Audio Database

The

DENON PMA-760
79,800yen(1983 release)

Description
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The stereo Integrated Amplifier which carrying the power amplifier unreturned [ of 0dB ] etc. inherited the technology of PMA-790, and was developed.

The power amplifier which eliminated the negative return loop unreturned [ of 0dB ] is carried.
This system is a thing adapting the technology developed by POA-8000 in which it does not return, and has structure using a direct distortion servo circuit. A direct distortion servo circuit compares the signal (main signal + distorted ingredient) and incoming signal which are acquired from the output side, detects only a distorted ingredient, then carries out phase inversion of this distorted ingredient, and is adding it to the input side.
Static distortion is driven into the domain of zero by this operation. Moreover, the noise which appears in the output side of amplifier was also regarded as a difference with an incoming signal, and is removed. [ as well as a distorted ingredient ]
Since there is no feedback of a signal and time delay does not arise by this, dynamic distortion which affects the Hearing impression quality is suppressed. Moreover, in order that there may be no NFB circuit, it is not influenced by the back electromotive force from a speaker, but the distorted increase and generating at the time of speaker connection are suppressed.

The power transistor of Pc200W is adopted as a power amplifier part final stage. Furthermore, the quality of a Class-A and efficient coexistence of Class B are aimed at with the direct Class-A amplifier system.

The perfect direct-current composition which does not use a coupling capacitor for all the signal courses from the input terminal for MC cartridges to a speaker output terminal is adopted.

The large-sized toroidal transformer of 260VA, the mass capacitor of 30,000microf, the first recovery diode of the high-speed rectification which reduced switching distortion, etc. are adopted as a power-source part.

The super equalizer is adopted as an equalizer part in order to pull out the engine performance of MC cartridge.
This has attained RIAA deflection 20Hz-100kHz}0.2dB.

Tone control and a high-speed protection circuit are carried.

Output Power-source Super

Rating of a mode
Form Integrated Amplifier
<Power amplifier part>
Circuit system Unreturned [ of 0dB ] power amplifier system
Output power
(both channel drive, a sine wave continuation output, 20Hz - 20kHz)
150W+150W (6ohms)
125W+125W (8ohms)
Input sensitivity/impedance 150mV/47kohm
THD (20Hz - 20kHz, Output-power-3dB o'clock) 0.003% or less
Cross modulation distortion
(at the time of a 60Hz:7kHz=4:1 and Output-power equivalent amplitude output)
0.002% or less
TIM distortion Below a measurement limit
Slew rate }300v/microsecond or more
Output bandwidth (IHF, both channel drive) 5Hz - 80kHz (THD 0.025%)
Frequency response (at the time of 1W output) 1Hz-250kHz+0 -3 dB
Output load impedance (1kHz) 0.1ohm
Output terminal Speaker AorB: 6ohms - 16ohms
Speaker A+B: 12ohm-16ohm
Headphone: 490mW/eight ohms
<Preamplifier part>
Circuit system Super equalizer system
Input sensitivity/impedance Phono MM: 2.5mV/47kohm
Phono MC: 0.2mV/100 ohms
Tuner, DAD/Aux, Tape:150mV/47kohm
The maximum except take-off/Output power 12V/150mV
RIAA deflection (MC) 20Hz-100kHz}0.2dB
THD (at the time of 1kHz and 8V output) 0.002% or less
<Synthesis>
Signal to noise ratio (IHF-A, input short circuit) Phono MM: 87dB (at the time of a 2.5mV input)
Phono MC: 70dB (at the time of a 0.25mV input)
Tuner, DAD/Aux, Tape: 110dB (at the time of a 150mV input)
Tone control Bass: }8dB (50Hz/100Hz)
Treble: }8dB (10kHz/20kHz)
Subsonic Filter 20Hz, 6 dB/oct
Muting -20dB
Loudness characteristic Low-pass: +7dB (100Hz)
High region: +6dB (10kHz)
Power source AC100V, 50Hz/60Hz
Power consumption (Electrical Appliance and Material Control Law) 230W
Dimensions (a base, a knob, a terminal included) Width 470x height 132x depth of 413mm
Weight 12kg