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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 4674 Registered: Feb-07 | I've been having some issues with my amp lately. It all started when I went back to using a CD player as a source (as opposed to the PC/DAC setup I was using previously). What's happening is that when I play music I hear a very high-pitched whine coming from the speakers. It's very subtle, but nonetheless, very noticeable, and annoying. It almost sounds like that background white noise that a plasma TV or a computer will make when on. It's only present when a song is playing, and it's coming equally from each speaker. I've tried all the usual trouble shooting. I've swapped out tubes - all 12 of them, I've switched interconnects, swapped out speaker cables and even tried different CD players. The only time it doesn't happen is when I take a CD player out of the equation and use a PC/DAC combo. So here is my question: Is it at all possible that the transport or laser in the CDP(s) is somehow transferring this noise to amp? |
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Gold Member Username: HawkbillyNova Scotia Canada Post Number: 1263 Registered: Jul-07 | If the problem goes away when the cdp is out of the loop then that would lead me to believe your amp is fine. I'm not sure what in the cdp would cause a whine. What cdp are you using now ? The Jolida ? |
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Gold Member Username: MagfanUSA Post Number: 2176 Registered: Oct-07 | Some kind of capacitor going south, and bleeding over into the signal path? Bad / leaky shielding on the interconnects? Any way to try another CD player? Even a universal player from the TV room would do for test purposes. Maybe try some different ICs. Bad ground / void in the shield? And while your at it, try some different inputs on the amp. Maybe a cap at the input....per RCA, is going bad? Are there any motor controls or light dimmers on when this happens? Hair dryer? A 100:1 long shot (against) would be some problem with any power conditioning, if used. |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 4675 Registered: Feb-07 | Hey guys. This has happened with 2 consecutive CD players. At first I thought it was the CD player, so I returned that, and tried a different brand. Same result. Tried... different interconnects, different inputs on the amp, different speaker cables. It's not a mechanical whine coming from the CD player, but a high pitched whine/ringing from the speakers. No power conditioning (plugged straight into the wall), my wife doesn't blow-dry her hair at night during listening sessions :-) |
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Gold Member Username: HawkbillyNova Scotia Canada Post Number: 1264 Registered: Jul-07 | So, the only time the noise is there is when the cdp is in the loop, but you've tried different cdp's with the same result ? Just want to make sure I understand. Are you connecting the DAC to the same input as the cdp's, or a different input on the amp ? Do you have a cheap, long interconnect so you can try running the cdp at a greater distance from the amp, just to see if it's a proximity thing ? |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 15953 Registered: May-04 | . What's happening is that when I play music I hear a very high-pitched whine coming from the speakers. It's very subtle, but nonetheless, very noticeable, and annoying. It almost sounds like that background white noise that a plasma TV or a computer will make when on." White noise and a whine are two different things and might indicate two different problems so, it would be beneficial to distinguish between the two sounds. White noise is more what you hear in between channels on a tuner and I think we all know what a whine sounds like. White noise in a tube amplifier is often the sign of a bad tube or a bad connection which can oftentimes be found at a tube pin connection or a switch contact. You say you swapped tubes, how did you do that? With a completely different set of tubes? Or, did you just move tubes around? Noises common to both channels are most often located only in those areas which are common to both channels. While Murphy has a sense of humor when it comes to expensive audio systems, he usually doesn't afflict two identical components - one in each channel - at the same time. That would take the problem down to either the front end of the power supply or the ground plane. Ground noises don't tend to be either white noise or a whine. Rectifiers and transformers make noises which would be common to both channels. It's possible either a bad rectifier tube or a power transformer that's worked its way loose might be causing the problem. Transformer noises do not typically choose to occur only when music is played and then not exist when the music goes away. First question would be, does your amp use tube rectification? If so, did you swap out the rectifier tube? As leo suggests, whiney noises tend to come from outside of the system and are caused by motors or other drains on the AC circuits which would introduce noise through the electrical system of the house. They would almost always be common to both channels due to the location at which they enter the system. The problem once again is these noises aren't normally able to discriminate between music and no music. They are there when the other appliance is drawing current and not there at all other times. There might be something in the circuitry of the Manley that would make this peculiar to the Stingray