Tôi có 01 Amly Denon PMA 770 cần bán, em này quá khủng CS 290W rất dê ghép loa, chất âm denon thì quá nổi tiếng rồi.........hàng zin, nguyên bản, hình thức còn đẹp.
Giá bán: 3tr8
Xin liên hệ trực tiếp để có giá tốt nhất......................SĐT: 0982021110
DENON PMA-770
98,000yen(around the 1981 time)

Description
 
The Integrated Amplifier which supplied original technology, such as amplifier unreturned [ of 0dB ], a direct A system, a super equalizer, and was developed.

MC input terminal to the speaker output terminal considered it as the whole page Capacitor-Less (perfect direct-current composition) which uses not a capacitor for the main signal course, and has formed the signal course into pure & high speed thoroughly.
This perfect Capacitor-Less composition suppressed direct-current drift by adopting the direct direct-current servo circuit carried in PMA-970 or PMA-950, and has secured super-low-pass stability.

The MC/MM super equalizer is carried and the outstanding RIAA deflection characteristic of 20Hz-100kHz±0.2dB exceeding the high region play threshold frequency of a high-class cartridge is acquired.
Composition consists of the NF form direct-current amplifier and CR form equalizing filter by newly developed low noise dual FET, and the first rank has composition of the parallel differential amplification by dual FET of a direct direct-current servo system.

The amplifier unreturned [ of 0dB ] is adopted as a power amplifier part.
The amplifier unreturned [ of 0dB ] takes out ingredients (distortion, noise, etc.) other than an incoming signal for the signals (main signal + distorted ingredient etc.) acquired from the output side of the main amplifier in a direct distortion servo circuit as compared with an incoming signal.
This distorted ingredient is amplified in a direct distortion servo circuit, and also phase inversion is carried out, and it is added to the input side of the main amplifier. By this, a distorted ingredient is negated and static distortion is suppressed.
Furthermore, with the amplifier unreturned [ of 0dB ], since [ through which a signal flows only into one way ] a direct-pass, dynamic distortion does not occur. Moreover, noise ingredients other than static distortion are also cancellable as a difference of an incoming signal by the effect of a direct distortion servo circuit. Furthermore, the buffer (emitter-follower) which separates a voltage magnification stage and an electric power magnification stage is designed, and in order that there may moreover be no NFB loop, a voltage magnification stage is not influenced by a speaker. Furthermore, since the excessive amplification degree by NFB is not needed, it has the various features -- an intermediary coarse magnification stage can constitute simply

Circuit composition of the power amplifier part was used as the 3 steps of differential current mirror by first rank low noise FET, by the complimentary emitter-follower, attained low impedance-ization and has separated it completely with the electric power magnification stage.
Moreover, an electric power magnification stage is used as the output stage of a high-speed power transistor 2 parallel push pull, from the output terminal, it applies a direct direct-current servo to the first rank of a voltage amplifier at overalls, suppresses direct-current drift, and is attaining super-low-pass stabilization.
Furthermore, the zero crossing linear bias circuit of DENON original is adopted as an output stage, and generating of the switching distortion by cutoff of a power transistor is canceled.

In order to reduce the distortion at the time of speaker real load, the real drive circuit is carried.
In a real drive circuit, the real drive line by an electronic device is set up, and it writes with an A.S.O. (Area of Safety Operating: safe operation domain) line and the protection line approached extremely,Even if a speaker load operation line becomes large at the time of the Oide power, a protection line is not contacted but the thing of the engine performance of a transistor done for a high power drive up until last minute is possible.
This is reducing the distortion at the time of speaker real load to 50 by about 1/.

The aluminum radiator was made to separate equalizer amplifier and power amplifier, and the mutual intervention is eliminated.
Moreover, the input change is attaining shortening of wiring as remote control.

The large-sized toroidal transformer which thought the rate of voltage fluctuation and the leakage flux as important, and a 44,000-micro F mass capacitor are adopted as a power-source part.

Real-time tone control is adopted as tone control.
This consists of only passive devices required for tone control, has neither a distortion of the tone circuit itself, nor a problem of S/N, and is suppressing the influence on a main circuit.

The comparison audition of two MC or two MM is also possible by switch operation of the front panel.

A Rec out selector, the Subsonic Filter, the direct couple switch, the mode switch in which a stereo reverse play and a monophonic play are possible, and the loudness control switch are carried.

The high-speed protection circuit is carried.


Rating of a mode
Form Integrated Amplifier

Circuit system Unreturned [ of 0dB ] power amplifier system
Output power
(both channel drive, a sine wave continuation output, 20Hz - 20kHz)
140W+140W (4ohms)
100W+100W (8ohms)
Input sensitivity/impedance 150mV/47kohm
THD (20Hz - 20kHz, Output-power-3dB o'clock) 0.005% or less
Cross modulation distortion
(at the time of a 60Hz:7kHz=4:1 and Output-power equivalent amplitude output)
0.002% or less
Output bandwidth (IHF, both ch(es) drive, THD 0.035%) 5Hz - 100kHz
Frequency response (at the time of 1W output) 1Hz-250kHz+0 -3 dB
Output load impedance (1kHz) 0.08ohm
Output terminal Speaker AorB: 4ohms - 16ohms
Speaker A+B: 8ohm-16ohm
Headphone: 390mW/eight ohms

Rec out)>
Circuit system The super equalizer system by a direct direct-current servo
Input sensitivity/impedance Phono MM: 2.5mV/47kohm
Phono MC: 0.125mV/100 ohms
Tuner, Aux, Tape:150mV/47kohm
The maximum except take-off/Output power 10V/150mV
RIAA deflection (MC/MM) 20Hz-100kHz±0.2dB
THD 0.002% or less (at the time of 1kHz and 8V output)
Signal to noise ratio (IHF-A, input short circuit) Phono MM:90dB
Phono MC:73dB
Tuner, Aux, Tape: 110dB (at the time of a 150mV input)
Tone control Bass: ±8dB (100Hz)
Treble: ±8dB (10kHz)
Subsonic Filter 18Hz, 6 dB/oct
Loudness characteristic Low-pass: +7dB (100Hz)
High region: +6dB (10kHz)
Power source AC100V, 50Hz/60Hz
Power consumption (Electrical Appliance and Material Control Law) 290W
Dimensions Width 434x height 132x depth of 407mm
Weight 12kg