I recently picked up a Naim HDX player for my living room and have been impressed with it - the only issue was that I noticed that the dynamics seemed a little flat when compared to my REGA ISIS VALVE and even the Raysonic CD228. Obviously the conveniences of being able to play hundreds of ripped WAV files from the internal drive and 24 bit FLAC files from a networked drive (via my iPad as a controller) was incredible, but the sound quality still just didn't cut it for me.
I went online and checked the NAIM power sections and landed on the XPS and 555PS units. Then found a guy on ebay who runs his own site http://www.custom-hifi-cables.co.uk/contact-us - his name is SEAN and he lives in LEEDS.
Anyway I gave him a call and he mentioned his CHC-XPS and we discussed upgrading the unit even further with Mundorf capacitors at extra cost. It took him a few weeks but during the time he educated me on the internals a little.
The total cost was just under £1,500 - much less than the cash that NAIM are asking for their power units.
The XP5 XS - Naim's stripped down version of the XPS
The original (olive) XPS, and the 555PS (top end PSU) can be seen on this page (2nd and 3rd from bottom of page):
This is the current version of the XPS - bigger transformer, but that's about it compared to the old (olive) XPS:
Naim tend to use 10,000uF caps made by BHC - a very good make for sure, maybe just as good as the Nichicions that Sean uses, but the Mundorfs are still the best. Note that Sean uses two 10,000uF capacitors per rail (6 rails in the PSU means 12 caps in total needed), whilst Naim only use a single 10,000uF cap per rail. Sean also uses a choke filter between the caps, this removes any high frequency noise from the rectifier diodes switching on and off - the result is cleaner power into the regulators.
In real world terms, I have noticed a huge increase in dynamics, and the bass is even tighter and more focused (The Trilogy 933 and Fostex TH900 pairing is just incredible anyway).
I have attached an image of the insides of this custom power section and a little shot of my 'night time' music section in my spare room - great to lie on bed and listen to this!
Edited by zardon - 9/25/13 at 6:39am