HPA-nxV200 R2 based dual mono amplifier
Configuration:
Dual mono (2 x 500 VA), separate supplies for input stage (2 x nx Volt One) and output stage (90.000 uF per channel).
The amp was easy to build and worked as expected “out of the box” The nx Volt Ones needed adjustment, but if you give them a proper input voltage, they behave exactly as described. The questions I had during building were promptly answered by Anthony. And had I bought the right secondary trafos right away, I would not have needed his support at all.
Listening Impressions
To set my personal bias straight: I have been passionate about Hi Fi for + 40 years, I have heard a lot of gear, including top of the line amps from Audio Research, Naim, McIntosh, Classe, PassLabs, etc– and I am lucky enough to have a pair of very capable speakers (Audiovector SR6AA), so below I am not implicitly comparing to budget gear.
At first power on, it sounded edgy and veiled, but that changed gradually over the following 6 weeks to transform itself into probably the best amps I have ever heard. Since the difficult start it has been growing on me. But it does need some serious burning in – and it would be unfair to judge it before that has taken place. I had it turned on 24/7 for several weeks but kept getting better over time.
Without signal, it is dead silent. It depicts a large 3-dimensional soundstage- very broad, extending well outside each of my speakers, and so deep that some of the musicians seem to be playing from behind the rear wall. It is very detailed and will let you in on even the tiniest sounds and details – without even the slightest trace of sounding analytical, thin or “naked” . It combines the ability to place each sound source precisely on the stage with the ability to integrate everything into an organic scenery. With good live recordings, the soundstage is huge and it is as if you could walk up there blindfolded aand still know precisely where the players are.
And somehow my speakers are now much more easy to place in my room – this amp seems to maintain the tonal balance much easier than its predecessor that needed much more support from the rear wall - or the low end weight would be lost.
What probably has enticed me the most is the perfect tonal balance – electric organ, trumpet, cymbals,l etc. - are rendered with body, warmness ( if called for) detail and nuance. It renders perhaps the only quality of a tube amp that I have been missing hitherto : the low midrange “ juiciness” of voices, winds drums.
It is difficult for an amp (and speaker too, for that matter) is to render the “body part” of cymbal, hi hat etc with the proper sense of weight and dimension, and at the same timecommunicate the fine nuances of the decay as the sound travels towards the walls of the room in which the sound was recorded – the aussie masters this discipline.
It kicks with a vengeance, but at the same time it retains all the detail and delicacy you could ever ask for - so macro and micro dynamics are in perfect balance, it seems. And it is infull control, whatever the music and the sound level.
All this is delivered in a very natural, spacious and coherent way, a way that lets me focus on the music, that comes to life end blooms in my room.
This is an amp that does everything important right.
Some have compared their “Aussie” with some very renowned gear, concluding that their Aussie was better. If I remember correctly, comparing to the gear that I have heard, I totally agree. I believe it must be up there, among the very best.
I know I sound less than objective - but there is a reason for my enthusiasm: My Aussie is an exceptionally communicator of music. I really do believe that something special is going on here.
Ole Thomsen
Denmark
System
CD: Sony 707ES, heavily modified with ZapFilter
PC with Sound Blaster X-Fi Titanium HD Audiophile Sound Card (I know, but surprisingly good)
Preamp: Own design, with DACT attenuator, relay switched signal and ground paths and selectable passive or active (AMB labsα20) line stage) Houses a separate DAC (NewClassD).
Speakers: Audiovector SR6AA (4 way speaker with Audiovector Avantgarde Air Motion Transformers)
Music
Eva Cassidy: Live at Blues Alley, Songbird
Miles Davis: Kind of Blue, Sketches of Spain, Porgy and Bess, Bitches Brew, Dark Magus, Get Up with It, Cellar Door Sessions, Agharta, Pangaea
Dire Straits: Private Investigations
Hans Theessink, Terry Evans: Visions
Grateful Dead: The Closing of Winterland
Nick Bärtsch: Ronin Live
Jan Garbarek Bremen
Keith Jarrett: Sun Bear Concerts
Eagles: Long road out of Eden
Anuar Brahem: The Astounding eyes of Rita
Cat Power: The Covers Record.
And: Thord Gustavsen, Josefine Cronholm, Zawinul Syndicate, Joni Mitchell, Rickie Lee Jones, Ane Brun, Massive Attack, Faithless, Primus…
Various classical music.
