Audio Database

The

Pioneer M-73
75,000yen(around the 1980 time)

Description
 
Stereo power amplifier which adopted 2 power transformers.

The 2 steps of ±2 powering and differentials amplification current mirror circuitry and the final-stage parallel push pull pure complementary circuit are adopted as a circuit system.

A power-source part is adoption of 2 power transformers which improve a dynamic behavior, and has eliminated the cross interferencee between channels.
Moreover, with a stream composition with the capacitor of 12,000 micro Fx4, even if there is a low-pass continuous sound of a large swing, it reproduces with a margin.

The large-sized peek power meter with a logarithmic comression circuitry which can carry out the Direct reading of the output is equipped.

The protection network constituted from a quick electronic circuitry of a reliable power relay and a response is adopted, and a speaker and a transistor are protected from an emergency outage.

Two speaker output-terminals are carried and a play of A+B is also possible.

It is the panel design which can be mounted on EIA specification rack.


Rating of a mode
Form Stereo power amplifier
Circuit system 2 steps of differentials whole page hardwired-connection parallel PP pure complimentary
OCL circuitry
Effective output (both channel drive, 20Hz - 20kHz) 85W+85W (8ohm)
THD
(at the time of 20Hz - 20kHz, and an effective output)
0.05%
Cross modulation distortion (50Hz:7kHz=4:1) 0.05%
Output bandwidth (IHF, both channel drive, 8ohm) 5Hz - 45kHz (distortion 0.05%)
Frequency characteristic (at the time of 1W output) 5Hz-100kHz+0 -1 dB
Input terminal Input: 1V/50kohm
Output-terminal A-B: 4ohm-16ohm
A+B: 8ohm-16ohm
Headphone: 4ohm - 16ohm
Dumping factor (20Hz - 20kHz, 8ohm) 30
SN ratio (IHF, A network, a short circuit) 115dB
Supply voltage AC100V, 50Hz/60Hz
Power consumption
(Electrical Appliance and Material Control Law)
210W
Maximum electric power consumption 650W
Dimensions Width 480x height 142x depth of 390mm
Weight 15.2kg
EIA specification rack mounting unit 3U