though so it's worth investigating. "No power conditioning (plugged straight into the wall) ... " You might try a noise/spike filter. Doesn't have to be expensive, just anything that claims to have EMI filtration. Don't use an old one as these filters do wear out over time. It's all but impossible for the speakers to generate any noises on their own. Same for cables. "This has happened with 2 consecutive CD players. At first I thought it was the CD player, so I returned that, and tried a different brand." Then it's probably safe to assume the problem doesn't exist within the CD player itself. "Really, Holmes, how you do this is astonishing!" "The only time it doesn't happen is when I take a CD player out of the equation and use a PC/DAC combo." That the noise occurs when the source device is powered through the AC system seems to indicate a place to look here. Here's what I would do. 1) Try another device into the inputs of the amplifier. Make this a portable, battery powered device like an iPod or MP3. No noise? Then the problem exists somewhere in the AC circuitry of the house/system. Noise? Then the source player is not the problem (which we already expect) and the only other component in the system which would commonly react to electrical noises would be the amplifier. 2) Shut down the circuit breaker to any other appliance that might be causing interference on the AC lines. Reinsert the offending CD player and check for noise. No noise? Then the problem is most likely in EMI being picked up by the system. Noise? Then the problem is contained to the system itself and would appear to be isolated to the amplifier. 3) Run a long extension cable to power the amplifier from another circuit somewhere in the house. No noise? You need an electrician or a quality noise filter inserted in the system's circuit. I wouldn't expect this to be the case. Noise? Call Manley, go through the isolation exercises you've performed to suggest the amplifier is having problems. You've tried everything else that would normally isolate the problem to a single component. . |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 4677 Registered: Feb-07 | The sound is hard to explain (or maybe I'm just not good at explaining sounds). But the closest I can think of is (like I mentioned) that high pitched noise a plasma TV makes, or you know how after a really loud concert you have the high pitched ringing in your ears? That sound. My methodology with the tubes was that I had a spare, good EL84 that I used it to swap out each one of the tubes in the amp. I also had a extra set of splitter tubes to swap out the existing 6414 splitter tubes, and finally, I tried a spare set of 12AT7s as well. I never really thought it was the tubes anyway since the sound is coming equally from each channel. If it was a tube, its a fair assumption that the offending noise would only come from that channel, right? I will try some of your other suggestions. |
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Platinum Member Username: PlymouthCanada Post Number: 16051 Registered: Jan-08 | David Unhook all RF's source like computers, Wi-fi, wireless phone. I had a problem with my wireless headphone, the wi-fi router made interferences. The cdp can act like a receiver. Try to ground all hardware! |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 4678 Registered: Feb-07 | Really eh? I do happen to have a wireless router in the same room. But it's been there for years, why would it just all of a sudden start picking up RF signals? |
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Gold Member Username: Nickelbut10Canada Post Number: 3440 Registered: Jun-07 | Most routers are on a smart connect for the channel frequency. Usually it is not a problem, however if the router has been shut off or rebooted recently it could have re-assigned itself a different freq. channel. I doubt this is the cause but its worth a shot to totally power off the router and see if you can hear the issue. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 15955 Registered: May-04 | . "I never really thought it was the tubes anyway since the sound is coming equally from each channel. If it was a tube, its a fair assumption that the offending noise would only come from that channel, right?" Not necessarily, a rectifier tube functions at the front of the power supply converting the incoming AC line voltage to a functional DC voltage to run through the circuitry of the amplifier. There is no AC voltage in the signal processing circuits of the amp, all DC. The rectifier tube, or the rectifier section of the power supply if the amp uses solid state rectification, would affect both channels in equal proportion. The EL84's are a straight pentode type power tube. In this case, there is one tube per channel in a single ended circuit or, in a push pull circuit, one tube per (each half of the) "push" or "pull" side of the circuit. The 12AT7's are a "dual triode" vacuum tube. There are two complete tube sections in each tube envelope. A designer could use both halves of each tube in parallel/series or split the two sections and use one half of each tube for each channel. The convention today - and largely for the last forty plus years in quality audio products - is to only use one section of each tube and ignore the other half. Why this has come to be the norm is not clear to me as this sort of arrangement means you aren't using the full potential of the tube. It also means additional cost when you have to buy two tubes to do the job of one. Some small amount of crosstalk might