NAP-250 causes rush/rattle noise - what to do?

Posted by: Chrisk7 on 31 August 2002

Hi there,

hope anybody might have an idea how to solve my problem (before I have to contact my dealer).

My equipment (CD2/NAC72/HiCap/NAP250) makes noises which become most apparent at the peak levels of the music (but they are also there at lower levels but then not as obvious though).

When I listen to a solo instrument (e.g. piano) it bothers me mostly. There is no dissortion in the sound but a kind of rush together with a little rattle as soon as there comes a signal from the source.

I have tried different sources, a new speaker pair but at the end it appears that the cause of the rattle noises is to be the NAP-250 or alternatively, the NAC-72/HiCap. I have bought the power amp just recently, but I was not aware of the problem until now when I moved into a new house (where I am able to turn the preamp more up).

So, has anybody had similar problems? Might it be the capacitors in the NAP-250, or something else? Needs it to be serviced?
I know best is to have it checked/repaired by the dealer, but maybe there is somebody who can give advice.

THANKS

Chris

Posted on: 31 August 2002 by Bob Shedlock

It seems as if something is in need of servicing. But, since you just changed households, I check or recheck all the installation basics first.
There's lots of possible causes. It could be the the 250, could be the preamp with a pre-existing condition that you are now just able to hear with the greater volume applied. Fine tooth your set up, connections, stands, etc. It's free and may solve your problem.
I have a chrome bumper hi which was giving me fits until I discovered the small pins inside the din plugs were sliding back into the case when a cable was hooked up, making for a very poor connection. Once I straightend that out, sings like a bird. Point is, could be something subtle. Good luc

Posted on: 09 September 2002 by Henry Cosker

Chris

I had identical symptoms and cure as Mark, and I also initially blamed the tweeter. Sounds like a recap is due.

Kind regards
Henry

Posted on: 12 September 2002 by greeny

Sounds stupid I know, but are you sure the sound is comming from the HiFi. It could be inducing some vibration in a window/ornament/TV/furniture etc, this can sometimes not be as obvious as it would appear.

You say you are in a new house, so it could be environment related.

The above is correct though when a recap is required this can manifest as a distortion (not volume dependent) in the tweeters.

Posted on: 12 September 2002 by Martin Payne

quote:
Originally posted by greeny:
Sounds stupid I know, but are you sure the sound is comming from the HiFi. It could be inducing some vibration in a window/ornament/TV/furniture etc, this can sometimes not be as obvious as it would appear.

This is good advice.

I have had a rattle coming from a metal gas fire near the speakers. Though I had a serious problem for a while!

cheers, Martin