RSX-1067 buzzing with only speakers connected

[Jay Sylvester]

A few weeks back, I purchased a 1067 receiver from my local dealer. When I hooked it up, I heard a distinct buzzing sound coming from all the tweeters in my system. The buzz was volume dependent, but still quite audible at very low volumes. Since it was coming from all 7 speakers in my setup, it was easily audible at my listening position (about 4 ft. from the surrounds, 6 ft. from the front/center channels). Suspecting a ground loop, I unplugged all components and left only the speakers connected. The buzz remained. I power my whole system through a Monster HTS1000 and SurgeX surge protector, but just in case it was a power problem, I borrowed a Richard Gray 400 from my dealer. That didn't help either. The 1067 uses a two-prong plug, so I couldn't try a cheater plug.

The last remaining culprit was airborne interference working its way into the receiver. David from Ascend Acoustics was helping me troubleshoot the problem, and he had me place my cordless phone close to the receiver; it buzzed and crackled like crazy. Seems like the 1067 has really poor RF shielding.

I dropped off the 1067 at my dealer so he could check it out. His tech claimed to hear nothing. Since I was in the middle of a move, I left it with him until I could hook it up in my new home, thinking that maybe this interference might not exist in my new location.

I hooked it up last night in the new place, and the same buzz is still there. Just what exactly could be causing this buzzing noise? It's driving me insane.

My old Technics receiver is dead silent. It passes the cordless phone test just fine. What's up with the Rotel?

[soundhound]

Have you tried isolating the inputs 1 by 1? It would be suprising if the Rotel is actually generating this (unless your'e unit has a hardware problem). When you say buzz it sounds like 50 or 60 hz line noise (depending on the country you hail from). More times than not issues like your'es can easily be tracked down by isolation (process of elimination). External cable routings can have as much to due with noise as ground schemes. Again I would eliminate the inputs 1 by 1, find the culprit, and go from there.

[soundhound]

OOps, sorry Jay, I just read your'e post a little more in depth and you have taken steps to isolate the issue. If it were me I would make certain I dont have any line cords routed by signal or speaker cables (inductance is a powerfull force allthough you say its from your'e tweets wich rules out 60 cycle humm)It is o.k. to cross them but bad practice to run them paralleled. If it is indeed the reciever I would see my dealer and request a replacement. Bob

[Jay Sylvester]

I have my power cables and interconnects well separated. One or two of them cross, but I make sure they're perpendicular to one another.

Not much I can do aside from disconnecting everything but the speakers. Pretty much rules out another component causing the problem.

The buzzing comes mostly from the tweeter but partially from one of the woofers. I'm using Ascend 340's all around in a 7.1 setup, which have dual 6.5" woofers.

[w6000]

Buzzing From Tweeter

Hi Jay,
I am having the same problem with the 1098. I got the 1098 about 8 months ago but recently I have noticed a buzz from the tweeters. I have not contacted the dealer regarding this B/C I want to switch the cables around to see if it goes away. I just thought it was interesting that you had the same problem with a different product from Rotel.

[Jay Sylvester]

I did a lot of research on the 1067 before buying it. Not from an audio quality standpoint; I had already owned an RSP-1066 and RMB-1075 in the past, and knew the sound quality would be top-notch. I was looking for reliability issues.

I was surprised at the amount of buzzing/hissing complaints I saw on the Rotel family of receivers and processors. I figured it was just a vocal minority and that most receivers in the field are just fine. My 1066 hissed a bit, but it wasn't audible from more than a few feet away.

Looks like I got nailed though. This buzzing is terrible.

[Bostonears]

I purchased a 1067 when they first came out. I experienced a 60 Hz buzz from all my speakers when nothing else was connected to it. (It was not a ground loop, and the AC power was filtered through a quality Panamax line conditioner.) The 1067's buzz was faint, but clearly audible from my seated position during quiet passages. I brought the unit back to the dealer, and it did the same thing there. Then we checked his unit on display. Sure enough, it had the same problem, although he hadn't even noticed it. I think Rotel failed to properly shield some of the components in the 1067, at least in the early units. I thought this was particularly ironic, because Rotel marketing literature touts how power supply design is at the core of their engineering.

I returned the 1067, and ended up with a 1068 processor and a 1066 amp. This combo exhibits none of the speaker buzz I heard from the 1067, even when installed in the exact same place as the 1067.

[Jay Sylvester]

I have a feeling my 1067 will be going back to the dealer as well. I've already suggested a 1068 with some type of amp as an option, and he seemed receptive to that.

[SQconstable]

Me Too

I know this thread is old but I sent my Rotel RSX-1067 for repair on the same sorta issue:

No matter what input is selected, no matter which outlet the amp is plugged into, and even without anything connected other than speakers.... I hear a fixed 60hz (with some high freq harmonics) buzzing/humming out of all speakers, independant of volume.

