by CycleCoach » Thu May 10, 2018 11:16 am
This is a review, well sort of.
It’s taken me quite a while to get my thoughts in order since I took the plunge and ordered a “starter pack” of P20/A20 and cables, and I’ll be honest I’ve spent a lot of the spare time in between listening to music rather than preparing to write this.
I need to rewind a bit. After an extended hi-fi free period (caused by kids and their destructive fingers, followed by their sporting aspirations which took up all my spare time,) I dragged my old stuff out to see what I had.
Basically I used to have the “old favorite” LP12 (Lingo, Ekos, Troika) with Naim NAC 32/5 NAP 135s and a pair of Isobariks. The speakers were U/S thanks to toddler tweeter pokage, so I found an old pair of Rogers LS4a in the loft to use instead.
The one thing I was determined about is that I didn’t want to go for analogue again. Why? Well for one thing there was a day when my brother visited with a portable mini-disc player and I fed it through the system (I had a spare input for a Walkman Pro) The compressed MP3 files sounded BETTER than the turntable. It was the beginning of the end for my analogue obsession. Add a couple of house moves into the mix and other things became more important.
I started listening to my laptop through a cheapo NAD amp and looking on t’internet for information. The first thing I noticed was that Hi-Fi isn’t such a big deal anymore, it seemed to be more centred on willy waving about expensive esoterica ownership. I started using the Naim amps again at this point.
Long story short, I happened on HFS and asked a couple of questions. Mostly the replies were surly to start with (I now know there is history – but I knew nothing of all that stuff then!)
In the end I was encouraged to try the A/P 20 starter set on a 30 day trial. Nothing to lose so why not? But how could it possibly sound better than my beloved Naim (which I had paid £4k+ on?)
And the conclusion?
The lil’ combo blew the Naim stuff away. Really. There was a clarity I had never experienced before. I was used to what I can only describe as a certain “graininess” to the sound, but this was absent. In the past I was constantly turning the volume up in a misguided attempt to hear through the mix – this was no longer necessary. I never felt that there was a shortcoming in the power stakes either – this went plenty loud enough for me. The sound wasn’t perfect though there was a tizz in the treble and plumminess to the sound which I blame squarely on the Rogers speakers with their BBC style crossovers and metal tweeters.
Longer term things have moved on quite a bit, I acquired a P50sa on eBay, along with a pair of Cube 1s and LS6 speaker cable from friends here on HFS, and this week some SSP Mk2 interconnects. On the front end I splurged the £4 to try the mysteriously wonderful Chinese DAC (now with matching power supply (details of this elsewhere,)) but for the time being the A20 is still the heart of the system.
On paper this should be a bit of a mismatch but it is a testament to the little amp that it more than holds its own in this system – I’m never thinking about it like I was about those crappy speakers, It just does its job. It does its job exceedingly well, and I have been able to hear the improvements of each change in the system clearly.
I wish I had taken the plunge earlier, but hesitated, even though NVA offers a 30 day no quibble return policy (I wanted to hear before buying I guess,) but now you can even trial the loan set of the world-beating little combo in your own home, so even that tiny hurdle is removed. I really couldn’t recommend this amp more highly.
Current System: Macbook Pro, Starting Point Systems DAC 3, NVA P50SA, NVA A20, NVA LS6, NVA Cube1
Post by eagwok33 » Sun May 27, 2018 9:28 pm
Finally, here are some impressions of my new A20x amp. The A20x was at first supposed to replace the A30 according to the Doc’s info. In the meantime the Doc changed his mind as the A20x was apparently not an improvement over the A30 and the A20x will not be produced anymore. Anyway, as it is the first NVA amp I own, I will let you know what it did musically in my system.
Well, it is a neat looking little amp for only £326 (incl. shipping). One could judge the amp by size and price, but this would be a big mistake! Why? Because, this little amp performs surprisingly well, when connected to my high efficient (98dB) and easy to drive Haigner horn loudspeaker-system. (My experience with higher gain amps – various chip amps for example - on my horn system has not been so great so far).
I started my listening sessions with the A20x after about 24 hours of having the amp just powered on in my system. Paired with my DIY passive pre amp the A20x was fun from the start, with a lively and energetic way to play music. As the gain of this little amp is quite high, I could use just the 6 to 9 o’clock range of the volume pots of my preamp. Beyond that range the music played became so loud via my horns that I feared my nice neighbors, who live in the apartment above us, would no longer be our friends.
I’d like to state that lately I changed the Alps Blue stereo potentiometer to Nick’s (lurcher300B) recommendation of the mono version of the Tocos Cosmos carbon track potentiometers. This has been a clear improvement to my ears and results in more foot tapping during listening sessions. So, a big thanks to Nick for his tip! (I use a pair of 20K log type ones for my DIY passive pre).
During the first two weeks in operation (I left the amp continuously on), the performance of the A20x improved noticeably. At the beginning, the sound of the amp was closed-in in the mid-range, especially when listening loud and the amp sounded more forward and in your face, in comparison to the amps I normally use in my system.
