Speaker humming.....PLEASE HELP!!!

Discussion in 'Audio Hardware' started by mikedifr0923, Dec 4, 2017.

  1. The FRiNgE

    The FRiNgE Forum Resident

    Low level hum from a cartridge (turntable) is common. Personally I am ok with barely audible at full gain, which as you say can become inaudible some distance away or when the volume is set at a realistic level. This will not harm your equipment, a ground loop will not harm your equipment. Hum can be caused by bad cables, sometimes different grounding methods, a ground loop. The most common cause of hum is an AC magnetic field (EMR) electro-magnetic radiation which can be present in the ambient air, or carry through the AC lines of your home. (and ground wires with a ground fault) EMR is generated mostly by transformers nearby, phone chargers, door bell transformer, thermostat transformer, your power amp, light dimmers, refrigerators, AC fans, a laptop computer power supply, a wireless printer, and even the step-down utility transformer on the power lines, or a street light, a traffic light control box.

    All of the above offenders can overwhelm audio gear, even when grounded properly and well shielded. That's also of great importance, shielding!!! Some audiophile cables are NOT well shielded, although I do not know off-hand if Blue Jeans is one of the bad ones. Edit: Blue Jeans looks ok, just visited their site, nice Taversoe connectors with spring "grippers".

    Some pre-amps are more subject to EMR than others. For instance, the phono input may be internally strapped to chassis of one brand, or a floating ground of another brand. Certain turntable manufacturers pick up ground through the Left channel RCA jack, others a separate ground wire to chassis. Under certain conditions, one brand turntable may hum with a particular pre-amp, but be perfectly quiet on another... sometimes two can be incompatible.
     
    Last edited: Dec 7, 2017
    mikedifr0923 likes this.
  2. mikedifr0923

    mikedifr0923 Forum Resident Thread Starter

    Location:
    New Jersey
    Thank you. That makes me feel a little better. Like I said, just paranoid with the old marantz shorting out on me. Maybe it was a coincidence. I don’t know.

    I just need to try and get everything to the noise level it is with just the hafler/marantz/Oppo and I’ll be happy, as long as that’s not hurting anything. I just wanted to be sure that little bit of noise didn’t kill the marantz “death by 1000 cuts”

    I ordered new hdmi cords just Incase they were bad and I will go trial and error until I figure it out. I suspect it’s TV/Cable related. The hum I had with the phono pre hopefully goes away when I plug it into the same surge protector/ground. But I can live with it at the level it was at with the old marantz if I can just get it there
     
  3. stereoptic

    stereoptic Anaglyphic GORT Staff

    Location:
    NY
    What happened exactly with that Marantz? Did you check for a fuse to see if that revitalizes it?
     
  4. mikedifr0923

    mikedifr0923 Forum Resident Thread Starter

    Location:
    New Jersey
    I did not yet. It had shut off on its own a couple times over the span of a few weeks. But was playing more frequently than usual and didn’t think anything of it....Then last Saturday after a long day of testing new speakers it just shut off and gave me the blinking red light and couldn’t be reset at all. Once I get these other issues resolved I’ll figure that out
     
  5. jea48

    jea48 Well-Known Member

    Location:
    Midwest, USA
    I asked you in an earlier post what equipment you were using with the system that uses a 3 prong AC grounding power plug. You answered only the phono preamp. The rest of the equipment you said uses a 2 blade plug. I assume that also means any video or digital equipment. Any other thing that is connected to the audio system by data cables, interconnect cables, video cables, HDMI cables. No other equipment that uses a 3 wire grounding type power plug.

    I said for a ground loop to exist on the safety equipment ground you need a difference of potential, voltage, to exist between to different earth grounds. IF a difference of potential exists and a completed circuit is made current will flow. The 60Hz current is nothing more than a signal that is fed with the signal of the audio equipment.

    To find out if your hum is caused from a ground loop on the safety equipment earth grounds you need to break the ground loop circuit. You could break the ground loop circuit by unplugging the 3 prong power plug of the phono preamp from the AC power outlet or disconnect the CATV provider's coax cable "F" connector from the input of the splitter.