I had noticed this the first week I received the amp (around late Spring of 2005) but felt it wasn't annoying enough to do something about it. However, now my ears are much more keen to hearing these types of ambient noise, especially when watching a suspenseful movie as I await the foreshadowing.

I had emailed Rotel and they simply said to bring it back to the place that sold it to me. I shipped mine off December 22nd and it's now Jan 16th... dunno how long these things take to get repaired/replaced.

I hope I get the same amp if there has to be a full replacement because I don't want to change my configuration - that 1067 is one helluva unit, and even has subwoofer phase adjust (distance parameter).

Has anyone else experienced buzzing issues from this amp or any other Rotel's?

[Boombox]

Has anyone thought of speaker sensitivity?

91 - 94db < speaker sensitivity values tend to produce a hiss. I have a 94db speaker and when the pre-amp (RC1070) is switched on, the tweeters start to hiss...

for a short while, my RB1070 stood on top of my sub (which has a 100W built in amp) and the static was clearly audible...

[KAP]

I'm on my 2nd 1067. The first was returned for the famous crackling sound caused via a bad board of some sort. The one I have now also emits a buzz from all speakers that is noticeable when the volume is set to zero. However, my buzz is not noticeable at any normal listening volume.

[SQconstable]

Remember, we're not talking about noisefloor hiss.. that's normal.

We're speaking of buzzing, specifically.

Well guess what?!? The store called me up and said Rotel had "repaired" the amp. Crazy thing is that Rotel had stated they "couldn't duplicate the buzzing problem". I can't imagine that Rotel, of all people, cannot hear this yet anyone else points it out to me including my wife's mother Sounds more like a design flaw to me.

Anyway, I went to the store to check out my amp. I insisted that they hook it up and let me prove what I was hearing. Now, to my shock, the amp wouldn't even turn on. The relay kept clicking and never latched on to stay on! The unit was possibly broken from shipping via UPS (they're not too soft on boxes there).

So the local store had a new unit sent over to replace it. Meanwhile, the store would send back the old one. They called me today to come pick it up, and also that they hooked it up so I could take a listen. I put my ears to the midrange of the B&W 603 and oh crap... you wouldn't believe this, but it buzzes too. A NEW UNIT!!! I told the salesperson "No that's not necessary." He came over and heard it too so I'm kinda happy it's not just me that has this supposed "super-hearing" we have. Cheater plus won't work to fix this type of buzz. Unfortunately, the 1067 already only has a 2-prong plug - ground lifting already employed here!

Then the manager came in and we explained the issue. He was kinda baffled at the whole situation, even since a 2nd new amp had same problem.

The buzzing is loud, to me. The B&W 603's at the local store are 8 ohm. The buzzing in the medium-level store environment still wasn't loud enough to mask it at a foot away, so imagine what I go through, with five 4 ohm speakers in my setup. MUCH louder. This is bad.
:evil:
I am awaiting another week of the store-to-Rotel interaction via emails and phone calls so I can decide what is gonna happen with this. I'd be fine getting an RSX-1056 instead and get the difference applied to my account somehow, but ideally I'd like the same amp with no buzz. Unfortunately, I think every new 1067 buzzes. This is a serious design flaw.

Why does a $2000+ amp have buzzing, when a cheap wal-mart receiver has NONE?!? Don't even try to tell me that higher end amp circuitry has more noise.

So if I get my credit, what should I go for? I'm worried about going with Rotel again so my other options need to include something as powerful regarding the whole bass management, crossover, and distance controls (distance control for the subwoofer is an amazing feature, and it's basically like phase control). I think Classe amps are somewhat on the expensive side, condsidering Rotel's sound quality is already good enough for me. Anyone have experience in other brands/models under $3000 for a preamp-amp combo (or separates)? 7.1 isn't neccessary but I had the 1067 for future use of Zone 2.

What happens from here is up to Rotel's discretion so I really hope things turn out for the best.

[SQconstable]

I'm on my 2nd 1067....The one I have now also emits a buzz from all speakers that is noticeable when the volume is set to zero. However, my buzz is not noticeable at any normal listening volume.

What's most irritating to me is when you're watching a movie in the quiet of the night.. and when there's a quiet scene, then you hear all that buzz This is totally unacceptable.

Even with 8 ohm speakers with low sensitivity, it's still unacceptable. My guess is that Rotel is fully aware of the problem, although they will not admit it because that means they'd have so many people wanting repairs or replacements. It seems to be an issue of them not wanting to deal with the problem.


I would like to add something very important here:
The RSX-1067 hooked up at the local store in the next room is 1.5 years old (manager said so) and it has absolutely no buzzing (checked today again). The room where they connected mine up is on the same power. I should have gone with something else cause this is just too irritating for the money they want for a 1067. :Z


*update* the demo amp DOES buzz.

