speaker hiss

Ok, I know I've run across this topic somewhere here before, but I can't seem to find it. I'm getting speaker hiss from my 970/7500 combo. They are connected via monoprice rca cables. Doesn't matter what volume, I have the hiss. If I'm listening at fairly loud levels I don't hear it from my listening position, but I walked by one of my speakers the other day and I could hear it while the music was playing. I had my former Oppo 980 hooked up directly to the 7500, and no speaker hiss then, so I'm guessing it's from the 970 and not the amp. I don't recall having this issue with the 970/7075 or 970/7125 combo. Anything I should look at doing or any suggestions for a fix??

The first thing to look for is a power cabel or even interconnect that is crossing, or even very close to, your speaker wires.

I've looked at the usual suspects (power cable, etc) but I don't see any near the interconnects.

Does it occur on all of your speakers or is it only one? Could be a bad cable or connector. Try swapping the cables around and see if the hiss moves or goes away.

Nope, it's audible on all of them.

Do you get the hiss from all sources on the 970 ?
You might try disconnecting the source to see if the his cintinues, that would at least narrow the search to either source to 970 or 970 to 7075 to speakers.

The hiss is present when I turn on the 9770/7500. Doesn't matter what source I select. Maybe I will try a different outlet for my amp and see if that makes a difference.

Turn the amp on by itself and check for the hiss. Then turn on the 970. That should narrow it down. If the hiss is there with only the amp then check the connections on all of your speakers. If you are using bare wire make sure no stray strands are touching the cabinet or any others. If you are using banana plugs check those connections by reconnecting with bare wire. If the hiss appears when the 970 is turned on I would borrow some other interconnects and see if it makes a difference. If it doesn't contact outlaw for some help.

Thanks, I'll try that and see what I find out.

Xenonman,

No noise from the amp alone whatsoever..dead quiet. I'd thought about changing interconnects. I have some old Kimber PBJ's I'll hook up to my mains and see if that eliminates the hiss.

So the hiss starts when you turn on the 970?

Yes.

I've still got this problem and it's really becoming annoying for me...re-routed power cables, switched to new interconnect cables from 970 to 7500 (Outlaw PCA's), new interconnects from BD player to 970, new speaker cables...no improvement. I'm thinking the origin is at a high frequency (I only hear it from the tweeters). Any suggestions?

Other possibilities include noise from other devices in the house (dimmer switches are a prime example, but refrigerator compressors can also do some weird stuff). I'd ask about cable TV service, but ground loop hums from ill-behaved cable service tend to be at a lower frequency than you are describing.

Never noticed it on my previous 970 nor the receivers I used as preamps. Don't have any dimmer switches in the house, and I have DirecTV. I'm really at a loss of how to 'fix' it. My amp is a "B" stock, don't know if the problem is with it. I'm going to try to hook up my Oppo direct and see if I still get the hiss (didn't recall it with my 980 though).

If the amp is dead quiet when it is on by itself it is NOT the problem. With everything else off and only the 970 on, is the hiss there? If so, disconnect each source one at a time until the noise changes. If it does not change, the 970 is the issue. Check the treble controls and other controls which could cause increased high frequency. I have had multiple DirecTV boxes fail on me so I would suspect them first.

I'll try disconnecting sources. DirecTV box is only connected via optical to the 970, so that's an easy one. That and the Toshiba HD-DVD player are the only 2 components I've had since I began noticing the hiss. I'll keep you posted what I find out. Thanks for the suggestions.

Don't ignore the optical input. Also I read somewhere where the unused optical ports have to be plugged. Most components come with plugs installed and you remove them to insert the optical cable. They then get lost for all eternity. I would guess to prevent scattered light noise.

I think the plugs are to protect the internal optics, and the 970 may have hinged doors instead of plugs.

The 970 does have hinged doors on the optical inputs. . BTW, disconnected the optical from my DirecTV receiver...hiss is still there. Toshiba is next on the list. If that doesn't do it, I'm left thinking it's the 970.

I'm having the same problem with my 970/7075 combo although I have to be pretty close to my speakers to hear the hiss.

1. It sounds a lot like the hiss from the old cassette tapes and only occurs on the tweeters.
2. It occurs no matter what input is active even on input with nothing attached.
3. It is somewhat linear with respect to the volume knob position (As I go from min to max on the volume knob it starts out constant than at about half way up it starts to get louder until it's pretty obnoxious).

I'm guessing the noise is being generated internally to the 970.

It's either a poor job of decoupling the DC power supply which I can't do anything about.
OR
It's noise being injected through the back panel ports. I'm thinking about trying some RCA Shorting Caps on the unsed inputs. Other forums point to unused RCA-type digital audio inputs as prime noise generators as they are high bandwidth inputs.

I've ordered a handful of these to try out:

RCA Port Cover/Shorting Cap

I'll post again after I try them out.

EEman,
That exactly describes what I'm experiencing. Let me know how those work out. Since they are a cheap fix I'll be ordering some too if that solves the problem.

John

Do you have dimmers on the lights in this room or nearby? I had hiss from this with an amp that seemed to be prone to this sort of interference.

Nope, don't have any dimmer switches in my house at all.

Do you have an antenna hooked up for the tuner and is it grounded? Try removing the antenna and listen for the hiss. The 970 does not have a grounded plug so maybe your have a ground loop somewhere in the system. If any of your gear has a 3 prong plug, pull the plug and try the system. Have you switched the bass management switch? Does it change the sound if you do? Also, make sure all of the rear panel connection points are clean and clear of any debris which could be shorting them out. With EVERYTHING disconnected from the 970, except the outputs to the 7500, is the noise there? Does the volume increase when you turn up the power? If so, call Outlaw. They have a lot of experience with ground loops and all sorts of other stuff. They will help you out.

The shorting caps were not the solution.
I also tried XenonMan's suggestions and none of them changed the characteristics of the noise.
Back to the drawing board...

Sounds like the 970 needs some time at home with the Outlaws. Is it still under warranty?

I unplugged my 970 from the Belkin surge protector/power strip and plugged it directly into the wall. No change. Guess I will have to call Outlaw next week (mine is still under warranty). Just hate to have to send it back (if that's the remedy).

Talked to Scott...my 970 is going to take a trip back to the Outlaws.