Audio Database


Pioneer C-90
170,000yen(1986 release)

Stereo control amplifier which aimed at the review from the origin of amplifier and was developed as the compilation.
The basis of the design concept of an simple is best and the technology which Pioneer has cultivated are supplied unstintingly.

It has a twin mono-construction structure which used the 3 transformer multi-power supply as the base.
Including having made the power-source part of L/R become independent the whole transformer, the layout on the printed circuit board was also separated for every block, and the instability of the lateralization accompanying separation aggravation is banished.
Furthermore, the circuitry of a video-system system and the power source of an electronic control system have the thorough structure of supplying from power transformer with an another audio system, and a voltage stabilizer.

A function switch is interlocked with at the time of an audio-source play, and the new circuitry (PAT.P) which turns OFF the power source of a video-system system automatically is carried in the video-system system circuitry.

In order to negate an oscillation, various vibration proof parts are adopted.
The polycarbonate is used for an insulator and the internal loss is absorbing the oscillation efficiently greatly.
Moreover, the circuitry platform is fixed by the rubber vibration insulator, and it has prevented an oscillation getting across to a part because the rubber vibration insulator which connects a platform and a chassis achieves the duty of a damper.
And in the receptacle bottom of a transformer, while the internal loss has constructed the board of the copper which was greatly excellent in adhesion and absorbs a fine oscillation, a magnetic distortion is prevented.
Moreover, the copper plating screw was used for attachment of the printed circuit board, a chassis, a transformer, etc., etc., the fine oscillation was absorbed, and a magnetic distortion is prevented.
Aluminum Naked material with a large mass of 110g is adopted as a volume knob.

The relay and electronic switch which were examined were made the change of the function, it takes them, leading about of the product line to chlorofluocarbon and a panel was reduced sharply, and a loss and a failure of a signal are prevented.

The hybrid MC transformer scheme by the combination of MC transformer which made the turn ratio the conventional one-half, and the equalizer amplifier which raised the gain of the decrement of a boost ratio is adopted.
Since a turn ratio can use few parts and bold-line material, while direct current resistance decreases, the stray capacity between coils also falls, and the high region property is improving sharply.

The copper plating treatment of the whole chassis is carried out, and a magnetic distortion is reduced sharply.
Moreover, the property to be easy to subside even if a heterogeneous metals (a hard metals and soft metals) will be unified, it is hard to receive an oscillation and it receives an oscillation has been acquired.

An electronic formula was not used for the volume but the scheme which drives a mechanism type high-grade volume by a motor is adopted as it. This motor is a clutch type, and in the case of a manual operation, since a motor separates, a comfortable operation feeling can be enjoyed.

Sharpness, the detail, and the full-scale video-system enhancer that noise cancellation can control independently, respectively are built in the video-system part.
Furthermore, Rec Monitor Out is equipped, and it can record, monitoring the enhancing effect at the time of a picture recording.

Rear Attached
Rotary Hybrid

Rating of a mode
Form Stereo control amplifier
Input sensitivity/impedance Phono man month: 2.5mV / 50kohm
Phono MC/40ohm: 250 microvolts/40 ohm
Phono MC/3ohm: 125 microvolts/three ohm
compact disk, Tuner, Tape Play1, 2, VDP, VTRs 1, 2, and 3, TV Tuner:150mV /, 50kohm
An Output voltage/impedance Tape Rec: 150mV / 1kohm
Pre Out: 1V/600 ohm
Phono maximum permissible input
(1kHz, 0.1% of distortion)
Phono MM:200mV
Phono MC/40ohm: 20mV
Phono MC/3ohm: 10mV
Tone control Bass: ±9dB (100Hz)
Treble: ±9dB (10kHz)
SN ratio (IHF, short circuit)
A network
Phono MM:96dB(5mV)
Phono MC: 86dB (500 microvolts)
Tuner, compact disk, Tape Play, VDP, VTR: 109dB
Supply voltage AC100V, 50Hz/60Hz
Power consumption
(Electrical Appliance and Material Control Law)
Dimensions Width 457x height 124x depth of 404mm
Weight 9.7kg
Adjunct Remote control CU-C001