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FX-Audio D2160 Integrated Amplifier with Bluetooth – Review

andreasmaaan

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#21
There are some, Lyngdorf 3400 for instance ... I'm running a Technics SU-G700 right now, it's also an FDA (Full Digital Amplifier)
I'm not sure actually. That Technics says it uses a PCM1804 chip, which is a DA converter. That would imply that DA conversion occurs prior to the amp stage.

And I'm not sure about the Lyngdorf either, the specs list RCA outputs which also suggest that DA conversion occurs before the amp stage.

Do you have any further info on these which shows that they are direct digital amps?
 

Blumlein 88

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#22
I'm not sure actually. That Technics says it uses a PCM1804 chip, which is a DA converter. That would imply that DA conversion occurs prior to the amp stage.

And I'm not sure about the Lyngdorf either, the specs list RCA outputs which also suggest that DA conversion occurs before the amp stage.

Do you have any further info on these which shows that they are direct digital amps?
http://lyngdorf.com/tdai-2170/

In the following link, they mention the 3400 is based upon the Equi-bit technology. This was how the Tact Millenium and later Tact amps work. Boz at Tact and Lyngdorf were together then split into the two companies. Even the Tact took various digital inputs and upsampled them (384 khz internally), but the entire signal path to the output stage was digital. So there may be some enhancements and differences, but they probably are a direct digital amp with conversion taking place in the power output section.
 

Blumlein 88

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#23
To add to my earlier post. Tact had cards you could add rather like desktop computers in their preamps. One was an analog input stage. It had a DA converter on the card. So any RCA analog connections were immediately digitized. My assumption is the Lyngdorf does the same. The power amp took a digital input only (which could come from any digital source) and had an RS232 connection between pre and amp for volume control, and some other features.
 

maty

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#24
[Polish] https://audio.com.pl/testy/stereo/wzmacniacze-stereo/2703-lyngdorf-audio-tdai-2710

to English with Google: https://translate.google.com/transl...3-lyngdorf-audio-tdai-2710&edit-text=&act=url


  • Rated power (1% THD + N, 1 kHz) [W] 8 Ω, 2x 98
  • Rated power (1% THD + N, 1 kHz) [W] 4 Ω, 2x 190
  • Sensitivity (for maximum power) [V] 1x 0.2
  • Signal-to-noise ratio (A-weighted filter, with reference to 1W) [dB] 72
  • Dynamics [dB] 92
  • Damping factor (relative to 4 Ω) 77
:confused:
 

andreasmaaan

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#26
The PCM1804 are used only on analog inputs, and for analog to digital convertion, If that help this is the schema of the SU-G700 View attachment 17482
Ok, that was obviously a momentary brain absence on my part - the PCM1804 is an AD converter not a DA converter, which is perfectly consistent with this being a direct/pure digital amp, as is this schematic (to the best of my limited technical knowledge) :)
 
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#27
It will be very interesting to have internal schema of the Lyngdorf and the FX-Audio to compare different approaches..
 

maty

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Blumlein 88

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#29
[Polish] https://audio.com.pl/testy/stereo/wzmacniacze-stereo/2703-lyngdorf-audio-tdai-2710

to English with Google: https://translate.google.com/translate?sl=pl&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=https://audio.com.pl/testy/stereo/wzmacniacze-stereo/2703-lyngdorf-audio-tdai-2710&edit-text=&act=url


  • Rated power (1% THD + N, 1 kHz) [W] 8 Ω, 2x 98
  • Rated power (1% THD + N, 1 kHz) [W] 4 Ω, 2x 190
  • Sensitivity (for maximum power) [V] 1x 0.2
  • Signal-to-noise ratio (A-weighted filter, with reference to 1W) [dB] 72
  • Dynamics [dB] 92
  • Damping factor (relative to 4 Ω) 77
:confused:
The frequency response looks right. The low pass filter on the Equibit stuff was optimized for 6 ohms. But notice at 20 khz they are still within 1 db of the flat response. The SNR above is probably without a filter to remove the ultrasonic switching. With one in place the things are so quiet they are hard to measure. The claim was SNR of 110 db. I haven't measured it with anything that would have told me that low a level, but the Tacts were better than 72. I've had one on some K-horns once, and they were dead silent. Rated for .01% THD+n at 150 wpc at 8 ohms and twice that at 4 ohms.

As we well know you can't always trust specs from the maker.
 

maty

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#30
A lot of "old" class D technology have SNR-A at 1 watt < 80 dB

To compare amps it is better to consider SNR-A at 1 watt.