    Just because when you unplugged the phono preamp power plug from the AC power outlet and that broke the ground loop circuit, stopping the hum, in no way does that mean the phono preamp is at fault. IF your hum problem is caused by a ground loop I would be willing to bet the problem, fault, is how the shield of the CATV coax cable is earth grounded.

    Changing SPDs, Surge Protectors, or buying new HDMI cables will change anything, imo.

    Please, please, disconnect the CATV provider's coax cable from the input of the splitter and check for the hum.

    Or cut all audio and video connections, therein, interconnects, video cables, HDMI cables, or what ever else is electrically connected to the audio system so is strictly run as a stand alone audio system.

    The TT, Phono preamp, preamp, power amp, speakers. If the TV is close to the audio system and you still hear the hum/buzz unplug the TV from the AC power outlet for a test. Especially if it is a plasma TV. If you have a router close to the audio system try unplugging it as well for the test.

    Jim
     
    The FRiNgE likes this.
  6. mikedifr0923

    mikedifr0923 Forum Resident Thread Starter

    Location:
    New Jersey
    I got you, I appreciate the help.

    I wasn’t saying the ground loop is now fixed with the phono pre unplugged, just that it isn’t contributing to my current issue. If it happens again when I plug it back in I will work on that. But I have read a ton that plugged into different outlets and grounds could cause that. I want to get it all plugged into one.

    I am eventually completely separating audio and video. Just gonna take some rearranging of that room that I can’t do right now (long story) but I would have to run some LONG cords to the amp if I did that

    I don’t intend to plug the marantz into the tv permanently, I wanted to just check some settings. But I think I just saw the marantz app is compatible with mine, might be able to do it through there. The Oppo I will have to connect though, I’ll figure that out

    Wires I just wanted to make sure were shielded. I had some pretty old hdmi cables. Might have been the first ones sold LOL. I’m comfortable with my rcas

    Modem/router are in the same room but I had them unplugged the other night and plugged in last night and no difference

    I do need to unplug the cable from the splitter. I had just unplugged from the TV

    Thanks again for the tips from you and everyone else. Gonna play around this weekend and hopefully figure it out
     
  7. Classicrock

    Classicrock Forum Resident

    Location:
    South West, UK.
    All equipment should ideally be connected through one distribution strip from a single mains socket otherwise ground loops are likely.
     
    mikedifr0923 and The FRiNgE like this.
  8. mikedifr0923

    mikedifr0923 Forum Resident Thread Starter

    Location:
    New Jersey
    Yeah I figured. I ordered a new surge protector that has enough outlets for everything
     
  9. stereoptic

    stereoptic Anaglyphic GORT Staff

    Location:
    NY
    I'm no expert, that seems to be what happens when one tiny strand of a speaker wire touches the wire from the opposite connection (positive makes contact with negative) and the circuitry prevents any further damage by shutting down. Try plugging it back in and see if the headphones work. If so, then hook up the speakers (with the power off!) very carefully and make sure that the wires are neat and tidy (or use banana plugs)
     
  10. The FRiNgE

    The FRiNgE Forum Resident

    The op said the Marantz was used as a pre, and connected to a Hafler p-3000. However a good call on the speaker terminals, as it is possible a strand of wire may be caught in the terminals, and shorting out. I have seen this before with amps/ receivers I've acquired for refurbish and resale.
     
    stereoptic likes this.
  11. Twodawgzz

    Twodawgzz Well-Known Member

    I hope this means you've searched this forum. Lots of great info and suggestions on the topic of hum, ground problems, etc.
     
  12. chervokas

    chervokas Forum Resident


    A couple of things. First, just so you understand what's going on with those ground connections on turntables -- what you're doing when you connect one of those turntable wires to chassis ground of a preamp or integrated is you're grounding the tonearm tube. That ground wire connects the tonearm tube to chassis ground. This allows the arm tube to function as a shield for the unsheilded wires running through the arm. It also factors into the shielding scheme of many phono carts which have bodies that shield the cartridge motor and which require continuity between body and arm through the mounting screws. The turntable tonearm always needs to be grounded or you'll get a fair amount of pretty nasty hum and buzz in most rooms because phono carts and unshielded phono cables are antennas for induced noise from environmental sources -- like transformers in other audio gear, power cords, switch mode power supplies, fluorescent lighting, etc.

