AAARRRGGGHHH! Please make the buzz stop!

[PENG]

I’m not sure what “lifting the ground means” but when I switch back to the balanced interconnects, the buzz is there. With the unbalanced RCA’s, it’s gone.

As you know by now, if you have 2 prong plugs the ground is already "lifted", except that the neutral is still grounded at the panel and there is nothing you can do about it by code and for safety.

Back to the noise issue, I recall you said you were hyper-sensitive to such imperfections so can you tell us how loud the noise really is. How far from the speakers can you start hearing it? Are you sure the noise level remains constant as you turn the volume up? I know you said with the Rotel it stayed the same but are you sure when you were turning the volume you had the unbalanced RCA interconnects between the Rotel and the amp? You were busy trying different things I just wanted to be sure because this is an important point.

I am hoping there may be an outside chance that the noise you are talking about is in fact quite "normal". I have never come across a system that is completely silent when it is turned on and the volume cranked up. With the volume turned down though, any hiss and hums should be almost inaudible even if you stick your ear on the speaker's grill. Noise specs are given as a ratio and even a decent S/N ratio of 110 dB still means there is noise to be expected.

 

[Rickster71]

Craig, I might've missed this in the thread, has this Buzz recently started, and in a set-up you've had a while?
If so, try to think back as to what changed and if it coincided with the buzzing.

If this is a set-up you've had a while, and was without noise, something had to change and introduced this noise.
Part of that change may be a component going bad.

Do you have a sub-panel in the house, or only the main panel?

 

[CraigV]

As you know by now, if you have 2 prong plugs the ground is already "lifted", except that the neutral is still grounded at the panel and there is nothing you can do about it by code and for safety.

Back to the noise issue, I recall you said you were hyper-sensitive to such imperfections so can you tell us how loud the noise really is. How far from the speakers can you start hearing it? Are you sure the noise level remains constant as you turn the volume up? I know you said with the Rotel it stayed the same but are you sure when you were turning the volume you had the unbalanced RCA interconnects between the Rotel and the amp? You were busy trying different things I just wanted to be sure because this is an important point.
I am hoping there may be an outside chance that the noise you are talking about is in fact quite "normal". I have never come across a system that is completely silent when it is turned on and the volume cranked up. With the volume turned down though, any hiss and hums should be almost inaudible even if you stick your ear on the speaker's grill. Noise specs are given as a ratio and even a decent S/N ratio of 110 dB still means there is noise to be expected.

Which still leaves me wondering about the interaction between the preamp & amp using the XLR cables with their ground, even though the buzz was still present even after I took the ground wire out of play.
About 10"
The minor buzz from either the Rotel or the B&K is the same when using RCA connects
I'm starting to think the same thing, although I do recall having a piece of equipment that made no noise with no signal (can't remember which one though)

Craig, I might've missed this in the thread, has this Buzz recently started, and in a set-up you've had a while?
If so, try to think back as to what changed and if it coincided with the buzzing.

If this is a set-up you've had a while, and was without noise, something had to change and introduced this noise.
Part of that change may be a component going bad.

Do you have a sub-panel in the house, or only the main panel?

Only one panel in the house, and everything inside is very clean. I first noticed the noise with the Rotel when I inadvertently got close to the speaker while a DVD was paused. When I say I’m “hyper-sensitive” to such things that is to say I’m far more disturbed by this anomaly than most other people, and I was sure the Rotel must be defective, so I went on Audiogon and bought the B&K straight away. When I got it, I hooked it up via the same RCA cables, and the (quieter) buzz was still present. That’s when I decided to try the XLR, which in turn made the buzz louder, and it increased with the volume increasing.

Again let me state how appreciative I am for everyone’s input, suggestions & help.

 

[PENG]

If you can hear it from 10" away with the volume turned down then we need to get to the bottom of it. If you can hear it from 10" only when the volume is turned up then you may be just being too sensitive to this sort of things. Hopefully TLS, Rick or others will come up with more hints.

On a somewhat "positive" note, I know for a fact that even for high end gear, as long as you have sources connected to the preamp inputs, you will hear a little hiss and/or hum if the volume is cranked up and the source signals are absent. One thing to keep in mind though, it is often difficult to hear any such low level noise or buzz in most dealer's demo room because they typically are not as quiet as our own H.T. room and have many equipment turned on. In the past I have to tell them to turn things off and I would put my ear right on the speaker grill.

 

[highfigh]

As you know by now, if you have 2 prong plugs the ground is already "lifted", except that the neutral is still grounded at the panel and there is nothing you can do about it by code and for safety.

