PDA

View Full Version : Speaker Hum/Buzz



Ned Ludd
2007-05-13, 15:51
I am wondering whether someone can help with the following problem.

I have been using a Naim Nait 5 with a CD player, but recently substituted a Squeezebox for the CD player. The problem is I get a constant hum/buzz through the speakers which I never had with the CD player. Any suggestions for resolving the issue would be much appreciated. I should add that I am technically challenged, so keeping the advice as simple as possible would be helpful.

Here is additional detail (whether it is relevant I have no idea) and I would be happy to supply more if it would help:

* when I told the company about the problem, Squeezebox sent me a different power supply for the Squeezebox, but it made no difference. It is a Group West, Model AUT-05-1600; Input: 100v-240v, 50-60Hz/0.3A; Output: 5v-1600mA

* The Nait and Squeezebox are plugged into the same electrical wall outlet -- it is the same outlet I used for the Nait/CD player combination

* I am using the same connection cord that I used with the CD player which was supplied by the dealer when I bought the Nait; it connects to the Squeezebox with RCA jacks

* I tried moving the Nait and Squeezebox away from other electronic equipment and using a different electrical wall outlet -- no luck

* The hum/buzz stays at a constant level -- it makes no difference if I adjust volume levels or move equipment around

* The hum/buzz comes out of both speakers at the same volume

* I am using a pair of Boston Acoustics VR950s (they are probably about 10 years old; I don't think they make that model anymore)

* Nothing but the Squeezebox and speakers are hooked up to the Nait

* I tried plugging the cord into the CD and Tuner input in the back of the Nait -- it made no difference

* the Nait inputs are the "DIN" type

* the Nait uses a three pronged grounded power cord

* the equipment is used in the United States

Mitch G
2007-05-15, 11:53
My first thought is that it's a ground loop.
An easy way to test this theory is to get a cheater plug (i.e. a plug that takes a 3-prong plug as an input and has a 2-prong plug for plugging into the wall) and use the cheater plug with the Nait.
If the buzz goes away, it's a ground loop.
So, then you need to find the source. If you have an outside antenna or cable service plugged into the same system, it's probably the culprit. The solution is to get the cable service grounded to the same ground used for your electrical. Or, there are do-hickies that you can plug in the coax path to fix the problem.

If you go to avsforum.com and search ground loop, you'll find all sorts of possible solutions depending on the situation.

Hope this helps,


Mitch

OffBeatMammal
2007-05-17, 13:38
sounds like, as Mitch said, a ground loop is your culprit. Interesting it only shows up with the Slim device not the CD player - wonder if the output levels are slightly higher on the CD player, or the power supply in the CD player was better grounded (was it a 3 pin plug?)

Are all the power leads straight, or are any coiled/twisted (can induce hum), likewise the lead from squeezebox to the speakers

the other possibility would be interference on the run from the squeezebox to the speakers...

one quick and easy suggestion is to stick a ferrite core around the speaker cable (those little blocks you find on power cables and some USB connectors) ... they're interference sponges ;)

you can also try it round the power line *but* don't ever loop that lead too tightly or you'll get induction problems that can start with interference and end up with a fire!

Ned Ludd
2007-05-18, 08:28
The power cords are pretty straight. I don't think that is causing the problem. I am now wondering whether a ground loop isolator between the Nait and the Squeezebox would kill the hum. I've seen a few references to them while researching the problem. From what I have seen thus far on a few posts, the pairing of a Squeezebox with a Nait apparently presents a problem with regard to speaker hum.