With great SNR the sound is more detailed, more 3D and fill the room.
 

maty

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#31
Talking about class D amps, I just have commented:

https://www.diyaudio.com/forums/vendor-s-bazaar/281361-hypex-ncore-nc500-build-post5597850.html

Marantz Is Back: 40th-Anniversary Marantz KI Ruby Series | The Absolute Sound

The integrated’s amplifier section uses a special switching technology (though Marantz prefers not to call it Class D) similar to that found in Marantz’s PM-10. There’s no analog-to-digital conversion, but the signal gets transformed into pulses with the driver circuit increasing the pulses’ amplitude. While this approach is said to be powerful and efficient, it requires the use of an output filter. Rather than putting a feedback loop before the output filter, Marantz uses a patented technology that takes the feedback right from the speaker connection and allows the amp to correct for distortion...
Marantz US | PM-KI Ruby



They seem Hypex NC500 like Marantz PM-10.

Inside:

[BIG pìcture] https://www.safeandsoundhq.com/prodimages/PM-KI RUBYC.jpg
 

FrantzM

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#32
Marantz has to be older than 40... IIRC it was founded in the early ,50s by Saul Marantz
 

JJB70

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#33
I'm not sure how anybody could describe a brand which has retained a full range of hi-fi and AV gear without interruption for as long as I can remember as "being back on the map" as per the Absolute Sound article. Especially when some of their gear is still extremely well regarded and when they are one of the few companies that still seem to offer everything from entry level products through to high end. The 6006 CD & amp are often name checked as the default very good without going silly products in their categories over here.
 

maty

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#34
The important thing is that a recognized brand bet for the use of Hypex NC500 modules in the expensive integrated and power amplifier. He uses his HDAM to maintain his traditional sound signature so appreciated by many lovers of acoustic music (classical, jazz ...).

I have dudes about other module, IcePower 1200AS2, to play this kind of music (very great phase shift).

https://www.diyaudio.com/forums/class-d/321578-phase-shift-class-amplifiers-affects-sound.html

I suspect that almost all Class D technology has such a problem (to me). Sub and woofers, OK with class D. But tweeters, better with class A or AB I think.

An example: KEF LS50 Wireless:

https://www.amazon.com/Wireless-Pow...931048&sr=1-3&keywords=kef+ls50+wireless&th=1
 

andreasmaaan

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#35
The important thing is that a recognized brand bet for the use of Hypex NC500 modules in the expensive integrated and power amplifier. He uses his HDAM to maintain his traditional sound signature so appreciated by many lovers of acoustic music (classical, jazz ...).

I have dudes about other module, IcePower 1200AS2, to play this kind of music (very great phase shift).

https://www.diyaudio.com/forums/class-d/321578-phase-shift-class-amplifiers-affects-sound.html

I suspect that almost all Class D technology has such a problem (to me). Sub and woofers, OK with class D. But tweeters, better with class A or AB I think.
Looking at your thread in DIY Audio, do you appreciate that the phase shift shown in your graph in post #1 is a phase shift in the output impedance of an electrical device (an amplifier), while the phase shift discussed in your post #5 is phase shift in the frequency response of the acoustic output of an audio system?

Perhaps your understanding of these concepts has developed since you made those posts, but at the time you made them, you were conflating two completely distinct and unrelated phenomena.
 

maty

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#36
The speakers graphs are measured in anechoich chamber or equivalent, always in near field -> ROOM does not intervene.
 

andreasmaaan

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#37
The speakers graphs are measured in anechoich chamber or equivalent, always in near field -> ROOM does not intervene.
Are you responding to my post?

This is still an entirely unrelated issue.

There is no relationship between the phase of the impedance response of an electrical device and the phase of the frequency response of a speaker whether measured anechoically or in-room.

The two are simply separate and unrelated.
 

maty

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#38
Then, tell me why the class A/AB amps designers try that the impedance is only resistive, without reactance. In the real world, the phase only varies a few degrees in the audio band in traditional amplifiers.
 

andreasmaaan

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#39
Then, tell me why the class A/AB amps designers try that the impedance is only resistive, without reactance. In the real world, the phase only varies a few degrees in the audio band in traditional amplifiers.
I'm happy to discuss that, sure.

But first, you need to clarify your understanding of the difference between (a) electrical impedance and (b) frequency response.

Please stop conflating these two phenomena. When you've understood the difference between these, I'm happy to discuss what effects a non-flat output impedance in an amplifier might have (which are entirely different to the effects you seem to believe it has).
 

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