    Now, I have had trouble following exactly what hums and what doesn't in this thread, so I'm not clear that the actually source (or sources) of hum has/have been determined. But I think there's a lot of confusion about turntable ground connections. These aren't generally related to the motor of the turntable -- which is the only part of the turntable connected to a power supply (that any any lights). And problems with turntables and hum and buzz are not related to the kind of common ground loop and ac leakage current problems that are the most common cause of hum and buzz in home audio -- they're most commonly related to carts and tonearm wires picking hum induced hum from an environmental source. The ground connection of the tonearm is an important part of a turntable's ability to protect from environmental noise. Some arms have freestanding ground wires. Some wire the arm ground connection to one of the chassis ground connections of one of the audio signal wires. But either way you always need to connect the arm tube to ground to shield the wires running through it. If a shield is not connected to ground it can shunt noise to ground.

    As to your second question. A ground loop absolutely could present a symptom of persistent low level hum. In fact, that would be a common symptom. A ground loop is not going to damage your electrical equipment -- a ground loop occurs where there are multiple paths in a signal chain to what is supposed to be ground -- it's just going to annoy you and get in the way for your ability to lose yourself in the music. Getting hum down to zero is not that easy actually with our single-ended audio gear and in our EMF-radiation heavy world and homes, with AC leakage current between AC and ground being common, and with so many things we're plugging in full of different ground paths -- so very low level hum or buzz only audible with ear to speaker is, in many cases, a good as one is going to get with home hifi in common set ups. It can still be annoying though over time. Have you tried floating the chassis safety grounds with cheater plugs?

    It sounds to me like there could be multiple sources of hum in this system (often the case), and if it's hum from only when the TV is plugged in to the receiver, it's not necessarily related to the turntable. One may relate to cable routing, have you made sure that all RCA signal cable are routed well away from power cords, power supplies, TVs, STBs, routers, the transformers of any and all gear? Have you made sure that if RCAs and AC cables need to be near one another they're not running parallel but crossing at right angles?

    Sound though like your primary probably may relate to the connecting of the video gear, which I don't have a deep personal experience with. However, I do know that ground hum related problems are not uncommon with AV systems where a STB connected to a incoming cable line in terms of the coax shielding or the grounding block etc as @jea48 notes above. I'd follow his advice on trying to troubleshoot that. Then on top of that I suspect cleaning up some of the wire routing in and physical location of some of the gear will likely reduce the noise further.
     
    dynodog, The FRiNgE and mikedifr0923 like this.
  13. jea48

    jea48 Well-Known Member

    Location:
    Midwest, USA

    I thought you said the only piece of equipment in the audio / video system that uses a 3 wire power cord and grounding type plug is the phono amp.

    Hafler 3000

    POWER CORD GROUNDING
    The power supply cord is of a three wire grounded type, designed
    to reduce the risk of electric shock sustained from a live cabinet.
    It is assumed to be of suitable length for most uses of the
    equipment. The use of extension cords and power strips is
    discouraged unless they are of suitable rating to deliver the
    required total current for safe operation of all connected equip-
    ment.
    POWER CORD GROUNDING
    The power supply cord is of a three wire grounded type, designed
    to reduce the risk of electric shock sustained from a live cabinet.
    It is assumed to be of suitable length for most uses of the
    equipment. The use of extension cords and power strips is
    discouraged unless they are of suitable rating to deliver the
    required total current for safe operation of all connected equip-
    ment. Furthermore, extension cords or power strips must provide

    http://www.hafler.com/pdf/archive/MAN1461C_P1500_P3000_man.pdf

    Are you using a ground cheater on the amp?

    From your original posted message.
    IF the Hafler is indeed grounded, connected, to the safety ground of the AC power outlet then that opens up many other possibilities for the hum being a ground loop problem.
    Does it use a 3 wire power cord and grounding type plug?

