Nait XS-2 damping factor

OK! thanks Richard!

Electricity in Japan is a bit of a challenge.  My old company supplied two different specs for 3-phase & three for single phase.  

For consumer electrics,  single phase is 100 volts,  also another area has 200v but that is easily adapted/converted to 100v.   The problem is the mix of 50Hz & 60Hz over different regions;  eastern Japan (from Yokohama, Tokyo up to Hokkaido) is 50Hz,  & west (Nagoya, Osaka, down to Kyushu) is 60 Hertz.    

Thank you MIKE-B, I am living in OSAKA, so it's 60Hz as same as USA. 

Richard! I have last question!

I intend to purchase the 115V for USA model !

Does it work well in Japan (100V/60Hz)???

Best Regards,

Kazu

Kazu, I'm not the one to ask here as I've never tried a 115v unit on 100V mains.  There are some members here who have successfully (I think) used 115V Naim kit in Japan, so hopefully they can comment or try the forum search facility.

I don't think there are many people who buy amplifiers by looking at the damping factor. Personally, I would just get a high-quality but high-current Japanese amp from the likes of Luxman, Accuphase etc. to drive the PMC instead of looking at the damping factor. However, if you would like to follow PMC's recommendation of the Nait XS since it is a "reference amplifier" for the PMC DB1s, then a US model is the one to get.

RYDER, My Speakers are the DB1s BY ProAc!

not by PMC

Damping factor is not a popular subject here, possibly because compared to some amplifier designs Naim amps tend to have relatively low DF, or so I am led to believe, and some members are quick to criticise talk of DF. However a high DF has almost universally over the years been cited as beneficial for controlling bass - keeping it 'tight' - paricularly in speakers with low physical damping of cone movement. Whether that applies to the ProAcs I have no idea - Tobyjug's post suggests not, but if in doubt it could be taken up with the manufacturer - meanwhile the experience of Naim amp owners who have used the same speakers would undoubtedly help the OP consider what may be suitable. 

DF is often quoted at 40 or 50 Hz, being an area of bass down to which a majority of reasonably decent speakers will go, into 8Ω or sometimes 4Ω (latter will be half the value of former)  - as indicated by Huge it is important to be sure you are comparing like with like, in particular ignoring anything quoted only at high frequencies. Speaker cable resistance can be significant if high DF is desired.

Transformers in Europe must be made to an EU standard which allows +/- 10% either side of nominal so the transformers can tolerate variables well.  Assuming the USA spec transformer is made to the same standard, & as the Naim spec is 100-120V 60Hz,  it should be OK. 

I would certainly never criticise talk of damping factor, but in forty years of Hifi ownership I've never even thought about it. I just listen to the systems and see if it sounds ok. It certainly seems a very odd way to choose an amplifier but hey, why not?

Hungryhalibut posted:

I would certainly never criticise talk of damping factor, but in forty years of Hifi ownership I've never even thought about it. I just listen to the systems and see if it sounds ok. It certainly seems a very odd way to choose an amplifier but hey, why not?

Listening is certainly the best way to decide on any hifi gear (though HH and I have both bought without doing that!).

The difficulty is when someone lives somewhere where listening before buying is not an option, and instead has to base decisions on research, including specifications and reviews, latter whether by professional reviewer or user forums. Best anyone in that position can do is read and ask widely before deciding. (And if study or a trusted source suggests damping factor is significant, then it is relevant to explore.)

Mike-B posted:

Transformers in Europe must be made to an EU standard which allows +/- 10% either side of nominal so the transformers can tolerate variables well.  Assuming the USA spec transformer is made to the same standard, & as the Naim spec is 100-120V 60Hz,  it should be OK. 

This may not be a safe assumption, as the tolerance of transformers is to cope with a variations in mains supply voltage, which themselves have a tolerance. The Japanese nominally 100V supply has a tolerance of either ±10% or ±15%, depending possibly on supplier, so conceivably could go as low as 85V, though that should be worst case not normally, and likely only at times of extreme demand. If better guidance than Richard has been able to give re acceptability and possible effect on performance, isn't this a question best put to Naim technical support?

One option not discussed might be a 100 to 115V or a 100 to 240V step-up transformer in the mains supply, which should be readily available commercially ad a self-contained device that the amp would plug into, not requiring any modification of the amp - though whether or what effect they might have on sound quality I have no idea. 

[@mention:34793668795216885]: I think I'm one of the Naim users in Japan they may be referring to. I have a full rack of Naim kit and it is all 115v. I actually bought this in the UK and have the 115v gear serviced in the UK still but recent customs and tax charges back and forth are making me think more carefully about next time.

