NAC 252 Service

Posted by: John Willmott on 19 May 2018

Besides the NAP 250DR all my Naim equipment has been pre-loved.

A couple of years ago I decided the NAC 282 I had needed a service but, prior to sending it off, realized I would be without music for a couple of months so purchased a pre-loved 2002 vintage NAC 252 to take over duties in the 282’s absence.

I had absolutely no intention of keeping the 252. I was totally satisfied with the 282 .. I just wanted to listen to and experience the 252 during the 282’s absence. If the 252 was OK then I would just move it on, if it was obviously in need of a service then I would pay for a service and then move it on.

How naïve can one be ?

Even being 14/15 years old the 252 was better (yes, better) than the 282 .. it had far more heft and majesty than the 282. More detail and more musical engagement than the 282 ..

When the 282 came back from service I listened to it exclusively for a month .. but to my ears it did not rise to the level of the 252. It did have zest and enthusiasm but lacked the breadth and depth of the 252 .. so, I moved it on and actually made some extra coin over what what I had laid out for it, plus its service.

Roll the tape forward to January of this year and I’m thinking the 252 is now 16 years old and it may be time to book it in for a service, even though I had not heard anything that led me to believe that the 252 was failing at all.. AV Options booked me in for the April intake .. May delivery ..

Between January and sending it off on vacation the music from the 252 gradually became flaccid, distinctly flaccid .. the bass became bloomy and boomy, notes were fuzzy .. if ever there was a case of perfect timing this was it.

As you may have gathered this thread really has to do with the change in the 252 since it’s been back .. I will forgo the usual hyperbole and just say that there is not an ounce/inch/unit of anything resembling flaccid in this box now.

I let the 252 warm up for 24 hours when it came back and the first track I played was: ZZ Top .. Gimme All Your Lovin’ .. Eliminator.

The opening bars of this track are a quick staccato drum roll and instead of hearing a “Boom Boom Boom” as I had before the service there was a “Whack whack whack” .. taut, crisp and succinct .. wonderful.

It has just gotten better since that first track … an absolutely amazing pre-amp. And, thanks Chris West at AV Options.

Posted on: 19 May 2018 by Adam Zielinski

Well done John - I do like my 252. Need to check if it’s due for servicing. Thanks for the tip!

Posted on: 19 May 2018 by cdboy

Excellent result. Well done.

Posted on: 19 May 2018 by Consciousmess

Isn’t it the Supercap which needs servicing not the 252?

Posted on: 20 May 2018 by Simon-in-Suffolk

Depending on age, servicing can apply to the PSU (SuperCap) and NAC itself. There is more to servicing than just checking and replacing the reservoir capacitors within the PSU.

To the OP, I agree the 252 is a cracking preamp, and is closer to the 552 than the 282 in terms of performance in my experience. (I have only compared DR versions)

Posted on: 20 May 2018 by ChrisSU

I’m surprised you didn’t buy an old 552 to tide you over while the 252 was being serviced. Then you mught have decided it sounded a bit flaccid after all ????

Posted on: 20 May 2018 by Foot tapper

Great to hear John.

As others have indicated, Naim changes more than the large electrolytic capacitors in power supplies when it services equipment. When the Service Dept. has serviced my pre-amps, CD players etc., it also changed dozens of small yellow tantalum capacitors, as well as the odd resistor that may have aged and/or drifted out of spec. While the pre-amps do seem to last longer than those components with a power supply, 15-16 years seems to be about the age when pre-amp performance drops off the edge of the cliff.

Enjoy your lovely new system!

Best regards, FT

Posted on: 20 May 2018 by stuart.ashen

My 252 is a similar vintage but was sounding great except that the volume pot had become noisy. Sent her back home for a new pot plus service and now she is good as new! Apart from new caps I was surprised to see a software update was also performed. And I was not charged for the new pot. Well done Naim!

Stu

Posted on: 20 May 2018 by Claus-Thoegersen

I sent my 252 head unit back for service just before christmas. Unfortunately I had no backup system other than my qb. I also sent off my ps 555 for service and dr, and my Snaxo since it would be cheaper even though it is a only 10 years old. This means I cannot say how much the 252 improved the setup, but all these upgrades have made a big difference, and now I can wait about 5 years until my last supercap needs a service and dr upgrade.

Posted on: 20 May 2018 by nigelb

John, I see you have a, let's say, unusual SuperCap. I used to have a PS like that on my NDS. Moving to a Naim 555 DR was a night and day change. If you like your 252 now, you are going to love it with a proper SuperCap (preferably DR).

Posted on: 20 May 2018 by John Willmott

@chrissu .. The purchase of the 252 initially was merely a "tide me over" purchase and I had every intention of moving it on .. If, as you suggest, I had bought a 552 I would have been under no illusions that I would have not moved it on .. that would have been too much temptation.

@consciousness .. @ foot tapper : the work order says "Rebuild service .. including replacement of all Tantalum & Electrolyte caps and output relays" ..

Whatever that means .. I know that the music is faster, crisper and more detailed.

Nigel: I suspect you are right and I have to admit I'm already thinking along the lines of if it sounds this good with a faux SuperCap what will it sound like with the real McCoy ? Another forum member adept at spending other people's money .. Tsk Tsk.

Posted on: 20 May 2018 by nigelb

Yes John, I have never had any problem in spending others' money. But I need to hang on a bit tighter to my own as I know this bug can stress out a weary bank manager if left unchecked. It's called upgraditis I believe and it is incurable.

I know. Why don't you buy a proper SuperCapDR to 'tide you over' (what I am not sure) and see how things pan out. crazy

Posted on: 20 May 2018 by Gordon Lau

I have just sent off my 252/SC for servicing at the Hong Kong dealer. Both units are circa 2009 but Pre-loved. As I am gonna keep them for awhile, thus thinking this is an investment warranted.

Apparently my SC has been DR-ed sometime ago and the technician at the dealer reckoned the work’s being done by him. Interestingly he reckoned my 252 would be the 1st one being recapped locally. Fingers crossed and can’t wait to get them back.

Posted on: 21 May 2018 by John Willmott

Gordon: Out of pure curiosity can you tell me what motivated you to have them serviced ? Their age or some other factors ?

Posted on: 21 May 2018 by sktn77a

stuart.ashen posted:
My 252 is a similar vintage but was sounding great except that the volume pot had become noisy. Sent her back home for a new pot plus service and now she is good as new! Apart from new caps I was surprised to see a software update was also performed. And I was not charged for the new pot. Well done Naim!
Stu

Stu: What "software update" was done on the 252?

Posted on: 21 May 2018 by Gordon Lau

John Willmott posted:
Gordon: Out of pure curiosity can you tell me what motivated you to have them serviced ? Their age or some other factors ?

Age is one and the other is due to the fact they were 2nd hand. Cosmestic wise they look perfect but then I want the peace of mind.

Posted on: 22 May 2018 by stuart.ashen

SKTN77A,

thought it might be interesting to see the worksheet that came back with my 252. Very happy with the results. The software update version is in the work summary.

Stu.

Posted on: 22 May 2018 by sktn77a

Interesting...... I wasn't aware of any upgradeable firmware/software on these preamps (?!)

Posted on: 22 May 2018 by stuart.ashen

I believe the switching and other processes are digital, so I guess there is an updated bit of code to improve the internal management. The digital section is only turned on if the remote is being used as far as I remember (to improve sound quality). Hopefully someone with more knowledge will correct me or add some detail.

Stu

Posted on: 23 May 2018 by Drewy

Is it just me or do they get through a lot of work in only two hours?