Noise specs are given as a ratio and even a decent S/N ratio of 110 dB still means there is noise to be expected.

Kind of- if the amplifier has no ground pin, the chassis is grounded to the neutral, instead of that pin. In the audio path, lifting the ground on a balanced input or output lifts pin 1, which is at the same potential as the chassis. Pin 3 is not at the same potential, often about 50 Ohms above. This difference is usually enough to minimize noise injection and with balanced cables being twisted pair with shield, it's really the best way to send the signal. If pin 1 is lifted, it's best to do it at the end that's farthest from the preamp, so its chassis can be the common ground point. The preamp power cord is usually grounded for this reason.

Also, "Star Grounding" isn't a physical configuration as much as an electrical one. It means that every piece in the system has zero potential (Voltage) difference between them.

 

[highfigh]

Which still leaves me wondering about the interaction between the preamp & amp using the XLR cables with their ground, even though the buzz was still present even after I took the ground wire out of play.
About 10"
The minor buzz from either the Rotel or the B&K is the same when using RCA connects
I'm starting to think the same thing, although I do recall having a piece of equipment that made no noise with no signal (can't remember which one though)



Only one panel in the house, and everything inside is very clean. I first noticed the noise with the Rotel when I inadvertently got close to the speaker while a DVD was paused. When I say I’m “hyper-sensitive” to such things that is to say I’m far more disturbed by this anomaly than most other people, and I was sure the Rotel must be defective, so I went on Audiogon and bought the B&K straight away. When I got it, I hooked it up via the same RCA cables, and the (quieter) buzz was still present. That’s when I decided to try the XLR, which in turn made the buzz louder, and it increased with the volume increasing.

Again let me state how appreciative I am for everyone’s input, suggestions & help.

Just to recap- you connected the speakers to the power amp and had nothing connected to the input, right? When the amp turned on, did you hear anything? A thump, did you see the woofers move out and back in, slowly? Hiss, buzz? If you hear it with only the speakers and power amp connected, either a component has become loose , failed or a ground issue has arisen.

If no noise, you connected the preamp to the power amp with the power cords plugged into the same receptacle or power management device, right? What did you hear with the preamp and power amp on, using the balanced cables vs the unbalanced cables with RCA plugs? If you now hear noise, it could be from a grounding issue or it could be radiated noise. Do you have a portable AM radio and/or a cassette Walkman? If so, you can use it to sniff out the noise source. AM noise is often a buzz and EMI (Electromagnetic Interference) is often more of a hum but it can be either, or both. As you move the AM radio or Walkman closer to the noise source, it will become louder. At this point, it may just be a matter of proximity to the source that's causing your problem. You can verify this by moving the equipment farther from the wall, any electronic/electrical device it may be close to. Don't forget that anything on the other side of the wall is a good candidate as a source.

Just for grins, make sure the preamp and power amp are connected and on, then go to each of the light switches and outlets, so you can pound on the wall next to them. If you hear any crackling or popping sounds, you have a loose wire or bad switch/outlet or possibly a hidden break in a wire.

I didn't see an answer before- how are the wires and cables arranged? Near any power wires, parallel to any and closer than 12 inches?

 

[dougg]

Ground Connections, or crossed Polarity in circuit

Turn off all Breakers except the One to the Amp and Componets, then check for Noise. You may have a crossed Polarity in a circuit. If noise is gone, turn on Breakers one at a time to see if Noise returns.
How old is the House. The outside ground Rod connection may need cleaning.
Doug S.

 

[TLS Guy]

If you can hear it from 10" away with the volume turned down then we need to get to the bottom of it. If you can hear it from 10" only when the volume is turned up then you may be just being too sensitive to this sort of things. Hopefully TLS, Rick or others will come up with more hints.

On a somewhat "positive" note, I know for a fact that even for high end gear, as long as you have sources connected to the preamp inputs, you will hear a little hiss and/or hum if the volume is cranked up and the source signals are absent. One thing to keep in mind though, it is often difficult to hear any such low level noise or buzz in most dealer's demo room because they typically are not as quiet as our own H.T. room and have many equipment turned on. In the past I have to tell them to turn things off and I would put my ear right on the speaker grill.

I agree completely.

