Audio Database


Lo-D HA-1100
130,000yen(1975 release)

The stereo Integrated Amplifier which concentrated the technical capabilities of the Lo-D to the development goal, and developed to it making the amplifier which is synthetically worthy.

2 steps of differentials constant current drive emitter setting inverted Darlington pure complimentary OCL circuitry was used for the power amplifier part, and it has realized the low distortion.
Moreover, the linearity of a current characteristic is good by the parallel push pull of the pair transistor to which the property was equal, and also the large capacity power supply has realized the faithful transmit from the Koide power to the Oide power.

The three-step stream composition which used the FET differential amplifier for the first rank is adopted as the equalizer stage, and a big dynamic margin and low distortion have been obtained by driving with ±2 power source.

The same difference input form three-step stream-composition amplifier as an equalizer circuitry is used for a tone control circuit, and the final stage serves as an emitter-follower by a constant current load intensity. Thereby, the failure of an SN ratio and the surge of the frequency characteristic by the location of a tone are stopped.
Moreover, to this tone control, it is able for the change of a turnover frequency to be able to perform Bass and three steps of Treble(s), and to adjust them to a more favorite tone quality. Furthermore, it is also possible to acquire the flat frequency characteristic with a tone-defeat switchpoint.

22 contact switchpoint type Attenuator is adopted as a volume.
Moreover, the 3 steps of additive expression gain selector is carried.

Loudspeaker B level adjustment is carried.

The termination of Phono2 can carry out 6dB variable [ of the input level ].

The electronic formula protection network is carried.

The low filter and the high filter of a two-step switching type are carried.

The mode switch and the loudness switchpoint are carried.

Rating of a mode
Form Integrated Amplifier
<Power amplifier part>
Circuit system 2 steps of differentials whole page hardwired-connection grounded-emitter inverted Darlington
Pure complimentary OCL
Effective output
20Hz - 20kHz, both channel drive : 90W+90W (4ohms)
80W+80W (8ohms)
1kHz, both channel drive : 100W+100W (4ohms)
90W+90W (8ohms)
1kHz, one-side-channel drive : 110W/110W (4ohms)
100W/100W (8ohms)
Dynamic power (IHF) 220W (8ohms)
THD 0.1% (at the time of an effective output)
0.006% (at the time of 1 / 2 effective output 1kHz)
Cross modulation distortion (70Hz:7kHz=4:1) 0.03% (at the time of an effective output)
0.03% (at the time of 1W output)
Output bandwidth 6Hz - 50kHz
Frequency characteristic 6Hz-60kHz+0 -1 dB
Input sensitivity/impedance 1V/70kohm
Output-terminal A, B, C:4ohms - 16ohms
A+B, A+C:8ohm-16ohm
Headphone jack: 4ohms - 16ohms
Dumping factor 60 (1kHz, 8ohms) or more
S/N (IHF, A network) 100dB or more
<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
Phono2:1.6-6mV/50kohm (succession variable)
Tuner, Aux1, 2, Tape PB1, 2:100mV/50kohm
Phono maximum permissible input Phono1:430mV (RMS, 1kHz)
2:330-1300mV (RMS, 1kHz) of Phono(es)
An Output voltage/impedance
Tape rec1, 2 : 100mV/1kohm
Pre out: 1V/28 ohm (rate)
15V/28 ohm (maxima)
Frequency characteristic Phono(RIAA deflection): 30Hz-15kHz±0.3dB
Tone control
Bass: ±10dB (50Hz, 100Hz, 150Hz)
Turnover frequency: 150Hz, 300Hz, 600Hz
Treble: ±10dB (6kHz, 10kHz, 20kHz)
Turnover frequency: 1.5kHz, 3kHz, 6kHz
Filter Low: 15Hz/30 Hz, 12dB / oct
High: 8kHz/16 kHz, 6dB / oct
Loudness control (Volume-30dB) + 13dB (100Hz), +7dB (10kHz)
S/N (IHF, A network, input short-circuit) Phono:75dB
Tuner, Aux, Tape PB: 90dB
Attenuator - 5, -10, -20dB (addition is possible)
The semiconductor used Transistor: 61 pieces
FET: Eight pieces
Diode: 32 pieces
Supply voltage AC100V, 50Hz/60Hz
AC outlet Power-switch interlock: One line
Power-switch un-interlocking.: Two lines
Power dissipation
(Electrical Appliance and Material Control Law)
Dimensions Width 468x height 188x depth of 395mm
Weight 18kg