[DL86]

This isn't related to a RSX-1067 but a similar problem. But I would like to share my experience with my RB-1080. I initially had Accusound speakers running off the rotel and there was a significant buzzing noise probably audible 1-2 ft away maby a tiny bit more. I then upgraded my speakers to paradigm studio 100v3's, the buzzing noise was completely gone.

[SQconstable]

Whoa.

That is unbelievable! Was your buzzing noise proportionate to volume or was it a fixed level? How weird.. The only real difference that the amp is seeing between two different sets of speakers is a load. Differences in impedance can explain sensitivity issues, but for it to totally go away is theoretically impossible... very odd. It's possible that something else was changed in the system, even if miniscule, at the same time of the upgrade. Dunno.. have to think hard about that one but the only thing I could imagine removing hum/buzz is noise-cancelling transformers which would have such an electrical loss that they'd be poor choices to be used in professional designs. Intercom speakers use them though but that's a different monsta.

The only other interaction I could foresee with loudspeakers and amps is the passive crossovers. They're only introducing inductance and capacitance to the output. Although capacitors are basically filters, they'd have to cutoff much of our audible range to completely eliminate buzzing/hum, and that'd be detrimental for musical that plays out of the speakers.

[PewterTA]

Unless there was a grounding/crossover issue in the Accusound speakers and the 1067 just happened to be picking it up/amplifying it through the speaker???

[SQconstable]

Well with this type of amp, there can't possibly be any active servo/monitoring on the speaker outputs. There's also no grounding when it comes to passive crossovers - that's just inductive, capacitive, and resistive load across an "unbalanced" pair. With Rotel amps, although there's alternating current between the (+) and (-) leads, it's all really meant to be one-way (i.e., sound cannot be picked up at the amplified, run back through the pre-amp stage, and amplified). That's just not possible with this class of amp.

[DL86]

I think it had something to do with the impedance. The accusound was a 6 ohm and the paradigm was a 8 ohm. However the paradgim was 2 db more efficient than the accusound. To hear the buzz on the paradigm you would need to put your ear right up against the tweeter. But the hum from the bass drivers I would say is gone, can't hear anything.

[SQconstable]

The B&W 803's at the Home Theater Store are 8 ohm and you could hear it from 1-2 feet away in a moderate noisy environment. True, going to a higher impedance does make it harder for the noisefloor to come through, but it's still unbearable on the 803's, and much worse on 4 ohm's. I got this amp for it's 4 ohm stability since I already had 4 ohm studio monitors.

[Bostonears]

Has anyone thought of speaker sensitivity?

91 - 94db < speaker sensitivity values tend to produce a hiss. I have a 94db speaker and when the pre-amp (RC1070) is switched on, the tweeters start to hiss...

Amp hiss is fairly common when using high sensitivity speakers. But the 1067 buzzing problem I described in my earlier post was at 60Hz, and my speakers are only rated at 89db.

[SQconstable]

sorry posted on wrong thread

[dbart]

I had the exact same problem with my Rotel 1095 amp. Bought a ATI 3000 balanced amp and the noise is completely gone. So it has something to do with the amp and not the speakers.
Common mode noise rejection built into balanced amps will solve this. The Rotel gear seems to be sensitive to dirty AC power somehow.

[SQconstable]

True, it's not about the speakers.. it's the amp that's doing it.. but some speakers are more sensitive than others and it can either help "mask" it or expose it more.

Hmm I still feel there's something different about the guts of that demo 1067 at the local store. It's on the same dirty power then, but it's not buzzing.

*update* - the demo 1067 at the store DOES buzz

[kurtholz]

i hate to add this, as it is a snake oil investment, but it worked wonders for me, i am using a Rotel 1095 amp to drive my rear surrounds and rear center, i was getting a lot of noise out of them, that hissing noise that drives us crazy

i like a full surround sound, and i have 805s as rear's so they put out such great sound, the point is, i have them dialed up a bit to get more out of the rears

my personal preference, anyway, the point,

i switched the stock power cord for a more expensive aftermarket one, noise is 100% gone

you might try it

good luck

Kurt

[Kevin D]

Just to rule it out Jonathan, can you swap power cords with the demo unit at the store that doesn't buzz? Maybe Rotel switched manufacturers of power cords??

Kevin D.

[kurtholz]

oooops, i forgot to mention, i also had a 15 amp dedicated line put in with hospital grade outlet, this cut out probably the first 50% - 60% of grunge,

slight detail i forgot to mention

senility , i am embracing it with open arms, hahahaha

good luck

Kurt

[SQconstable]

i hate to add this, as it is a snake oil investment, but it worked wonders for me, i am using a Rotel 1095 amp to drive my rear surrounds and rear center, i was getting a lot of noise out of them, that hissing noise that drives us crazy

i like a full surround sound, and i have 805s as rear's so they put out such great sound, the point is, i have them dialed up a bit to get more out of the rears

my personal preference, anyway, the point,

i switched the stock power cord for a more expensive aftermarket one, noise is 100% gone

you might try it

good luck

Kurt

I don't understand a correlation between hissing and a power cord. Power cords are only supplying the power supply with power. Hissing is something we associate with the preamp and amp stages, not the power supply.

