NAP 250.2 on USA power

Posted by: Trickfi on 29 August 2017

Hi all,

In the next few months I'm going to be making a move to the USA and am just starting to think about what I'm going to do with my gear.  I'm currently running NAC 272/NAP 250.2.  In my house in the UK I have them plugged into a circuit on a 16A circuit breaker (MCB), and when I do occasionally power them down it can take several attempts to get them powered back up again without tripping the breaker.  I understand at a high level, this is to do with the initial load the 250 draws.  Once powered up I never have any issues with it.  It has been my plan for a long time to switch out the breaker (and wiring of course) to support 32A load.

Since my move is for an unknown duration (likely to be at least a couple of years though) I will be going into a managed apartment block (renting).  I understand the circuits there are typically 15 or 20A at the most.  I am quite happy to get Naim to convert my gear to 110V but am worried when I get there I'll have worse issues than I have today with getting it powered up.

A part of me is wondering whether it's going to be time to downsize to something like a Uniti Atom and some stand mounters for the move.  Given how happy I am with my setup though, I really want to avoid this if possible.

Does anyone have any experience/advice on this?

Many thanks

Posted on: 29 August 2017 by Allante93

Once you get here, just check with Audio Plus!

North America Authorized Naim Repair Facility.

Nice bunch of Guys!

They quoted me a nice price!

So I would imagine, it's all good!

Allante93!

PS. I was bidding on an 2011 SC from the United Kingdom.

And was factoring total cost!

Posted on: 29 August 2017 by seakayaker

Depending where you are heading to in the states you may want to check if there are any Naim dealers in the area. If so, contact them to check out their used inventory. You may be able to put together a fairly inexpensive kit for your stay  her in the US. You could possibly ship your own speaker cable/interconnects/rack etc. The cost of the electrical conversion going back and forth vs the cost of buying used and selling/consigning with a dealer when you leave may be an opportunity to enjoy your music while your here at a reasonable expense. 

Just a thought.....

Posted on: 29 August 2017 by Blackmorec

Given that your amp has a 4A slow blow fuse, do you think its correct that your amp is tripping a 15A breaker. I'm not familiar with the power-on current draw of Naim amps but to me it sounds odd that its tripping a 15 amp MCB

Posted on: 29 August 2017 by Trickfi

Thanks for the replies.  I have considered buying when I arrive, the area definitely does have a couple of dealers.  However, given the reasonable cost of conversion (£140 a unit) and the fact I have to ship quite a bit of other stuff anyway, cost wise it seems to make sense to move what I have - assuming it will work.

Naim amps tripping MCBs is not unheard of on here or to my dealer (having looked at it when it first happened).  I have a type B MCB which I understand is fairly quick to trip versus a type C.  It works totally fine on my 32A ring.

I may get Naim service to check it over when it goes in, just to make sure.

Posted on: 29 August 2017 by joe9407

i'm in NYC and don't have a problem firing mine up -- and i haven't heard much chatter on here over the years regarding breaker-tripping-250.2s. so i'd say get 'em converted and safe travels!

Posted on: 30 August 2017 by ltaylor
Blackmorec posted:

Given that your amp has a 4A slow blow fuse, do you think its correct that your amp is tripping a 15A breaker. I'm not familiar with the power-on current draw of Naim amps but to me it sounds odd that its tripping a 15 amp MCB

The slow blow fuse can withstand a high current briefly. The problem here is the high current drawn by the transformer when the voltage is near the crossing point. This is what trips the breaker. This will explain it better than I can https://en.wikipedia.org/wiki/Inrush_current I used to have a 1000VA toroidal which would regularly trip a 32A breaker until I swapped it for a class C breaker.

Posted on: 31 August 2017 by Huge

LTaylor is right: The correct answer is to fit a type C MCB.

This has a slower break response to allow for device with large switch on surges (such as the inrush current of the huge toroidal transformer in a 250).  All this does is to slightly delay the switching response, the maximum constant current that can be drawn before tripping remains the same so it still protects the wiring fine.

Posted on: 31 August 2017 by HedgeBre

TrickFi - I also made the move to the US from the UK and Grahams HiFi in London (authorized dealer) did the power conversion for me, all works like a charm just like it did in the UK. Its simple for them or Naim to do it. I also had a Grahams hydra which i also bought to the US and just changed the plug on that. 

Posted on: 31 August 2017 by Allante93
HedgeBre posted:

TrickFi - I also made the move to the US from the UK and Grahams HiFi in London (authorized dealer) did the power conversion for me, all works like a charm just like it did in the UK. Its simple for them or Naim to do it. I also had a Grahams hydra which i also bought to the US and just changed the plug on that. 

Eric @ Audio Plus.

He quoted me on SC conversion, 230 to 115!

Nice bunch over there, that installed new optical laser lens on my Cdx2, smooth as silk.

I missed out on a UK  SCDR, they bided the price up to high!

3.6 K GBP.

Msrp = 4.315K GBP

But I don' think you would have any problems!

Audio Plus Naim's North America Authorized Repair Facility!

Allante93!

 

 

Posted on: 31 August 2017 by perizoqui
Trickfi posted:

A part of me is wondering whether it's going to be time to downsize to something like a Uniti Atom and some stand mounters for the move.  Given how happy I am with my setup though, I really want to avoid this if possible.

Does anyone have any experience/advice on this?

I'm in the US, as are many others on this forum, and no issues whatsoever. My 300 works very well, as does my 90A circuit to charge my Tesla. No need to downsize your stereo. Electricity works quite well here, having invented it's use and all

Your dealer in the UK can take care of the 5 minute solder job involved in converting the two transformer windings from serial (UK) to parallel (US). Or you can do it here, but unless you're coming to Chicago, I'd get it taken care of there. They charge an arm and a  leg to do it here.

Welcome to America!

Posted on: 31 August 2017 by Adam Meredith
perizoqui posted:
Your dealer in the UK can take care of the 5 minute solder job involved in converting the two transformer windings from serial (UK) to parallel (US). Or you can do it here, but unless you're coming to Chicago, I'd get it taken care of there. They charge an arm and a  leg to do it here.

Probably (100%) a good idea to change the mains cable and fuse - and replace the voltage sticker. Also nice to be in the same country as the person who altered it - just in case.

Posted on: 31 August 2017 by perizoqui
Adam Meredith posted:
perizoqui posted:
Your dealer in the UK can take care of the 5 minute solder job involved in converting the two transformer windings from serial (UK) to parallel (US). Or you can do it here, but unless you're coming to Chicago, I'd get it taken care of there. They charge an arm and a  leg to do it here.

Probably (100%) a good idea to change the mains cable and fuse - and replace the voltage sticker. Also nice to be in the same country as the person who altered it - just in case.

Of course! Thank you. But the mains cable is a standard plug so you can pick one of for $5 at any Best Buy. The fuse needs changing, and Naim recommends using LittleFuse, that's on another thread on this forum. You can buy those for $1 on Digi-Key. 

Posted on: 31 August 2017 by Richard Dane

And don't forget the new voltage label - otherwise things could get confused and rather expensive further down the line...

Always best to get something like this down properly - Naim's service dept. have witnessed some (literally) shocking voltage re-wires on stuff bought secondhand and sent in for service.