Over heating NAP250DR

It's less about lack of power and more about thermal dissipation.  The NAP250 uses the case as a heatsink.  When it works hard in warm weather it can begin to get hot - once it reaches 70 degrees the thermal trip is activated and this protects the amp.  How much circulating air do you have around the amp?  close confines within a rack can be a problem.  Cooling the case with circulating air from a fan can help.

Pushing way too hard. Heat can't dissipate fast enough. Either turn it down. Get a 300 or put a cold airflow across the unit when at high volume. Ie a fan. Shouldn't be able to hear it.....

Sorry Richard couldn't see your post when I answered. 

No problem TB, glad to read we concur...

Thanks - had similar advice from the NAIM Facebook page.

What speaker cable?

Monkadil's profile says NACA5.

ah ok, then its not an unsuitable cable making the amp go unstable

60-70%? Those S-400's are pretty loud at that setting.  How big is your room and are you deaf?

https://forums.naimaudio.com/to...582#1566878606409582

jon honeyball posted:

ah ok, then its not an unsuitable cable making the amp go unstable

We don't know the length though...

60-70 on a 272/250DR/S400 combo in even a large domestic sized room will be producing sound pressure levels that are damaging to the hearing in a relatively short time.

Hear we go again =   .........  seriously folks,  'too' loud & such descriptions of loudness are all a bit pointless.  We've all got tablets or smartphones & they have all got SPL app's in their app stores.  They don't claim to be that accurate,  but the numbers they give are a darn sight more meaningful that a Naim volume display number or a 'too' loud description.

So how many dB's does the SPL meter show from the S400's with the 272 volume on 60 or 70

I get 75-85dB C weighting, slow at a setting of about 35 with 272/300DR/Spendor SP2s.

That's using a calibrated microphone (a minDSP UMIK-1) 2.4m from the speakers.

One of the things that impressed me the most on Naim equipment besides the sound quality, was the ability of having a big level of sound ( beyond of good sense and what I think reasonable ) with low power output ( 65 to 80 W ) and almost no heat from amp´s ( used 150x, 250, and 135 ), I live in a warm country, special at this time of the year, my krell 300il heat´s so much that can be used in a barbecue, but Naim, runs smothly without any problems.

So I suppose that DR on a 250 besides improvement on sound brings it also improves the runing temperature of the amp.

NOTE:  Tested recently an Naim NS01 and also the temperature reached by this equipment was higher than the one that I have on my 250 and 135.

My front room is  4.58m (15') Max X 4.12m (13'6') - I wasn't in the room when it was playing that loud, I would have gone deaf as suggested. Ive moved the 250DR on the top so its open to the air. Ill monitor the heat levels but I doubt ill be running it for such a prolonged period at those levels again.

I'd be inclined to put it back where it was, to keep it away from the 272, keep the volume down and get a mu-so or Qb if you want to hear the music in another room. We used to multi room by opening the doors (as JV once joked) but now have a Qb in the kitchen and it's great. 

Monkadill posted:

My front room is  4.58m (15') Max X 4.12m (13'6') - I wasn't in the room when it was playing that loud, I would have gone deaf as suggested. Ive moved the 250DR on the top so its open to the air. Ill monitor the heat levels but I doubt ill be running it for such a prolonged period at those levels again.

  multi room by opening the doors (as per JV's jape); that would do it.

Was he joking?

My experience with Nap 250DR : It's already plenty loud at 9 o clock

10 o clock is very loud. 

I've had mine at 11 o clock, and that was for my teenager's birthday party.

It was loud enough for the whole garden, pounding out dance music for 6 hours straight.

I've never managed to shut down a Naim amp as I know it will take care of itself, but my beloved speakers could get damaged not to mention the real issue of going deaf.

I would second the advice of HH, a QB or MUSO in a second room is a bargain to get that Naim sound.  You get a DAC, a few amplifiers, streaming and that Naim sound in one box, a much overlooked triumph in engineering, at the price point.

Richard Dane posted:

It's less about lack of power and more about thermal dissipation.  The NAP250 uses the case as a heatsink.  When it works hard in warm weather it can begin to get hot - once it reaches 70 degrees the thermal trip is activated and this protects the amp.  How much circulating air do you have around the amp?  close confines within a rack can be a problem.  Cooling the case with circulating air from a fan can help.

I guess it's only so many topics one can discuss, and trust me, During Mr. Richard Danes Tenure, he's heard  them all, tenfold!

But never the less, when your Naim's iconic 250, shuts down, its darn right frustrating!

Can't recall the thread this exact moment, but I've probably got it archived.