A Naim deal can order you a unit form Naim that meets your requirements within reason. So A US dealer can order a 240v unit and a UK dealer can order a 115v unit if required. Before purchase my dealer and I contacted Naim about Japan 100v and variable frequency voltage. The response was that Naim transformers are tolerant within +/- 10% of the stated voltage. Most new homes in Japan actually output 103.9v which is within the range for a 115v unit. I've had 5 Naim boxes powered on for 2 years with no issues.

What you MUST be careful of is earthing. As you know, a mains socket with a earth pin that you can also confirm is truly earthed is not very common here. Naim rely on the earth very heavily and performance will greatly suffer unless you can provde this. So please check your earthing arrangement and get a multimeter out and measure your AC current.

Interestingly, I had an ex Naim dealer in Japan appraise a 282 today. Sadly the market for second hand Naim in Japan is not much. A recent 282 goes for next to nothing it seems. I was advised to keep it.

Innocent Bystander posted:

This may not be a safe assumption, as the tolerance of transformers is to cope with a variations in mains supply voltage, which themselves have a tolerance.

It was the same assumption my cmpy used for many years spec'ing & adapting EU & US transformers, motors & control equipment to work on Japanese (all countries) voltages. 

Also worth noting that Naim's website still lists products as available in 100v. I also raised this with Naim via my dealer way back in 2013 when I asked for 100v models. When I was told there were no 100v models anymore I pointed to this as an error in the website.

The response I got was that these are the supported voltages, not a list of transformers available and the website is correct. All listed voltages are supported via the 2 different transformer voltages Naim produce.

Just be extra careful. Naim honor the warranty for exports to Japan but you won't be able to get the stuff serviced here. Except for Muso etc. Naim pulled out of Japan in 2008 and the ex dealer I spoke to sees no chance for that to change in the current market.

If you are a fan of British hifi, Linn has a firm dealer base here and service department. Chord is readily available too. Personally, I prefer to accept inconvenience and use Naim. I did have to wait several years till we bought a new flat with stable AC voltage and earth though.

Thank you so much for your advice, feeling_zen!

I am very pleased that I could communicate with a kind Japanese at this forum. Moreover, I would like to contact to you in Japanese. Because I want to know about the naim dealer in UK whom you purchased your 115V naim units from...etc. Could you communicate with each other by e-mail or at other forums, please?

Best Regards,

Kazuhito

Kazu, forum policy here is that all communication between members is open to all and must be conducted in English.  Posting e-mail addresses is strongly discouraged as the forum is publicly viewable.  You can post on another members wall, but also note that this is viewable by all as well.  There are no secrets here, ironically this is the best way to keep members as safe as possible.

Please take a moment to read through the forum rules, thanks.

Sorry RICHARD!

I don't know if Richard would email one member's email address to the other on request if they bith agree, given the clear purpose of enabling the correspondence in this case?

[@mention:1566878603942595] I can take this offline with the OP. But my advice is still going to be, no unauthorised mods; only authorised dealers; and ask Naim if in doubt.

My recommendation is to keep it on the thread.

Understood Richard, but we can't discuss which dealers we use on the forum despite that hardly being classified information.

FZ, you can post who your dealer is. If you prefer, use the wall post function - just be aware it is subject to forum rules and visible to moderators.

In the interest of transparency all I've relayed to the OP is the following - the only idfference was the language which I cannot be bothered to translate verbatim but this is close enough.

Any dealer can order any type of voltage unit. Whether they agree to or not is another matter. I have a special relationship with my dealer from time I spent working there in the 90s so it was no issue to supply me 115v units. If you are interested you can contact them and ask. I used Overture in the UK. I cannot guarantee that they will agree to do this for any other customer. But there are other dealers.

You can also just order a 115v unit from the US as a non special but international order.

Just be wary that in Japan, since there is no dealer network there is no way to get things serviced here. Naim use very good sounding capacitors but require recapping at 8-10 years by an authorised dealer. Plus there is the issue that if you find the Naim sound is not to your liking, because Naim is not popular here, the resale value is near junk.

Other than contact details for the dealer, I don't beleive I've left anything out.

Regarding DF... I agree with Huge, the DF is only meaningful when the amp is in circuit with a speaker load, and the DF is a measure that describes the control the amp/speaker circuit to control uusually mechanical resonance of the loudspeaker. Therefore the effect of DF is only meaningful for a given speaker design and in the limit a speaker in a given room with given speaker cable.... a lot variables.

I would have thought a more useful measure of an amplifier is its source impedance... better more consistent performance from an amplifier would be given with a lower source impedance.   However DF could be used IMO for comparative measurements of amp / speaker matching for a given set of speakers and amps.

Absolutely Simon. I've found that my lightly damped amplifier matches my highly damped speakers.

Hopefully OP will find the same with the ProAcs.

C.