Naim has unveiled a new range of ND network streamers including a replacement for the range topping NDS that will be available “In summer 2018”. The ND5XS 2, NDX 2 and ND 555 are all new, ground up designs based around the streaming engine developed for the Uniti range. Which means that as well as being UPnP streamers they also have Airplay, Bluetooth, Chromecast, net radio, Spotify Connect and Tidal onboard alongside digital inputs. Specs for the DAC include the ability to decode PCM up to 32-bit/384kHz and DSD128, not massive numbers but more than adequate for any music you’d actually want to listen to.
Digital inputs extend to coaxial on RCA and BNC, optical and USB for disc drives, there are dual wi-fi antennas for situations where Ethernet connection is not available. The two bigger models have a five inch colour TFT screen that is engineered so that data transfer is switched off when the image is static in order to keep down noise. In fact noise reduction is the essence of this range, because it’s the enemy of sound quality in digital systems. Each ND has a switch mode supply so that it can remain ready for action without exceeding energy efficiency regs on standby (0.5W) but this hands over to a linear supply when the streamer is operating. They also share a SHARC DSP that provides 16x integer oversampling with Burr Brown DAC chips operating purely as converters with none of their filtering or other features engaged.
The ND5XS 2 (£1,999) has all of the above features except the display, a small green light indicates connection to the network. Naim’s thinking being that users will operate all of these streamers with the app (iOS, Android). It has a BurrBrown 1791A DAC, RCA or DIN analogue output and switchable earthing. The NDX 2 adds the option of adding an external power supply such as an XPS PSU or PS555, but has a substantial transformer on board, big enough to be in one of Naim’s power amps in fact. This model has the TFT display with which you have the option of white or green text alongside the album artwork shown when streaming. You get an RF remote handset with this model and discrete filter circuits rather than the op-amps of the current NDX.
All the best stuff is held back for the ND 555 (£12,999 plus PSU) where no screw torque has been left unchecked in the quest for maximum sound quality. Those screws hold the lid on the case for the streaming engine to protect it from noise, but this is just one example of the extremes that engineers Roy George and Steve Sells have gone to. Others include the direction of internal wiring the use of custom made polystyrene capacitors on the output stage, WBT Nextgen RCA sockets and a suspension system that uses brass weights to keep out vibration above 10Hz. The internal power supply uses DR regulators for the first time in a streamer, an approach that drops the noise floor by a claimed 15dB over the previous LM13 regulators. The way that clocking is done has also changed, the DAC clock runs the Ethernet input rather than the two being slaved together, an approach that Naim thinks is unique to this machine. One nice touch for this model is a brushsed aluminium remote handset with green illumination.
Roy George commented that it was a tough challenge to improve on the NDS, and there were “no big wins in the listening tests”, he had to look at the wiring arrangements, the aforementioned lid on the input board and develop an I2V from the circuitry of the Headline headphone amplifier. But if the dem I got was any indication he has pushed the potential of streaming audio to a new high with the ND 555.