Tweeter hum

[ray5]

Hi! I am noticing a hum from all my tweeters recently. The only change has been change in Dishnetwork receiver without really any connection changes. Also when I start the system there is a brief blip from all speakers. Never happened before. Anyone know why? Thanks,
Ray

[Pio]

Usually hums (ground loops) are caused by equipment with 3 prong AC cords.
If your using a pre / power amp combo with XLR connectors, use that and it will solve the hum issue.
If XLR is not an option, unplug the dish receiver from the to confirm that's whats causing the hum and not that something else is not working right, check this link out:

http://www.audioholics.com/tweaks/connecting-your-system/ground-loops-eliminating-system-hum-and-buzz

[ray5]

Usually hums (ground loops) are caused by equipment with 3 prong AC cords.
If your using a pre / power amp combo with XLR connectors, use that and it will solve the hum issue.
If XLR is not an option, unplug the dish receiver from the to confirm that's whats causing the hum and not that something else is not working right, check this link out:
http://www.audioholics.com/tweaks/co...m-hum-and-buzz

Thanks. I'll try that but the new dish network receiver was plugged into the conditioner as was the last. Since I have the rotel processor XLR is not an issue. Will test though.
Ray

[dukester]

Usually hums (ground loops) are caused by equipment with 3 prong AC cords.
If your using a pre / power amp combo with XLR connectors, use that and it will solve the hum issue.
If XLR is not an option, unplug the dish receiver from the to confirm that's whats causing the hum and not that something else is not working right, check this link out:
http://www.audioholics.com/tweaks/co...m-hum-and-buzz

Not an expert at this but i was experimenting with some rca cables last night. Result was very annoying hum. Removed the rca cables and it disappeared. Could it have been poor shielded cables or the cables being too close to a power cable, or both?

[ray5]

I will try out moving the cables but nothing except the above has changed. I have decently shielded Transparent cables. But who knows? Will give it a shot. Thanks.
Ray

[ray5]

Usually hums (ground loops) are caused by equipment with 3 prong AC cords.
If your using a pre / power amp combo with XLR connectors, use that and it will solve the hum issue.
If XLR is not an option, unplug the dish receiver from the to confirm that's whats causing the hum and not that something else is not working right, check this link out:
http://www.audioholics.com/tweaks/co...m-hum-and-buzz

Here is what happened. I unplugged the receiver, the hum did continue, even with switching to CD or airport source etc. What really troubles me is that when I switched again to blu-ray there was a moderatly loud blip and the channel lights in front of the CA 5200 channel 1,2,4 and 5 went flashing red!! But not channel 3. I powered everything off and tried again and it did it again.
I dare not try again. I hope this did not hurt anything.
Please help. Thanks,

[beden1]

Here is what happened. I unplugged the receiver, the hum did continue, even with switching to CD or airport source etc. What really troubles me is that when I switched again to blu-ray there was a moderatly loud blip and the channel lights in front of the CA 5200 channel 1,2,4 and 5 went flashing red!! But not channel 3. I powered everything off and tried again and it did it again.
I dare not try again. I hope this did not hurt anything.
Please help. Thanks,

Did you check ALL of your connections to see if any are loose? Also check the end connectors to see if any have become damaged from being removed. Also check to see if any RCA cables are running in parallel with any power cords. Unplug the Dish receiver and plug it into another outlet to see if that has anything to do with the hum. Check all power cords to make sure their connections are secure.

You may also need to change RCA cables, one set at a time, to see if any have issues.

Some power amps do not like some cable boxes, and your Dish receiver may be conflicting with it. Also try plugging your amp directly into the wall socket, and preferably on a different circuit as your other gear.

It's usually trial and error, but if it's not the new Dish receiver, it has to do with something that got damaged or changed when you hooked it up, even if you don't think anything has changed.

[beden1]

Since your amp had some flashing lights, you may have also burned out a capacitor or something else within the amp. You could call Rotel to see what they think from the messages the amp is sending.