expplain the adversion to mixing channels in the same envelope. But, when your NOS 12AT7 goes KAPHLOOOOOWIE!!!, you're tossing out the other half of the tube that probably has little to no wear on its section. Most of the small signal tubes used in audio are similarly designed with dual sections though some tubes combine a triode and a pentode to serve as a complete amplifier in one envelope. I think you'll find the 6414 is also a dual triode. Therefore, depending on how Manley configured the tubes, one pre amp/driver/splitter tube could affect both channels. The problem that comes up in your situation is the noise only exists when music is playing and only from a source player other than the PC/DAC combination. It's safe to assume the PC is better shielded from RFI and EMI than would be a conventional CD player. That would lead us down the path of trying to figure out what has changed since the last time you had a CD player in the system - without noise being present. If there have been no internal changes to the system - a defective amplifier perhaps?, then you have to look to external changes. These might include changes that are several rooms away or possibly aren't within your own home. If a neighbor has added a device which leaks EMI, you could be picking up those signals. It's very possible things have changed since I last had to deal with noise issues - certainly the amount of devices which produce radio frequencies has increased ten fold - but RF pick up can typically be characterized as either a faintly heard radio station or the buzzing sound of radio frequency devices. Take a portable AM radio and hold a RF remote control next to it then push any button on the remote. It's likely you'll hear the buzzing sound of lower frequency RF coming through the radio. That doesn't sound like what you're hearing. Most of the newer RF type devices have moved their radio frequency upwards into a range (UHF) that would be largely inaudible even if it were impinging on an audio component. RF also has a fairly limited range of operation so, if you moved the system to another location, the chances are the nosie would disappear if it were RF based. UHF can travel over 200' but you probably wouldn't hear the effects of UHF interference. EM frequencies can travel a good distance and along with the appliances within your own home something in your neighbor's house or out on the pole could interfere with your system. EMI is more likely to travel through electrical cabling but newer devices could cause noises to jump from place to place. If you've managed all the experiments I've listed and you still have noise issues, then I think your recourse is with Manley. First, though, you might want to give a hard think on what might have changed in your location since the last time you had a CD player in the system and didn't experience this noise. And, of course, it's certainly possibe you've had a new filling in your teeth or a USB socket installed into your brain and all of this is in your head. If that's the case, do a search engine for high quality aluminum hats. Good luck. Think logically and you'll probably find the problem even if it just comes down to diagnosing one component as the culprit. From what you've said so far, my guess is the problem is in the amplifier and could be something as minimal but difficult to trace as a cold solder joint. . |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 15956 Registered: May-04 | . Nick's information on the router frequency reboot might be a good place to begin when you're shutting down possible sources. It would be a source of RF that has a constant output rather than most RFI which is either obviously radio frequency based and the station you're picking up can be located on the radio dial or is fleeting when it comes from devices such as garage door openers. Even if this would prove to be the problem, the system is picking up noise through a spot that is acting as an antenna. Defective solder joints can act as diodes and become a fancy verion of a crystal radio set. A call to Manley would still be in order though many manufacturers have given up on trying to completely stop RF and EM interference and prefer instead to leave the fix up to the customer and their own localized resources. The problem has largely disappeared over the years as HAM radio isn't as popular as it had been in years past. But, just for sh*ts and grins, you might walk the neighborhood looking for any tall (30'-50') radio transmission towers that have gone up in the last few months. . |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 4679 Registered: Feb-07 | "'And, of course, it's certainly possibe you've had a new filling in your teeth or a USB socket installed into your brain and all of this is in your head. If that's the case, do a search engine for high quality aluminum hats. " Trust me, I've taken this into account as well - thinking maybe it was psychological, but other people can hear the noise as well, which rules out me being crazy (this time). There actually is 50' foot tower maybe a 5 minute walk from here, lol. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 15958 Registered: May-04 | . If it's a HAM radio tower, it's still fairly unlikely to be the cause of your problem. HAM radio was typically picked up just like CB's were heard over systems thirty years ago - as an obvious radio station. Back when I had my Dayton Wright pre amp I lived in an appartment across the street from a parking lot. When CB's became popular, the cars would park two feet away from each other and talk across the vast divide on their CB's. Lots of times I heard every word they said through my system. If you run out of options, it's still worth considering but it's pretty far down on my list of possibles. If it's some other sort of tower, then there may be a reason to be suspicious if that tower went up since you last had a CD player in the system. , |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 4680 Registered: Feb-07 | It was the outlet the CD player was plugged into. Back when I got the Wyred DAC I plugged it into a different outlet than what I usually use, then when I sold that and went back to a CDP, I just plugged that in with the same cord. Switched the CDP plug into a different outlet, and noise is gone. |
