2. amps-preamps
  3. 169435-165413

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
erik_squires
16,118 posts
 
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.
secretguy
1,712 posts
 
I have T1s and my experience doesn't jive at all with that of the OP.
atmasphere's avatar
atmasphere
11,837 posts
 
@knowitall  If I were you I'd give the amp a chance to break in. I know it sounds a bit weird because that module has a lot of feedback and shouldn't need break-in, but our customers have reported this phenomena and we use a similar amount of feedback in our class D module.


As @erik_squires has pointed out, there is quite a lot of difference from one class D amp to another- IME at least as much as you might hear in tube amps. The fact that you so easily hear the differences between the various opamps indicates the module itself is pretty transparent.
erik_squires
16,118 posts
 
there is quite a lot of difference from one class D amp to another


Exactly, so even if one instance of a Class D amp had terrible phase shift problems (and the one George keeps using does not) it would still not be a stand in for all Class D amps.

Further, I’ve played my ICEpower 250 ASP’s for a number of seasoned audiophiles and never has any of them point out anything of what George complains about. He's using the wrong measurement to prove a problem that doesn't exist which only he can hear.
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