I have a Bel Canto amp that has terrible transformer hum when I turn my plasma TV on. If the TV is off, the amp is as quiet as can be. On PS Audio's site, they have a product called a Humbuster to remove DC from the lines which apparently cause transformer hum. Could the issue I am having be caused by my TV sending DC through the lines to my amp? Anyone have any experiece with the Humbuster? Are there any cheap fixes?
Blue- Almost all ground loop issues are caused by the ground being closed either on:
1.) Satellite/Cable feed coming INTO a TV.
2.) The TV itself.
So yes, I can definitely tell you its your damn TV.lol. A high end product like a Bel Canto amp will pick this up. Adcom? ahh not so much. My old NAD did not either. Threw in a Bryston, and it revealed it.
You can try a home remedy. Sometimes it works, sometimes not. Use an extra Coax In/Out connection on the Plasma to ground to something. I know a guy who had this problem with a Sony LCD, and he grounded the whole tv using a coax cable. It took the hum out of his system as soon as the other end touched an object of ground from the TV. Worth a shot before getting the humbuster. Bryston engineers told me that the little adapters such as the Humbuster work wonders.
Thanks. Funny that my Simaudio Titan doesn't reveal any of these issues. So, you are saying to try running a coax from the TV's coax input to a piece of metal such as another component chassis?
(There is only one coax in on this tv, which although I have it hooked up, I use the HDMI in from my Anthem.)
Used to be, on cable lines and splitters, that if there was an open connector, interference could happen. The fix was to screw on a terminator. This is a simple resistor on a cable connector to cap off the offending open connection.
Sometimes some amps just don't like the system they are in. I also had a big fat 5 channel Rotel amp in my system for a day or two, no hum with it either. As soon as the Bryston was in it, it started whining. Unplug the coax from either the satellite receiver or the TV, it was dead quite. It now lives by itself, much happier with its own kind(Bryston pre). I have a second Sony LCD in my two channel system as well, and it has no problems with it. As soon as I bring down into the theater, it complains.lol. Moral of the story...Some amps just don't like to be in some systems.
BlueMark- perhaps its time to build another system based around the Bel Canto?lol. They really are very nice sounding pieces. It just seems it doesnt want to cope with your Plasma.
The BC was purchased to give me great 2 channel sound in my 7 channel home theater system which it certainly does. It's not that easy or feasible to start purchasing things like plasma TV's to see if they are compatible with the BC. I would prefer to find a solution for the system I have now as I am very fond of each of the components I have. If I were to change anything, it would be the BC as it appears to be the incompatible component, but like I say, I would prefer to find a fix for the system rather than change components.
My first suggestion would be to contact the manufacturers. Call the TV people and call BC. They know their products better than anyone else. They are in a better position to give advice than anyone on a forum.
If you don't want that advice, take one of the ideas above or, as I suggested earlier, try grounding the chassis of the TV and the amplifier to the center screw of your AC outlet. A common ground point such as that will probably either reduce the noise significantly or increase the noise dramatically.
I assume you did buy the outlet tester I suggested and you know the outlets are wired properly. If you don't know that, you need to find out.
Take Nick's suggestion and connect the "F" type coax connector to an unused jack on the TV and touch the other end's "F" connector to the center screw of the outlet. The cenetr screw of the outlet should always be a reliable true ground point. The tester will tell you whether your outlet is wired to provide that ground.
It is a good idea to disable the unused jacks on a system as they represent a source of noise. I would be surprised if the open (video) jacks on the TV are the source of transformer hum in the associated amplifier but electricity does strange things and most everything is worth a try before you spend dollars on something that is just as iffy about solving the problem.
Buy some 1/4 watt resistors somewhere around 75Ohms in value and solder the two ends to the hot and ground tags of your connectors, one side of the resistor to the hot (usually center tag) and the other to the ground side. This will then terminate the open jack with the proper amount of resistance. This can be done for either video or audio jacks. Then you just start plugging these into your system to see what happens. Always keep the volume control down to a low level when plugging anything into or out of the system and ideally you only plug in or out when the system is powered down and then power up to make checks.
You mentioned in the last thread the amplifier only hums when it is in proximity to the TV. Any chance you can just rearrange your system so the two are not seeing one another?