Now, if we were talking about hum or buzzing, then I'd try a line conditioner and if that'd work, I'd stop there. I have personally never heard of hissing being theoretically changed by changing power cords.

Are you sure the noise you were experiencing was just hissing? I'm hearing a distinct hum out of my woofer and I can almost actually feel it in the cone.

With a two-prong electrical cord, I'd figure they'd either work or not. Anyone else experienced this? I've tried 3 power cords that were supplied with the 3 new amps. I'll bring this up with Rotel but I'm sure they'll act like there's no connection between hiss and power cords. I'd never believe it either. Maybe something else was changed?

Another question, ... what in the world got you thinking to change that power cord in the first place? Most people would naturally trust a short power cord for 8A of current and see little reason to "upgrade" it.

[SQconstable]

oooops, i forgot to mention, i also had a 15 amp dedicated line put in with hospital grade outlet, this cut out probably the first 50% - 60% of grunge,

slight detail i forgot to mention

senility , i am embracing it with open arms, hahahaha

good luck

Kurt

I bet that's the reason.

Maybe I have bad lines just like my store on that one room that the new units buzz in? Their demo room has got to either be different *something* or a totally different design on the Rotel.

[kurtholz]

well, i am just getting ready for the big change this week, as i climb out of the stone age, my plasma goes up Thursday

so i am replacing cables etc, with proper lengths to get everything as neat and perfect as possible, i bought 2 power cords off audiogon that are 1/2 meter so instead of having a 4 ft long stock power cord laying around, it goes right to the wall

i have one other aftermarket cord i put on my Arcamdv29, it does improve the sound

can't explain it, but it seems to work for me

oh to answer your first question, buzz, hiss, humm, not sure i could differentiate , kind of a personal perception thing i think

i'm sure your right

good luck

Kurt

[jbk]

I am very new to this stuff but I have had a similar problem with my rotel rb1080 connected to my rsx-972. I am sorry if this may be a stupid suggestion that you have tried already. Anyway, I am using ok quality dh labs interconnects between the two and reasonably cheap cables on the others. I found that the tweeters buzzed with all other components unplugged from the wall. The buzzing was present when i had the interconnects btw the amp and receiver connected but gone when I unplugged the interconnects. Anyway to cut a long story short i realised that i still had the tv signal cable connected (despite the tv itself being disconnected from the power) and when i removed that from the wall the buzzing stopped. At your dealer does one of the rsx1067's sit near a tv while the other one is in an a dedicated audio only room perhaps. Anyway probably a silly suggestion but you seem to have tried everything else

Josh

[Elvis]

oh to answer your first question, buzz, hiss, humm, not sure i could differentiate , kind of a personal perception thing i think

i'm sure your right

good luck

Kurt

A buzz buzzzzzzzzes,a hiss hissssssssses,a hum hummmmmms,very different sounds to me.

[kurtholz]

A buzz buzzzzzzzzes,a hiss hissssssssses,a hum hummmmmms,very different sounds to me.

OK, i got it now.

:-)

good luck with the noise gremlins, glad mine have all gone somewhere else

Kurt

[chinets]

I think all the buzzzzzzzzzzzziiiiiinnnnnggggg comes from Kurt!!!!!!!!
Congrats on your plasma Pal!!!!
Take care and please E-Mail me about your funny story.
Chau,
Chinets

[kurtholz]

I think all the buzzzzzzzzzzzziiiiiinnnnnggggg comes from Kurt!!!!!!!!
Congrats on your plasma Pal!!!!
Take care and please E-Mail me about your funny story.
Chau,
Chinets

buzzzzzzzzzzzzzzzzzzzzzzzzzzz, what i can't hear, all that static, it's just leftover distortion from my old Rotel products, they are known to bounce around the house for years

hahahhahahahha

I'll drip you an email

Kurt

[SQconstable]

At your dealer does one of the rsx1067's sit near a tv while the other one is in an a dedicated audio only room perhaps. Anyway probably a silly suggestion but you seem to have tried everything else

Josh

Ooh this is a good question.. The two new units that were buzzy were on a hutch/desk with no TV's in the same room. The demo was in the next room over, ontop of a high shelf, but right above a TV. And that one doesn't buzz. Either way, your problem was more of a grounding issue between components. Mine is with just random 1067's with nothing else connected.

*update* the demo 1067 at the store DOES buzz as well