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