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How cool is a digital poweramp (Class D and alternatives) running compared to classic Class AB ?

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As spring & summer are approaching (slow this year compared to last) I will be not be able to use my dear Ayre MX-Twenty-R power amps, as they produce too much heat.

 

As a 1st step, I have decided to acquire a headphone set (Sennheiser HD800s) to be used in combination with my T+A 8 DSD dac, which has a decent Headphone amplifier.

Still, as I have no expereince at all with headphones, I will need to learn appreciate them.  With some music (already difficult with speakers) I find it impossible to use headphones, as the soundstage does not get enough space (/time) to develop/integrate itself.

E.g. I am a fan of Rodrogo & Gabriela, but listening to their records through headphones is just not working for me.  My brain is getting crazy trying to follow the right and left channels output with not a millisecond of time to create a soundstage.

 

OK, back to the topic question.

I would like to explore  alternatives for my current amps, that would not heat up my dedicated music room (directly under the ceiling).  As I have VERY sensitive neighbours, there is no way to create some kind of airflow (unless using airco adding a lot of noise).

So, besides the headphones, my 1st step would be to investigate the possibility of using digital amps with my current speakers Magico V3's.  

Later on, I may probably investigate digital speakers as well, but Magico has killed the resale value of my V3's by the new A3's offering.

 

Looking forward to personal experiences with digital power amps running cool (or not) and hopefully still a nice sound quality.

 

Dirk

 

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Pretty simple.  Class D amps are usually at least 85% efficient.  Meaning if you are playing 100 watts on the amp it will consume 118 watts from the electrical plug and only dissipate into the room as heat 18 watts.  A conventional class AB amp might put out 100 watts while consuming 250 or 300 watts so 150 to 200 watts gets dissipated into your room.  

 

Of course your actual average power output is likely to be far less than 100 watts.  Depends on a few factors, but probably would be nor more than 10 wpc at your speakers.  Class AB amps still might sit and idle at 50 watts or more.  Depends upon the particulars of how they are biased.  Class A amps draw maximum current all the time regardless of output. 

 

In the case of your Ayre amps, they show 120 watts power consumption with no signal in their specs.  So that times two means 240 watts at all times.  Plus a few more when you are playing music. 

 

So you'll probably go from say 300 watts of heat dissipated into your room to maybe only 20 or 30 with a class D amp.  Just one example a Bel Canto Ref500 idles with no signal at 10 watts. 


And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. 

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On ‎5‎/‎10‎/‎2019 at 4:47 AM, esldude said:

A conventional class AB amp might put out 100 watts while consuming 250 or 300 watts so 150 to 200 watts gets dissipated into your room.  

 

The 200W into 4 ohms Silicon Chip magazine SC ULD3, for example , has a quiescent output stage Bias of 70mA, so I feel that you may be overstating  Class AB amplifier current demands.


How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

 

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6 hours ago, sandyk said:

 

The 200W into 4 ohms Silicon Chip magazine SC ULD3, for example , has a quiescent output stage Bias of 70mA, so I feel that you may be overstating  Class AB amplifier current demands.

Although Dennis' example might be a little high, in general I do not think he is of the mark by too far. It seems to mostly depend on how high the amp's outputs are biased into Class A. I am fortunate in that my amps have a bias level switch. They run quite warm on high, and only lukewarm on low. 70mA seems pretty low to me. Class A bias beyond avoiding cross over distortion is often because it sounds better. I am sure that this is the case for the OP's Ayer gear. I didn't think Class D I have heard cottoned well, but then again I am not that experienced with higher end ones.


Forrest:

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100 Watts of audio will create a lot more noise for the neighbors than the  cooling air flow difference between a Class 'A' amp and a Class 'D' amp.

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I use a class D dual mono power amp based on hypex NC500 modules with a T+A DAC 8 DSD and Magico A3. At normal listening volumne (around 70-75dB), the amp do not heat.

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4 hours ago, satbox said:

I use a class D dual mono power amp based on hypex NC500 modules with a T+A DAC 8 DSD and Magico A3. At normal listening volumne (around 70-75dB), the amp do not heat.

Great to hear.

Happy with the A3?

Dirk

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10 hours ago, ddetaey said:

Great to hear.

Happy with the A3?

Dirk

Hi Dirk,

Yes, very happy. the A3 are really amazing.

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On 5/9/2019 at 11:47 AM, esldude said:

In the case of your Ayre amps, [their specs] show 120 watts power consumption with no signal

 

Likewise, to compare the heat generated by a digital (or any other) amp, simply look at its specs for power consumption at idle and at higher power output.  The idle power consumption is more important unless you listen to extremely loud music.


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