Just added an additional 500PS to the NAP 500

EricE posted:

and whooooo does this work!! Like everything is improved, the transparency, the depth, the bass, the heights, the lack of distortion. I just have a real instruments and persons in front of me. The increased headroom makes it shine. Of course depending on your speakers, mine are Magico S5, one should really consider this. With the 552 we are not in the Statement league yet but we are getting close....

can you add additional 552 ps to the nac 552 too?    i didn’t know that the nap 500 can be powered by 2 X 500 ps.

I think it was tried and not generally touted when all the two 555ps malarky started but not with magico S5. I didn’t think you could buy a 500ps on its own so if there’s a spare head unit how does it compare with a pair of one channel driven 500s? I assume active isn’t an option with magico.

We tried this at the factory many years back.  On the face it initially things sounded bigger and more exciting.  However, further listening showed there was something not quite right - things were too separated out and there was an unnaturalness to the sound - it gave the impression of musicians playing less "together". IIRC, Roy speculated that it may have been down to certain "parasitic" effects of running only one side of the power supplies.  Bottom line was that it wasn't an upgrade from Naim's point of view and so not something they could recommend. 

Erice, enjoy it, and of you are still liking it more after a few weeks then good for you.  But once the initial excitement has subsided, you may want to try going back to the standard set-up.  But who knows, maybe it better suits your Magicos compared to SL2s and DBLs...?

Thanks for all remarks. The Magico's are quite demanding so I guess this might be a reason I am still enthusiastic about it. Keep you posted and get back in a few weeks.

@Richard: Many years back means before DR upgrade ?

Eric, oh yes.  It would have been around 2005-6 or thereabouts. 

FWIW, a few Naim owners out in the US have reported success running NAP500s as just mono amps - i.e. just running one channel of both the PS and the amp head unit.  

Its a shame that there is no development regarding separating the supplies......I guess its a case of it you want more bite the bullet and get a statement........  my brother worked at Heybrook doing amp design/building and he found similar results when converting the 100w poweramp into monoblocks as a trial.... somehow it just sounded more together as a std stereo supply even though initially it sounded more open and impressive .....sounds like Roy was probably onto the same thing...... 

I just returned from a short vacation and listened again to the system with 2 times 500 PS. If I neglected the more open and larger image, I felt that the image was less coherent and more digital. The music was no longer an organic whole.

Going back to the original situation with one 500 PS immediately brought back the nice familiar sound. A nice experiment but it failed, apparently people in the factory know better. (Thx Richard) 

But here is a suggestion for Naim's developers. Are there any ideas for upgrading the NAP 500 power source? In the last decade there must have been developments that could benefit the power supply. And an upgrade would close the gap between the NAP 500 and the Statement, which would be nice ...

The DR went some way towards that.

Do you have a second 500 head unit to go with the ps? Try them as monos (one channel through each amp) while you have the chance, assuming it's not a DR and a non DR you have.

Of course you are right regarding the DR upgrade of the head unit. Fact is that Naim also upgrades through their power sources. I have noticed that doubling the ps  on the head unit brings benefits but also important disadvantages. Would be nice if Naim could eliminate the negatives and introduces a power upgrade. 

I only had one head and two ps, so double mono was not possible. 

There is one member who is running 6x500 active in a single channel per amp mode, and obviously felt the very considerable cost was worth it. Another member I know of uses pseudo-monoblock NAP200s into high efficiency speakers and felt that was about as large an upgrade as moving from his 282 to the current 252. Naim goes to a lot of effort in giving individual stages their own dedicated power supply via Burndies, but the duties of those stages between channels are still shared .  This is just a logical extension-like running a 555 or NDS with dual 555PS. 

I have tried 250s running as single amp passive, double amp biamp running all four channels passively with biwire,  and double amp in a single channel pseudo-monoblock configuration, and then compared those combinations to a pair and then a quartet of NAP135s in conventional passive, biamp passive (with all four amps) and fully active (with all four amps). 

The pseudo-monoblock 250s got close, but never quite approached the NAP135s. One thing for sure though-active Tukans ran with 4x135/Snaxo/Supercap were something quite special-especially when they had their backs covered with a Linn Seismik subwoofer. 

For historical interest it was forum member Onthlam who first tried running the NAP500 as single channel pseudomonoblocks, into DBLs circa 2004 or so and never looked back, until hs shipped the DBLs to China. 

As I have pointed out before, I am unsure that running the power supplies asymmetrically is necessarily a bad thing. In the early days of active configurations, speakers were vertically biamped via the Snaxo, with one power amp running tweeter with one channel and the woofer with the other-giving dramatically different loads and current draws between channels-and yet this was considered a good thing. Later generation Snaxos however are horizontally split. 

Finally, back in the mid 80s, it was quite fashionable for to run a  certain model preamp (Audio Illusion tube model) is pure dual mono-a full preamp per per channel, and those that ventured into that madness uniformly proclaimed a significant upgrade, inspite of the preamp being a low current device. 

I did attempt running a NAC52 of two Supercaps, using a dedicated supercap for just the 15V front panel duties, but could never get the auto-muting to disengage, indicating there was some problem splitting the earths and giving a current loop. I considered a non-working 52 as a sonic failure and did not ever repeat this test. One brave soul (in Singapore I think) actually managed to get a dual Supercapped 52 to work and loved the results) a year or two later.

I also fooled around quite extensively with the 552 preamp. 

I am glad the OP did try the dual PS configuration (how did you end up with 2x500PS as they are not available individually). Maybe repeating the experiment with a 'hydra' power chord shared between the 500PS would restore the reported downsides?

Hi Ron, actually I am still intrigued by the sound of two x PS so much that I will give it a try. Nowadays I am using M-Ways cabling which sounds fabulous. The owner will be more than happy to fabricate a tailor made hydra cable. So give me a few days and I get back. 

Regarding getting an additional PS I guess i was just lucky. A French dealer had a spare 2 year old one for sale. 

The hydra connection did not make a real difference. One PS is still definitely better! For me the story is closed now. 

My brother did some work on this at Heybrook - separating the power supplies....in a single amp....he noted issues such as those raised by Naim ......  he maintained it was something to do with complex interrelationships of fluctuating earth paths. A total separation ie full mono-blocks seemed to cure the issue....and maintain the benefit...but in Heybrooks context was not cost effective.