# 2x555DR vs. 1x555DR on a ND555 **URL:** \ **Category:** Streaming Audio\ **Created:** [October 9, 2019, 12:33am UTC](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450 "2019-10-09T00:33:09Z")\ **Posts on this page:** 20\ **Page:** 24
**Author:** ![Dunc](https://community.naimaudio.com/user_avatar/community.naimaudio.com/dunc/32/66755_2.png) [@Dunc](https://community.naimaudio.com/u/Dunc)\ **Post date:** [October 25, 2020, 6:12pm UTC](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450/467 "2020-10-25T18:12:23Z")
Thanks for the reply, bit like naim themselves, i dont fully see why. I could understand it more if say the 555ps had the un used regs and bits disconnected, as even if not being used, they still have power going through them and if you put a meter on the pins in the socket, you will still have the volts there, just nothing on the end off them, so they must still generate some noise, as everything does, x this by 2 in both boxes, plus add a second large noisy transformer and mains cable and it all starts to become hard to take in. But i am not going to say it doesn’t make a difference, i was just one off the ones, that at the time couldn’t hear any difference at all, when i tried it. ---
**Author:** ![Darkebear](https://community.naimaudio.com/user_avatar/community.naimaudio.com/darkebear/32/262_2.png) [@Darkebear](https://community.naimaudio.com/u/Darkebear)\ **Post date:** [October 25, 2020, 6:13pm UTC](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450/468 "2020-10-25T18:13:49Z")
The initial test was with CD555 where I though it made exactly the same sort of differences - so it was not a surprise to me that it did the same with ND555. Possibly Naim also optimized somewhat the ND555 to accommodate that better as an option. DB. ---
**Author:** ![Richieroo](https://community.naimaudio.com/user_avatar/community.naimaudio.com/richieroo/32/40009_2.png) [@Richieroo](https://community.naimaudio.com/u/Richieroo)\ **Post date:** [October 25, 2020, 6:56pm UTC](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450/469 "2020-10-25T18:56:46Z")
OK day 3… bass definately much better…cleaner more tuneful…excellent. Some extra details more apparent… + a little more space and air. Voices and instruments seem more sonorous … very pleased so far … I will report back in more detail in around a week or so… ---
**Author:** ![Darkebear](https://community.naimaudio.com/user_avatar/community.naimaudio.com/darkebear/32/262_2.png) [@Darkebear](https://community.naimaudio.com/u/Darkebear)\ **Post date:** [October 25, 2020, 8:38pm UTC](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450/470 "2020-10-25T20:38:07Z")
> [@Dunc](#): > > I could understand it more if say the 555ps had the un used regs and bits disconnected, as even if not being used, they still have power going through them and if you put a meter on the pins in the socket, you will still have the volts there, just nothing on the end off them, so they must still generate some noise It is current drawn into a load that allows for the noise. The nose voltage is in two main parts: - from the regulator - From the ND555 injecting noise Voltage measured, with no current drawn, is not the same as having it connected to a complex noisy load (the ND555). Disconnect the load and the regulator will sit there idle and not be back-injecting anything onto the other Regulator, because nothing is driving it. Noise in the Regulator itself will be a random ‘shot-noise’ thing which should be very low - especially with the DR supplies. Noise from the ND555 will be dynamic signal-correlated noise - Naim will try to minimize it for sure but in the real world of things it will be there and generating a current flow - which the Regulator will try to minimize the voltage component of but the current has to pass back through it to the transformer - where it will then be shared with other things using the transformer. This is where the noise is getting ‘in’, so simply un-plugging the feed on one Burndy will eliminate it totally. DB. ---
