Difference between revisions of "Harman/kardon HD 7725"
 
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Kurzbeschreibung:
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__NOTOC__
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== Data ==
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{{navigation}}
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'''General'''
 +
* Manufacturer: [[Harman/kardon]]
 +
* Model: HD 7725
 +
* Type: CD-Player
 +
* Years of manufacture: 1995 - 1998
 +
* Color: Black
 +
* Remote control: yes
 +
* Dimensions: 443 x 103 x 326 mm (WxHxD)
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* Weight: 8,6 kg
 +
* Original price approx.: 1'999 DM
  
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Das Flagschiff von Harman/Kardon von 1993. Sehr aufwändig aufgebauter CD-Player.
 
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Er besitzt ein Antiverzerrungskonzept RLS (Real Time Linear Smoothing), das den Datenstrom auf zwei 18-bit-Wandler (PCM 61 K) pro Kanal aufteilt; einer erhält ihn um einen Abtastwert zeitversetzt. Das Differenzsignal beider Konverter spiegelt den Verlauf der Ausgangskurve wider. Damit speiste Harman einen Kondensator, der seine Spannung nicht sprunghaft, sondern nur stetig ändern kann und somit das treppenförmige Wandler-Ausgangssignal glättet, sprich, das Signal entspricht schon fast exakt dem Musiksignal. Nach den Wandler steht eine aufwendige Differenzialeingangsstufe, die diskret mit Einzeltransistoren aufgebaut ist. Beide Ausgänge für den fixen und variablen sind mit Einzeltransistoren diskret aufgebaut.
 
  
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Allgemeine Daten:
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'''Connections'''
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* Dual 18-bit linear Burr Brown DA/Wandler (PCM61K) in höchster (K) Selektion, Real Time Linear Smoothing (RLS) Technik (vermutlich die erste Generation).
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* Outputs:  
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* Diskret aufgebaute Ausgangsstufe für den fixen und variablen Chinch-Ausgang.
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** 2 x Cinch (1 x fixed, 1 x variable)
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* Differenzialeingangsstufe diskret aufgebaut!
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1 x Digital Coaxial
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* Diskret, getrennt für den Digital- und Analogbereich, aufgebaute Stromversorgung!
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** 1 x Digital Toslink (SPDIF)
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* Regelbarer Kopfhörerverstärker, dieser hat einen Dual OPV NJM4580 verbaut.
 
  
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Technische Daten:
 
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* Frequenzgang: 2 Hz - 20 kHz
 
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* Verzerrung: 0,0025%
 
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* Dynamikbereich: 98 dB
 
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* Rauschabstand: 104 dB
 
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* Kanaltrennung: 98 dB
 
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* Ausgangsspannung: 2,1 V
 
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* Ausgangswiderstand: 150 Ohm
 
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* Fehlerkorrektur: CIRC-System, mäßige Fehlerkorrektur laut Test im Stereoplay.
 
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* Verstärktes Chassis
 
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* Maße: B:44,3cm H:10,3cm T:32,6cm
 
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* Gewicht: 8,6kg
 
  
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Ausgänge:  
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'''Technical Data'''
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2 x Cinch (1 x fix, 1 x variabel)
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* Frequency response: 2 Hz - 20 kHz
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1 x Digital koax
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* Distortion: 0,0025%
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1 x Digital Toslink (SPDIF)
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* Dynamic range: 98 dB
 +
* Signal to noise ratio: 104 dB
 +
* Channel separation: 98 dB
 +
* Output voltage: 2.1 V
 +
* Output impedance: 150 ohms (fixed); 1250 ohms (variable).
 +
* Error correction: CIRC system, moderate error correction according to test in Stereoplay 4/93.
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* Amplified chassis, remote control.
  
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Sonstiges:
 
  
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Fernbedienung
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* Further data at "Hifi-Engine": [[https://www.hifiengine.com/manual_library/harman-kardon/hd7725.shtml]]
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verstärktes und bedämpftes Gehäuse
 
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== Testberichte ==
 
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* Stereoplay 4/93: Absolute Spitzenklasse I, Klang: sehr gut.
 
