Deciding if I like Class D.


I recently purchased Goldenear 1R towers. I was powering them with my Oultlaw 770 initially. I’ve also used a 350 wpc McIntosh a friend owns.. I realize the Outlaw is not audiophile grade, but it’s actually better than most give credit for.  Anyway...

Even though the built in subs are powered, the towers still benifet from a good amount of power, up to 650 rated, so I have been on a quest to find the right amp.

I purchased a set of Hypex Ncore NC1200 Monoblocks with custom buffer boards, and it came with Sparkos 2590s Opamps as per my request. The Goldenears are slightly forward, and I was told Sparkos was the way to go because the were warmer in presentation .

So, I let the amp break in, playing it when I wasn’t home at 85 to 95 DBs for a few days, and gave it some good material to assess it.

I was immediately disenchanted, because the amps sounded very dull, and the highs were rolled off considerably. When compared to the A/B amp the D was not pleasing to my ears. My hearing is slightly diminished from combat, but the A/B was much more detailed.

So I called the company that made amp, and he was very polite and helpful. He sent out a set of Weiss OP2 and Sonic Imagery 990 opamps,to see if I preferred the sound characteristics. Well, the difference was significant.

I am using a Marantz 8805 preamp in pure direct mode . Using BlueOs Streamer, using both optical, and a analog outputs for the testing.. Analog is required to get the MQA files to give full resolution.

To me, the Sparkos just killed the sound. I could honestly see why reviewers would say the treble in particular, was not musical. If I had to live with that sound, I would not..

The Sonic 990 was much better. Much more detailed, better sound stage, just better overall.. Then, I tried the Weiss. Well, that was another level altogether. It sounded like the McIntosh, perhaps better in some regards, but to be honest, it takes a lot time and A-B testing to really be sure. None the less, after hearing the Weiss, it was obvious that they were superior to everything else.

So, I called the manufacturer to let him know my findings, and he said, well, I should give the Sonic 990 another try. I asked why. He said the Weiss would add over 600 dollars for the two pair over the Sparkos and Sonic Imagery.

So, that would bring this setup to over 3100 for the pair. And I could buy a ’good’ high power A/B for that used or even new.

I’ve read a lot of opinions on this forum, and I know the consensus is that D is good, but not great. I know people usually defend what they own, so I needed to hear it for myself. Without a basis of comparison, I’d probably never know the difference, but to be honest, aside from the Hypex getting much louder, and without any audible distortion, I really think the A/B *may* still be more musical, but dammit, I’m not 100% sure. It’s subtle at best.

After hearing the Weiss Opamps, I’d not be satisfied with anything else, but with them, the price is commensurate to A/B.

I’d really appreciate your input on this subject..

BTW, I have purposely left out the company I bought it from, because I think component wise, they are all pretty similar,and I don’t want to start any BS.

I will say though, at the end of the day, the op amps make-or-break the amplifier.

Thank you
Rick




knowitall



I was not addressing you at all Eric, I’m sure you think your knowitall, but far from it

The real OP knowitall in a PM he sent me, when he started this thread, asked for my opinion, so I gave it to him.

As for you Eric, usually you want to start something, well here ya go.

Class D amps do not have the phase shift George claims they do.
Don’t know why your addressing me, but I need to answer your slanderous **** ****.

Eric knows nothing, I have measured it myself, and it’s confirmed by that graph taken from a test bench measurement product review of it.


George’s interpretation of this is:
  • Based on misreading of the wrong chart
  • Provably / measurably false
  • He constantly uses it to prove an audible problem only he can hear.
  • One he continues to push despite being corrected by actual amplifier manufacturers
Eric again knows nothing, he’s quoted a lofi blogger that also has no idea, he probably coerce him into doing it on his blog, maybe they are related or one in the same.😵



Post removed 

My measurements confirm it.
Here it is once again snapshot taken directly from the Icepower 1200as2 PDF

Clearly states that the "red trace" is the "phase shift" measurement of the amp from 20hz to 20khz!

And the blue trace is rising output impedance/distortion, probably because of diminishing feedback, which will increase distortion.
https://ibb.co/K0HTQ3K
Don’t know why your addressing me,

@georgehifi

Because I am sick of your lies and misappropriation of technical data. I am sick of you bashing anyone who even mentions Class D, not to mention your lack of courtesy and victim blaming. I had thought at least on this ridiculous point using the wrong chart to prove the unproveable you’d felt spanked enough to learn your lesson.

I have measured it myself, and it’s confirmed by that graph taken from a test bench measurement product review of it.


Please show us the product review which shows anything near that graph. The graph you post is directly from B&O / ICEPower and it is not of the output. it is measured across the output filter. Very different thing. If you measured this, then you would be putting your leads somewhere inside the amp module and not the output connectors. The phase shift at the output taps is much lower than you keep quoting and as @atmasphere and others keep telling you in the billions (hyperbole) of previous times you have attempted to use that chart. Given that the same source for your chart has posted both the phase shift at the output filter (irrelevant ) and the phase shift at the actual speaker output you’d think you would switch to using the correct one, but that doesn’t fit with the narrative you keep bashing Class D amps with so you pretend it didn’t happen.

I didn’t post my measurements because they are boring. If you were right, then switching from my Luxman to my ICEpower ASP 250 amps would show significant phase shift using OminiMic, and... they don’t!! The speaker amplitude and phase plots are perfectly normal.