**Author:** ![Robbo](https://community.naimaudio.com/user_avatar/community.naimaudio.com/robbo/32/141550_2.png) [@Robbo](https://community.naimaudio.com/u/Robbo)\ **Post date:** [October 26, 2020, 8:21am UTC](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450/471 "2020-10-26T08:21:19Z")
You are 2 days ahead of me Richieroo! Will be interesting to see how things progress, although I have decided to leave mine on silent, on a playback loop, until the weekend. Will stick to vinyl in the meantime. As I commented to my dealer, my expectation is that the dual PS’d ND555 will now reach the level of listening involvement of my fairly lowly turntable, so flipping from a week of vinyl back to digital replay on Friday will be an interesting comparison! ---
**Author:** ![NigelB](https://community.naimaudio.com/user_avatar/community.naimaudio.com/nigelb/32/474043_2.png) [@NigelB](https://community.naimaudio.com/u/NigelB)\ **Post date:** [October 26, 2020, 11:17am UTC](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450/472 "2020-10-26T11:17:09Z")
Why can’t this thread just end! Pleeaaase! I think Richard should introduce a ‘Wealth Warning Notice’ on certain threads. Such threads could be denoted as ‘ **D** amage **A** ll **M** onetory **N** est-eggs’ ---
**Author:** ![Darkebear](https://community.naimaudio.com/user_avatar/community.naimaudio.com/darkebear/32/262_2.png) [@Darkebear](https://community.naimaudio.com/u/Darkebear)\ **Post date:** [October 26, 2020, 1:14pm UTC](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450/473 "2020-10-26T13:14:59Z")
> [@NigelB](#): > > Why can’t this thread just end! It can - as soon as you are telling us how much you are enjoying your new PS addition. 🙂 🐻 But otherwise - I’m sure you will sensibly resist! Sometimes not spending money - especially when you don’t really need too - on HiFi is very sensible! …that concept may get me banished… DB. ---
**Author:** ![Richieroo](https://community.naimaudio.com/user_avatar/community.naimaudio.com/richieroo/32/40009_2.png) [@Richieroo](https://community.naimaudio.com/u/Richieroo)\ **Post date:** [October 26, 2020, 5:38pm UTC](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450/474 "2020-10-26T17:38:15Z")
I agree I think the power demands on the digital side modulate the the transformer which in turn generates low level hash which being digital could be pretty high frequencies … the transformer probably also broadcasts this down the power lead … which is possibly why you have a preference for plug order…I am sure some one more technical will enlighten me further… ---
**Author:** ![Inmynaim](https://community.naimaudio.com/letter_avatar_proxy/v4/letter/i/f07891/32.png) [@Inmynaim](https://community.naimaudio.com/u/Inmynaim)\ **Post date:** [October 26, 2020, 6:35pm UTC](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450/475 "2020-10-26T18:35:52Z")
> [@Darkebear](#): > > Sometimes not spending money - especially when you don’t really need too - on HiFi is very sensible! > …that concept may get me banished… Heretic!!! 😂 ---
**Author:** ![Bluesfan](https://community.naimaudio.com/user_avatar/community.naimaudio.com/bluesfan/32/573_2.png) [@Bluesfan](https://community.naimaudio.com/u/Bluesfan)\ **Post date:** [October 26, 2020, 6:43pm UTC](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450/476 "2020-10-26T18:43:19Z")
Disgraceful. Stone him I say! 😆 ---
**Author:** ![Inmynaim](https://community.naimaudio.com/letter_avatar_proxy/v4/letter/i/f07891/32.png) [@Inmynaim](https://community.naimaudio.com/u/Inmynaim)\ **Post date:** [October 26, 2020, 6:45pm UTC](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450/477 "2020-10-26T18:45:24Z")
> [@Bluesfan](#): > > Disgraceful. Stone him I say! 😆 Reminds me of a certain very tasteful film! ---
**Author:** ![Darkebear](https://community.naimaudio.com/user_avatar/community.naimaudio.com/darkebear/32/262_2.png) [@Darkebear](https://community.naimaudio.com/u/Darkebear)\ **Post date:** [October 26, 2020, 8:44pm UTC](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450/478 "2020-10-26T20:44:57Z")
…but I’m just trying to help! 😕 It is always good to decide if you: - have money and want something, - have not enough money and still want it, - don’t want it whatever! The second bullet above is most tricky. DB. ---
