Annoyin noise from Stratos...help

JoeW · « **on:** 8 May 2004, 06:05 pm »

I had my Stratos on for over a year with no problems. I recently turned it off to change out an Aragon Soundstage for a Rotel RSX972 receiver (I needed the extra money so I could buy a nice stereo preamp).

I connected the front l+r pre-outs of the Rotel to the Stratos until I could find a deal on a preamp. Well, after turning the Stratos back on I can hear a high pitched oscillating static from my tweeters on my main speakers. It is annoying from almost 20 feet away. It always occurs when the Stratos is on. Even when the Rotel is off. The only time it is diminished is when the RCA's are disconnected from the Stratos (but even then I still hear it slightly).

I thought it might be the Rotel but I recently bought a McCormack RLD-1 preamp that goes between the Rotel and the Stratos and the noise is still there. So it must be the Stratos.

What is this damn noise all of a sudden? I cleaned the rca and banana connectors to no avail. You can hear it during quiet moments in movies and music. My wife can't even stay in the same roof because it is so irritating.

Any ideas would be welcome.

Joe W.

Marbles · « **Reply #1 on:** 8 May 2004, 06:18 pm »

Quote from: JoeW

The only time it is diminished is when the RCA's are disconnected from the Stratos (but even then I still hear it slightly).
...

That sounds like you have a grounding problem with the new equipment.

If the new pre-amps have a 3 prong plug, you might want to try a "cheater plug" to see if this is the problem.

If you have cable TV hooked up to the pre-amp, you might also want to try disconnecting it from the system to see if this is causing the ground loop hum.

JoeW · « **Reply #2 on:** 8 May 2004, 11:29 pm »

I've isolated the noise to the Rotel RSX-972 reciever.

Whenever I remove it from the equation the sound goes away.

So now what? How do I fix this ground loop problem?

rosconey · « **Reply #3 on:** 8 May 2004, 11:34 pm »

use a ground lifter-goes on the 3 prong plug and only has 2 prongs for the wall-2 for a buck or so

KarlDL · « **Reply #4 on:** 9 May 2004, 02:43 am »

... and if lifting the power cord ground doesn't work ...

Is anything connected to the receiver's antenna input? If so, disconnect and see if the noise goes away. As suggested by Marbles, you could have a ground loop problem with a cable TV or antenna connection.

JoeW · « **Reply #5 on:** 9 May 2004, 04:08 am »

Victory is mine!

Thanks to you all I have located the offending culprit.

I removed the cable coax from the wall and viola! No more sound. How this affects the stratos I have no idea since it is in no way connected to it. And why it would show up all of a sudden is beyond me.

But I ran the coax from the wall into my power conditioner/supressor and out to the cable box and BAM, the nice clean sound of nothing!

Thanks to you all for your insight and ideas.

bubba966 · « **Reply #6 on:** 9 May 2004, 04:28 am »

Well, if the cable box or the TV/display was hooked up to the Rotel in any manner (even if it was audio only), that's how the hum became a problem.

Sounds like the Aragon didn't pass the hum on to the Stratos, but the Rotel did. So it's probably been there the whole time. You've just not heard it until the Rotel was introduced.

Marbles · « **Reply #7 on:** 9 May 2004, 04:28 am »

Glad to hear it is fixed!

Unproperly grounded CATV antenna (cable) is a VERY common problem in HT systems.