Lamp making my receiver buzzzzz... (1 Viewer)

[Michael Cucka]

Hello -
I posted earlier about my Marantz 9200 starting to buzz a couple of weeks ago - the unit itself, not thru the system. After going thru all possibilities, it finally came down to be caused by a standing floor lamp in the same room :frowning:
This is a simple incandescent lamp - two 60W bulbs, no dimmer - with a two position switch (bright and brighter). The recvr buzzes more at the lower brightness than full position (sort of like a dimmer, eh...?).
If the lamp is on, having my 9200 plugged into any outlet in my house causes it to buzz - even in a different room. And vice versa...
Since it's a cheap lamp, I know I can get rid of this problem by trashing the lamp - but I'll need something to read by in the room
Any suggestions to eliminate the problem with either this current lamp or any future ones I buy to replace it - short of a dedicated line?
Thanks!

 

[Kevin C Brown]

Try any AC filter a la Panamax, Monster, Adcom, etc.

I've personally had more problems with a halogen lamp with a dimmer. (Worse buzz with the dimmer cranked down than up, somehow that extra "resistance" gets back into the line or something.)

Could also try a different outlet too to try to get on a different (part of the) circuit.

 

[Michael Cucka]

Thanks, Kevin - I didn't put details from my original post here, but my system does run thru a Monster PowerCenter 3500 for filtering, etc. Also, during my trouble-shooting I noticed that if the lamp was on, plugging the 9200 into any outlet in my house (even a different room) caused it to buzz.
I even have a second identical lamp in an upstairs bedroom (fairly remote from the listening room) and if it is on, it makes the 9200 buzz (albeit not terribly loud).
I'll probably wind up replacing the lamps - but with my luck, those will make it buzz as well :frowning:
Take care -

 

[Chu Gai]

since the lamp is the issue, that's what needs either replacing or 'repairing' with a better switch. if you've got a local electrical supply house around, pay them a visit and see what they'd recommend. The dimmers, even your types, are very inexpensive and are prone to throwing out hash. you might also consider lamps based on incandescents.

 

[Michael Cucka]

Thanks! The lamp is already a simple incandescent with 2X60W bulbs and only a simple toggle switch (see above) - what type of replacement switch should I ask about?

Regards -

 

[Bill Kane]

As much as I hate to face it, I think more and more of us home system users are experiencing electrical hash as much from internal "backwash" as external RF and EMI sources (the radio xmtr tower, the nearby powerline etc.)It may mean that our standard surge protector/power centers with their AC noise filters aren't up to the job.
A recent discussion by a guest speaker on avsforum, the chief product engineer from FurmanAudio, seems to confirm this. Yes, I know he represents the sale of big black boxes, but still, there's an electrical engineering underpinning to this. For fun, I'll make this LINK.
What I am concluding, is that the Big Fix is going to have to be using a Balanced Power or at least an Isolation Transformer that work on common mode currents which can induce hum in A/V equipment. Isolation xfmrs are said to eliminate magnetic field radiation while BP works on radiated electrostatic fields in connected power cords.
At the HT consumer level, problem is these boxes range from the $1,000-$1,200 class (B-P-T; MonsterPowerHTPS 7000; Panamax Max 5510 (new) to $1700-$1800 (Furman IT-Reference; Smart Garbage Collector and others).
Here in this thread, obviously its better to go through a series of lamps than buying one of these transformers. But as we keep adding electrical/electronic devices in our homes, I wonder where the tipping point will be when the "backwash" overloads our HT systems and we are forced to consider these "ultimate" power filter/conditioners, if not running a dedicated circuit, which may not be exclusive. And of course, we still will want to see field reports that these devices really WORK.
Food for thought....
bill

 

[Kevin C Brown]

I'll 2nd the nod for balanced power. Secrets at Link Removed has a bunch of reviews. I have an Equitech 2Q, and couldn't be happier. The Monster 7000 is also a very nice unit. Very reasonably priced too. And some of the BPT units are as cheap as $700 (the BP-2) for what you'd need to power an HT.

 

[Bill Kane]

Kevin, thx fpr popping in...

