Audio Database


Pioneer A-150D
118,000yen(around the 1985 time)

The Integrated Amplifier developed as a triangle drive system aiming at the improvement in the total balance of amplifier.

In order to strengthen a power-source part, the large-sized power transformer which became independent to each of Lch and Rch of power amplifier is adopted, and power is supplied to each output stage and the voltage amplification stage from two transformers.
Furthermore, a transformer for exclusive use is arranged also on the power-source part of an equalizer amplifier, and it has become the extravagant design of supplying an electric current to Lch and Rch.

It not only separates a power transformer, but it is pursuing the ideal of separate amplifier to the construction itself,Not only a power transformer but a rectifier circuit and a power source capacitor adopt the thing only for Lch and Rch completely, and also a power amplifier part separates completely the layout of each part article, a product line, a radiator, etc., etc., and puts its heart and soul into a monophonic stream composition, such as keeping a signal from crossing etc. There is no cross interferencee on either side by this, the occurrence of cross modulation distortion was suppressed, and the high separation is realized.

While obtaining the outstanding resolution and transparent feeling by adoption of the line straight circuitry which jumps a tone control and the mode etc., the capacity of the source like compact disk is demonstrated.

In order to correspond also to a variation of the rapid impedance of the digital source with an intense peek component, a large capacity power supply capacitor called 20,000 micro F of one side channels is adopted as the power-source part of LchRch.
Furthermore, the current-supply-source capacity 32A which exists also two to 3 times of the usual amplifier is attained, such as carrying out 3 parallel connection of the power transistor per one side channel, and making it a triple push pull.

Switching distortion carries the non switching circuit TypeII which improved further the non switching circuit which is not generated theoretically, expands the area of switching distorted zero further, and is attaining much more wide band-ization.
Moreover, immediately after power-switch ON and at the time of the Taishin number input, the idle current which is carrying out the drift continuously by transition of outside temperature etc. is stabilized, and the occurrence of the thermal distortion resulting from this is suppressed.
Furthermore, the nonlinear distortion of an output stage is raised to abbreviation 1/30 by detecting and rectifying the difference of an input signal and an output signal.

Examination is carried out also to part each and a copper lead wire is adopted as main component partses, such as a capacitor and a resistor. Moreover, the oxygen-free-high-conductivity-copper line was adopted also as main product-line material and a very-thick power cord, and also thorough nonmagnetic-ization, such as performing nonmagnetic tinning also to an input/output terminal, is attained.
Furthermore, a speaker terminal adopts the vice type which sticks a cable by pressure firmly, and is performing the current supply source without a loss. Moreover, technical pursuit and the thorough audition are repeated until dividing a grounding point into a power supply system and a signal system etc. results in a detail.

The hybrid MC transformer is adopted and the high region property is sharply raised by reducing a boost ratio by half.
Thereby, it excelled in the phase response, and DCR (direct current resistance) is also low and the gentle low-pass play whose dyne ping was effective is realized.
Two impedance values are also established and the matching with various cartridges is enabled.

An input terminal is considered as those with five line, and the product line of especially the shortest in circuitry in the position of compact disk, and serves as a specification of digital priority, such as using a quality part.
Furthermore, two tapes monitors have also equipped, it is total and seven input/outputs are supported.

The sub- wood of the photograph was an option.


Rating of a mode
Form Non switching Integrated Amplifier
Effective output
20Hz - 20kHz : 150W+150W (6 ohm, both channel drive)
120W+120W (8 ohm, both channel drive)
1kHz: 200W+200W (4 ohm, both channel drive)
160W+160W (6 ohm, both channel drive)
130W+130W (8 ohm, both channel drive)
THD (20Hz - 20kHz) 0.003% (at the time of an effective output)
Cross modulation distortion (50Hz:7kHz=4:1) 0.003% (20Hz - 20kHz, 120W, 8ohm)
Output bandwidth 5Hz - 60kHz (IHF, both channel drive, THD0.01%)
Output-terminal Speaker(4ohm-16ohm): A, B, A+B
Tape Rec:150mV
Dumping factor 100 (20Hz - 20kHz, 8ohm)
Input sensitivity/impedance Phono man month: 2.5mV / 50kohm
Phono MC: 0.15mV/3 ohm, 0.25mV/40 ohms
compact disk, Tuner, AUX, Tape Play1, 2:150mV / 30kohm
Phono maximum permissible input (1kHz, THD0.003%) MM:250mV
Frequency characteristic Phono man month: 20Hz-20kHz}0.2dB
compact disk, Tuner, AUX, and Tape Play:2Hz-100kHz+0 -3 dB
SN ratio
(IHF, A network, a short circuit)
Phono MM:90dB
Phono MC:76dB
compact disk, Tuner, AUX, Tape Play: 110dB
Stereo separation 90dB(1kHz)
Tone control Bass: }8dB (100Hz)
Treble: }8dB (10kHz)
Filter Low: 15Hz, 6 dB/oct.
Supply voltage AC100V, 50Hz/60Hz
Power consumption (Electrical Appliance and Material Control Law) 350W
Dimensions Width 420x height 151x depth of 427mm
Weight 16.6kg
Option Sub- wood JA-A120 (4,000yen)