Class D amps , what’s out there.

[maty]

I have a thread in a very audiophile forums, Audiocircle.

Amplifiers with IcePower 1200AS2, class D module

https://www.audiocircle.com/index.php?topic=156237.0

The best implementation, of this module or NC500 are made by Apollon. I appreciate love for good engineering and doing things well:

https://www.apollonaudio.com/

Two days ago, I received an e-mail from Nord about the new revision of its buffer for the NC500, rev D.

https://www.nordacoustics.co.uk/upopampchoice.

Clas D is very sensitive to RF / EMI interferences -> the modules implementation is very important!

 

[maty]

Apollon-Audio-Hypex-Nc500-based-Amplifier-top

More implementation pictures in the middle of the page:

https://www.apollonaudio.com/apollon-hypex-nc500-class-d-amplifier-nc800-sl/

 

[maty]

To admin:

Can you delete this thread? Since you have deleted my last comment, delete this thread as well.

Except for requesting some additional measurement, I will not participate again in these forums, where I do not feel comfortable, so we will all be happier.

 

[Thomas savage]

To admin:

Can you delete this thread? Since you have deleted my last comment, delete this thread as well.

Except for requesting some additional measurement, I will not participate again in these forums, where I do not feel comfortable, so we will all be happier.

No, I moved off topic posts out of the original thread and started this one so that off shoot could carry on. Folks are free to mention and explore all available implementations of class D amps here. I think it could prove useful.

 

[DonH56]

When I had to build discrete amplifiers I routinely used 0.1% resistors with very low or known tempco. 0 tempco resistors are available, but sometimes it is better to have a known tempco to compensate other tempcos in the design.

Would you have a link to their new opamps? I did not recognize them off-hand but not an area to which I pay much attention.

 

[Ron Texas]

The Appolon amplifiers are reasonably priced, around 1,000 Euros. Less than a pair of Hypex kits.

I would love to see a Crown XLS 1502 or 2002 tested here. Not exactly Class D, but PWM with a proprietary energy recovery feature.

 

[amirm]

I would love to see a Crown XLS 1502 or 2002 tested here. Not exactly Class D, but PWM with a proprietary energy recovery feature.

I have a Crown XLS 2 series that someone has loaned me. Will review soon....

 

[bigx5murf]

I believe most Pioneer AVR are class D now as well.

 

[amirm]

I believe most Pioneer AVR are class D now as well.

The Elite ones certainly are and that is what I have in our living room. Not sure about the rest.

 

[DonH56]

The Elite ones certainly are and that is what I have in our living room. Not sure about the rest.

Correct, Elites are, rest are not (at least last I checked). I recently gave my old SC-27 to my son for his system (keep passing down the older stuff, not worth selling anymore).

 

[bigx5murf]

I would've swore Pioneer was putting class d amplification into even entry to mid level AVR over 10 years ago. I believe I had one, it was a VSX seven hundred something

 

[DonH56]

Certainly not ten years ago as that is roughly the vintage of my old Pioneer and only the top Elites had it then. They switched to an IR design a few years later and may have expanded but I am not sure. Nor am I sure what they are using now.

 

[trl]

The Elite ones certainly are and that is what I have in our living room. Not sure about the rest.

Seems that 50DA and 70DA are Class-D, however the measurements I've seen are worse than their older Class-AB designs.

https://www.avhub.com.au/product-re...0da-k-integrated-amplifier-review-test-490709
- first time when I see aPioneer amp below its own specs: instead of 65W across entire audio band they can only deliver 53W @20Hz
- also, the nominal power @1KHz is..."no comments".
- the loudness looks unusable, at least not within a Hi-Fi chain; they should probably have a look to Yamaha how loudness contour should look like
- SNR sucks (confirmation also here https://audio.com.pl/testy/stereo/wzmacniacze-stereo/2531-pioneer-a-70da!

However, very good freq. response and exceptional crostalk...really hard to beat these numbers with a Class-A amp, don't know how they managed 87dB @20KHz, but I'm glad they did. Until they'll get a new and improved Class-D line amps, I see no reasons why getting one of these. Me not like it, sorry...

 

[MetalheadRich]

The Elite ones certainly are and that is what I have in our living room. Not sure about the rest.

I would certainly be interested in seeing measurements of that.

 

[trl]

https://audio.com.pl/testy/kino-domowe/amplitunery-av/2775-pioneer-sc-lx801

Pretty high THD, at least comparing with similar Class-AB Pioneer AVRs. Also, req. response is totally strange...probably because of the low-pass filter from the outputs...don't know.

However, I'm sure the output sound is good enough.

 

[svart-hvitt]

BIGGER AND BETTER

Research and development in class D designs goes on. Here’s what Icepower writes for the coming AES in Dublin:

«Switch-mode power audio amplifiers, also known as class-D, have become the conventional choice for high power applications. This paper presents the considerations for designing a high power audio amplifier power stage. This includes an overview of loss mechanism including reverse recovery losses which are increasingly important at higher output powers. A 4 kW prototype amplifier is implemented. Absolute maximum ratings shows up to +/- 190 V output voltage swing and 6.5 kW for sine wave burst. THD+N levels go down to 0.003 % for 100 Hz and are generally below 0.1 % up to clipping at 4 kW in a 4 Ω load».
Source: http://www.aes.org/e-lib/browse.cfm?elib=20348

 

[maty]

DEVIALET Expert 140 PRO

[Polish] https://audio.com.pl/testy/stereo/wzmacniacze-stereo/3055-devialet-expert-140-pro

to English: https://translate.google.com/transl...macniacze-stereo/3055-devialet-expert-140-pro

• Rated power (1% THD + N, 1 kHz) [W] 8 Ω, 2x 102
• Rated power (1% THD + N, 1 kHz) [W] 4 Ω, 2x 203
• Sensitivity (for maximum power) [V] 1x 0.23
• Signal-to-noise ratio (A-weighted filter, with reference to 1W) [dB] 71
• Dynamics [dB] 91
• Damping factor (relative to 4 Ω) 290

Only € 5,200

 

[Djsedaw]

Here's my class d amp, I call it the excitonium

It has one of these

One of these

All in this lovely stylish case with such things as wires, connectors and things!

 

[vavan]

Correct, Elites are, rest are not

You know, pioneer avrs outside US do not wear that elite badge, yet some of these are class D

 

[vavan]

I'm sure the output sound is good enough

Right, at least ess 9016 in my pio 901 doesn't sound any worse than 9018 in parasound hint and 9038 in oppo 205