What struck me most, and I have to say that this had me a little worried, is the amplifier’s ultra-concrete solidity that makes the CH sound just a little sweet and even a little polite. The Evolution STA’s bass really is sublime and reminiscent of that of the Analog Domain M75, AVM Ovation A8.3, and Anthem STR. It is full-size, unrestrained, rock-solid, full-bodied, and weighty, but not in a thick, enriched, or loosely gripped manner as it can be with many powerhouse amplifiers, such as I feel is the case with certain Bryston amplifiers such as the 4B cubed. By the same token, the Evolution STA most definitely does not have the kind of bass that you’d expect from a Class-D amplifier, far from it actually. I have always found the bass from ICEpower, Pascal, and NCore amplifiers to be a little on the lean side, but as I found with the ST-10, NuPrime blissfully deviates from this pattern. It’s deeply saturated and full-bodied yet fast, articulate, and nimble.
With such perfectly-chiseled bass, it is not unusual for the midrange to break the spell by deviating in solidity or overall character, for instance by being too lean or too forward, or most common, to be hard or even edgy, but this is absolutely not the case here. The amp sounds very much of one piece and its midrange follows the superbly well-balanced foundation in all parameters. Just like the bass, the midrange is concrete, clean, open, and expressive, without sounding lean or being devoid of saturation or harmonics. I’d go as far as to say that this is one of the best and most supremely neutral midrange performances that I have heard. This is not a cool-sounding amp, but it also doesn’t try to hide its solid-state nature under a layer of smoothness or warmth. And it is not particularly lush or liquid. Indeed, people who prefer more of a triode tube sound will no doubt feel that the NuPrime lacks smoothness or romanticism. However, I often feel that amplifiers that do sound smoother usually do so at the expense of liveliness and immediacy. Moreover, while a nice dose of rich juiciness can be utterly seductive for a couple of songs, when an amplifier injects all the music with the same flavor I tend to get bored with it after a while. Rather than adding any kind of sweet sauce, the Evolution STA simply relays the music as unedited as it can. Meanwhile, there is excellent tonal saturation and great texturing without even a sliver of edge or hardness.
Following the bass and midrange perfectly, the Evolution STA’s treble is energetic, articulate, and direct, but again without being edgy or hard. If anything, the treble is a bit dry and ever so slightly dark. Indeed, this is one of the areas where the NuPrime cannot achieve the same lofty results as the CH, but in an absolute sense, the treble, too, is really good.
The Evolution STA strikes a visual resemblance to the ST-10, and sonically, it also reminds me strongly of it. While especially the amplifier’s bass and overall solidity are reminiscent of the ST-10, at the same time, I hear a level of linearity, refinement, and low-level detail that I do not recall having heard from the little amp. As mentioned, the Evolution STA’s is not on the same level as the A1.5 in terms of resolution, fluidity, and refinement, which is fair enough of course, but I feel that the AMG-STA also sounds airier and more refined and certainly more fluid. I think it’s fair to say that, like the ST-10, the Evolution STA is just not the most fluid amplifier on the planet. But because the amplifier is otherwise so great, I sincerely doubt that this will be a decisive factor for anyone unless one is specifically looking for tube-like warmth and liquidity and/or state-of-the-art low-level resolution.
Speed-wise, the amplifier strikes a perfect balance, it is neither slow nor fast but never slow and never speedy. It has got great PRaT, even if its immense control can sometimes make it slightly more static in its presentation. Well, strike that, it’s more fitting to say that it is just less relaxed and free-flowing than some other amplifiers. But, very importantly, this one absolutely knows how to party! While it can be less gushy or emotionally captivating with certain delicate music, the amp’s engagement factor with very nearly every other kind of music is simply off the scale. The amplifier even knows its way with classical music and even sounds remarkably convincing with massed violins and big orchestral music.
A surprising strong suit of the Evolution STA is the soundstaging. In this area, the amp miraculously performs on par with the CD A1.5, providing a wide, deep, and room-filling stage with strong focus and depth. The main difference here is that the A1.5 tends to project more to the rear while the Evolution STA projects more to the front, more in your face, if you will. As far as I am concerned, this is merely a matter of perspective and not one of quality.
When considering Class-D amplifiers, timbre or tonality is an important aspect. All too often, amplifiers of this sort sound deprived of harmonics and saturation, but here too, the Evolution STA shines. Its superbly natural timbre, combined with its exemplary solidity makes the best of piano and other percussive acoustic instruments. All too many amplifiers, even Class-AB designs, can make a grand piano sound more like a wall model or even a bit like a synthesizer, but not the Evolution STA. What this amplifier does magnificently well is to lend weight, body, and saturation to instruments, and vocals alike, and with plenty of warmth if needed, but without ever tipping over into mushiness or ever sounding colored in any way. This amplifier sounds full-bodied and it can sound smooth or warm so long as the recording dictates it. The amplifier will not overlay the music with any added softness or warmth of its own.
