Voltage transformers

Jonathan,

See this thread here:

http://forums.naim-audio.com/eve/forums/a/tpc/f/58019385/m/7312969107/p/1

The consensus from many owners (I don't know how many of these had experience of such issues however) seemed to be to have the conversion done. However I'm in the US temporarily and decided to get a 110v to 240v transformer - rated at 1kW.

I'm an electrical engineer and was looking for some theoretical evidence as to why the transformer would adversely affect the sound quality, but none was forthcoming. My 1kW transformer is rated more highly than those in my XPS, HiCap and 180 so is unlikely to limit dynamic performance. I don't see what it can do wrong, as it's merely the penultimate transformer in a long line of transformers between power station and the DC supply in my boxes. This is my opinion however, and many disagree.

Maintaining an open mind, I enquired about having the mod done to Naim North America, who quoted $150 per box - which I'd have to have done twice (convert back before going home) on at least 3 boxes, which seemed a lot of money. I decided not to. Others have paid considerably less in the UK for the same job, so that's an option.

The decision is yours!

Good luck,

Phil

Thanks Phil. I agree that 3 (or in my case 4) boxes converted every year (I move around a lot) is (a) expensive, (b) a hassle and (c) cannot be good for the units in the long-run.
1kW sounds big for a hi-fi system. Would it be the case that the bigger, the better? Are some transfomers better quality (number of windings or whatever)? I would instinctively think that the inherent quality of home electricty (I am currently in Beijing) is such that the transfomer wuld be th e least of my worries in this regard.

At last, a pragmatic approach!

The PSU in my XPS is 500W, and I believe they're 'overspecified' in order to allow for rapid transients and peak signals etc. I presume the HiCap and 180 are not dissimilar, so I chose 1kW to 'overspecify' again. I don't think that the bigger the better is a good approach. Too small isn't enough, and too large is excessive and unnecessary. Off the top of my head, larger trannies probably need more windings, so do they look like a more inductive load etc etc.. Hmmm, can't think, it 2am and I've just finished a report. Will look into it and post back with a clearer head!

Mine's about 4-5 inches cubed, doesn't hum, and is in the next room so that it's no-where near the boxes (It's not toroidal so is likely to be more 'flux leaky' than is ideal).

I don't think converting the boxes is bad for them, I understand the transformers have a centre tap, so a 'simple' resolder of the mains connections to the transformer, a change of fuse, and a new lead is all that's required. However, it would amount to a fair bit of money at the rates I was quoted.

Have fun!

Phil