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

Showing 2 responses by atmasphere

Question is: Is the best Class D better than the best Class A?

Answer: No

Rider: But Class D is a value shortcut and you may get better sound at a relatively low pricepoint.
Price is not the only reason to consider class D. Class D offers some advantages to the designer- for example, the distortion the amp makes is not dependent on the output section. Its generated in very different ways and so has a different distortion signature than traditional solid state (which tends to be bright).


How designers take advantage of this fact varies tremendously from amp to amp. A lot is in the execution. As a result a blanket statement such as seen in the quote above is likely false- the correct 'Answer:' is 'It depends.'
@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.