The PS Audio device might be a last ditch effort to resolve the problem. It is again very unlikely the TV is introducing DC back through the AC lines - particularly if the TV is connected to a surge protector/line conditioner since most of those devices would give some visual indication of a line fault of that order and are likely to block DC by themself - but electricity does strange things. If you haven't yet tried cutting the ears off the polarized ground lift and reversing the position of the plug in the outlet, I would try that before spending money.
Jans post provides a lot of great idea's. One thing Jan said about making it so they don't see each other is a great idea. Are they both plugged in to the same power source? Have you tried running a long extension cable to a different power circuit in the house for the BC? Just throwing ideas out there.
My first suggestion would be to contact the manufacturers. Call the TV people and call BC. They know their products better than anyone else. They are in a better position to give advice than anyone on a forum.
Did that and it was of no help.
If you don't want that advice, take one of the ideas above or, as I suggested earlier, try grounding the chassis of the TV and the amplifier to the center screw of your AC outlet. A common ground point such as that will probably either reduce the noise significantly or increase the noise dramatically.
I never indicated I didn't want help. That is why I am here and I did try all suggestions so far and none worked yet.
I assume you did buy the outlet tester I suggested and you know the outlets are wired properly. If you don't know that, you need to find out.
I tested the wiring and from what I can tell, it all appears ok.
Take Nick's suggestion and connect the "F" type coax connector to an unused jack on the TV and touch the other end's "F" connector to the center screw of the outlet. The cenetr screw of the outlet should always be a reliable true ground point. The tester will tell you whether your outlet is wired to provide that ground.
As indicated in an earlier post, there is only one coax connection on the TV and it is being used, but I will try this to see if it makes any difference.
It is a good idea to disable the unused jacks on a system as they represent a source of noise. I would be surprised if the open (video) jacks on the TV are the source of transformer hum in the associated amplifier but electricity does strange things and most everything is worth a try before you spend dollars on something that is just as iffy about solving the problem.
Nothing is connected that is not used.
Buy some 1/4 watt resistors somewhere around 75Ohms in value and solder the two ends to the hot and ground tags of your connectors, one side of the resistor to the hot (usually center tag) and the other to the ground side. This will then terminate the open jack with the proper amount of resistance. This can be done for either video or audio jacks. Then you just start plugging these into your system to see what happens. Always keep the volume control down to a low level when plugging anything into or out of the system and ideally you only plug in or out when the system is powered down and then power up to make checks.
I'm not sure I follow this.
You mentioned in the last thread the amplifier only hums when it is in proximity to the TV. Any chance you can just rearrange your system so the two are not seeing one another?
It appears to hum only when the TV is on. Rearranging is possible, but certainly not practical, and then there is the wife factor.
The PS Audio device might be a last ditch effort to resolve the problem. It is again very unlikely the TV is introducing DC back through the AC lines - particularly if the TV is connected to a surge protector/line conditioner since most of those devices would give some visual indication of a line fault of that order and are likely to block DC by themself - but electricity does strange things. If you haven't yet tried cutting the ears off the polarized ground lift and reversing the position of the plug in the outlet, I would try that before spending money.
I just received an e-mail back from PS Audio where I described the situation and their answer was quote: "It sounds likely that the plasma is causing a DC offset on the AC, if this is the case, a Humbuster will stop the transformer hum in the eVos. The only way to know for sure will be to try the Humbuster."
Maybe a sales pitch, but I managed to find a used one for $125 online, so we'll see if it really works when it arrives.
Jans post provides a lot of great idea's. One thing Jan said about making it so they don't see each other is a great idea. Are they both plugged in to the same power source? Have you tried running a long extension cable to a different power circuit in the house for the BC? Just throwing ideas out there.
As indicated in my response to Jan, rearranging is possible but not practical. Besides, the cost of wiring to make this happen would outweigh the price I paid for the Humbuster, assuming it works. But your suggestions are appreciated.
Is it possible to move the BC away from the TV...just for a test? There are 2 ways for bad stuff to enter electronics. Thru any lines/wires connnected and Wireless...thru the air 'RF' or its relatives. Plasma TV's generate a huge field. If the sound reduces or goes away, that will tell you something. If it stays the same, back to humbusters and that kind of fix. A large isolation transformer can work in cases like that. No DC can pass.