 

[TLS Guy]

Which still leaves me wondering about the interaction between the preamp & amp using the XLR cables with their ground, even though the buzz was still present even after I took the ground wire out of play.
About 10"
The minor buzz from either the Rotel or the B&K is the same when using RCA connects
I'm starting to think the same thing, although I do recall having a piece of equipment that made no noise with no signal (can't remember which one though)



Only one panel in the house, and everything inside is very clean. I first noticed the noise with the Rotel when I inadvertently got close to the speaker while a DVD was paused. When I say I’m “hyper-sensitive” to such things that is to say I’m far more disturbed by this anomaly than most other people, and I was sure the Rotel must be defective, so I went on Audiogon and bought the B&K straight away. When I got it, I hooked it up via the same RCA cables, and the (quieter) buzz was still present. That’s when I decided to try the XLR, which in turn made the buzz louder, and it increased with the volume increasing.

Again let me state how appreciative I am for everyone’s input, suggestions & help.

I'm just heading to the Twin Cities right now. Our fifth grandchild was born this morning. So I will nor be following closely, now, but you are pretty much sorted, I think.

 

[Segars]

Got a similar issue!

Hi guys,

So glad to see that people are actively troubleshooting this issue! I just got an XPA-5 this past week, and introduced it to my system. Like Craig, at first I didn't notice the buzz/hum coming from the amplified channels (via the XPA-5), that is until I decided I was going to dial in the subwoofer phase -- something I've never gotten around to doing, and in hindsight, I would have been far more at peace had I not stuck my ear up to the speaker and observed the buzz/hum.

I know for a fact that my speakers (Fronts - Elemental A6-6t6- MTM's and Surrounds - ERD-1's) and my RX-V663, and my subwoofer were as silent as can be. When I installed the new subwoofer, I had some issues with low level humming, but I corrected that by putting it on the same socket as the 8 socket strip that powers the rest of my gear.

The problem now is that I can't stretch the XPA-5's cord to a dedicated outlet. It's just not physically possible given the short length of the cord and the distance of the outlets. So, I've got a very short extension running to that, that connects it to a dedicated outlet, but its one separate from the subwoofer (bottom outlet) and the strip (top outlet).

I've been trying a bunch of different things that have been listed above, but not quite to the extent that craig has gone, nor as thorough.

I plan on going through just about everything, short of rewiring the house, as that is an expensive and time consuming endeavor, one that I'm not willing to endure to spare the minor hum/buzz.

Here's what I've done thus far:

- Tested the outlets with a cheap outlet tester (the yellow one, with three lights that indicate whether there's a basic wiring fault) and found that the grounds on the outlets in my HT circuit weren't quite right, or properly grounded.

- Replaced the three trouble outlets with new "professional" 15A outlets and made sure they were properly wired and grounded. (note: the outlets were seemed to be "chained" or in a stream, with TWO lines coming in, six wires a piece -- 2 hot, 2 neutral, 2 ground. Does that mean anything to you guys?)

- Swapped out the battery backup surge protector for a simpler, "HT Power Strip" with 12 outlets. No luck. Tried putting the Amp, Pre-amp and the gear on it, minus the sub. No luck. Went back to the old strip.

- Disconnected the main coax input from the cable box in the basement, no luck. Hum/buzz still there.

- Tried unplugging the pre-amp (RX-V663) and the hum/buzz went away.

- Unplugged the RCA pre-outs from the XPA-5 and made sure all speaker interconnects were snug (banana plugs) and that the speaker wires are as far from power wires as possible. Also ran the XPA's plug, via a super long extension cord to a different circuit downstairs (HT is on the second floor). Powered up the amp, and speakers are dead silent. Powered down, plugged in the FR RCA (Front Right), powered up, dead silent. Sweet, right!? Powered down, and added the FL RCA to the mix, powered up, and the buzz/hum was back!!! ARRRRGGGGHHHHH, indeed.

- Alternatively, I unplugged the FR RCA and powered on the unit, and the FL speaker was dead silent too. So wouldn't that mean that the cables themselves are fine, as are the speaker wires, IC's? Where is this cursed hum/buzz coming from, and why does it make a difference when multiple speakers are plugged in?

Here's to hoping that we (Craig and I) can get our setups sounding as clean as possible. Will try more suggestions that others have posted, and will post results as I get them.

Don't worry Craig, you're not alone!

 

[CraigV]

Just to recap- you connected the speakers to the power amp and had nothing connected to the input, right? When the amp turned on, did you hear anything? A thump, did you see the woofers move out and back in, slowly? Hiss, buzz? If you hear it with only the speakers and power amp connected, either a component has become loose , failed or a ground issue has arisen.

