Audio Database

The

Lo-D HMA-8300
140,000yen(1976 release)

Description
 
Stereo power amplifier which adopted the Distributed information-processing Network Architecture harmony (E class drive) scheme.

The Distributed information-processing Network Architecture harmony scheme is a circuit system which realized the Oide power-ization of amplifier efficiently through the musical analysis of a level distribution, at the peek of a music signal, the Oide power and usual work as Koide power, and an operation equivalent to the Oide power amplifier is carried out effectually.
This has realized the weight saving of amplifier, expansion of an area of safe operation, low-pricing, and low-distortion-ization.

the Distributed information-processing Network Architecture harmony scheme is adopted as a power part, it consists of a low voltage power source and each ±2 power source (a total of four power sources) of the high voltage power supply, and this has realized Oide power.
A current mirror circuitry is adopted as a Class-A driver circuitry, and the power stage drive is performed.

The meter which can carry out the Direct reading of the peaking capacity level in the value of power is carried.

The Subsonic Filter which eliminates the harmful oscillation besides the audio frequency band generated from the curvature of a record etc. is carried.
This filter can carry out "on-off" if needed.

The transformer adopted as the power-source part has adopted the thing of about 9kg heavy weight class, and two low 18,000 micro F(63V)±2 power-source dual chemical capacitors of a grounding impedance, and two 10,000-micro F (125V) four capacitors are adopted as Kem Cong for power sources.

The loudspeaker relay newly designed with the formation of large power is an object for the large power sources of the rated current (AC15A) and surge current (AC60A), and has become a thing in which a direct-current shutdown is also possible.
Furthermore, a contact structure is a silver contact, takes a large contact surface product, is holding down to less than 25mohm, and is reducing the tone-quality failure. Moreover, since the structure of blowing out a magnetism with the magnet which contains the arc discharge between contacts which poses a problem at the time of the Oide power shutdown accompanying the formation of large power is used, even if it uses it for a long period of time, the failure of contact resistance etc. has decreased.

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


Rating of a mode
Form Stereo power amplifier
Circuit system Two-step differential-amplification whole page hardwired-connection 4 power-source quantity
efficiency pure complimentary OCL
(Distributed information-processing Network Architecture harmony scheme)
Effective output
(Both ch(es) drive, THD 0.1%)
200W+200W (4 ohms, 20Hz - 20kHz)
200W+200W (8 ohms, 20Hz - 20kHz)
220W+220W (8 ohms, 1kHz)
THD
(20Hz - 20kHz)
0.1% or less (at the time of an effective output)
0.005% or less (at the time of 100W output)
0.03% or less (at the time of 1W output)
Output bandwidth (IHF) 5Hz - 30kHz (8ohms)
Frequency characteristic 5Hz-80kHz+0 -1 dB
Input sensitivity/impedance 1V/50kohm
Load impedance 4ohm-16ohm
Dumping factor (8ohms) 50 (20Hz - 20kHz)
100(1kHz)
Channel separation 80dB (1kHz, 8ohms)
S/N (IHF, A network) 110dB
The semiconductor used Transistor: 40 pieces
Diode: 47 pieces
IC: Two pieces
Supply voltage AC100V, 50Hz/60Hz
Power dissipation 210W
Dimensions Width 435x height 182x depth of 395mm
Weight 24kg
Option Carrying handle TA-1 (5,000yen)