Just to let you know, where I’m coming from:
I listen mainly in the near field of these full-range horns, i.e. the distance is about 2.7m. I always have loved the sound of low-powered SET amps connected to my horns as there is a magic in the mids and treble of such amp designs to my ears, and an openness, speed and fluidity in the reproduction of music, which I truly love and admire. One can get easily addicted to that...
Transistor amps can be superb but are different in this area to my ears and normally not as magical. But as always, there is a trade off with most low-powered SET amps in my experience and this is the bass slam and the overall dynamic impact of the music, also when mated with efficient speakers. For example, when I'm listening to a great rock band – let’s say Led Zeppelin - at very loud levels with my 2A3 SET monos in my system, the slam and dynamic impact of the lower registers is kind of missing.
I have heard some low-powered SETs with massive output transformers and well executed low impedance power supplies made from experienced tube amp builders, which can deliver the slam in the lower registers and the overall dynamic of music, but such amps are rare and, honestly, at this stage, I’m not experienced enough to build them.
This said, my current reference amp is the M2 clone amp, a DIY project I have done with a friend of mine, who suggested building two of these amps, one for each of us. This M2 clone is based on a First Watt = Nelson Pass design and is a class-A transistor amp, with an auto-former as voltage gain stage and a push pull Mosfet output stage. This amp is rather low in gain (14dB) and fits well to high efficient speakers. My M2 clone amp is very fluid, balanced and musically pleasing (connects you well to all kind of music played). It is dynamic, has bass slam (no wonder, it has 2x 320VA transformers in the ps) and is very quiet in operation when connected to my horns. My SE tube amps still have the edge in sheer treble magic, but listening to music through my M2 clone with my NVA phono3 / BBPSU is so much fun, that I don’t care about the tube magic the M2 can’t do.
Back to the A20x – as the review is about this amp
Regarding musicality, drive and dynamic shadings of reproduced music, this little amp is a real positive surprise after it is run in. It is more forward and rough sounding than the M2 clone, but with its lively and fluid reproduction of music the A20x is a fantastic bargain for the money! On many recordings, instruments are reproduced with energy and verve and make me smile. The A20x has a more energetic way of reproducing music fed from vinyl or CD than the M2. And for this entry level amp, the bass performance is astounding! Of course, the M2 has more weight, authority and slam but the liveliness of the NVA amp’s sound results in a well tuned bass for sure.
If the recording is on the hotter side - as some of the brass sections on Blue Note Jazz records - this liveliness and energetic performance can be too much, though and the music reproduced over my horn ls-system in the near-field then becomes a bit too nervous and forward sounding, which makes it harder to follow the message of such music.
But hey, the amp has cost £300 (plus shipping) and has been designed as an entry level NVA amp. This said, the performance of the A20x is a bit of a miracle to me.
The only downside is a slight hum the amp produces connected to my high efficient horns, which you can hear from the listening seat in quiet passages of classical music for example or when no music is playing. (The hum increases somewhat with turning the volume up). It is not transformer buzzing as these small transformers are dead quiet in operation. It is a hum the amp produces also when connected to the speakers alone (but then lower in level), i.e. without the preamp (amp inputs shorted with cinch plugs). I assume this hum is audible, due to the amp being connected to high efficient speakers. In comparison to the A20x, my M2 clone amp is a lot quieter connected to the horn ls-system.
Taking into account, how much I invested in parts and chassis alone for my M2 clone amp - I would say roughly 3 times more than the price for the A20x – the money / performance return is by far smaller than the price difference! Ok, the M2 is the quieter, more musical and natural sounding amp plus has more heft in the bass department, but the A20x with its lively and energetic reproduction of music comes very close to this. The price / performance ratio of the A20x is definitely superb and a real challenge to beat!
A20x and P50sa:
Paired with the P50sa I bought recently from Derek (Klimangelis) all I said before about the A20x remains valid. On top of that, you get slightly more musicality as the synergy of the NVA combination comes through fully. Richard choose the resistor values on the stepped attenuator of the P50sa very well as the high gain of the amp on my horns is a lot better under control with the stepped volume attenuator, than with my DIY passive pre with log potentiometers. What I mean, is the range of volume I listen with the P50sa is wider (from 6 to 12 o'clock in my system compared to 6 to 9 o'clock with my DIY passive pre). So, it is easier to set the volume for lower levels of music replay.
Still, the gain of the amp remains too high connected to my horn speaker-system. This means, the steps beyond 12 o'clock are for my taste too big to really enjoy the amp fully. One or max. two further volume steps result in most cases in a too loud music replay! So, beyond 12 o’clock, more and smaller resistor steps would be ideal for the A20x given my listening environment with high efficiency on the loudspeaker side. I’m sure for not so efficient speakers the gain of the A20x will be exactly right.