If no noise, you connected the preamp to the power amp with the power cords plugged into the same receptacle or power management device, right? What did you hear with the preamp and power amp on, using the balanced cables vs the unbalanced cables with RCA plugs? If you now hear noise, it could be from a grounding issue or it could be radiated noise. Do you have a portable AM radio and/or a cassette Walkman? If so, you can use it to sniff out the noise source. AM noise is often a buzz and EMI (Electromagnetic Interference) is often more of a hum but it can be either, or both. As you move the AM radio or Walkman closer to the noise source, it will become louder. At this point, it may just be a matter of proximity to the source that's causing your problem. You can verify this by moving the equipment farther from the wall, any electronic/electrical device it may be close to. Don't forget that anything on the other side of the wall is a good candidate as a source.

Just for grins, make sure the preamp and power amp are connected and on, then go to each of the light switches and outlets, so you can pound on the wall next to them. If you hear any crackling or popping sounds, you have a loose wire or bad switch/outlet or possibly a hidden break in a wire.

I didn't see an answer before- how are the wires and cables arranged? Near any power wires, parallel to any and closer than 12 inches?

I installed 2 fresh 20amp breakers and 2 separate runs of 12-2 wire. I had the amp plugged into one outlet, and the preamp in the other. Then I tried both on the same outlet, both in the Belkin, one each in the Belkin/outlet combination…all with nothing hooked into the preamp, and still got the buzz. The only difference has been switching from the RCA cables to the XLR.
I also made sure to move isolate speaker cables, interconnects & power cables.

 

[Segars]

JWhen the amp turned on, did you hear anything? A thump, did you see the woofers move out and back in, slowly? Hiss, buzz? If you hear it with only the speakers and power amp connected, either a component has become loose , failed or a ground issue has arisen.

When I power on the amp, with or without RCA inputs, I get a kind of "poof hiss" noise, right when the status LED lights come on for the 5 channels. It doesn't continue beyond that, but of course the hum/buzz does from the woofers.

In other news, I've since powered down just about every circuit in the house, except for the one my HT setup is on, and it had no effect on the buzz/hum coming from the speakers.

Also worth noting is that -- I might have mentioned this before -- I can't get the hum/buzz to stop so long as all of the RCA inputs are connected. It seems the most problematic input channels are the Center and Front Right. While I might be able to get the other channels dead silent without the C and FR, as soon as I plug one in, it starts up -- and let me be clear that I'm powering down and up whenever I hook in the respective inputs.

More specifically though, it doesn't seem as though the Amp will drive anything beyond any two active channels silently. The more plugs go in, the more defined and widespread the buzz/hum gets.

Truly frustrating.

Any thoughts? I have, by the way, emailed Emotiva tech support but they are obviously not at the office on the weekends, so I suppose I'll have to wait for an official word from them until tomorrow.

 

[Adam]

The problem now is that I can't stretch the XPA-5's cord to a dedicated outlet. It's just not physically possible given the short length of the cord and the distance of the outlets.

Welcome to the forum! Sorry that you are also having this issue. It can be frustrating.

I just wanted to mention the idea of getting a longer power cord. I figure that you won't get one today before talking to Emotiva, but it's a thought as you can find them for fairly inexpensive. For example, Monoprice has this 15-foot 14AWG power cord for under $5. I'm guessing that's at least as thick as what came with the XPA-5.

 

[CraigV]

Well today I got on the phone & called both Emotiva & B&K. After explaining everything to each companies technicians, the conclusion is there is no fault with either piece of equipment. The guy at B&K said the board for the XLR connections may have gone bad, but not likely. He’s thinking there’s some kind of incompatibility issue, and without really knowing anything about the Emotiva gear, he can’t really make any definitive conclusion. He also said (as did the tech from Emotiva) that an XLR run of only one meter is not practical, as the system was designed to eliminate noise in longer runs (3+ meters) and the additional circuitry added in the XLR cable was un-necessary. So, for now it looks like I’ll be sticking with the RCA connections. The hum produced from this combination isn’t as serious as I first thought; I just went way overboard with thinking there “had” to be something wrong. In an ideal world there would be no noise/distortion, and perhaps with the right combination of equipment this can be achieved – I just need to accept what I have is fine the way it is, and I shouldn’t let a little hum bother me as much as I do.

Thanks again for all the help/advice.

 

[highfigh]

I installed 2 fresh 20amp breakers and 2 separate runs of 12-2 wire. I had the amp plugged into one outlet, and the preamp in the other. Then I tried both on the same outlet, both in the Belkin, one each in the Belkin/outlet combination…all with nothing hooked into the preamp, and still got the buzz. The only difference has been switching from the RCA cables to the XLR.
I also made sure to move isolate speaker cables, interconnects & power cables.