Do you regard yr BP unit as an "ordinary" noise floor lowerer for yr system, or more aggressively, as a vigorous co0rrective/palliative for extraordinary grunge/hash?

Do you get my drift? I dont think from what I read that a BP is a cure-all -- it can eliminate any hum but perhaps not all hiss -- still heads above surge protectors' filters.

bill

 

[Kevin C Brown]

Here's how I think of it:
"Filters" are the easiest and cheapest to try. I had an Adcom ACE-515 for years, then a 615 for a short while.
Maybe I'd put stuff like the Richard Gray units a notch above a typical filter. But some systems don't realize any benefit from the RGPCs.
Then I'd put balanced power next up in the food chain. I'd say that balanced power gets the best/lowest noise floor. But there are 2 things a balanced power unit won't do: voltage regulation and perfect AC sine wave.
As far as voltage regulation, my unit has a V readout, and I've never seen my V swing outside of 117 to 121 V. So I can say I don't think I need that.
As far as a perfect sine wave, there are only 2 companies that give you that: PS Audio and their Power Plants, and ExactPower.
PS Audio, IMO, gives you perfect AC. But they are big, heavy, expensive, and inefficient. ExactPower gives you a perfect sine wave, voltage regulation, but I don't believe that they give you as low a noise floor as the PS Audio units or balanced power. In fact, in the Secrets review of the ExactPower EP15A, they say close to an ideal solution is the EP15A with a separate balanced power unit. Gets you close to PS Audio performance, but much cheaper. And it doesn't double your electric bill.

 

[Michael Cucka]

Had my dealer over last night to play with some things and really the only solution seems to be to eliminate the lamp. Even tried a Tice Audio Power Block III and the buzz remains.

Really seems to be something with the switch in the lamp since even lamps that have dimmers or halogens don't cause this buzz on my 9200.

Thanks!

 

[Joe Szott]

Yeah, buy a new lamp from Target for $20 and be done with it

 

[Chu Gai]

Well Michael, it may well be that your lamp is broadcasting in which case the cheapest solution is another lamp. However reading this post, I do have some things I want to just unload with some of it being germaine and some of it just stream of conciousness.
As I read this thread, and many more like it on this forum and others, I think back to when I'd gone to watch my older son playing baseball. He had been on 2nd base, where I could tell something was wrong by the way he favored one foot. A long single to the right field corner brought him home, and his labored running indicated to my eyes he was in serious pain. He crossed home and I made my way to the fence where he hobbled to sit with his team. He saw me and said that his foot was killing him. I said maybe you've broken something and we should go to the hospital. Looking at me, he sat down, removed his shoe and took out a rather small sharp rock. When I asked him why he hadn't called time at 2nd and had it removed, he replied that Lenny, the boy who'd hit the long single, doesn't hit well when he has to wait. The point of this story is that I see situations where people opt for expensive and possibly unneeded approaches when more common sense ones should be investigated and implemented first. Mind you now, I'm not advocating against the purchase of power conditioners in all the various flavors that are out there. Rather I am advocating for a more rational approach to matters.
Since the influx of noise from a multitude of sources is a concern for many individuals, I think in general there are certain prophylactic measures that should be taken before investing in some sort of power conditioning or massaging. Primarily, I think that involves placing ones components on a separate circuit with no shared grounds. Before you even THINK about balanced power, first fix your grounding problems, repair/replace/move sources of noise. When you don't have ground loops anywhere, when you've eliminated or minimized noise emitters and you have a clean and coherent grounding system, then IMHO you can start to consider balanced power if you have noise problems.
In situations with noisy dimmers it depends on how that noise is getting into your system as to the ultimate success of an approach. If it's solely through shared AC lines then move the offending device to somewhere else or replace it with a better and quieter unit. However if this grunge is also coming through the airwaves and overwhelming the built-in 'immunity of our components, then balanced power or whatever won't do squat. Bill, I'm not so sure what you mean in the way of transmitters and RFI. Personally I live within 1 mile of over a dozen of microwave, K, and Cu band transponders and other radar dishes that are used for programming and some satellite monitoring. There are I believe at least 2 other such facilities within 5 miles of my home. There are also a couple of ham operators and maybe it's that I'm lucky, but I don't seem to have an issue with RFI polluting what it is that I own.
From my understanding, one of the "problems" with balanced power is that all devices are connected in parallel to the output of the unit. The net effect is that the power quality can be no better than the unit that has the worst power line common mode operation. If you've got ground loop problems without balanced power, you'll still have them with balanced power. Now most of the stuff you connect to a balanced power device will have some sort of transformer. So long as it's the only device connected, one has an ideal situation. If you plug in a device that has any EMI filters (beefy aftermarket power cords ring a bell?) things change. In order for them not to have a negative effect, the EMI filters that are present would have to be identical on the neutral and live lines going into your device. Do you know for a fact that these filter components were matched to 1/10 % or better? Plug in more units like the one I just described and we've managed to asymetrically load our device and much of the effectiveness of our balanced power device has been negated. Personally, I think an approach using good isolation transformers will yield at least as many benefits as a balanced power device. Their performance won't be compromised when you plug your equipment in nor will it lose its senses when a lamp is plugged in either.
Manufacturers of balanced power systems claims that balanced power solves all ground loop problems in audio and video systems. It's further claimed that you get much better noise. Now my understanding is they had their great successes in audio primarily in the professional audio field where equipment had a chassis leakage problem and in those cases they were looked upon as a miracle. However if that's not the problem I can't see it doing any better than any other isolation transformer.
Lastly for those in favor of overkill and maybe its not so much so when one is contemplating running a new dedicated circuit for their HT system is to consider using a star grounding system if possible. In a star ground each receptacle ground has it's own path to earth ground. In a bus ground, the receptacles grounds are run in series creating different ground potentials between pieces of gear and possible eddy currents which can cause noise.
As far as people who have issues with radiated RFI and there's nothing that they can do about it, it would seem that in the way of cables or interconnects, those types that utilized a star-quad geometry would be best suited to dealing with these issues. Plugging up unused connections also sounds like a prudent approach.
Sorry for rambling but it's just my $0.02. Cough up another 5 or so and have some Starbucks.