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* HiFi-Vision 10/93: sehr gut
 
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* Stereo 11/93: homogen farbiges Klangbild
 
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* HiFi-Test 1/95: Testsieger sehr gut
 
  
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=== Bilder ===
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'''Special Features'''
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* Remote control
 +
* Reinforced and damped housing
 +
* Sony drive
 +
* Laser: KSS 210A
 +
 
 +
 
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== Comments ==
 +
* Other models in the same series:
 +
* Preamplifier:
 +
* [[Harman/kardon AP 2500 Signature Series]]
 +
 
 +
 
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* Power amplifiers:
 +
* [[Harman/kardon PA 2100]]
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* [[Harman/kardon PA 2200]]
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* [[Harman/kardon PA 2400]]
 +
 
 +
 
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* [[Integrated Amplifier]]
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* [[Harman/kardon HK 610]]
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* [[Harman/kardon HK 620]]
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* [[Harman/kardon HK 640]]
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* [[Harman/kardon HK 660]]
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* [[Harman/kardon HK 680]]
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* [[Harman/kardon HK 1200]]
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* [[Harman/kardon HK 1400]]
 +
 
 +
 
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* [[A/V integrated amplifier]]
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* [[Harman/kardon AVI 100]]
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* [[Harman/kardon AVI 150]]
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* [[Harman/kardon AVI 200 II]]
 +
 
 +
 
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* [[Tuner]]
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* [[Harman/kardon TU 930]]
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* [[Harman/kardon TU 950]]
 +
 
 +
 
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* Receiver:
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* [[Harman/kardon HK 3250]]
 +
 
 +
 
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* A/V receivers:
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* [[Harman/kardon AVR 10]]
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* [[Harman/kardon AVR 21]]
 +
* [[Harman/kardon AVR 25]]
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* [[Harman/kardon AVR 70]]
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* [[Harman/kardon AVR 80]]
 +
 
 +
 
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* CD player:
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* [[Harman/kardon HD 710]]
 +
* [[Harman/kardon HD 730]]
 +
* [[Harman/kardon HD 7625]]
 +
* [[Harman/kardon HD 7725]]
 +
 
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* [[CD Changer]]
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* [[Harman/kardon FL 8300]]
 +
 
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* Tape Deck:
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* [[harman/kardon TD 420]]
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* [[harman/kardon TD 450]]
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* [[harman/kardon TD 470]]
 +
 
 +
 
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== Pictures ==
 +
* Extract from brochure: Harman/kardon HD 7725
 +
[[File:Harman Kardon HD-7725-Prospekt-1997.jpg]]
 +
 
 +
 
 +
== Reports ==
 +
* Report in "Stereoplay 4 / 1993: Absolute top class I
 +
 
 +
* Report in "Hifi Vision" 10 / 1993: very good
 +
 
 +
* Report in "Stereo 11 / 1993: homogeneously coloured sound image
 +
 
 +
* Report in "Hifi Test" 1 / 1995: test winner very good
 +
 
 +
 +
* The flagship of [[Harman/Kardon]] from 1993. Elaborately built CD player.
 +
* It has an anti-distortion concept RLS (Real Time Linear Smoothing), which splits the data stream to two 18-bit converters (PCM 61 K) per channel, one receives it time-shifted by one sample. The Burr-Brown converter is an R2R converter whose current output applied to the IC pin is fed back directly to the PIN of the internal operational amplifier in the standard Burr-Brown circuitry used in the HD7725. The differential signal of both converters, voltage-converted by the DAC's internal op-amps, mirrors the output waveform. Thus Harman fed a capacitor, which cannot change its voltage abruptly, but only steadily and thus smoothes the staircase-shaped converter output signal, i.e. the signal already corresponds almost exactly to the music signal. * After the converters there is an elaborate summing double differential amplifier stage, discretely constructed with single transistors. Both outputs, for the fixed and the variable, are discretely built with single transistors. Output coupling capacitors have 220 uF/25V (Panasonic "Pureism").
 +
 
