# 272/555DR/250DR --\> 222/555DR/250 observations **URL:** \ **Category:** Hi-Fi Corner\ **Created:** [August 11, 2023, 6:30pm UTC](https://community.naimaudio.com/t/272-555dr-250dr-222-555dr-250-observations/30311 "2023-08-11T18:30:23Z")\ **Posts on this page:** 1\ **Showing post:** 91
**Author:** ![gthack](https://community.naimaudio.com/letter_avatar_proxy/v4/letter/g/7ea924/32.png) [@gthack](https://community.naimaudio.com/u/gthack)\ **Post date:** [August 28, 2023, 10:48am UTC](https://community.naimaudio.com/t/272-555dr-250dr-222-555dr-250-observations/30311/91 "2023-08-28T10:48:03Z")
The streaming board is the same, the Stream Unlimited NP800 manufactured for Naim > [@NDX 2 or NSC 222?](https://community.naimaudio.com/t/ndx-2-or-nsc-222/28950/67): > > Hi @IanRobertM, NDX 2 and new classic streaming products all use the NP800 (our custom streaming card from StreamUnlimited). It will not use the 810 card. The NP800 has master mode clocking, larger memory and LVDS for low noise digital board to board connection. That board does all the network stuff, before sending the resulting digital data to the DAC. It’s the DAC implementation that is different between ND5 XS2, NDX2 and NSC222. By DAC implementation I mean everything from the streaming board IO through the DAC used, to the DIN/RCA plugs in the back of the unit. And even then the context within which the NP800 sits is different, as I think there are “upstream” changes between the above too, relating to streaming board isolation, but I cannot recall well enough what they are to find related posts/threads --- _[View the full topic](https://community.naimaudio.com/t/272-555dr-250dr-222-555dr-250-observations/30311)._