Hi all,

I have a set of KRK RP6 active monitors and they hum, just with the
mains plugged in. So there is no mixer, no XLR cables, nothing, just
the power cable and I turn them on, HUM. Here is what I've tried...

Moved them to different rooms, still hum.

Turned off all the power in the apartment except the outlet one speaker
is plugged into, still hum.

Bought a socket tester, says that they are properly grounded.

Tried a line lifter (3 to 2 prong thing) didn't help.

What else can I do? Is the Ebtech Hum X going to cahnge anything? I
read somewhere that if my line lifter didn't work that won't either.
Any thoughts? Experiances?

Cheers

Sixstring.

On 7 Jan 2005 21:28:37 -0800, wrote:

Hi all,

I have a set of KRK RP6 active monitors and they hum, snip

1.) Short the input
2.) If hum is still there, send them back.

dB

"DeserTBoB" wrote in message
...
On 7 Jan 2005 21:28:37 -0800, wrote:

Hi all,

I have a set of KRK RP6 active monitors and they hum, snip

1.) Short the input
2.) If hum is still there, send them back.

dB

If all else fails, try reversing the mains lead - live and neutral.

Mike

wrote:

I have a set of KRK RP6 active monitors and they hum, just with the
mains plugged in. So there is no mixer, no XLR cables, nothing, just
the power cable and I turn them on, HUM. Here is what I've tried...

Do they hum with the input pins 2 and 3 shorted?

Moved them to different rooms, still hum.

Turned off all the power in the apartment except the outlet one speaker
is plugged into, still hum.

Bought a socket tester, says that they are properly grounded.

Tried a line lifter (3 to 2 prong thing) didn't help.

What if you take them to another building? Possibly you have line noise.
Possibly they are just plain defective. Is the problem a hum, or is it
really more of a buzz than a hum?

What else can I do? Is the Ebtech Hum X going to cahnge anything? I
read somewhere that if my line lifter didn't work that won't either.
Any thoughts? Experiances?

No, the Hum X is a transformer box. It's very helpful when you need to
break signal grounds on unbalanced connections. But, you don't even have
any signal grounds to break.

Do you also get this noise on an AM radio tuned between stations?
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

I think it must be line noise... I reversed the polarity still same
problem... No radio singles in these but I had first tried a pair of
Beringher Truths and got hum and radio. The KRKs I only got hum.

So today I returned them and settled on a pair of Yorkvilles YSM1's and
they sound good.

Thanks for all the help!!

Sixstring

wrote:

I think it must be line noise... I reversed the polarity still same
problem... No radio singles in these but I had first tried a pair of
Beringher Truths and got hum and radio. The KRKs I only got hum.

Line noise? It sounds like the internal amp(s)or power supply were
defective. Why didn't you try another pair of them?

"Joe Sensor" wrote in message

wrote:

I think it must be line noise... I reversed the polarity still same
problem... No radio singles in these but I had first tried a pair of
Beringher Truths and got hum and radio. The KRKs I only got hum.

Line noise? It sounds like the internal amp(s)or power supply were
defective. Why didn't you try another pair of them?

Possibly, the hum was vertical synch from a nearby TV station. The
radio-like sound might have been TV audio.

In article writes:

Line noise? It sounds like the internal amp(s)or power supply were
defective. Why didn't you try another pair of them?

With two of them doing the same thing, I suspect that it wasn't a
manufacturing defect, but rather a design problem.



--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me he double-m-eleven-double-zero at yahoo

wrote:
I think it must be line noise... I reversed the polarity still same
problem... No radio singles in these but I had first tried a pair of
Beringher Truths and got hum and radio. The KRKs I only got hum.

So today I returned them and settled on a pair of Yorkvilles YSM1's
and
they sound good.

Thanks for all the help!!

Sixstring

Is your apartment near a TV station transmitter? or FM radio statoin
transmitter?

Mark

Actually in total I tried 2 sets of the Beringhers, they both hummed
and got radio signals. I Tried 3 individual KRK's because one of them
had something loose in it, all three hummed. The Yorkvilles I have had
two sets and none have hummed.

And as for the radio towers or TV, there is nothing that I know of, I'm
in the city but fairly residential.

Has anyone ever had this happen with higher end monitors? I was
wondering is this is some of where the extra cash go's into a nice set
of monitors.

Cheers

Sixstring

When you can hear the "radio", try to identify the station.

That will be a big clue to your problem.

Does it change when you move the line cord around? or the unit?, or
anything?

Do any other electronics in your apt mis-behave?


Mark