Had the pleasure of the comparison between NDS and ND555 at Acoustica this evening.
System was Core / NAC552 / 300DR into B&W 803D3 with SuperLumina throughout. NDS / 555DR vs ND555 / 555DR swapping the interconnect between the sources (hence keeping the same input on the pre). All electronics on Fraim. Chord C-Stream for ethernet. Nice to see the continuation of the green logo. The ND555 and its 555DR PS are on the top shelves in the picture above. Thankfully, we didn't have to suffer more of the upper range of Focal speakers today.
The ND555 is an evolution of the NDS. It uses the same B-B DAC but with a different power supply design. In fact, as you might expect from Naim, there are a number of power supply changes inside the ND555. Each "stage" (digital, analogue, clock) has its own dedicated and DR fed power supply inside the box (in addition to DR in the physically separate 555PS of course). The digital section is similar to the new platform in the Uniti range and therefore supports the latest stuff such as Roon. It is housed in its own dedicated metal box which "floats" inside the ND555's main case - it is mechanically and electrically isolated from the DAC and analogue stages which themselves sit on suspended thick brass plates. The screen is also shielded internally. There was also an explanation about how there are two clocks - an input clock that can vary its timing to match the incoming data feed and a second clock to time the DAC. Not sure about this and how that's a benefit when there's a buffer involved, but there you go. "Normal" Naim Burndy cables are provided with the ND555 for connection to the power supply (or supplies as there is an option to use 2x 555PS units with the ND555).
Although I'm not a big fan of the B&Ws, this was probably the best I've heard from them. They have a slightly un-natural treble and a squidgy bass that doesn't appeal to me. A little boom caused by the room too, but it wasn't excessive nor overwhelming. NDS first of course, then we swapped between the 2 sources a few times before settling in to a longer listen to the ND555. Jason from Naim was looking after the demo.
First thing to say is that the NDS doesn't "sound broken". It does a great job, just as it has done for a long while now. We started with an acoustic guitar track then onto a trio of female folk singers listening to the NDS. The trio was then played again for 40 seconds or so before switching over to the ND555 and listening to the same track again. We selected some Shelby Lynne and repeated the process.
Its not a "gob smacking" change for me - its more subtle than that, but that shouldn't de-value the size of the upgrade, its just that you have to think about it rather than have it fed to you on a plate. The instruments most definitely separate more clearly, the edges of notes are better defined without being edgy, you can hear more of the way in which a note is plucked on a string or how a bass line starts and stops more clearly. Yet these more clearly defined instruments don't stand alone as the timing seems more coherent, enabling them to make better sense of the "whole" of the tune. But the biggest impact for me was the added emotional element, particularly in Shelby Lynne's voice. That was what stood out for me, once we'd settled into the changes.
Worth a longer audition at home, whilst the VFM, as ever, continues to be a personal choice of course.
Thanks to Acoustica and Jason for a very effective and relaxed dem.