Discussion of Class D Amps Application & Experiences

I wouldn't worry to much about the op amp the stock TI LM 4562 will measure right there with any discrete sparkos or sonic imagery. The newer iterations of Class D show better bench numbers but when you start getting into harmonic distortion numbers <-100 you're not going to be able to tell any difference anyway. Adding tubes to Class D amps seems self defeating to me you're adding distortion to an amp made for neutrality. The best at giving great detail without fatigue I have heard are amps with Purifi but Hypex is very close I haven't heard  ICE amps so they could be better though the few  measurements  I have seen on them aren't as good.

I had the ARC sp16 prior to the Class D amp and have had that combo for ~10 years now and still content. Next pre-amp will probably be SS. Maybe a Benchmark pre/DAC device is what I am thinking currently. 

Arc sp16 has a nice basic function remote.

djones511,651 posts04-23-2020 10:08amI wouldn't worry to much about the op amp the stock TI LM 4562 will measure right there with any discrete sparkos or sonic imagery.

I don't know your background, I don't know you. I hope you read
this.

This is from my ears to this forum, I'm very familiar, with the LM4562 NEC, E.I. T.I, op amps. played with them all, rolled them all.  ALL the discretes, I sampled, the SO was much better, even the Burson with the high failure rate due to poor regulator choice and potting problems.  

I worked with Andrew at Sparco labs to resolve some issues with the early Nord buffer boards, and the op amp SM sockets for my Mac
gear, and a few others.

From sparco webb site:

"Our discrete voltage regulators have at least 15 times lower output noise, 52dB (about 300X) better rejection of any noise coming into them, and 4X better load regulation than any other 3 terminal IC regulator that one can find to compare them against."

The regulators are the key to the Class A op amps, without this type of regulator, you can't take FULL advantage of the great discretes available,
or their sonic superiority.

Yamaha, Marantz, B&W, Channel Islands Audio, Meridian, Kharma, MM Audio, and Exodus, and about a dozen more use, Hypex NC modules

The difference in SQ between who does, and who doesn't, is very easy to hear and enjoy.

The comment on "A tube front end" is purely subjective, and you have the right to be WRONG, just as I do. I know how it sounds because I've done Mac, CJ, VTL, Marantz, and two handbuilt line preamps. ALL sounded wonderful, and pure sonic nuggets, with options...

If OPs ears are good, he'll notice the differences and certainly change them if he like. With the op amp/tube roll option, you have a lot of sonic latitude.   

Without those options, what other options do you have, PCs and ICs
No thanks...

Seems to be something djones51 hasn't tried, or, has has he?

WHY would you limit the OP options when it's obvious you, haven't hear the most popular class D boards available, ICE. I use them for bass duty. They are as good as any Hypex without op amp upgrades. For some, that's exactly what they like.. WHY? It's ALL they own. Second some ICE modules have a built in PS, that lets you expand. You can 1 or 2 amp modules depending on the model, at a very low cost. Great option.

SMPS1200 hypex power supply were powering most of 1ET400 amp modules, I listened too. Again not even close to a NCs with buffer board. Apples Oranges...Maybe djones51 listened to something else, DUNO, wasn't real clear.

Second I will only comment on what I've heard. What I've really sat down with. Not a day at a show, or a listening room. normally weeks at least. I read then I listen, and listen and.........

Happy hunting..

Regards

I had a pair of Nord NC500 rev D monoblocks for about 8 months before I decided to sell them and go back to class AB. I used them with Golden Ear Triton 2+ speakers, Bryston BDP-2 streamer, Schitt Yggdrasil DAC. Preamps were Schitt Freya and Parasound JC-2. I tried a variety of cables although nothing too exotic (all under $1K per cable or pair). 

These amps replaced a Krell FPB-300 which died and I couldn't justify the cost of getting it fixed. 

I used both the Sparkos and Sonic Imagery Op Amps. I found the Sparkos to be a little more to my liking - presentation was a bit more relaxed and top end was a bit smoother. 

What I liked: Very efficient. Lightweight and easy to move around. Good dynamics and clarity with very quiet background. Decent but not exceptional sound stage. 

The reason I replaced them: they lacked the excitement I was used to with the Krell. They just sounded boring to me. The imaging was also not as deep and wide as with the Krell. Granted, the Krell was a much more expensive amp in its day, but I was hoping Class D efficiency and more modern design would allow me to get close to the Krell performance at a lower cost. 

I ended up replacing the Nords with a Parasound JC-5 which I'm enjoying very much. A little different sound than the Krell (almost a year between listening to the Krell and JC-5 and I was using a different preamp), but the JC-5 is a beautiful sounding amp with effortless power that is also emotionally engaging. 

I wouldn't rule out Class D in the future, but probably not any time soon. 

@jaytor That's what I was after! Some real world, hey I tried this but didn't like it because, straightforward honest first hand experience. I must admit, I have heard/read a lot about class d build, specs. and prices but not much of anyone extolling their virtues. Thank you for your response!