M300 TO M600
Just had a pair of M300's upgraded to M600's and let's just say I am a happy bunny. The M600's builds on the strengths of the M300's but with greater scale, dynamics, tighter bass, more detail and all this adds to the musicality. In conclusion if you are using M300's and have £500 to spare get them upgraded. If you don't use NVA even if you are using more so called 'exotic' kit and are wondering, then don't hesitate give it a try and you may be pleasantly surprised, I was, I did and I am.

A60 TO S300
Thanks for turning my A60 upgrade around so quickly; just one more example of your superb customer service. I thought I would drop you a short note to share my impressions of the new S300 configuration. To be honest, I wasn’t expecting a leap in performance – the A60 is a lovely amplifier – but a significant improvement there certainly is. My sound system has acquired a beautiful silkiness through the mid and top, and I wonder whether this may be due in part to the new power supply taking better control of the ribbon HF units in my Quad Z1 speakers. I can best describe the overall change as ‘less’ rather than ‘more’, in the sense that something has been taken away that was producing a subtle degree of impurity across the audio spectrum. New sounds in the back of the mix are discovered, distinct in placement, timbre and clarity. This amplifier is extremely revealing, as opposed to being ‘analytical’, if that makes sense. The old adage that “the wider the window, the more muck flies in” certainly applies, but this amplifier does not deal cruelly with less-than-perfect recordings; instead the open window lets the dust blow away. As an unexpected bonus, before the upgrade the A60 was prone to interference from the TV in the room below, which was cured by running the amp via a mains purifier unit. Now this sensitivity is gone and the purifier is redundant. I couldn’t be happier with the upgrade. Thanks for all you are doing to keep the NVA ethos alive and well.

A80 TO M600
I took advantage of the offer earlier this year to upgrade my A80s to MkIII spec and after a short wait for Tomasz to return to the UK a received them about four weeks ago. I really liked the A80s in their MkII but they where never silent to the extent that I had put them on isolating pads to reduce the hum being transmitted through the wooden shelf they were on, not a particular issue when listening but just an annoyance. The first thing was the total lack of hum in either the 'new' amps or the BMU, so much so that I wouldn't know they were on if not for the red LEDs. First listen was Rovo and System 7 Pheonix Rising, it sounded a bit constrained but I expected it to take a while to bed in so was not concerned. What was it really impressive was the space in the mix and also more texture to some elements. This has become a bit of a theme with more listening over the last few weeks as the tightness went but many tracks shone with coherence and again that extra texture which really pulls you in. I also noticed that there was seemingly more grunt, this may be just better resolution of bass lines but I am generally listening at slightly lower volume levels. This comes on the back of upgrading my P50 SA to the new spec last year and I have to say it is a real pleasure doing business with Paul and Tomasz, and the products are just great.

A80S TO M600
The upgrade to MKIII spec is not at all subtle. It's not easy to describe what's special about NVA amps, but for me it comes down to the way the sound fills space - it has a distinctive kind of presence, that's very natural and very addictive. It goes without saying that the amps have retained this quality, and so the NVA magic is still there. But otherwise it's like having a new set of amps - increased detail, better separation, better imaging, deeper and more controlled bass, higher and more detailed highs. The MKIIs were certainly no slouch in any of these areas, but still the jump to MKIII is significant and not at all subtle. And importantly, even with the more detailed highs, the sound is still as natural and unfatiguing as ever - I could (and will!) listen for hours. A couple of small points: The MKIIs emitted a quiet, but still noticeable hum. Likewse, the speakers when connected to the MKIIs would emit a quiet hum, noticeable when no music was playing. The amps and the speakers are now completely silent. Tomasz and Paul are clearly onto something with the MKIII component changes. I sent the amps in the new boxes, which worked very well, and the turnaround was speedy. Tomasz had clearly given the amps a good clean as well - they came back looking better than they went out. To sum up, the upgrade to MKIII spec is money well spent. Thanks guys! :grin:

A80 TO M600
Have played a lot of albums since the now completely silent mono blocks arrived back. After a few hours they were sounding very good and the improvement is far from subtle. Most noticeable was a greater sense of separation and space in respect of everything I played. This stands out when electric guitars and other lead instruments are accompanied by acoustic guitars providing rhythm, as on Bowie’s Ziggy Stardust album. It was also very noticeable with piano on the 70s Queen albums I played. When the power chords enter the mix the increased separation allows the piano to remain distinct more so than before, examples being “We are the champions” and “Spread your wings”. The improvement also applies to the acoustic guitar on the latter. There is a similar improved separation effect with lead and backing vocals exemplified on tracks such as “Long away” where Freddie Mercury’s prominent backing vocal to Brian May’s lead vocal contributes so much to the mood, emotion and dynamics of the song. Over more time it became apparent that there was an improvement in dynamics. I found myself reducing the volume by one or two notches with no decrease in the sound level on peaks. The A80s look the same but the components inside are obviously superior and the music has never sounded so good. On the basis of what I am hearing I highly recommend the Mk 3 upgrade.