    For a test try using a ground cheater on the Hafler power cord plug and check for the hum.
    https://images-na.ssl-images-amazon.com/images/I/41V7CUiIGzL._SY463_.jpg
    Make sure to put a piece of tape on the metal ground tab on the ground cheater so it does not come into contact with the 6/32 trim screw that holds the wall cover plate on the duplex receptacle. The 6/32 trim screw is grounded to the ground terminal screw of the duplex receptacle. (NOT THE CASE on IG, Isolated Ground, type receptacles).
     
    The FRiNgE and mikedifr0923 like this.
  14. RiCat

    RiCat Forum Resident

    Location:
    CT, USA
    Just a thought having owned Hafler and other gear with 2 prong plugs. First you will find those on older gear as all new is required to have 3 prong to be UL approved. But here is the thing about those 2 prongs. One is always slightly bigger than the other and outlets are suppose to have 1 slot larger to accommodate that prong. We would think that all gear is wired so that the larger prong is the "ground" (outlet wire to the ground bus in the panel) but this is not so. This is one of the issues with the older 2 prong plugs eliminated when the standard went to 3 prongs. I would think that your new power strip will be 3 prong. Make sure all your plugs are big prong same side. I had a Conrad Johnson preamp that had 2 prongs the same size. I asked them about it and they said it was so you could reverse the plug if you encountered just what you are reporting. Once you get your power strip I suggest first plug in the Hafler, attach the speakers and turn it on. If it has gain adjustments turn them up and see if you have silence. If you do then add items one at a time first just plugged in then connected to the preceding piece. If it hums try reversing the plug in the strip. Rinse and repeat until you find the piece causing the hum. This is nothing more than systematic trial and error elimination procedure. If you have to keep notes and keep it simple. GL
     
    mikedifr0923 likes this.
  15. mikedifr0923

    mikedifr0923 Forum Resident Thread Starter

    Location:
    New Jersey
    No. I said I wasn’t sure on the hafler or the marantz. The marantz definitely does not. I can try that, I have one somewhere. Thanks
     
    Last edited: Dec 8, 2017
    jea48 likes this.
  16. mikedifr0923

    mikedifr0923 Forum Resident Thread Starter

    Location:
    New Jersey
    Thanks, appreciate the tips. I will look at the prongs. The trial and error is what I had tried to do last weekend and thought I had it, but obviously not haha.....gonna try again this weekend but be much more meticulous about it now
     
  17. mikedifr0923

    mikedifr0923 Forum Resident Thread Starter

    Location:
    New Jersey
    The thing is, speakers weren’t connected to the marantz. It was just being used as a pre.
     
  18. mikedifr0923

    mikedifr0923 Forum Resident Thread Starter

    Location:
    New Jersey
    Thanks....appreciate the info. This is all new to me, like I said. The conversation has been all over the place a bit trying to respond to various questions...unfortunately that’s how the hum has presented. I do think I have a couple issues. The phono pre is/was one that I had for a while, but that was low enough to where it didn’t disturb the music listening so I didn’t worry about it. That was before adding the power amp, it was just hooked up to the old marantz. I don’t think it’s the TT. Didn’t have any noise at all with previous preamps I used with it.

    Once I started adding other pieces of equipment I started having other issues....especially now with the TV. I do think the TV/Cable is at least one of the issues. Ultimately I am just going to separate them when I have some money to buy more equipment

    I think and HOPE the phono pre will be fine once I plug it and he TT into the same strip as everything else.
     
  19. stereoptic

    stereoptic Anaglyphic GORT Staff

    Location:
    NY
    Sorry, I was referencing the other Marantz but he was using prior to this problem. It's mentioned somewhere up above in the thread
     
    mikedifr0923 likes this.
  20. Classicrock

    Classicrock Forum Resident

    Location:
    South West, UK.
    I think you should start with TV. I found a useful guide to tracing hum problems and fixing.

