NAIM DR Series Power Amplifier Rollout

Naim Headquarters, Salisbury, UK  13 November 2015

Naim brief the PRESS on the technology and explain the rollout of the new DR augmented line of NAP power amplifiers:  

​With a good attendance of UK Press: Hi Fi News, Hi Fi World, HIFICRITIC, Haymarket (What Hi Fi and Gramophone) and Hi Fi Plus, NAIM expanded on their  earlier Munich Show announcement for the new DR amplifiers, at that stage previewed as prototypes. The day began with an introduction by the new CEO Trevor Wilson, who noted that NAIM sales were still rising and that their commitment to the traditional hi fi separates market would continue, especially in respect of the close bond which has been struck with historic customers and enthusiasts. After rolling out Spotify compatibility, Tidal was the next project and NAIM have worked closely with Tidal to get the project underway smoothly. I agree with Steve Harris that access to Tidal is undoubtedly a great asset especially for validating potential purchases but in a high quality system, in our view, Tidal does not quite provide the particular subjectively connected quality of live replay from a raw CD.

Before and after NAP series amplifiers laid out for inspection, with Trevor Wilson at the head of the table flanked by Paul Messenger (left) and Andrew Everard (right).

Design chief Steve Sells took us through the technology issues. He explained some of the subtleties of power regulator design, noise, impedance and rise time and had cooked up a cunning and revealing demonstration of the improvements achieved in this area. With a well crafted test rig using music feeding power to a silent dummy load, he took three amplifiers through their paces: one unregulated, one standard regulated and one DR regulated, while feeding the now amplified noise and distortion on the supply rail to a loudspeaker.
 
For the unregulated supply rail the noise was substantial, frankly a noisy racket comprising hum and programme, all half wave rectified, with almost zero music content.  In the case of the majority of unregulated amplifiers, some of this noise is also present in the signal to the loudspeaker.
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For the regulated power rail the hum and the music distortion was much reduced, this familiar from the improved sound of these established regulated supply power amps. Finally, when the DR amplifier power line was put under the aural microscope, it was essentially silent, free from noise, hum and  that dreaded music modulation distortion.

The old NAP 300 amplifier board, one channel with NA 007 TO3 power transistors.

The new 300DR amplifier board with low capacitance ceramic power transistor isolators and the new higher current, ultra matched Statement NA 009 power transistors.

​In particular the more complex, balanced output NAP 500DR design needed to be finished and then NAIM were at last ready to show off the renewed range. They remain one of the few companies with the nerve to A/B old and new models to a critical audience, here working in NAIM’s listening room with the latest version of the Focal Scala floor stander the MK II.  The gathered critical ears had the opportunity to sequence the audition in any order for the old and new NAP models, 250, 250DR, 300, 300DR and 500, 500DR, with just tens of seconds delay for each switchover. A massive stack of amplifiers and power supplies had been assembled, on FRAIMS of course. 

Experienced hand Jason Gould, now appointed UK Sales Manager, ran the comparisons

​Sound quality could have been even better without the need to have all the amplifiers powered simultaneously, ready to go, but what sounds emerged were more than sufficient for us to hear clear, unambiguous differences. In the case of the comparison of the 500 with the remaining models, we had to make allowance for a small +1dB gain for the 500. The crew wisely choose not to alter the volume control setting for any of the tests, which variation could have added further confusion.
 
The sound quality differences between new and old were far from trivial or the merely incremental. ‘Freshened up’ is hardly adequate, more ‘turbo charged’. Not only was the price/performance hierarchy clearly demonstrated - you really do get what you pay for - but the quality gain over the outgoing models was substantial, in terms of bass extension, timing and tune playing, as well as sound stage focus and scale, clarity, delicacy and image depth. Not least, the new versions also demonstrated improved rhythm and listener involvement. 
 
To me, the mostly costly of the set, the 500DR, sounded rather like a smaller version of the Statement power amplifier which I enjoyed for some months reviewing it for the hificritic). Perhaps this isn’t surprising since the two do share a similar circuitry and build topology and now have many parts and design aspects in common.