Audio Database


Lo-D HCA-8300
60,000yen(1976 release)

Stereo control amplifier developed supposing the pair with the Distributed information-processing Network Architecture harmony scheme power amplifier.

The 3 steps of first rank FET differential-PNP differential-constant current drives NPN hardwired-connection 7 stone stream composition is used for the equalizer circuitry unit.
The unguided metallized polyesters film capacitor which the Capacitor-Less (interrupt control logic) scheme was excellent in the input, and excelled [ output ] in the high region property is used for a coupling capacitor, and the modification of the frequency characteristic and a phase response is aimed at.
Moreover, the modification of many properties is aimed at by using low-noise FET and a high resisting pressure low-noise transistor, and applying sufficient feedback for stability over a wide band.

The 3 steps of first rank FET differential low electric-current drive PNP push pull hardwired-connection 6 stone stream composition is used for a tone control circuit, and it is using low-noise FET and the high resisting pressure low-noise transistor which were selected carefully, and has realized low-distortion-ization.
Moreover, the scheme which can perform continuously the tone-quality variable which a tone volume serves as a defeet in the center a variable one, and does not have a surge is adopted.
furthermore, 2 axis volume -- right and left -- the volume can be controlled separately and a tone-quality correction is also possible by a change and tone-defeat switchpoint of a turnover frequency.

In order to improve the fault which had been generated in the conventional trimming scheme Detent volume and from which a damping characteristics shifts to a typical values every step, the Detent volume of 32 contacts which use a new method mask is adopted as a volume.
The damping characteristics is aiming at the improvement in S/N when being able to adjust 0 to -30dB at a 3dB step from a 2dB step and -30dB to -70dB, and also it adopting a 4-unit gang volume, and hearing it with a small sound volume.

The low filter circuit is carried.
Moreover, the three-step gain selector which extends a fine-tune span is carried.

A Phono1 level fine tune is possible.

The headphone amplifier circuitry is built in.

A muting works by a reed relay at the time of the power source on.

The rack handle currently used with the photograph was sold as an option option.

Rating of a mode
Form Stereo control amplifier
Circuit system Equalizer amplifier: 3 steps of first rank FET differential PNP constant current drives
             NPN hardwired-connection interrupt control logic
Control amplifier: 3 steps of first rank FET differential constant current drive PNP push pull hardwired connection
Input sensitivity/impedance Phono1:2-6mV/50kohm
Tuner, Aux1, 2, Tape1, 2:100mV/50kohm
Maximum permissible input Phono1:400mV-1,200mV (RMS, 1kHz)
Phono2:400mV (RMS, 1kHz)
Tuner, Aux1, 2, Tape1, and more than 2:10V
An Output voltage/impedance Tape rec (pin): 100mV/600 ohms
Tape rec(din): 40mV/80kohm
Pre out: 1V/600 ohm
Headphone: 70mV/90 ohms
Maximum output level Pre out: More than 7V
Rec out:20V
Frequency characteristic
(RIAA deflection)
Phono1, 2:20Hz-20kHz±0.2dB
Tuner, Aux1, and 2:5Hz-100kHz+0 -1.5 dB
S/N (IHF, A network) Phono1, 2:75dB
Tuner, Aux1, 2, Tape1, 2:100dB
Remains noise Pre out: 8 microvolts
Headphone: 40 microvolts
Distortion (20Hz - 20kHz)
Phono1, 2 : 0.005% or less (1V)
0.01% or less (20V)
Tuner, Aux1, 2 : 0.005% or less (1V)
0.01% or less (7V)
Tone control
Bass: ±10dB (50Hz, 100Hz)
Turnover frequency: 150Hz, 300Hz
Treble: ±10dB (10kHz, 20kHz)
Turnover frequency: 3kHz, 6kHz
Filter Low: 20Hz, 12dB / oct
High: 8kHz, 6dB / oct
Loudness control
(Volume -30dB)
Gain selector - 5, -10, -20dB (addition is possible)
The semiconductor used Transistor: 26 pieces
FET: Eight pieces
Diode: 16 pieces
IC: Two pieces
Supply voltage AC100V, 50Hz/60Hz
AC outlet Power-switch interlock: Two lines
Power-switch un-interlocking.: Two lines
Power dissipation 9.5W (Electrical Appliance and Material Control Law)
Dimensions Width 435x height 152x depth of 308mm
Weight 6.5kg
Option Carrying handle TA-2 (3,500yen)