Audio Database


Pioneer SM-101
49,800yen(? at the 1970 in-the-early time)

Stereo power amplifier which devoted in the maniac youth and was designed.

In order to obtain the uniform power covering a low distortion and a wide band, the whole page hardwired-connection pure complimentary OCL circuitry is adopted.
Moreover, the Mie diffusion type power transistor with the destructive intensity with high PNP and NPN developed for Oide power is used for a transistor in the pair.

In order to make DC potential into the stable thing, two steps of differential amplifier is used.
The stability is conjointly increased with the temperature-compensation circuitry.

The original circuitry which combined the relay and the electronic circuitry (eight transistors, 10 diode) is adopted as a protection network.
It prevents the direct-current balance of an output stage collapsing, the differential amplifier's detecting this, if a direct current component flows, and cutting a relay circuit, and a direct current flowing into a speaker.
Moreover, when the speaker output-terminal was short-circuited, or when an excessive electric current flows into an output stage, the alternating-current component of an output stage is detected, a relay circuit is cut, and it has a structure which protects a power transistor.
At the time of power-switch ON, it works as a muting, and prevents an unpleasant noise coming out from a speaker.
The indicator of the front panel blinks at the time of a protector operation.

The output level meter is carried in the front panel.
The sensitivity of meter can be switched to Off, and 0dB-10dB five positions of -20dB-30dB.

Two inputs are carried and can be switched with a front switchpoint.
Moreover, the Input-sensitivity selector of a constant input impedance is carried, and if needed, four positions are changed and are made.

The speaker phase circuit changing switch which achieved the right-and-left independency is carried.
Moreover, the change of A, B, and A+B is possible for a speaker output-terminal by those with two line, and a selector.

One set of one-set property data is attached.


Rating of a mode
Form Stereo power amplifier
Circuit system Whole page hardwired-connection complimentary OCL circuitry
Music power (IHF) 240W (4ohm)
170W (8ohm)
Effective output 片 channel drive
70W/70W (8ohm)
90W/90W (4ohm)
Both channel drive
60W+60W (8ohm)
78W+78W (4ohm)
20Hz - a 20000Hz output (both channel drive)
50W+50W (8 ohms, 0.15% or less of distortion)
THD 0.1% or less (at the time of an effective output)
0.05% or less (at the time of 8-ohm and 35W/35W output)
Cross modulation distortion 0.1% or less (at the time of an effective output)
0.06% or less (at the time of 8-ohm and 35W/35W output)
Output bandwidth (IHF) 5Hz - 30000Hz
Frequency characteristic 8Hz - 70000Hz, and +0 -1 dB
Input sensitivity/impedance (an effective output, 1kHz) 0.5V, 1V, 2V, 5V/50kohm
Load impedance 4ohm-16ohm
Dumping factor 40 (8 ohm, 1kHz)
A hum and a noise (IHF short circuit) 95dB or more
Meter sensitivity selector OFF, 0dB-10dB-20dB-30dB
Level meter (L, R) 0dB=70W/8 ohm
The semiconductor used Transistor: 26
Diode: 24
Supply voltage AC100V, 50Hz/60Hz
Power dissipation 125W
Maximum electric power consumption 330W
Power receptacle Interlock: One line
Un-interlocking.: One line
Dimensions Width 430x height 144x depth of 337mm
Weight 10.7kg