Not that cables are all-important, what kind are the balanced ones? Are they braided or the usual twisted pair with a shield? The IxOS crap I mentioned had no-name XLR plugs and jacks, braided wire (looked like 18ga speaker wire) and some kind of nylon mesh. They listed for $400/2m pair and when I saw them, I was NOT impressed.

If you have a meter (and I think I remember seeing that you do), measure the resistance from each pin in the plug to the corresponding pin on the other end. Unless the shield is just not doing its job, this may be due to a bad solder joint on pin 2 or 3. You should basically see ZERO resistance. Touch the leads together and subtract that from what you measure on the cables.

 

[TLS Guy]

Well today I got on the phone & called both Emotiva & B&K. After explaining everything to each companies technicians, the conclusion is there is no fault with either piece of equipment. The guy at B&K said the board for the XLR connections may have gone bad, but not likely. He’s thinking there’s some kind of incompatibility issue, and without really knowing anything about the Emotiva gear, he can’t really make any definitive conclusion. He also said (as did the tech from Emotiva) that an XLR run of only one meter is not practical, as the system was designed to eliminate noise in longer runs (3+ meters) and the additional circuitry added in the XLR cable was un-necessary. So, for now it looks like I’ll be sticking with the RCA connections. The hum produced from this combination isn’t as serious as I first thought; I just went way overboard with thinking there “had” to be something wrong. In an ideal world there would be no noise/distortion, and perhaps with the right combination of equipment this can be achieved – I just need to accept what I have is fine the way it is, and I shouldn’t let a little hum bother me as much as I do.

Thanks again for all the help/advice.

I'm glad you are fixed up.

I think they both made a point that bears repeating, that in most domestic situations, the balanced connection will actually be inferior to unbalanced RCA.

The balanced low impedance connection was designed for very long runs and keeping RF from affecting long microphone cables.

Good microphone cables cost a small fortune, I know because I own a lot of them! They have to be carefully made and tested so that the conductors carrying the signal are identical. Also the output and input ends have to be designed to very close tolerance. Any errors in the cables or the input and output op amps, will increase noise over a standard unbalanced connection.

At the old Quad factory, the professional units were all built with hand picked components and carefully tested for perfect balance. They were priced significantly above the domestic versions for that reason.

Peter Walker, who had a habit of being right about most things, was very much opposed to the trend to balanced connections in the domestic arena. That is why none of his domestic equipment never had balanced connections.

 

[CraigV]

Not that cables are all-important, what kind are the balanced ones? .

Audioquest Diamondback

 

[PENG]

I just need to accept what I have is fine the way it is, and I shouldn’t let a little hum bother me as much as I do.

I bet you are among the few that could do well in a DBT.
Jokes aside, as I said before it is all about S/N, signal to noise ratio. If their is no signal you will hear noise only and noise is something that is facts of life. You can reduce it as much as you can but cannot eliminate it.

By the way, if you ever recall that "made no noise with no signal" piece of equipment please let me know and I will see if I can afford it.

 

[Segars]

Getting a "Humbuster III" from PS Audio shipped to me soon. Will see if that knocks out the interior mechanical hum on the amp, and if so, perhaps that will correct the hum in the speakers, supposing that the hum is being transferred due to the sensitivity of the amp's internals?

I'll keep you guys posted!

 

[Lordoftherings]

I'm glad you are fixed up.

I think they both made a point that bears repeating, that in most domestic situations, the balanced connection will actually be inferior to unbalanced RCA.

The balanced low impedance connection was designed for very long runs and keeping RF from affecting long microphone cables.

Good microphone cables cost a small fortune, I know because I own a lot of them! They have to be carefully made and tested so that the conductors carrying the signal are identical. Also the output and input ends have to be designed to very close tolerance. Any errors in the cables or the input and output op amps, will increase noise over a standard unbalanced connection.

At the old Quad factory, the professional units were all built with hand picked components and carefully tested for perfect balance. They were priced significantly above the domestic versions for that reason.

Peter Walker, who had a habit of being right about most things, was very much opposed to the trend to balanced connections in the domestic arena. That is why none of his domestic equipment never had balanced connections.

Ah, I do agree with you, TLS Guy.

I've been saying that before for quite a long time actually, here and at other audio forums. But a lot of people cry fool.

Thanks for reiterating this fact; coming from you, it is more believable.

Bob