Musings on Class D .... is it actually 'there' now? Should we all be using it?

[montesquieu]

The big Radford STA100 is off with Valvebloke (/Ampregen) for a spot of attention after it (embarrasingly) started making noises while I was trying to show it off to some visitors from overseas who were staying with us for a couple of weeks.

In its place I've put a Tripath TA2022 jobbie I picked up from Duncan which he sold with some single driver speakers and a RPi with Dac ... 90w so more than enough in theory at least to drive the big Tannoys.

It hasn't got all the sortedness of the big Radford, in terms of detail or dimensionality - you'd hardly expect it to. But it certainly has something ... solid in the bass, really very pleasant in terms of timbre, it's actually quite sweet, very composed at the top end. A touch more detail and transparency, a touch better with space, and it would really take a bit of beating. (I've certainly owned 40w valve amps that would struggle to do what it does).

In a way this should't be surprising, my front end is really wonderfully well sorted now and with a tube preamp to hold it all together, so long as there's a match with the power amp, and the power amp has enough welly to light up the HPD315a's (which not all power amps do, by any means) all should be well at 90s, and indeed it is. I had great results with a 275w Lyngdorf Class D previously, before my front end was as sorted as it is now.

So I guess my question is whether there's a Class D amp that would really take on the likes of my Radford, and other high end tube amps, into real world speakers, and BEAT them? (you know what I mean, aside from high-efff). In my mind they've certainly made big Class A sold state muscle amps a bit redundant - why bother with all that brute force and heat, Krells and stuff, for difficult speakers, when Class D does it already? But it seems to me that in the 40w-100w sort of area, valve amps have still ruled the roost.

I've been looking at the NuPrime stuff (that came out of the NuForce technology before the brand name was sold off), Nuforce (current) of course, current Lyngdorf gear. Has anyone (I mean anyone impartial - of course Class D has its cheerleaders) really made a study of Class D and really made the comparison with tube amps? I understand there were quite a few about at the Munich show.

'Scuse me if I'm late to this discussion but I've been dismissive up till now based on my own ears of just how 'right' a good valve amp can sound - unbeatable to date, in fact, in my setup. But my sense is that things are actually changing. As switching rates get higher and higher, power supplies get cleaner, surely we are bound to reach a point where Class D doesn't just cut it in terms of measurement, but also cuts it musically as well?

And then what!?

Anyway I'm quite keen to get hold of some NuPrime STA-9s (bridgeable to 290w monoblocks!) to hear just what state of the art might sound like, unfortunately no UK distributor it seems. $650 USD / €699 Euros in Holland. But I think very interesting to try. Any UK-available alternatives? (At sensible dosh of course).

[Nihil Sleighride]

I was interested in the NuPrime amps too but didn't want to commit to ordering from abroad. Audiologica have the new Nuforce gear and in the end I just went for STA120 to give me a flavour.

Got to say really impressed with the little thing and would be happy to give their and NuPrime's bigger monos, like what you are interested in, a go in the future.

[YNWaN]

I've listened to NCore amps and directly compared them to another amp (not valve). The NCores had great bass control but sounded a bit lacking in life and texture in the upper reaches which made them a bit 'shut in'. I also own a very powerful Class D amp that I drive my speakers bass drivers with and have used that as a full range amp in the past. Again that had amazing bass control and an extraordinary stop-start sort of immediate sound - very strongly propulsive. The mid was a bit hard sounding though and the upper frequencies lacked differentiation and sweetness.

[montesquieu]

I've listened to NCore amps and directly compared them to another amp (not valve). The NCores had great bass control but sounded a bit lacking in life and texture in the upper reaches which made them a bit 'shut in'. I also own a very powerful Class D amp that I drive my speakers bass drivers with and have used that as a full range amp in the past. Again that had amazing bass control and an extraordinary stop-start sort of immediate sound - very strongly propulsive. The mid was a bit hard sounding though and the upper frequencies lacked differentiation and sweetness.

Yes this was my experience too of an early Hypex 180w amplifier and to some extend the Tripath 2022 ... but not so much with the Lyngdorf.

My question is really about the very latest implementations of the Class D concept, my sense is that things have been streadily improving ... the stuff in the past for the most part fell always short in comparison to good valve amps.

[Eisener Bart]

I've been looking at the NuPrime stuff (that came out of the NuForce technology before the brand name was sold off), Nuforce (current) of course, current Lyngdorf gear. Has anyone (I mean anyone impartial - of course Class D has its cheerleaders) really made a study of Class D and really made the comparison with tube amps? I understand there were quite a few about at the Munich show.

I wanna show you only 2 photos.

It was before.



Now.



And full post of onwer.

"Well its been quite a while since I posted my first comments about the R20's back in March. (#12 in this thread) There's a reason and its a long story. I'll spare most of the details but first I want to give a huge shout out to Jason and Bob for the incredible service and response they have provided. These guys are the BEST and are true professionals in every way!!! It is very comforting to know that these guys are there, passionately standing behind the terrific Nuprime products that they represent.

Next.......and please pay close attention to this; if you are using subs with a Neutrik connector like RELs, do not hook up the sub cables to both terminals. Next, do not only hook up the hot connector and let the ground float. Finally, DO attach the positive connectors to the positive terminal and the negative to the tiny "ground screw" to the left of the negative amp terminal. Otherwise you will blow up the amps like I did; repeatedly. :x Then you will have to send them back to Bob like I did; repeatedly.