**Author:** ![Zackwater](https://community.naimaudio.com/user_avatar/community.naimaudio.com/zackwater/32/516_2.png) [@Zackwater](https://community.naimaudio.com/u/Zackwater)\ **Post date:** [October 27, 2020, 11:09pm UTC](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450/479 "2020-10-27T23:09:22Z")
When, not if, I add the second 555dr how will I stack it in the fraim? I will have the following: (1) nd555, (2) 1st power supply for nd555, (3) 2nd power supply for nd 555, (4)nac552 (5) power supply for 552 (6) 500dr (7) power supply for 500dr and (8) Ansuz d2 power distribution unit. ---
**Author:** ![Richieroo](https://community.naimaudio.com/user_avatar/community.naimaudio.com/richieroo/32/40009_2.png) [@Richieroo](https://community.naimaudio.com/u/Richieroo)\ **Post date:** [October 28, 2020, 9:45am UTC](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450/480 "2020-10-28T09:45:40Z")
Resistance is useless… ---
**Author:** ![Joppe](https://community.naimaudio.com/letter_avatar_proxy/v4/letter/j/b38774/32.png) [@Joppe](https://community.naimaudio.com/u/Joppe)\ **Post date:** [October 28, 2020, 11:21am UTC](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450/481 "2020-10-28T11:21:02Z")
For looks and separation of PS from nonPS ideal I guess (or some minor order change): Left 552/555/500 (tall/tall) or 552/555/gap/500 (medium/std/medium) Right 552/500/555/555/ansuz (all std) ---
**Author:** ![BertBird](https://community.naimaudio.com/user_avatar/community.naimaudio.com/bertbird/32/881_2.png) [@BertBird](https://community.naimaudio.com/u/BertBird)\ **Post date:** [October 28, 2020, 8:04pm UTC](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450/482 "2020-10-28T20:04:12Z")
Who cares about money- you only live once. The corona topic again has shown how I,portent it can be to have a great system at home and just enjoy it… ---
**Author:** ![Meni](https://community.naimaudio.com/user_avatar/community.naimaudio.com/meni/32/410738_2.png) [@Meni](https://community.naimaudio.com/u/Meni)\ **Post date:** [October 28, 2020, 8:37pm UTC](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450/483 "2020-10-28T20:37:44Z")
👋 👋 👋 👋 ---
**Author:** ![Robbo](https://community.naimaudio.com/user_avatar/community.naimaudio.com/robbo/32/141550_2.png) [@Robbo](https://community.naimaudio.com/u/Robbo)\ **Post date:** [October 29, 2020, 7:47am UTC](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450/484 "2020-10-29T07:47:45Z")
Sneaky quick check in on run-in progress this morning. The system has been running on a random playlist loop, and I fell on You by Janet Jackson - wow, the bass control on this track is sublime!! Back to work - but looking fwd to the weekend! ---
**Author:** ![Richieroo](https://community.naimaudio.com/user_avatar/community.naimaudio.com/richieroo/32/40009_2.png) [@Richieroo](https://community.naimaudio.com/u/Richieroo)\ **Post date:** [October 30, 2020, 8:16am UTC](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450/485 "2020-10-30T08:16:08Z")
OK right … this is going to be difficult for me describe…up to around day 4 or so nothing but positive … punchier bass, tighter, deeper more tuneful etc, voices and strings amazing, stereo etc great … so all hifi boxes ticked and importantly very engaging to listen to. So in the last few days…the balance of my system seems to have shifted there seems to be more mid bass and the hi frequencies are slightly more recessed. The sound is still very good but ‘darker’ if that makes sense … it could be that I may now need to re-tune my sub (this rolls in below 55hz) and reposition the speakers… I hope not. I am sticking with everything unaltered until I have around six weeks on this new supply. I know this is a beast of a power supply and takes some time to settle … will report back again in another week or so… by the way some seriously interesting developments on the Witch-hat site … can’t say anymore… ---
**Author:** ![sbilotta](https://community.naimaudio.com/user_avatar/community.naimaudio.com/sbilotta/32/34144_2.png) [@sbilotta](https://community.naimaudio.com/u/sbilotta)\ **Post date:** [October 30, 2020, 11:07am UTC](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450/486 "2020-10-30T11:07:42Z")
> [@Richieroo](#): > > by the way some seriously interesting developments on the Witch-hat site … can’t say anymore… Anaconda? [Previous page](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450.md?page=23) [Next page](https://community.naimaudio.com/t/2x555dr-vs-1x555dr-on-a-nd555/4450.md?page=25)