To sum up the musical performance of the A20x / P50sa combination:
The pre / amp combo shines in the mids and with its sweet treble reproduction. So, well recorded classical music and especially string music is a joy to listen too. For example, some of the wonderful ASMF / Marriner / Argo recordings are a delight with this pairing. The liveliness and vividness of the reproduced music is a strong point of the A20x as it connects you well to most of the music played through the amp. On hotter recorded records, some Blue Note Jazz records as explained above or not so great recordings (for example Norah Jones – Broken from the LP “Not too Late”), the tendency to reproduce music a bit too nervous and forward sounding remains also true for the combination of P50sa /A20x (compared with P50sa / M2 clone).
So, what is my conclusion regarding the NVA A20x:
I learned that
• an amp doesn't have to be Class A to sound great This is good news especially for hot summer
days as the produced heat of Class A amps in summer is not so pleasant!
• never judge an amp’s performance by its size
• a minimalist design and expert knowledge of the designer plus his love for music are key
ingredients for a superb sounding amp and finally
• an amp doesn't have to cost a lot to connect you with your music
Enjoy your music,
by Stemcor1990 » Wed May 30, 2018 10:51 pm
Time for the review.....
Firstly, they look like a top of the range product. A very elegant silver braid finish and a bit thicker than my LS6. There’s really not much else to say. Just plug them in and listen.
Listening is where it gets interesting. The cables are not a night-and-day change. I think that my system has become too sophisticated for any change to make a significant improvement. What the cables manage is to make recorded instruments sound a bit more like real ones. I’m currently having something of a telecaster fixation (I won’t bore you with the details) and have found myself listening to some status quo during their transition from psychedelia to boogie. The cables just make that telecaster sound that bit more realistic. To be honest, this applies to all instruments and for me that’s good enough.
Vocals are rather good as well. Listening to Billie Holiday as I’m typing this and you can hear her voice on the edge of falling apart on Lady in Satin. One of the things I have noticed is that a good system makes some singers sound worse as you can clearly hear how badly they are singing ! I’ll let Ms Holiday off on that one. However, it can become quite engaging and enhances the “performance”
So I’ll end by saying that I have taken advantage of Green Wednesday and ordered a pair. If you are considering an upgrade then a pair of TSCS are worth considering and might be a better purchase than a bigger amp.
Post by Lordie82360now » Sun Jun 03, 2018 10:22 am
NVA Super Sound Pipe, Super Sound Cord, Chinese Dac and Allo Digione player
I am not so sure I know my Kernal from my elbow (I know I don’t) but my recent purchases of an Allo Digione player, SSP, SSC and cheap Chinese Dac have rekindled my interest in this hi fi “hobby”.
Not since hearing my first system in the early seventies have I been taken aback by the musicality of the sound presented by these components.
I have had a frustrating time trying to settle on a musical streamer with an intuitive app for control from iPad or iPhone, preferably the former - with a larger scene for older eyes. I have been through a number of examples over the last two years, but I really think the Allo Digione with Volumio 2 is the one (Hurrah shouts my wife!)
The digital coaxial 50cm Super Sound Pipe from NVA has been a revelation since direct connection to most of the former streamers and my Quad Vena with built in Dac. It is smooth, articulate and with a lack of fatigue making listening to music a renewed pleasure. The former, mainly Atlas interconnects, didn’t tame a “tizzyness” in the treble, but the SSP ironed that out completely.
The addition of a cheap Chinese Dac advocated by Richard and a pair of 70cm Super Sound Cords again from NVA via Quarknosis on Hi Fi Subjectivist (Thanks Quark) while bypassing the Vena’s dac has taken things to another level. It’s hard to quantify, but it just sounds even better to my ears and that’s what counts in the grand scheme of things. How can that be?
The only trade off is I have to increase the volume control slightly higher to achieve an equivalent sound level pre Chinese dac insertion.
The inclusion of an Ifi Power Supply for the Digione player is the most recent development, but I haven’t had time as yet to evaluate whether it makes a further improvement. The original Allo power supply now is attached to the Chinese Dac.
The Allo Digione player is the easiest way of getting all that is good from the Raspberry PI 3 with the minimum of fiddling about and is plug and play - just what I needed.
Volumio 2 is also great being user friendly on my iPhone although it doesn’t work with my iPad mini, a first generation machine, so that will have to be replaced. Doh!
It’s a great bit of kit and hopefully its the end of my quest for a digital source. Perhaps an aluminium case is the next move?
The combination with the NVA interconnects is a winner!
One word of warning - If you are impatient (it was out of stock on Volumio’s European shipping option at the time) like me and you import it direct from India - Import duties and a Fedex admin fee on top of postage are steep!
Digital Source: Allo Digione player, volumio 2, cheap Chinese Dac, Raumfeld Connecter 2, Ipad mini, Audirvana on iMac.
Amplifier: Quad Vena combined amp/dac
Interconnects: NVA Soundpipe 2, NVA SSC and Supra optical.
Headphones: Soundmagic sp150
Speakers: Quad S1, modded Rega Kyte and NVA LS1.