Hi All,
I recently was able to purchase a 2nd hand NAP 250, Serial numbers separate the one I already have by a year. However the version I purchased is a 230v machine and mine is a 240v.
I'll assume running a 230v poweramp on a 240v supply may change the volume? and that the specs of the transformer are different so the SQ is a different flavour?
My setup is a bit of a mish-mash, and granted if I had the money for the new stuff it would allow me to do it in the correct order. However, I heard an 82/SuperCap and 2x 250's about 20 years ago in a HiFi store in Auckland and I've had my heart set on that ever since! - so I upgrade when I can, and when the price is right, not a lot of 2nd hand naim in Aussie. Currently using a NAC 102 and Active Credos, source is a ND5 XS.
To complicate matters, I have a naxo, rather than a snaxo. The naxo uses 1 poweramp for Left channel (left for HF, Right for LF) and 1 amp for the right. so I assume with the NAP 250s being different internals that running it this way will be quite unbalanced. So I'm looking for advice on how to even up the different amps. I can think of two options.
a) Swap a couple of wires around in the naxo so one amp does LF (Left and Right) and the other does the HF (for Left and Right) - then use the trim pots inside to even it up to compensate for any volume differences at my preferred listening level. This is kind of hard to test since I'd have to have a listen, pull apart the system do some soldering, and then give it another a listen. If so which one should be HF the 230v ?
b) Leave the naxo as standard and just use the balance on the NAC102 to compensate.
Regards
Weta
Posted on: 18 October 2018 by Richard Dane
Weta, swapping the internal wiring in the NAXO for horizontal configuration falls outside of the forum's AUP. However, Chris Murphy may well oblige if you ask.
As for the NAP250s, you need to be a bit careful here. Best to have them as close as possible, so try to avoid where big changes happened. What years are we talking about here?
Posted on: 20 October 2018 by Weta
Oh ok sorry about that Richard.
I thought the 250s were a year apart, but that was for the Hicap, these are a few years apart!
Both were recaped 4 years ago and both by an authorised Naim service tech. How different are they between these years?
NAP250 = s/n 55840 = 1989
NAP 250 = s/n 168385 = 2000
Posted on: 21 October 2018 by SB
I could be wrong but this may just be a labelling situation. UK mains voltage was "harmonized" from 240V to the EU standard 230V a few years back. In reality nothing changed apart from the specification. The spec has a voltage tolerance and the UK nominal 240V is within the EU tolerance. Naim would have updated their spec to align with the 240-230V move.
That said there is a very big difference in age so the design could have also been changed in that time.
Posted on: 21 October 2018 by Simon-in-Suffolk
I agree, the mains voltage in the UK (single phase) is nominally 240 volts -6% +6% and was declared when harmonised with the EU as 230 volts -6% +10%... although nothing changed in terms of all our mains voltages suddenly being reduced, with EU harmonisation a greater mains variation is now permissible in the UK.. which I am not sure is a totally good thing.
Posted on: 21 October 2018 by Mike-B
You are right SB, the EU "harmonised" all voltages in 2003, this then allowed every country to show there nominal voltage as 230v ..... when in reality nothing was actually changed.
In UK - formally 240v - its now 230v +10% - 6% (from 216.2v to 253v),
In Europe - formerly 220v - its now 230v -10% +6% (from 207v to 243.8v)
Throughout EU/UK the frequency is 50Hz ± 1% (49Hz - 51Hz)
w.r.t. Naim, it means the transformers must be spec'd to work within those tolerances. i.e. 207 to 253 volts
Posted on: 21 October 2018 by Alley Cat
Biggest difference here is that the earlier one uses the Holden&Fisher transformer whereas the later one has the Nuvotem.
When did this change come into effect Richard?
I have two olive 250's, one from 1992/1993, the other from 1997/1998 when I went active.
I also got a chrome bumper NAXO as I preferred it to the olive offering available at the time.
Assuming my SBLs are still ok when I get them from storage I have been wondering about getting a SNAXO 2-4 while they're still available to allow differing amps if needed for HF/LF.
Posted on: 21 October 2018 by Willy
For a couple of years, first with IBLs and then with SL2s, I ran an olive and a chrome 250 on an olive snaxo 2-4, one on the right channel and one on the left. Nobody ever complained. I did investigate the internal rewiring of the snaxo to use one amp on the tweeters and one on the bass/mid however feedback from Naim was that this had a negative effect due to the earthing.
I suspect that, in my setup, the right speaker being nearer to the corner of the room and having a window on it's "inside" made more of a difference than any difference between the amps.
Regards,
Willy.
Posted on: 21 October 2018 by Weta
Hi Willy,
That's good to hear. Once I get another 4pin din to XLR cable, I think I'll leave everything as stock and live with each amp on each speaker for a while in that case.
I cant wait to swap out the 2 NAP90s for two NAP250s !
Posted on: 25 October 2018 by Weta
Thanks for all the advice.
I've swapped around the 250s from one speaker to the other as suggested and yes there is a difference in volume and in presentation (I think its easy for a subtle increase in volume to perceived as better SQ - but I think both factors are at play here). There is a non-naim 4pin to xlr cable on one of the NAP250s so I attempted to isolate that from the mix by swapping that around as well! however I chose to do this while also testing out a Whisky I got for my bday. Its fair to say that at this point mistakes were made, things got away from me, albums got rediscovered. The result is the Laphroaig makes a great present, and I'll need to repeat all of my testing in more "controlled" environment :-(
I've ordered two new cables so that should solve one of the variables.