 +
 
 +
* General data:
 +
* Dual 18-bit linear Burr Brown DA/converters (PCM61K) per channel in highest (K) selection, Real Time Linear Smoothing (RLS) technique (presumably first generation), tap of voltage output at converter IC.
 +
* Discretely built output stage for fixed and variable RCA output.
 +
* Differential amplifier discretely built!
 +
Discrete, separate power supply for the digital and analogue range!
 +
Adjustable headphone amplifier, this has a dual OPV NJM4565 built in.
 +
 
 +
 
 +
== Links ==
 +
 
 +
 
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[[Category:CD Player]]

Latest revision as of 05:52, 22 June 2020

Data[edit]

General

  • Manufacturer: Harman/kardon
  • Model: HD 7725
  • Type: CD-Player
  • Years of manufacture: 1995 - 1998
  • Color: Black
  • Remote control: yes
  • Dimensions: 443 x 103 x 326 mm (WxHxD)
  • Weight: 8,6 kg
  • Original price approx.: 1'999 DM


Connections

  • Outputs:
    • 2 x Cinch (1 x fixed, 1 x variable)

1 x Digital Coaxial

    • 1 x Digital Toslink (SPDIF)


Technical Data

  • Frequency response: 2 Hz - 20 kHz
  • Distortion: 0,0025%
  • Dynamic range: 98 dB
  • Signal to noise ratio: 104 dB
  • Channel separation: 98 dB
  • Output voltage: 2.1 V
  • Output impedance: 150 ohms (fixed); 1250 ohms (variable).
  • Error correction: CIRC system, moderate error correction according to test in Stereoplay 4/93.
  • Amplified chassis, remote control.


  • Further data at "Hifi-Engine": [[1]]


Special Features

  • Remote control
  • Reinforced and damped housing
  • Sony drive
  • Laser: KSS 210A


Comments[edit]











Pictures[edit]

  • Extract from brochure: Harman/kardon HD 7725

Harman Kardon HD-7725-Prospekt-1997.jpg


Reports[edit]

  • Report in "Stereoplay 4 / 1993: Absolute top class I
  • Report in "Hifi Vision" 10 / 1993: very good
  • Report in "Stereo 11 / 1993: homogeneously coloured sound image
  • Report in "Hifi Test" 1 / 1995: test winner very good


  • The flagship of Harman/Kardon from 1993. Elaborately built CD player.
  • It has an anti-distortion concept RLS (Real Time Linear Smoothing), which splits the data stream to two 18-bit converters (PCM 61 K) per channel, one receives it time-shifted by one sample. The Burr-Brown converter is an R2R converter whose current output applied to the IC pin is fed back directly to the PIN of the internal operational amplifier in the standard Burr-Brown circuitry used in the HD7725. The differential signal of both converters, voltage-converted by the DAC's internal op-amps, mirrors the output waveform. Thus Harman fed a capacitor, which cannot change its voltage abruptly, but only steadily and thus smoothes the staircase-shaped converter output signal, i.e. the signal already corresponds almost exactly to the music signal. * After the converters there is an elaborate summing double differential amplifier stage, discretely constructed with single transistors. Both outputs, for the fixed and the variable, are discretely built with single transistors. Output coupling capacitors have 220 uF/25V (Panasonic "Pureism").


  • General data:
  • Dual 18-bit linear Burr Brown DA/converters (PCM61K) per channel in highest (K) selection, Real Time Linear Smoothing (RLS) technique (presumably first generation), tap of voltage output at converter IC.
  • Discretely built output stage for fixed and variable RCA output.
  • Differential amplifier discretely built!

Discrete, separate power supply for the digital and analogue range! Adjustable headphone amplifier, this has a dual OPV NJM4565 built in.


Links[edit]

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