 

[Bill Kane]

Chu,
That's certainly worth $0.10 toward a cuppa Starbucks, and much to think about.
It seems to me i see two aspects in viewing ISO and BP: The makers/marketers sell them as devices that will improve your sound by substantially lowering the noise floor, whatever it may be; the "audiophile" approach.
Perhaps more sensible, you take the view that these devices are used to fix an unusual electrical interference problem. This of course can result in "improved' audio.
(I do not suggest that ISO or BP alone have anything to do with RF/EFI AC line noise which may be corrected independentally by such means as ferrite rods/coils, capacitors etc).
I totally agree to find-the-root-cause approaches and even a dedicated circuit before throwing big black boxes into the system.
It wud be nice to audition one, however, before spending the big bucks, to see what it does for "audio improvement" even absent any glaring problem in the system. Isn't that always an elusive but beaconing end-of-the-rainbow pot of 'goal'?
bill

 

[Chu Gai]

yes they'll lower the noise floor...under certain conditions but it's those conditions that are rarely talked about by these people. IMHO, one gets more valuable advice regarding interference and noise issues from people who deal in professional audio (stage bands, etc.) and from amateur radio operators and good qualified car stereo installation places. Rather heretical thinking I'm afraid.

 

[Kevin C Brown]

Aaay, there's the rub. I *don't* see my BP unit as improving anything. I see it as eliminating noise that isn't supposed to be there in the 1st place, and letting the true audio and video signal through without interference.
Most recording studios and some of the better movie theaters use balanced power. Just another way of applying the same concept as for balanced interconnects: common mode noise rejection. A more "natural" way of eliminating noise than filters. If you look here:
http://www.psaudio.com/articles/power_conditioners.asp
You'll see that a lot of AC "filters" can actually add distortion to your AC line. A filter isn't some magical device where you get "something for nothing."

 

[Glenn Overholt]

Try this one out if you haven't already. It has done wonders in some cases.

Get a piece of wire and connect it from the ground terminal on your receiver and then wrap the other end around the center screw of your wall socket.

Glenn