NAP 250.DR shutting down alone

Is it a brand new amp, or a serviced older amp with the DR upgrade?

Brand new

If it's brand new, it's not comparable to previous situations. How loud were you running it? 

It sounds like it may be due to the way you have the Hugo and Naim hooked up to test between the two, though that is just a guess on my part since that is the only thing that has changed in your gear.

What I meant by new is that I sourced it directly from a Naim dealer as a brand new unit... It has been serving well for the past few month, no issues at all...

I listened to the system with the NAC 282 volume dial set to about 11 Oclock for a couple of tracks only. The rest of the listening session was at 9-10 oclocl volume...

I have listened to the same system at louder settings for longer and never had any issues...

Perhaps try disconnecting one of the two DACs and try again. It may be an earthing thing. If it didn't do it before the Hugo was connected, that looks the likely reason. Hugo - the amp destroyer. 

Strange, would an issue with earthing explain the over heating?

I don't know, it was just an idea. But it didn't do it before the Hugo was connected, did it?

Nope, always ran very well. Never over heated.

There you go then, it's the curse of the killer Hugo. 

I seem to recall Steve J noted that his amps ran hot when used with the Hugo.

Although it was a couple of years ago and my memory isn't that good.

The only way to eliminate the variables is to revert to the kńown state: disconnect Hugo and revert to a regular mains lead.

Test the above for 1 day.

Swap mains lead for a PowerLine. Test for 1 day.

Add Hugo.....

etc.etc.etc...

Good luck Thijazi!

Will try, hopefully wife doesn't divorce me in the process

I forgot to mention, my speakers specs show sensitivity of 90 db SPL (2.83V/1 m) with a nominal impedence of 4 ohm, power handling is rated at 30W-300W without clipping

I run my Hugo into my Naim amps and they remain totally cool... so think that is a complete red herring unless your Hugo is faulty.. My NDAC made my 250 warmer, probably because of the slightly larger than life bass.

if nothing has changed with speaker cable.. ( which of course should be 3.5 m + of NACA5 or better) then a possibility is parasitic oscillations. How are you grounding your inputs.. Have you got one and only one grounded.. I use my CDX2 signal ground set to chassis. All other inputs are set to float, and of course the Hugo can only float its ground.

Simon

To be honest, I never looked at that, I recall only seeing one grounding switch on the DAC-V1 (today it is set to Chassis), but not on the other components. Any useful guide out there on how best to set the grounding options? Do you think it has something to do with the overheating?

If for some reason the grounding not being set right and is causing some sort of HF oscillation then it could... As far as guidance, Naim NACs need one and only one earthed ground on the inputs. This has often been the CD player, but in modern setups you can't assume a CD player, so Naim sources have a little grounding switch set to chassis or float. You simply ensure you either have a Naim CD player or only one other Naim source is set to chassis. All other Naim sources should be set to float along with most non Naim sources which might not have any option but to float, such as the Hugo.

So if your V1 is set to chassis, and is connected to your NAC at the same time as your Hugo and the other inputs are floating, you are sorted.. As you meet the requirements... The overheating is probably down to something else..

Curious thought, how do you set the SuperCap, NAC 282 or NAP 250 to either floating or non floating? I can only see this option on the DAC.

You can't - it's just the sources, such as CD players, streamers and DACs. The 272 also has the switch, which must be because it's a source as well as a preamp. 

If you don't have an earthing issue, it's most odd that it didn't happen before you connected the Hugo. Have you checked all the connections on all the wires?

I have used Hugo for more than a year, and it has never resulted in any problem with my Naim amps.

the problem lies elsewhere I am afraid.

250's can run quite warm, and warmer weather makes a difference to a permanently powered 250. How is its ventilation?

Fraim is of course ideal.

John.

J.N. posted:

250's can run quite warm, and warmer weather makes a difference to a permanently powered 250. How is its ventilation?

Fraim is of course ideal.

John.

 

Just to see if I can replicate the OP's fault - I've been 'abusing' my system for a couple of hours now - my NDX runs warmer than NAP250DR.... power amp remains cool as a cucumber... 
I think the fault is somewhere else.

My olive 250 and my 250.2 both threw in the towel intermittently  No such issues with a 300 though 

I can't recall a single occasion when my 250.2 got even warm, let alone hot.  And I provoked it a few times with Sabbath, ACDC etc .  As described, this sounds like a fault somewhere in the system. 

I suspect that the connecting of two DACs and the overheating happening at the same time is coincidence. My 3 month old NAP 250DR never even runs warm, let alone hot, regardless of what I do. So I'm thinking that your 250DR may have acquired a fault.

But the obvious thing to try is disconnecting the Hugo so it is all like it was before and then play some music loud.

best

David