Hi

I've moved into my new house which was rewired and the sparky put in a dedicated circuit for my AV kit and filtered sockets for my hi fi.

The Nait 5i amp has an oscillating hum / buzz ... ie varying volume over about a 6 - 7 second period.

There are other power leads and aerial cables behind the equipment rack but it still happens when everything else is turned off.

So two questions:

1. should the amp hum ? (I've had it 3 years and not noticed it before)

2. Any idea how to cure it ?

many thanks

Roger

"Filtered" sockets sounds like it could be a bad idea. NAIM is always said said not to like filters and conditioners.Have you tried the amp on another socket? Maybe the mains in your new place is "dirtier" than the previous supply.
I moved my kit down the room and found I was picking up interference from one of the power supplies around the PC it had a similarity to the hum you describe.
Sometimes the items have to be removed from the sockets to stop their effect.

Howard

Roger,
If I were you, I would:
1) unplug all the other bits of kit, one by one (not just switch them off) (have you got a Lingo?)
2) If this fails, try disconnected all other cables from surrounding kit
Let us know how you get on.
If nothing changes when you have done the above I suggest that you have
1) something wrong with your amplifier
2) something wrong with your spur (i.e. no earth)
3) something nearby is radiating a ghastly amount of RF (are you splitting atoms or Xraying in the next room?)

Hope this may help
don

quote:

Originally posted by RogerRoger:
The Nait 5i amp has an oscillating hum / buzz ... ie varying volume over about a 6 - 7 second period.

From the speakers or the amplifier case?

quote:

NAIM is always said not to like conditioners.

Well how come they always have such well presented hair-styles at hi-fi shows then?

If it is mechanical hum then disconnect your amp and plug it in somewhere else with nothing else connected - if the hum is still there then it suggests your amp needs some attention.

Don's advice is a good approach.

Hope you fix it.

quote:

Originally posted by ROTF:

quote:

NAIM is always said not to like conditioners.

Well how come they always have such will presented hair-styles at hi-fi shows then?

Take two boxes into the shower?

Yes and (safety message) No.

Who needs conditioners when you are Head and Shoulders above the competition?

IF your Naim kit and AV kit are connected could be that it is a ground loop issue. I have had it before on my NAIT, and if all else fails you can get a ground loop isolator from an electronics store for very little money, and put it on the line between your AV kit and Nait. There are previous threads on this issue in this forum.

If that is not it, then good luck. Hope it works out!

John

Ask the nice man at the factory,He told me to unplug the water bed for a few hours in the evening.Hum now gone,also said the hum the rest of the day would not hurt the amp .If you havnt got a waterbed then get one,you might have a hum but you wont have backache.

I didn't know water beds could be considered as sources.

Its the dam chinese thermostat that does it.
The original one was fine.Hummmmm.

quote:

Originally posted by Alan Walker:
Ask the nice man at the factory,He told me to unplug the water bed for a few hours in the evening.

Crumbs - that one (again).

Also - I asked one caller "Have you added any new electrical products recently?".

"No - just the recharger for the golf trolley - sitting on the other side of the sitting room wall."

"Try switching that off."

"That got rid of the hum - what should I do?"

We know - don't we.


Unfortunately - you have changed everything in your house move.
I would monitor the hum and see if it stops at times during the day. If so - does this coincide with some device ('fridge, pump, water bed, aquarium, arc welder, etc.) coming into operation? If you can identify any such source - it may either be faulty or measures may be available to prevent noise from this entering the house system.

If the hum is coming from your speakers - I've just wasted some time.