Harbeth Speakers burned out and we can´t find the reason

The Chameleon posted:

Dear readers,

Two weeks ago I came back from a business trip and I switched on as usual my NAIM equipment (NAC 82, NAP 250, Non-Naim PSU,  Naim CD 3.5, Phonosophie Turntable, Harbeth SHL5). Than I went to see a friend for 1 hour. After I came back to my house there was a strange smell like almonds and it seemed that it came from my stereo. Instead of switching everything off, I put on a CD and than it happened. A loud noise came through the Speakers and....... yes.....the tweeter in both speakers are in heaven as well as the dividing network.

I have sent the NAP and the NAC to the German Naim Distributor but they cannot find any defect. A recapping has been made two years ago. So now we still not know the reason what happened.

Is there anybody out there who could help with ideas or who had the same problem?

Thanks in advance and peace and love to you all!

Joerg

 

Joerg,

I don't have NAIM amplification , but I had a similar problem shortly after upgrading to a Lindemann 830s pre/858 power amp. 

I was listening to music on my system at a fairly moderate listening error, but distracted by something else that I was doing in the background.  I became aware of the volume of the system being turned down as if by using the remote control. When I checked the pre-amp, the volume control had indeed been set to zero. I thought this was a little strange but didn't worry about it too much. I simply returned the volume control to its to its previous level and returned to what I was doing.  

An hour or so later, I popped out to the local shops briefly (for about 20 minutes) leaving my system playing at a fairly muted level. When I returned home, there was a horrendous rumbling noise coming from my speakers, and I noticed that the volume control of my pre-amp was at its maximum position. I turned the volume down immediately, but initially it appeared that both of the ribbon tweeters in my Magneplanar 3.6Rs had blown. Luckily for me, the 3.6Rs  have an effective protection circuit built in, and when I replaced the protection fuses, the speakers were absolutely fine.

My Hi-fi dealer sent the pre-amp back to Germany to be checked out by Lindemann, who had never heard of a problem of this sort before. They were not able to find a cause for the problem, but they replaced all of the control boards (free of charge) as a precaution.  I have had no problems since the pre-amp was returned to me.

We exhausted all possible alternative reasons for the problem, such as an external signal triggering the remote control module in the pre-amp. However, nothing we came up with seemed plausible. My system is positioned in such a way that there would be no direct route to the infra-red remote sensor on the Lindemann pre-amp.

So, perhaps there was an external signal that triggered the remote, or possibly there was a problem with the control boards on the amplifier.  I simply do not know.

Do you have a remote control for your pre-amp? Could an external signal somehow have triggered the pre-amp's volume control?

Having had a similar problem, I certainly feel for you.