I finally received my US4+ this past Friday, and I've spent about 10 hours so far (which I recognize is nothing substantial) listening to this absolutely wonderful amp driving the Susvaras, but here are some preliminary thoughts and impressions:
For how polarizing the design of the amplifier has been, I personally am quite fond of it. Its understated chassis hints at the no-nonsense, no comprise nature of the amp. The volume knob especially is an absolute joy, although I do report the same slight static/ticking-like noise that others have already mentioned; regardless, this does not detract from my experience what-so-ever. The build quality itself of course is second to none.
This amplifier has more than enough power (voltage?) to drive the Susvaras to their 'full potential.' I have the amp set to +12db pre-gain and the volume knob usually hovers around the 12'o clock position except when playing certain DSDs where I have to turn it up to around the 3'o clock position. At high volumes, the amp does not falter in the slightest. Bass remains incredibly tactile and detailed, mid-range vocals retain their sense of naturalness and the highest registers of the treble vibrate with unparalleled tone and quality.
Detail retrieval is almost too good, if that were possible. This amp has already made me re-evaluate a good portion of my music collection, extracting out the most minute of (for the lack of a better word) details. Flaws in recordings are all dragged out into the light for all to see (listen) to.
I used the word tactile earlier to describe the kind of texture that the amp is able to produce. Being able to 'feel the music' has almost taken a physical form. It seems as if the touch of the piano keys, the picking of guitar strings, the bowing of violins, crashing of hi-hats have somehow been translated into physical sensations.
Selected tracks and impressions:
Beethoven's 9th Violin Sonata - Alina Ibragimova & Cedric Tiberghien (16/44 FLAC)
The opening chords of the violin take on a life-like quality, with the vibrato of each individual note singing with full voice. The most incredible aspect of this track, lies in the double stops played by the violin, you can feel the sense of space between the strings bowed, accurately adjudge the distance between the notes of the chord and the overtones formed by their interaction. The piano accompaniment is articulate and precise, with each voice being clearly projected and with every individual note of the broken chord being 'present'.
Il Trovatore Act 2: Il Balen Del Suo Sorriso - Dmitri Hvorostovsky (16/44 FLAC)
The late baritone titan returns with conviction singing with a melodic and passionate tone with the orchestral accompaniment being supple but appropriate, never infringing on his infallible vocals. Each instrument in the orchestral pit is accurately placed and the listener is put at the forefront of the action.
Moby Dick - Led Zeppelin II (DSD 64)
Another giant returns to life, John Bonham takes center stage in this instrumental by rock legends Led Zeppelin. The drum solo returns the listener into the seat of the late Bonham, with his comprehensive drum set laid out right in front of you. Each hit of the snare or hi-hat or cowbell or bass drum vibrates with a natural decay and inaudible tones are felt viscerally.
Hotel California - Hell Freezes Over (DSD 128)
No set of impressions are complete without this exalted track. First and foremost, the CLAPPING AT THE BEGINNING SOUNDS LIKE CLAPPING. For too long, the initial audience applause always lacked a sense of depth or something else that prevented them from sounding natural, but gone are those days with the Niimbus. At the risk of repeating myself again, each note in the opening chords are audible as the pick traverses across the strings of the guitar. The percussion (cajon, conga) alongside the bass create a solid foundation of the rest of the guitars to work their magic, Don Henley's vocals are forward in this recording. The interplay between lead guitar and the rest of instruments during the solo is an absolutely pleasure to listen to.The Niimbus has made me enjoy listening to this track again, and I don't think there is any higher praise I can offer the amp.
END OF IMPRESSIONS
Bottom Line:
The Niimbus US4+ leaves me wanting for nothing. It presents music in a way that is very much in line to my personal tastes. Natural, authoritative, tactile, are perhaps the best way for me to summarize the nature of the US4+. I very much look forward to continue my journey of music exploration with these.
------------------------------------------------------------------------------------------------------------------------------------------------------
Well this was my mini write up of the Niimbus US4+, apologies for bland language and any other miscellaneous mistakes. This was my first time attempting any sort of write up/review for audio equipment. I struggle to accurately translate and portray my impressions in a topic as subjective as sound through words and have developed a deep respect for people who are able to. Thank you for reading if you've somehow made it to the end. Any sort of feedback is very welcome, or if you want further impressions, I can provide that too.