[dan87951]

Usually these amps have protection modes and I bet you just tripped the rotel into protect mode which protected the amp and your speakers. Ground loops are annoying. If you aren't already using XLR connections I definitely recommend them!

[beden1]

Usually these amps have protection modes and I bet you just tripped the rotel into protect mode which protected the amp and your speakers. Ground loops are annoying. If you aren't already using XLR connections I definitely recommend them!

It may have been something else that caused the issue. I damaged a capacitor in one of my Classe amps when I was doing some connections and forgot the system was on. Fortunately, Classe serviced the amp and it came back in better condition than before the fault.

[ray5]

Thanks guys, the interesting part is that before I unplugged the receiver nothing like this ever happened. I have not switched anything back on yet, am going to check. I have the Furman IT20i. This time I plugged the receiver into the bank that is meant for power amps(there are 4 outlets) and not the bank of 8 that it was plugged before. I am not sure that will make any difference. And since I have a single circuit, plugging into another outlet of another circuit is not an option.

[emig5m]

Not an expert at this but i was experimenting with some rca cables last night. Result was very annoying hum. Removed the rca cables and it disappeared. Could it have been poor shielded cables or the cables being too close to a power cable, or both?

Had the same problem with some of the cheaper Monoprice.com rca cables where over half of my cables where causing a hum/buzz (tested each one, one at a time.) Ordered some cables from Bluejeanscable.com and the hum/buzz went away.

[ray5]

I have decent Transparent interconnects with networks on them. Shouldn't that help?

[emig5m]

I have decent Transparent interconnects with networks on them. Shouldn't that help?

I dunno... For me it was the process of eliminations. I tried different wall outlets (even with an extension cord from another room), moving my sub, unplugging all other gear except the pre & amp and even separating the pre/amp and narrowed it down to the rca cables. What was weird is that the pre amp could even be powered off but with the cables still plugged in, the hum would be there. It was actually the first I ever had a hum problem that required troubleshooting. For me the fix was to replace the 3 out of 5 cables that where bad but wound up replacing all of them with higher quality cables.

[aarsoe]

Does any of your equipment allow for rotating the phase? For instance some of my old Rotel gear only had two pronge cables connections, so it was possible to rotate the plug 180 degrees.
Best way to test is to unplug all cables except the power cables on all components. Then, using a voltmeter, measure if there are any voltage/current running between any two units. Simply put one of the measuremt pins on the cabinet on any unit and the other on any of the other units. If there is a phase issue then you should see half of your ac voltage - so you being in the US would see about 60 volts AC. If that is the case then see if you can rotate the power cable and reduce it to zero volt.
Also do the same measurements to the shielding of your cable tv cable if you have that. Often that is the issue, but can be solved with a ground isolater - radioshack have them..
Hope this helps..

[style]

But is like a "ground" problem?

you can have a good cionnection but a single "gear" can give you this bad problem...

like wrote Beben check ALL , product after product....

style

[ray5]

What is interesting is that this hum and the pops are not consistent. Is that usual if there is a ground loop issue?
For example after what I did above I don't hear the hum today but don't know if that will be consistent in the next few days.
The new thing may be that earlier I had everything but my amp(CA5200) plugged into a Monster surge protector. Then I got the Furman and now everything is connected there. Interestingly it's been a few months that this change has been done only a few days ago this hum and pop problem started.

[beden1]

What is interesting is that this hum and the pops are not consistent. Is that usual if there is a ground loop issue?
For example after what I did above I don't hear the hum today but don't know if that will be consistent in the next few days.
The new thing may be that earlier I had everything but my amp(CA5200) plugged into a Monster surge protector. Then I got the Furman and now everything is connected there. Interestingly it's been a few months that this change has been done only a few days ago this hum and pop problem started.

Regardless of your issues, you should not have your amp plugged into the Furman. Plug it directly into the wall socket.

[ray5]

Regardless of your issues, you should not have your amp plugged into the Furman. Plug it directly into the wall socket.

why?

