does your amp "HMmmmmmmm"?? (1 Viewer)

[Tom D]

Hello, the other possible source for your hum maybe the coax (cable feed). Try disconnecting your cable and see if the hum disappears. You may have to call your local cable company for repairs to their grounds.

 

[Leo]

What if I'm not using cable in my house? We are using Dishnetwork and I do have a line wired in the room using RG6 cabling.

 

[John Kotches]

Leo,

1) Plug the power amp directly into the wall.

2) Listen for hum.

3) Disconnect the Sat RG-6 cable from the Sat receiver.

4) Listen for hum.

If the hum is gone, your Sat system is improperly grounded at the antenna. The installer will have to come out and fix this.

If it isn't, it's a nother problem.

RicP outlined earlier why permanently disconnecting the ground is a poor solution, other than as a quick test to see if your problem is ground loop.

Ground lift switches on amplifiers operate differently and to the best of my knowledge don't compromise safety to "float" the ground.

Regards,

 

[Leo]

Took a closer listen and I don't have a hum but more of a hiss. The hiss is very faint with just the Marantz MA-500 turned on, but it becomes more pronounced when I turn on the Yamaha receiver with the Marantz turned on also. Any ideas?

At least it's not a hum. Whew!

 

[John Kotches]

Leo,

Congratulations, you're hearing the noise floor of your system. That's what it sounds like.

It's obscured during playback, so you don't notice it then.

Solution?

Upgraded amplifiers and Preamp/Processors.

I hear no audible hiss with all volumes at max on the Preamp/Processor + Analog Preamp + Amplifier.

Regards,

 

[Leo]

Thanks. Well I'll be upgrading the pre-amp this spring since I'm now quite happy with the Marantz MA-500 (easy upgrade path for multiple channels - my room is set up to support 7.2). So the fun part will be looking at pre-amps that fit my needs and have no hiss generated. Thanks for the help.

 

[rodneyH]

update, since it is "unsafe" to run a cheater plug, I checked all the wall outlets with an extension cord, hooked up to my amp, I found 1 after only a couple tries that is dramatically quiter than the 1 I was using, it is 80% gone, and can ONLY be heard up to 8-10" away on a very quite evening, I think that this is as good or 90% of what it was with teh cheater plug, ironically the one that worked the best is right smack behind the TV. Thanx again!!!

 

[Jeff]

Cheaters are ok to use if you can turn your amp on remotely and never have to touch it. I've been doing this with my Parasound amps for years, which have a very low level hum with some pre/pros.

Jeff