But winging it:

Naim's Achillis Heel, is it's Lack of Power!

Naim's answer is an upgrade path with increasing power.

Nap 200 ~ 70 watts

Nap 250 ~ 80 watts

Nap 500 ~ 140 watts

And trust me, if you Search, you will find cases where Naim's Top Amp (500), has been known to shut down, under idea conditions. 

If one likes the Naim Sound, there are trade offs!

Now here's the deal, if you need or want a little more. The Nap 300DR is the one, and Naim kicks in a fan to circulate and keep the temperature in check!

There are some that rate the 300, over the 500.

Of course, I can't Speak on that. 

But some  members replying on this very thread, have suggested that!

Otherwise, if you like to listen to your music from afar, and crank it up for periods exceeding an hour, partying, or intense listening secessions.

I'm afraid, you will have to join the Active Club!

MONKADILL, Enjoy Your Music!

JMHO!

Allante93!

Allante -  Naims achille heel is lack of power?

Naim sell amplifiers for domestic use - these are not PA rigs.

Just like Porsche 911 is not a SUV. 

I don't want an huge and heavy amplifier whose weight is over 100KG, will permanently heat my home, cause my electric bill to increase 400 % and then barely able to sound musical and rhythmic.

I love my 250 very much thank you. 

analogmusic posted:

Allante -  Naims achille heel is lack of power?

Naim sell amplifiers for domestic use - these are not PA rigs.

Just like Porsche 911 is not a SUV. 

I don't want an huge and heavy amplifier whose weight is over 100KG, will permanently heat my home, cause my electric bill to increase 400 % and then barely able to sound musical and rhythmic.

I love my 250 very much thank you. 

""Naim is sub standard - allegedly.

feeling Zen  Nov  4 2015

Naim amps can swing transients in a way other similarly powered amps just cannot do. But that isn't the same as a 30wpc amp being equivalent to a 60wpc amp. The fact that a Naim amp can swing those big transients sometimes better than a more powerful amp leads them to falsely believe that their constant output is higher than stated - but it isn't. That misconception might explain some negative opinions. A lot of dealers incorrectly deliver sales pitches like "30wpc of Naim is like 75wpc of Arcam" which is nonsense. Maybe a Nait can deliver a big/ger bang like the 75wpc amp but sustained output is a different story. Musically it is also a less relevant story unless your recording has very poor dynamic range. 

The fact is, if you are driving a consistently hard load due to volume and/or speaker load, more power will be required and there is no getting away from that. Naim cater for that with increasingly more powerful amps and the ability to go active (or bi/tri amp simply for power reasons). It costs a lot more to do this with Naim than some others but I don't see a problem in that. They are not about functionality and convenience but about delivering the best you can get and if the design decision leads to more power requiring considerably more expense to do properly then so be it.""

Personally, I think Naim make some fine Amps, and in most cases, as the Forum has suggest, including yourself, it does a fine job! 

But for those, that want more, There's always the Active Club! My Next upgrade! 

But when its all said and done, I could live with what I have! 

The only problem, I've been Active!  

Something one must experience, otherwise, they won't get it! 

Don't Take my word, Ask the Active Club! 

Allante93!

JMHO! 

PS.  I'm with YOU Analog:

I love all three of my 250.2s

I know, the 250 Dr is miles ahead of one 250.2!

Cdx2>282> HCDR > (3 x 250.2) > Fraimlite > Briks 

RICHARD DANEADMINISTRATOR
6/20/143:17 AM
Mike,
 
it's the thermal trip operating on your NAP250.  It shuts down when the temperature of the casing exceeds 70 degrees C.  
 
A few things can cause this: unsuitable cabling or cabling; connection or cable fault; "difficult" speakers with complex crossovers driven at high level; high ambient temperature with not enough air movement for the heatsink (casework) to expel heat.
 
In the old days with the original NAP250 driving tricky loads like Isobariks at high levels, some owners directed fans at the amps during the summer to keep them cool.  The NAP135 brought its own fan cooling, which is also found in the current NAP300. 
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Administrator
  
June 20, 2014 11:09 AM
Bert,
 
like 99.6% of power amps out there, the NAP200 isn't a regulated power amp and so when the going gets tough it just lets things slide a bit. A NAP250 isn't allowed to do that, so it has to work much harder (and gets hotter as a consequence). Remember too that there's much more inside a NAP250 - twice the transistor count for one thing.  For all that, unsuitable cabling will get a NAP200 hot.

Allante93!

PS. I'm with YOU, Analog

and Naim, and Mr. Richard Dane! 

That's All! 

Enjoy your Music Monkadill, and Analog!