[beden1]

What is interesting is that this hum and the pops are not consistent. Is that usual if there is a ground loop issue?For example after what I did above I don't hear the hum today but don't know if that will be consistent in the next few days.
The new thing may be that earlier I had everything but my amp(CA5200) plugged into a Monster surge protector. Then I got the Furman and now everything is connected there. Interestingly it's been a few months that this change has been done only a few days ago this hum and pop problem started.

I had a ground problem a few years ago that we later determined was coming through the TV cable because the cable to the house was not grounded properly at the street. It would be intermittent, and was heard mostly at night when our central heater was working. It took the cable company over a year to figure it out, after blaming everything in my house, and after I spent a fortune with an electrician and having the power company come out with their engineer.

These ground faults can also be caused by a dimmer switch that may have gone bad, or flourescent lighting, or a microwave oven, or, etc.

Since your problem is not apparent right now, it may also have been you just touching a bad RCA cable and temporaily moving it just right that the problem went away. But, the cable is still bad, and you'll only be able to trace it down through trial and error.

[beden1]

why?

Because the amp draws more power than the Furman can handle and it overloads the Furman. Plus, Classe told me not to, and to plug it directly into the wall socket. They had another reason for it that escapes me at the moment.

[beden1]

why?

In my three systems, I have the amps plugged directly into the wall sockets and everything else into a Furman Reference, etc.

In two of my systems with cable TV, I have the cable box plugged into a separate wall socket and circuit (I like to separate the cable box which is usually the biggest ground fault offender, as well as run the cable through a surge protector). In my two main systems, I have two dedicated 20 amp circuits going to each system, along with the original 15 amp service. In the system where I have three amps, I have them plugged into the 20 amp circuits and the rest of the equipment plugged into the 15 amp circuits through a Furman Reference or a Richard Gray.

[htsteve]

why?

Genrally because many conditioners, including quite good ones, will limit current in some form. Limiting current will limit an amps performance.



Hope this helps.

[dukester]

Genrally because many conditioners, including quite good ones, will limit current in some form. Limiting current will limit an amps performance.



Hope this helps.

How will the effects/limitations manifest themselves? Audible or measurable?

[ray5]

My cable feed does go from the wall to the Furman and then to the box. When I was researching the Furman I found from the company and many from this forum saying that it would not limit the current for the amp to perform to it's potential. As dukester asked is there an objective way to confirm this?

[aarsoe]

Don't think you can can use any measurable output as a guidance. In the end your ears should guide you to what you feel sounds better and use that config going forward..

As an example a really accurate audio chain may be correct, but if it leaves most recordings un-beareble then what is the point as you no longer are able to enjoy the music.

[htsteve]

How will the effects/limitations manifest themselves? Audible or measurable?

dukester,

My experience has been that the dynamics are compressed. The overall sound was a bit more compressed. Not horribly so, but still noticable in my room.



Ray5,

The easy way to test your system is to plug the amp into the wall.
Play a favorite passage or CD. One you know very well. Then plug the amp into the Furman. If you do not notice any degradation, then you should be OK. The sound does not change and you have additional protection. You may even get some better sound if the filtering on the Furman is really good (as I suspect it is).


Hope this helps.

[Glen B]

My cable feed does go from the wall to the Furman and then to the box. When I was researching the Furman I found from the company and many from this forum saying that it would not limit the current for the amp to perform to it's potential. As dukester asked is there an objective way to confirm this?

If you have your amp plugged into the Furman unit and hear no ill effects, leave it that way. Your Furman unit is rated at 20A which is as much capacity as you directly from the wall, with the inclusion of power factor correction. The Furman should serve as a buffer for instantaneous current demands from the amp, as stated in the manufacturer's specs.

Yes, some power conditioners can limit current and degrade amp performance, but this should not be the case with your Furman product. I use 20A balanced power with my amps, and its most noticeable effect is improved low frequency performance. The transformer stores energy and reduces the source impedance the amp "sees".