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Gold Member Username: MagfanUSA Post Number: 2183 Registered: Oct-07 | When I had an old truck years ago, I'd drive back and forth to work once in a while to keep it running / charged. NO radio, just CB. Well, from say....Irvine to Big Bear is about 50 miles and a guy up there was the biggest signal possible. Totally illegal with maybe 500 watts of afterburner. the guy took up his channel +- 2 additional channels and wiped out everybody near his frequency. totally illegal, but I think by this time the FCC had given up on policing the CB bands. Could the Wyred DAC have been effected...perhaps to a different degree, with the SAME problem as felled your CD player? Would the DAC have done better into your new, clean outlet? |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 15961 Registered: May-04 | . Glad you identified and recticfied the situation. But why is the outlet leaking the noise? That's definitely not a normal condition for an AC outlet. Is this something that requires further investigation and possible repair? . |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 4681 Registered: Feb-07 | Probably a good idea to look into it, eh? Since it's not bugging me anymore, though, it goes down on my list of priorities. |
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Gold Member Username: HawkbillyNova Scotia Canada Post Number: 1266 Registered: Jul-07 | Is that outlet on a different circuit ? Maybe some DC riding on it ? |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 4682 Registered: Feb-07 | Pretty sure it's on a different circuit. Same one the router 2 computers are plugged into. |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 4683 Registered: Feb-07 | and a cordless phone. Lot's of sh!t. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 15967 Registered: May-04 | . "Is that outlet on a different circuit ? Maybe some DC riding on it ?" I don't know how DC would enter an AC line. If it did, chances are it would immediately destroy any AC circuit based equipment that was plugged into it. The two are about as compatible as W and Saddam. The noise is probably being injected by one of the household devices/appliances. Open a drink and walk around unplugging equipment or shutting down circuit breakers. There's probably no real danger here but this isn't supposed to be what's coming out of an AC oulet. It's sort of like the guy who can light his kithcen faucet on fire due to the chemicals in the water which are the result of natural gas extraction and the "fracking" that accompanies the procedure. No, that's really dangerous and this is probably just an annoyance. Better to have it checked out though. . |
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Gold Member Username: MagfanUSA Post Number: 2188 Registered: Oct-07 | http://www.ohiohistorycentral.org/entry.php?rec=1642 Roll on, big river, roll on. |
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Gold Member Username: HawkbillyNova Scotia Canada Post Number: 1267 Registered: Jul-07 | "I don't know how DC would enter an AC line." I've heard of it happening. Channel Islands Audio makes a device for "cleaning" AC. http://www.ciaudio.com/products/XDC2 |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 15974 Registered: May-04 | . I've never heard of such a thing happening and I can't find any reference to it using a search engine. I'm familiar with a component leaking DC along with the analog signal through the interconnects and into the inputs of another component, but not through the raw AC feed. And I still have no idea where the DC voltage would originate in an AC line. Anyone care to guess? . . |
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Gold Member Username: MagfanUSA Post Number: 2198 Registered: Oct-07 | Jan, as you pointed out, and correctly, too, Copper Oxide is a semiconductor. My looking into it shows that rectifiers were made using it, along with Selenium. MAYBE, just maybe, an oxidized copper connection was rectifying the AC and letting it ride along? 50:1? 100:1? worse odds? |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 15976 Registered: May-04 | . Wow! I would think at 120VAC and 15 Amps that would require one h*ll of a lot of oxidation to have rectification occur. |
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Gold Member Username: MagfanUSA Post Number: 2201 Registered: Oct-07 | I think oxidized copper speaker cables eventually took out my beloved Carver Cube. I cut a foot off each end to 'freshen' them and still was awful. The insulation was decomposing and sticky on the inside. I donated them to a landfill. And Yes, It about 300:1 against this being causal. But don't forget, the crystal loonies are out there doing more with less. I'm having a seance later this month.....wanna come? |