Initial impression of the Nuprime ST-10 amp

Kim,
Funny you should ask.  I am sitting here in my living room waiting for the big brown truck to deliver the S500 at the moment. I figure I will be the last delivery of the day. 

I have been very impressed with the sound of the Nuprime amp as I have described above.  I have a 5 wpc Dennis Had EL 84 tube amp that I am selling and to make sure it is functioning properly, I swapped it out for the Nuprime amp.  Note that I am driving 94 db sensitive Spatial Audio Hologram speakers.  OMG, I was blown away with the sound of the flea-watt amp driving these speakers!  The mid-range bloom with the tube amp was just luscious, so warm and expansive.  The Nuprime amp had no such ability, but clearly excelled in LF control and HF extension.  I have had tube gear for decades and it clearly yields more warmth and sound of an euphonic nature.  If one has less efficient speakers, then these observations are not relevant as this flea-watt amp would not be compatible, but however the shoot-out between the NuPrime and Red Dragon comes out, and think I will keep one of them, I am not going to part with this venerable Dennis Had amp.  There is clearly magic in tube amps that class D's still can't match if the sound of tube amps is a sound you find appealing. 

Stay tuned.   Whitestix

Whitestix,

Dennis makes some good little amps,I've had the pleasure of listening to most of the models and I liked the El-84 and the Kt150 versions the best.I don't blame you for keeping it you never know how many more he might produce.

The only tube amp that I kept is a Yamamoto A09s it uses the 300b tube,It took me forever to find one and I have done several upgrades to it that I would never sale it.

Anyhow back to class d land,I did a comparison of the red dragon S-500 against the Nuprime St-10 again and I prefer the S-500 overall for the same reasons as listed above in the previous post,the S-500 has a lower noise floor and conveys the micro detail and nuances of a recording a little better.

Both amps are really good examples of modern class d amps and you can't go wrong with either one in my opinion.

Next comparison will be the S-500 with a Modwright Kwa-100 SE.

Best,

Kenny.

I got the Red Dragon class D amp today and it sounds very good right out of the box, although not as fleshed out as the Nuprime and  bit sibilant, but only slightly so.  It has an unsightly case, as others have observed.
 Still,it might be difficult to discern the Nuprime amp from the Red Dragon sonically at the moment, but I will do that comparison with 50-60 hours on the Red Dragon to be fair.  Notwithstanding my enjoyment of my Dennis Had EL84 tube amp, the two class D amps are quite amazing in their power and performance in such a small package.  By analogy, I think that one type of amp is like a Chardonnay and the other is like a Cabernet. I like both, but neither exclusively.

At the end of the day, I think one trades crystal clarity of the music, LF control, and dead silent background with the class D amps for the gloriously expansive, and palpable mid-range bloom of a tube amp. Neither can completely do what the other can do, yet.  Gents, at the price point of any of my amps, there is no such thing as the “absolute sound”.  Tube biasing and running big honking KT88’s in the summer heat of Sacramento would tilt me to the class D amp, but the Had amp with its four EL 84 tubes runs reasonably cool and needs no biasing, a hassle that I disliked with my Harmon Kardon gear.  My Spatial Audio Holograms are ~93 db efficient and it bears noting that the 5 wpc Had tube amp is no less engaging than that the 250-wpc Red Dragon amp. I run the volume pot on my Don Sachs tube preamp at 12:00 with the Had amp, while the volume pot runs at 9:00 for the same SPL with both the class D amps.  I have plenty of gain with any of the amps.    Obviously, if you have much less efficient speakers, my discussion of the comparison with my Had amp would be irrelevant to your situation, but not with respect to the sonic differences of a tube vs. class D amp.   My ears are 63 years old so take that into account. I would encourage any of you readers to compare, contrast, or refute my impressions.

The appeal of class D amplification is very easy to understand for the reasons described above.  If 10 years ago I somebody had told me that class D amps would sound this excellent, I would have been dubious. Yet, to my ears, such sonic performance is easily attainable for less than $2K, or a few hundred more with the Channel Island Audio mono-blocks, which I have heard and are excellent. Several audio companies have outstanding class D integrated amps, including NAD, that provide outstanding “one component” performance.  
Just my take,
Mark

Mark,

There is no perfect Amp at least I haven't found one yet.
They all have their own sound characteristics as you are finding out.
That's why I like trying different ones and comparing and most of them I could live with and use a long time and be happy with.

You may want to give the red dragon at least 100 hrs or more before you judge It's true character.You did get a S-500 is that correct.

Red dragon doesn't have the best looking cases that's how they keep their price down compared to others, I have a black one and It's not as noticeable for me.

As I tell a lot of people you need to figure out what kind of sound presentation you desire and go from there.That's the best way that I know how to describe It.

Best,

Kenny.

Right you are, Kenny.  I will run in the new amp for the requisite hours and then compare them.  I do have the S500 and like you, the black case is no bother to my eyes.  The ST10 has a main on/off switch on the back and a standby on/off switch on the front.  It is a bit of a bother having to reach to the back end to switch it on and off, but that is a trifling matter. 

I reckon in time the class D amps might be able to mimic the euphonic sound of tube amps and keep the speed and LF control.  My pal has the Nuforce/Nuprime Ref 9V3 mono blocks and for them he has retired his high end Krell amp, much preferring the REF 9.  Now, even further up the food chain of Nuprime is the Ref 18 and 20 mono blocks and I would expect that they are incrementally better than the ST10 I have.  Cheers, Mark