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74 Posts
Discussion Starter · #1 ·

if dont look price here %20 different price and it is not important but i dont belive that most expensive is better .. may be cheaper is better ..  what about amplifers and music ? I will listen Kef Q900 Will use sound card pc may be asus xonar or creative ZxR which amplifer is better if they same money ..

Marantz PM8005 is 12 kg
THD0.02% (20Hz – 20kHz, 2 channel driven, 8 ohms load)
Input Sensitivity/ImpeancePHONO:MM:2mV/47k ohms, LINE:200mV/20k ohms
Frequency response5Hz – 100kHz ±3dB (CD, 1W, 8 ohms load)
S/N RatioPHONO:MM:87dB, LINE:106dB, DIRECT IN: 125dB
Number of Channels2
Output Power70W (8 ohms), 100W (4 ohms)
Power TransformerShielded Toroidal Transformer
Current Feedback AmplifierYes
Speaker TerminalMarantz SPKT-1
Tone Control(Bass: 50Hz ±10dB, Mid: 900Hz ±6dB, Treble: 15kHz ±10dB)
Source DirectYes
Speaker A/BYes



Pioneer A-70 is 17 kg  eisa award
Main FeaturesA-70-K
Output Power per Channel90W
Impedance at Output Level• 4 Ω - 16 Ω (A / B)

• 8 Ω - 32 Ω (A + B)

• 4 Ω - 16 Ω (Bi-wiring)
Number of Channels2
Input Connections• SACD/CD

• Phono (MM/MC)

• Aux

• Network

• Digital Coaxial Input

• Recorder

• Tuner

• Power Amp Direct In


• SR In
Output Connections• Recorder

• Phones

• SR Out
Remote ControlMulti-functional remote control
Input & Output connectionsA-70-K
Digital Coaxial Input/OutputYes
Large speaker terminalsYes
Phono InputYes
Pre-amp OutputYes
Speaker A/BVersatile speaker configuration
Audio FeaturesA-70-K
Bass/Treble Tone ControlsYes
Power OutputA-70-K
Power output per channel90 W
Condition20 Hz - 20 kHz, 0,5% THD, 4Ω
Rated Power Output90 W per channel
Power RequirementsAC 220 - 230 V / 50 Hz
Power Consumption (in use / standby)74 W / 0.2 W
Auto Power DownYes
AIR Studio Sound TuningYes
Design• Separated Construction for Preamp and Power Amp

• Twin Block Shield Transformer

• Source Direct Mode

• DAC Mode

• Clean Ground Construction

• Isolated Power Supply

• Trans-Stabiliser

• Rigid Under Base

• Solid aluminium volume knob and front/ side panels

• Gold-plated Speaker Terminals (large type)

• Gold-Plated Analogue Audio Terminals

• High-Grade AC Power Cord
Amplifier SpecificationsA-70-K
AmplifierMOSFET Class D Amplifier
D/A Converter• ESS SABRE32 192 kHz/32-bit Audio DAC

• Asynchronous 192 kHz/32-bit USB DAC
Dimensions (W x H x D)435 x 141.5 x 361.5 mm
Weight17.1 kg

7,063 Posts
The Marantz amplifier will definitely sound better IMO.

On the other hand, there are much better-sounding amplifiers than the Marantz. I would not consider either of those amplifiers adequate for the KEF Q900, which needs a better one to allow it to perform the way it can and should.

The power ratings tell you almost nothing, and neither do the other specs.

Published amplifier power specs are based on a load test using an 8 ohm resistor for a load. Under this test condition, the distortion of any amplifier will be virtually zero.

When driving the complex load of a speaker system, the distortion of the amplifier may be 10 or 100 times more, depending on the particular loudspeaker and how well the amplifier and its power supply are designed. No published specification will give you much of a clue regarding how it will SOUND driving real speakers.

Speakers have different impedances at different frequencies and also may have capacitive reactance or inductive reactance. Look at the Stereophile article on the KEF Q900, and you will see the graph of impedance VS frequency, and also the reactance graph of the load it presents at different frequencies. It goes down to around 3 ohms at various frequencies, and the phase angle of the load can be as much as 45 degrees, both capacitive and inductive. This is a load that will will stress an amplifier quite a bit and tend to produce high distortion if the amplifier is not very well designed.

This is where the best-designed amplifiers distort less, and the others distort more. This is why there is so much difference in SOUND QUALITY.

In general, you will find that the best amplifiers have much larger power supplies, which can deal better with the difficult load of a speakers system. This can make them more expensive, obviously, but price is not always a good predictor of sound quality either.

In integrated amplifiers selling for under $1000, one of the best IMO is the Music Hall 15.3. Another good one is the NAD C326BEE. The Cambridge Audio 651A is also good-sounding.

If you can spend a bit more, the Musical Fidelity M3i is excellent, at $1500. It would really be perfect for those speakers.

Any of those four amplifiers will sound better than the Marantz, IMO, and have plenty of power for the Q900. Amplifiers from Pioneer and Yamaha and Onkyo are really crappy-sounding in my experience.

74 Posts
Discussion Starter · #4 ·

Thank you for your answer.i will look to nad. i have onkyo 929 ampifer 850 watt power supply but i dont know about stereo sound quality if we compare it with stere amplifer which sound quality will be better in stereo music i can use subwoofer on onkyo 929 but dont know wich amplifers stere performance will be good .. i think it built for cinema 18.5 kg and 5x120 watt continuos 0.1 thd 20-20.000  8 ohm load ... but pioneer is 17 kg only 2x90  and price is not very different ..  should i buy stereo preamp and use onkyo 929 as a power amp ? or i sell it and go to stereo amp ? i will only listen music not cinema

7,063 Posts
To get a really good-sounding preamp will cost $2000 or more. I really doubt if Onkyo power amp is what you want to use in any case.

NAD and Cambridge Audio Integrated amplifiers are probably your best bet if Music Hall is not available where you are.

What country are you located in?

74 Posts
Discussion Starter · #6 ·
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