: ±10dB (100Hz)
Treble: ±10dB (10kHz)
Filter Low: 40Hz, 6dB / oct
Loudness control + 9dB (100Hz), +4dB (10kHz)
(Volume -30dB)
S/N (IHF, A network)
Input short-circuit
Tuner, Aux, Tape PB: 90dB
The semiconductor used Transistor: 44 pieces
FET: Four pieces
Diode: 35 pieces
Supply voltage AC100V, 50Hz/60Hz
AC outlet Power-switch interlock: One line
Power-switch un-interlocking.: One line
Power dissipation 105W (Electrical Appliance and Material Control Law)
Dimensions Main unit: Width 435x height 144x depth of 388mm
At the time of a wood case using: Width 467x height 179x depth of 400mm
Weight 10.8kg
Option Wood case LA-200 (6,500yen)