Currently I'm running the amps with Maggie 3.7is (Mye stands), REL G2's, CAT Legend preamp, Shunyata loom, Triton v2, Typhon, VPI Signature with 3D arm, Koetsu Rosewood Signature, and a Modwright (tube mods) Oppo 105 in a highly treated room. I listen near field about 7' away from the center of the speakers and have spent hundreds of hours tweaking every component. This is a very revealing system that exposes almost everything upstream. Other amps I own and have used for comparison are Carver Black Beauty 305's (KT120's/ 300w each) and a pair of Conrad Johnson Premier 8's with all factory teflon and KT120 upgrades (also 300w each). Both of these all tube mono blocks are outstanding and grab the Maggies with a vice-like grip that won't quit. I've also got a GAT 2 that has temporarily been sidelined while the CAT Legend is commanding center stage. For about the past couple of weeks I have been mixing and matching these electronics to get a good idea about the R20's and as you can see, they are in pretty good company. Plus, I'm a hard core tube, planar, and vinyl guy and in the past have avoided solid state, Class D, and digital like the proverbial plague.

So, what's the verdict on the R20's? Unfrickingbelievable! First, the tonality is unlike anything that resembles classic solid state. Instead, the sound is warm, lucious, and full, with layer upon layer of detail. The attack is sharp and crisp but the decay leaves notes sort of hanging in space with each one wrapped in a bubble of three dimensional reverberant air. All of the textures seem just right too. On cello, violin or stand up bass, you can hear the bow or the plucking of a string, but then the wood of the instrument reverberates in space until that note naturally fades or is overcome by the next. Drum skins are unreal. Horns have a natural, glorious, power to them that captures all of the subtle breathiness of quiet passages, but explodes without a hint of shrillness at a crescendo. And look out for tympani drums; a loud thwack is like getting slugged in the jaw! Dynamics are off the charts. Plus these amps have presence in spades. At times, with the lights turned low, its like the music just showed up on the soundstage and I've been transported to the venue, without the slightest recollection that there are electronic devices actually converting electrons into notes. Its tough to decide what to play next, although I've found myself migrating repeatedly to live recordings because it all sounds so real.

Meanwhile, my tube amps are scattered around the floor like audio jewelry. Beautiful to look at, but..... Anyway, I'm really not one to get carried away and gush about the latest and greatest newcomer to the audio scene. But these amps are something unique, especially at the price. I almost wish they were bigger and heavier and maybe had some KT150's glued to the top of the cases. Or I needed a hand truck to move them around. That way I could sort of rationalize their world class status and come to terms a little easier with how good they sound.

One more quick snippet. Right now I'm listening to "A Case of You" by Dianna Krall. We've all probably heard that cut way too many times. But as the music is playing beautifully, I'm fascinated by her pedal work on the piano. Right beneath her voice and breath, the keys striking the piano wires, the ambient sound of the hall, and the occasional sniffle in the audience, is a strong visual impression of her feet decisively working the pedals. I haven't quite experienced that before. And with almost every album, the R20's are revealing more, much more, than I have ever heard before. These amps get my strongest possible recommendation, and if they work this well with my Maggies, they should have a pretty easy time with just about any other speaker.

Thanks again to Jason and Bob for their great products and for being such terrific folks to work with. You guys are the best!"
http://www.audiocircle.com/index.php?topic=140718.40


You may find plenty information from happy owners of NuPrime products here:

http://www.audiocircle.com/index.php?board=199.0

and direct link on STA-9:
http://www.audiocircle.com/index.php?topic=138614.0

[Eisener Bart]

sorry, repeated post.

[struth]

Think my monoblocks, which can be used as stereos as well are class D.... Ive got 4. Cheap I guess but to me keep beating other things i try. They are fairly heavy and were designed to be used in Juke boxes.

[YNWaN]

My question is really about the very latest implementations of the Class D concept, my sense is that things have been streadily improving ... the stuff in the past for the most part fell always short in comparison to good valve amps.

Both of the amps I tried are very recent Class D designs.

[RichB]

I still use an Amptastic mini-t with a Croft valve pre/phono up front. There's definitely something to be said about a valve pre with them. Where it fails for me is in the bass. Not for the lack of it, but in the quality and 'realness' and believability of it. Once you've heard it you listen for it.

I've recently been mucking around with an Arcam FMJ amp and compared to the mini t the bass sounds more right and authentic than with the mini-t.

[jandl100]

I've been a fan of class D amps for years.
Some are pretty tame, and would suit the P&S brigade more than me - the TA2022 chip falls about half way in my experience - a bit bland.
There's something distinctive about the sound of some class D that works for me - I especially like the (sadly) low powered TA2020 chip - there's an openness and transparency and sheer transient speed that sounds very close to real to me.

But of those I have tried (quite a lot!) I have never heard any that could compete with large valve or large non-class D solid state amps.
I guess the Crown XLS1500 was the most recent. Rated at 300wpc (8 ohms) it sure as hell did not sound like a 300wpc amp should. It didn't even come close to the awesome majesty of my old (220wpc) Parasound A21 amp.
Power supplies are to blame here, I guess - or the lack of adequate PS in the Crown.

I've not heard a class D fitted out with a pukka large PS - Rowland, ARC come to mind as possibles, maybe?
Perhaps that would do the job, I would certainly like to hear a heavy class D amp!