Pagine

Denon PMA-750 amplifier

Integrated Amplifier Features:

Non-NFB (Non-Negative Feedback) Amplifier, Zero Dynamic Distortion (Patent Pending)

Super Equalizer; Super Wide RIAA Deviation 20 Hz - 100 kHz ±0,2 dB (Patent Pending)

High Power Direct-A Amplifier 80 W + 80 W

Real Drive Circuit: Significantly Reduces Distortion Under Real Operating Conditions - When Driving Speakers

Clean Simple Circuit Design Combined wirh High Quality Construction

Real-Time Tone Control

Dual Speakers Output Terminals (A or B, A+B)

Dual Input/Output Terminals for Interconnection with Two Tape Decks

A Defeatable Subsonic Filter (18 Hz, 6 dB/oct) Eliminates Unneeded Ultra Low Frequency Noise

Direct Coupling Switch Removes Tone Controls from The main Circuit

Mode Switch with Facilities for Stereo Reverse and Monaural Reproduction

Loudness Control Switch

High Speed Protection Circuity

 

Principle of the Non-Negative Feedback Amplifier

The fundamental block diagram is shown as under. At first, input signal e, and inversed output signal e, are mixed at the input of the direct DS. amplifier. Then, the distortion component d is extracted. This d is amplified by the direct DS. amplifier and is inversed and fed into the main amplifier A, with the original signal e, Thus distortion is finally reduced dramatically and static distortion is brought to zero.

 


Specifications

Power Amplifier Section

Circuit Type:  All stage direct DC servo circuit

Rated Output Power (Both Channel Drive)

80 W + 80 W at 20 Hz to 20 kHz 8 0hm load (DIN, U.K. Europe, USA)

100 W + 100 W at 1 kHz , 4  load (DIN, U.K. USA)

50 W + 50 W at 1 kHz, 4  Load (IEC)

Total Harmonic Distortion :

0,008% (20 Hz - 20 kHz at -3 dB rated output 8  Load)

0,02% (20 Hz - 20 kHz at rated output 8  Load )

Intermodulation DIstortion :  0,002% below 7 kHz/ 60 Hz : 1/4 (at amplitude output equivalent to rated output)

Output Bandwidth:  5 Hz - 100 kHz (IHF T.H.D. 0,035%)

Transmission Characteristics:  1 Hz - 250 kHz =0 dB -3 dB (at 1 W output)

Input Sensitivity:  150 mV

Input Impedance:  47 k

Output Impedance:  0,08  (1 kHz)

Output Terminals: 

Speaker A and B Load 4 - 16 or A + B Load 8 - 16

Headphone/Stereo headphone

Equalizer Amplifier Section

Max. Output:  10 V (at 47 k  load)

Rated Output :  150 mV

Total Harmonic Wave Distortion :  below 0,002% (at 1 kHz, 8 V output)

Input Sensitivity/Impedance

Phono MM :   2,5 mV/47 k

Phono MC :  125 µV/100

Tuner :  150 mV/47 k

Aux, Tape :  150 mV/47 k

RIAA Deviation:

Phono MM :  within ±0,2 dB (20 Hz - 100 kHz)

Phono MC :  within ±0,2 dB (20 Hz - 100 kHz)

Overall Characteristics

Signal-to-Noise Ratio (IHF A network)

Phono MM :  88 dB (input terminals short-circuited for 2,5 mV input)

Phono MC :  72 dB (input terminals short-circuited for 250 mV input)

Tuner, Tape, Aux :  110 dB (input terminals short-circuited)

Tone Control Adjustable Range

Bass :  ±8 dB at 100 Hz

Treble :  ±8 dB at 10 kHz

Subsonics:  18 Hz at 6 dB/oct

Loudness

Low Frequency :  +7 dB at 100 Hz

High Frequency :  +6 dB at 10 kHz

AC Outlet:  switched x 2 100W Total, unswitched x 1 250 W

Power Requirements:  AC 120 V, 200 V, 220 V, 240 V 50/60 Hz

Power Consumption:230 W (USA); 400 W (IEC); 200 W (Hong Kong); 680 W Maximum Output

Dimensions (W x H x D):  434 x 132 x 407 mm

Weight:  12 kg


 

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