[style]

I'm in europa and we don't have like you electricity problem....the 230 is more clean and 9 high end system to 10 have the power amplifier direct at the outlet connect.....for better sound, dinamic, ....and we dont have ground problems ....

if you dont' have a dedicat line is (but too with a more dedicat line!) better go with te amplifier into a outlet and with the pre, source into another outlet...is the same line but have all the "gears" at the same "input" is not a good solution...

if you have a dedicat line in your program/target to do 3 x : 1 x the amplifier, 1 x the source and 1 for the ampli....
so you can forgot all the power bar, APC group,....well in Europa is so....

[ray5]

If you have your amp plugged into the Furman unit and hear no ill effects, leave it that way. Your Furman unit is rated at 20A which is as much capacity as you directly from the wall, with the inclusion of power factor correction. The Furman should serve as a buffer for instantaneous current demands from the amp, as stated in the manufacturer's specs.

Yes, some power conditioners can limit current and degrade amp performance, but this should not be the case with your Furman product. I use 20A balanced power with my amps, and its most noticeable effect is improved low frequency performance. The transformer stores energy and reduces the source impedance the amp "sees".

That's the rational I used to buy this unit. I did write to get Classe's opinion. Apparently Tom has been replaced by someone. Very poor answer which basically said, don't ask us ask Furman!

[style]

Glen B sorry but Classe dont say sure you to use a Furman or other power conditioner....
I have always receive as reponse from Classe that the top sound from our ampli Classe say go direct into the wall! so you go have the "Classé sound"

I have a friend who works at ClasséAudio and he always told me not to use our Classé ampli with products such as Furman between them and the wall.
well in Europa is really not necessary have a Furman or XY conditioners to make sweetdream...

sound quality apart this "produtc" can give you more problems than advantages.....

[beden1]

That's the rational I used to buy this unit. I did write to get Classe's opinion. Apparently Tom has been replaced by someone. Very poor answer which basically said, don't ask us ask Furman!

This is the person who has helped me at Classe for the past 4+ years and he is very helpful and knowledgable: Michael Sheehan, The B&W Group, www.bwgroup-support.com

[ray5]

This is the person who has helped me at Classe for the past 4+ years and he is very helpful and knowledgable: Michael Sheehan, The B&W Group, www.bwgroup-support.com

Thanks, I'll write to him. Tom has always been so great about questions!I hope he hasn't left the company.
Ray

[Glen B]

Style, you keep repeating what Classe has said to you and I get that already. My philosophy has always been to listen and judge for oneself and arrive at an informed opinion, versus blindly following what anyone says or making snap judgements without having tried a product. The funny thing is that Classe's company motto during the 1990s was "You Be The Judge!", meaning you listen and judge for yourself.

[ray5]

This is the person who has helped me at Classe for the past 4+ years and he is very helpful and knowledgable: Michael Sheehan, The B&W Group, www.bwgroup-support.com

Heard promptly back from Mike, very appropriately said they recommend plugging into the wall as conditioners may not be able to support the draw on peaks. He did not comment on the Furman I have which is understandable by company policy. But I have read several tests done by members of this forum that the current draw is not even close to 15 amps at peaks, rather closer to 4-6 amps. So, plugging into the Furman shouldn't matter. Though we are digressing from my original post but at least this seems clear. Thanks,
Ray

[beden1]

Heard promptly back from Mike, very appropriately said they recommend plugging into the wall as conditioners may not be able to support the draw on peaks. He did not comment on the Furman I have which is understandable by company policy. But I have read several tests done by members of this forum that the current draw is not even close to 15 amps at peaks, rather closer to 4-6 amps. So, plugging into the Furman shouldn't matter. Though we are digressing from my original post but at least this seems clear. Thanks,
Ray

Why not just follow the advice of Classe and plug the amp directly into the wall socket? Is there some particular reason why you feel the Furman will benefit your amp?

[ray5]

Why not just follow the advice of Classe and plug the amp directly into the wall socket? Is there some particular reason why you feel the Furman will benefit your amp?

Well, the reason I use it is to protect my investment. I know that it has a lot of built in protection but still............
May not be rational but I have plugged everything into the Furman for now. I have only one circuit(15 amps), though have plans for a dedicated 20 amp one sometime.

[ray5]

Whatever I did, for the moment it is resolved. Thanks a lot guys.
Ray