Interlinks
So far, I’ve listened to the Evolution STA using a stock power cable and the AudioQuest Fire interlinks, neither of which I guess are very likely to be used by prospective buyers. Not the former because I know that the other NuPrime amplifiers that I tested before sure benefitted from better power cables and not the latter because the Fire is even more expensive than this amplifier. But since they are my references, they had to be my starting point.
Changing the full and robust-sounding Fire interlink for the leaner and more refined, but also very neutral-sounding Driade Flow Link Reference 808 RCA cable, the balance shifts noticeably, and more toward sounding more like the A1.5 amplifier. With this interlink, the Evolution STA’s treble gains more fluidity and becomes a little bit airier while the cable’s slightly leaner yet highly articulate bass works well with the amp’s inherent solidity and fullness. On balance, the sound remains quite solid but is now slightly leaner. On the one hand, this makes the amplifier come across as more transparent but on the other hand, the fullness of timbre suffers slightly. But I think I know just what to do about that… 🙂
Power Cables
Swapping the stock power cable for a Belden 19364 with Bals schuko and Oyaide C-004 IEC does indeed deliver what I expect from it and restores the overall balance with the proper fullness and even better authority, along with just a nice bit of extra delicacy, compared to the sound with the stock power cable and the Fire interlink. Another huge benefit of the Belden over the stock cable is that of an even more realistic timbre and an even wider and deeper soundstage.
I was already a fan, but when integrated this way, with the Driade interlinks and the Belden power cable, the Evolution STA sounds positively fantastic. But while I’m at it, why not also try the amplifier’s balanced input. As fortune has it, I also have the balanced version of the Driade Flow Link Reference 808 cable. With the preamp adjusted -6dB to adjust for the differences in gain, believe it or not, the amplifier provides even wider soundstaging, and without creating a hole in the middle. The focus remains solid. While balanced interlinks usually tend to sound wider than single-ended connections, the difference here is larger than what I am used to hearing between the two connections. Additionally, I feel that the amplifier sounds just a bit crispier and cleaner, as well as even more authoritative and realistic when using its balanced inputs. On the other hand, the RCA inputs lend a slightly smoother touch to the sound, with the Driade cables at least. All in all, I’d say that the NuPrime amplifier’s two inputs provide equally good performance, but with slightly different perspectives.
Next: Speaker Cables
Nice review Christiaan! And also a thank you for following up on my suggestion to put two AMG-STA’s in dual mode to the test.
One little remark: on page 2 somewhere in the middle you mention AMG-STA which should be Evolution STA I assume.
Sooner or later, I will compare the AMG-STAs against the EVO STA and see if it is worth the extra investment..
Thanks Vincent! I double-checked but I don’t see an error. I presume you mean the following section? “but I feel that the AMG-STA also sounds airier and more refined and certainly more fluid”. This is correct:-)
Ah ok! I meant that section indeed. Then the AMG comparison came a little out of the blue for me, but if this was on purpose then all is good 🙂
It harks back to the introduction where I mentioned that the intention was to include elements of the ST-10 and the AMG-STA in the new Evolution STA amplifier:-)
After re-reading it, it is clear what you intend to say. My bad. Cheers!
No probs, Vincent, I appreciate the diligence and it’s always good to get feedback, especially since I am certainly not fool-proof! 😉
Hello my friend.
I have recently been so lucky with Shunyata Power cords and interconnect cables and I need one more interconnect cable from Dac to pre or from pre to Power amplifier depends on where it sounds best with my Shunyata Delta V2. I hope to see a review of Shunyata against Driade.
Thank you, can also send mee those CH Precision Gear when you fel bordet about them.
hi Christiaan,
Do you think the Audio-Gd HE-1 preamp and the NuPrime Evolution STA will be a good sounding combination ?
Best regards
I have not heard the Audio-Gd HE-1, but based on my experience with the Master-1, I would think that it would indeed pair very well with the Evolution STA.
Hi Ben, did you already experience the Evo STA combined with the Audio-GD HE1 and if so: was it the tube or transistor version?
Hi Christiaan,
Any following feedback on the comparaison with dual mono AMG STA vs Evo STA ?
Only that a pair of AMG STA amplifiers does not make an EVO STA. They remain very different, each with its respective strong suits. While 2 AMG STA’s sound better than a single unit, they still excel in fluidity, refinement, nimbleness, and air while the EVO STA excels in robustness, body, impact, and tonal saturation.
Thank you Christiaan.
Depending as well on the speakers. What could be your favorite option between the two with Martin Logan EL 11 ?