I would also have some other questions. Is the BC an ICE or Tripath design? The ICE modules usually have an onboard SMPS which is at 400khz or so. I don't know about Tripath PS requirements. 2 high frequencies sufficiently close together can produce a low frequency 'beat' tone, which you MAY be hearing?
I could move the BC further away, but not practical and the wife factor would make it difficult.
I don't understand your comment: "If the sound reduces or goes away, that will tell you something. If it stays the same, back to humbusters and that kind of fix. A large isolation transformer can work in cases like that. No DC can pass." Can you please clarify?
Blue:: I am just working on the idea that the problem is not coming down the wires but is being 'transmitted' in a wireless fashion. The test ....and due to WAF (Boy, I know about that one!) only a test, would be to increase the distance between the TV and the BC. If the buzz/hum goes away it is possible it is coming thru the air.
To clarify, NO DC can pass an Isolation transformer. Period. Anything that is AC CAN pass. My Panamax power conditioner has a smallish iso trans which I have all my low power stuff plugged in to. One of the theories you are working from is that somehow the TV is polluting your power w/DC? AS A TEST ONLY:: move the BC further from the TV. This was Jan's suggestion half a dozen posts ago, and based on all else, makes sense.
You can also try running the BC from an extension cord plugged into a totally different ciruit. You'll have to know where your circuits are distributed through the house - which you should know anyway - and pick a circuit that is a far away from the TV outlet's circuit breaker as possible.
Now, this alone can introduce a ground loop since the two devices could possibly be at different ground potentials when they are not sharing the same circuit breaker- but any noise will not be caused by the TV allowing DC to pass through the surge protector. And ideally, this shouldn't make a difference if the entire service panel and all of your circuit breakers are grounded properly to a true earth ground. Installing a dedicated ground is still one of the best ideas to get around grounding problems.
The ideal again would be to have all of your components "star" grounded to one earth ground, that means all components on the service panel see the exact same ground point. If the panel is grounded to a cold water pipe as is typical of older installations, not only is it considered dangerous by most current building codes, but you usually have several points where ground is located.
another good ground is the famous 1"x10' copper rod driven into the ground. Depending on soil conditions this is the way to go. Also, contact an electrician who owns some 'megger' equipment to check resistence TO ground
Water and electricity don't mix well. We had a Dallas electrician die from electrocution a few years back when he crawled under a house and got into some standing water that was running from a cold water pipe which had been used as a ground. Apparently there was a problem in the service box and somehow he found 120 Volts.
I've been waiting to report back until the corrective gear I've ordered arrives. I received the Ebtech ground loop isolators today and low and behold it has cured my speaker hum, so only the transformer hum remains. I will update you on that when the Humbuster arrives.
Have tried various scenarios/variations and currently I have the Bel Canto plugged into the Ebtech which is plugged into the Humbusster which is plugged into the Quintet. Seems to provide the best results so far.
Hum is gone thanks to the help of Mr Glen Wagenkenecht of Scarborough, Ontario. It turned out to be a simple fix. He contacted me after he saw that I wanted to sell the BC due to my frustration with the hum issue. He has the same amp and after persuading me that I would be hard pressed to find another amp of this musical caliber, he offered the following:
"The XLR/RCA switch is used to optimize the grounding at the amplifier inputs. Setting the XLR/RCA switch in the RCA position connects the RCA ground to the chassis and the power cable.
If using Balanced XLR cables then leave the switch in the XLR position, otherwise the negative XLR input will be shorted to the amplifier ground.
If using the RCA inputs and the Preamplifier has a floating ground then using the RCA switch position will give the lowest noise operation.
This will connect the system ground to the power ground at the amplifier.
Try connecting the RCA ground to chassis ground by depressing the RCA/XLR switch button (RCA position).
If this button is depressed and there is ground noise or hum then try setting this switch in the XLR position.
Putting this switch in the XLR position effectively lifts the RCA ground on the amplifier input and can prevent ground loop noise. This is especially useful for systems using more than one amplifier chassis or when using the eVo4 or eVo6 amplifiers in a system.
These procedures should be adequate to correctly ground most systems."
To think, BC could have told me that before I spent all this time and money on devices is a bit frustrating, but thanks to Glen, I am now hum free and hearing all the unrestricted music.