I had some really cheap speakers from a compact entertainment center on
my HK 520 receiver. There was a humm on the right speaker so I just
balanced everything to the left speaker. Now I purchased some new
Mission floorstanding speakers. Unfortunately, I still have the humm.
Here are the symptoms:

1) Humm is only on the right channel
2) Humm is only for analog input sources
3) There is no humm for optical input sources
4) When disconnecting an input the right channel has huge humm whereas
the left side does not.
5) After switching the L/R cable, i.e. L out on R in/R out on L in, the
humm stays on right channel
6) Humm is also there when listening through the headphones

I would appreciate any input on what you think the problem might be and
if possible how it could be fixed.

Thanks

"rob" wrote in message
ups.com...
I had some really cheap speakers from a compact entertainment center on
my HK 520 receiver. There was a humm on the right speaker so I just
balanced everything to the left speaker. Now I purchased some new
Mission floorstanding speakers. Unfortunately, I still have the humm.
Here are the symptoms:

1) Humm is only on the right channel
2) Humm is only for analog input sources
3) There is no humm for optical input sources
4) When disconnecting an input the right channel has huge humm whereas
the left side does not.
5) After switching the L/R cable, i.e. L out on R in/R out on L in, the
humm stays on right channel
6) Humm is also there when listening through the headphones

I would appreciate any input on what you think the problem might be and
if possible how it could be fixed.

Thanks

Perhaps humm while you are at the store buying a new amp? ;-]

rob wrote:
I had some really cheap speakers from a compact entertainment center on
my HK 520 receiver. There was a humm on the right speaker so I just
balanced everything to the left speaker. Now I purchased some new
Mission floorstanding speakers. Unfortunately, I still have the humm.
Here are the symptoms:

1) Humm is only on the right channel
2) Humm is only for analog input sources
3) There is no humm for optical input sources
4) When disconnecting an input the right channel has huge humm whereas
the left side does not.
5) After switching the L/R cable, i.e. L out on R in/R out on L in, the
humm stays on right channel
6) Humm is also there when listening through the headphones

I would appreciate any input on what you think the problem might be and
if possible how it could be fixed.

Thanks


Sounds like a grounding problem in the preamp section...somewhere. That
said, it wouldn't hurt to pop the cover and look for bad solder joints.
While you're in there, tighten every screw which holds a circuit board
to the chassis. Sometimes this can cause a hum issue, or worse.

Otherwise, you're on your own...consult a technician.

jak

Jak, thanks for the constructive and good advice. Just one question. I
did think about the preamp, too. But if this is the problem then why is
there no humm with the digital input? That one goes through the preamp
too, right? So I guess it boils down to what are the components before
both digital and analog go into the same path? Your advice of course
still applies but I just try to pin the problem down.

"rob" wrote in message
ups.com...
I had some really cheap speakers from a compact entertainment center on
my HK 520 receiver. There was a humm on the right speaker so I just
balanced everything to the left speaker. Now I purchased some new
Mission floorstanding speakers. Unfortunately, I still have the humm.
Here are the symptoms:

1) Humm is only on the right channel
2) Humm is only for analog input sources
3) There is no humm for optical input sources

Optical inputs are immune to grounding problems.

4) When disconnecting an input the right channel has huge humm whereas
the left side does not.

Does disconnecting the input cables cause the hum to be eliminated?

5) After switching the L/R cable, i.e. L out on R in/R out on L in, the
humm stays on right channel
6) Humm is also there when listening through the headphones

That is normal. the headphone jack is often hooked across the speaker
outputs with dropping resistors.

I would appreciate any input on what you think the problem might be and
if possible how it could be fixed.

Its probably a grounding problem - what's known as a ground loop.

Does removing the antenna cable have any effect?

What about disconnecting analog input sources, one at a time?