The articulation with the active woofer is sensitive
It totally depends on what you are personally after. If you want to Rock and roll and a live-concert-like “outgoing” sound, then the ST-10 or EVO STA is your best choice. The ST10 is even a little bit more of a party animal but less refined than the EVO STA. Do you want audiophile refinement, fluidity, air, and flow, then AMG STA is your best choice. Personally, I lean toward the AMG. ESL11A has very good bass control but like all Logans, it is a little lean in the upper bass, where the cabinet meets the foil so to say. Not all listeners are bothered by this though. If you find that you are, and you find this aspect more important than some others, then the ST-10 and EVO STA are probably the better options for you.
dear Christiaan,
Reading your comments the more I’m convinced that combining my Audio-Gd HE-1 preamp, the big brother to the Master 1 you have tested, with the NuPrime AMG STA power amp in mono mode will give the best sounding result I’m after with my open baffle speakers. The latter are dipoles speakers that you have used extensively in the past. My OB’s use 4x 10” woofers per side so that’s why I’m thinking the mono ‘d version of the AMG have the power to control the speakers well.
I listen to a lot of classical music and the refinement and fluidity you say these amps are capable of will suit this genre of music even more than the Evolution STA. Is that your opinion as well ?
Best regards
Hi Ben, indeed for classical, I would prefer the AMG-STA, either a single amp or the bi-wired pair. The AMG is never lacking control, not even with Magico Q5s which are really hard to drive. I don’t know how your woofers are connected and how low the combined impedance is, but I suspect that even a single AMG-STA may surprise you. If desired, you can always add a second unit.
Its all a matter of mixing and matching. I have good hopes for the Grimm Audio MU1, HoloAudio Spring 3 DAC, EVO STA combination (Jorma digital and Driade analog interlinks) together with my Magico A1s. EVO STA to arrive soon. Let’s see if the EVO STA can beat the AMG STA dual mono config 💪🏻
Hi Christian,
Taking the above setup in account, which reasonable priced (below 10k) preamp would fit best in your opinion?
Hi Vincent, to which setup are you referring? If you are asking for an ideal affordable preamp for the EVO-STA then I would say the AGD Master 1. However, I have not heard the higher-end AGD’s, nor NuPrime’s preamps other than the AMG-PRA. There seems to be a big gap between affordable preamps and the high-end with precious little in between. The next best preamp, price-wise, that I would recommend is the Aries Cerat Incito-S which will make a stellar sonic match but at ~14.000 euros it’s well obove your price point. Maybe the regular Incito (non-S) might be an ideal candicate.
Thanks for your answer. Yes I refer to the NuPrime EVO STA. Different affordable preamps that might match are perhaps
– Pass Labs XP12
– Mark Levinson 326s (2nd hand available for 4k)
– HoloAudio Serene
I talked to Marco (Hexagon) and he offered to try the COS D10 preamp
Hopefully there will be a match
Hi Vincent, A 326S second-hand might be quite nice although I never had much success with my 320S. If going second-hand, I think I would prefer a Jeff Rowland preamp such as the Synergy 2i. The Pass is not quite as fluid, airy, or refined as I would like and given the EVO STA’s character, I don’t think that would result in an ideal match. Holo is on the list to review (no timetable yet). The COD D10 slipped my mind because I see it as a DAC primarily with a preamp on board but its preamp section is actually excellent. Do let us know how you get on with the D10!
On my short list are:
– COS D10
– Audio-GD HE-1 Mk2
– Holo Audio Serene KTE
Will let you know the outcome.
Thanks for your hifi-advice 🙂
Short update: I got the chance from Schelto to try the Kora TB200 and got blown away. My search for a pre/power amp combo is over… although the Audio-GD HE1 Mk2 wasn’t bad at all
I have not heard the TB200 but the Kora TB140 has also surprised me. Almost the polar opposite in sonic presentation from the NuPrime AMG STA but a great amp indeed.
Curious if you have had an opportunity to compare the NuPrime to the Bel Canto REF600M?
Alas, I have not heard the Bel Canto.
Thanks for your advice
Good morning Christiaan.I have a question,would the nuprime evolution sta match well with the Totem Tribe Towers.If not which amp would you recommend to me.No i have an Arcam avr 850.Thanks in advance.
I have never tried any Totem speakers in my system so can’t really comment. My gut feeling is that they are nice and lively and direct and the combination with the EVO STA would likely result in a more solid, direct, and robust sound than the Arcam. But this is pure guesstimation on my part…
Now that the Evolution Two has arrived.. time for a review of the new kid on the block?
This was indeed discussed but so far no plans have been made just yet.
2 years after my purchase, I still enjoy very much my STA dual mono amps with ML 11a. A lot of times I surprise myself how good the sound is, so close to really.
This only short come I feel sometimes is the lower impact / softness on rocks but nothing terrible vs all great advantages.
Great to hear Phil! After owning the AMG STA in dual mono setup I switched to the Evolution STA. Little more dark but also more authority in general. Though the little AMG’s were more ‘fun’. I still thinking of purchasing them again fir my second setup. What preamp are you using?
They are directly connected to a DAC Totaldac D1 Core with volume control through KLR cables. The balanced vs imbalanced switch has a lot of impact on the restitution, much better with balanced position.