    How to find and fix hum in 3 easy steps
     
    RiCat likes this.
  21. RiCat

    RiCat Forum Resident

    Location:
    CT, USA
    The suggestion to look at the TV is important and valid. TV providers are notorious for using cheap grounding clamps and attaching them to any handy location. As part of your trials please disconnect the cable tv cable from the wall. If you are in your own house check the cable tv interface outside and see how they ground it. When I was chasing noise in my system one of the culprits was the tv cable. I had the company come out and proper ground it and even then my final solution was to run a grounding wire from one of the splitter blocks to the main panel/house ground. The thing to do is eliminate as many variables at the start and then proof each addition until the hummer is found. So much fun :)
     
    mikedifr0923 likes this.
  22. mikedifr0923

    mikedifr0923 Forum Resident Thread Starter

    Location:
    New Jersey
    Ok, so here is what I did so far:

    “-Everything in the room unplugged from the wall
    - cable coming into house unplugged from splitter
    - no wires touching

    Equipment: Speakers (wharfedale, will have to try out the elacs I bought which were connected over last weekend to make sure same results, although I was swapping them around then and didn’t seem to have any impact) Marantz reviver, Oppo, Phono Pre, TT, TV

    1) Hafler to speakers only - slight hum, can't hear once a foot or so away from speakers. Goes up and down with gain.
    2) plugged in dragonfly/iPad to Hafler no change. Listening is fine.
    3) plugged in oppo and Marantz into surge protector no change.
    4) connected Marantz (zone 2) to Hafler. No change, oppo connected to Marantz. Played oppo. Hafler gain all the way up. Marantz volume all the way up, no change. Ok
    5) plugged in TT and Phono Pre into same strip. Connected phono pre to Marantz. Pre turned on but nothing else, ok (this is improvement from before when it was an instant obstructive hum)
    6) Turned on TT. Hum is louder with this input but not obstructive. Volume up at listening level for TT (which is fairly close to max) Can hear slightly maybe 2 feet away as but at listening seat it is not noticeable.

    So for music listening, I can live with this if the hum is not doing any harm to anything, but wish I knew how to fix.

    Next:

    7) connected Marantz to TV and plugged tv into strip. Nothing. (This is where I was getting the guitar amp hum the other day)
    8) plugged 2nd power strip into wall (same outlet) that has computer, modem, router, powered sub (which I will eventually move...sub not connected to marantz yet)
    9) plugged cable into splitter. No change
    10) connected Marantz wireless to wifi. No change
    11) powered on computer, no change”

    So the only thing I have left to do is 1) the game systems, 2) connect sub to marantz and 3) connect cable box to the tv and cable to the box from the splitter. I was getting some of my bad humming with that disconnected before, but maybe I had a) bad wires or strip, b) wires touching that shouldn’t have been, AND an issue with cable. We will see.

    I now have the marantz set up to use the iOS app as controller and adjust settings so theoretically I don’t need that connected to the tv for music listening if I have to give up on video until I figure out. Again, ultimately I will get a real good pre just for music listening and marantz will be surround only

    Hopefully when I turn everything on this morning nothing changes from last night.

    This is fun! And by fun I mean really not
     
    Last edited: Dec 10, 2017 at 7:29 AM
  23. chervokas

    chervokas Forum Resident


    If you have hum with just the amp and speakers, sounds like at the very least you should a) look at how the speaker wires are routed -- are they near electrical cords or anything like that; and b) maybe thing about having the hafler serviced -- what's that piece 20, 25 years old? Have you ever had a cap job done on it? Could very well be leaky electrolytic caps in the power supply adding to the hum there.

    It also sounds like you're still getting more noise than you should be from the turntable rig and certainly hum should not increase when the turntable motor is turned on unless the motor itself is inducing electrical noise in the phono cart or injecting some kind of mechanical noise, which is really a major design flaw in a turntable if that's happening. Is the cart well shielded -- what cart is it? How is the motor shielded? When you turn the motor on, can you feel vibration of the plinth and/or tonearm?

    Also you say you have no wires touching -- but how far away from one another are they (esp. signal cables from power cables), and do the signal cables, if they have to cross power cables, cross at right angles.
     
    stereoptic likes this.
  24. mikedifr0923

    mikedifr0923 Forum Resident Thread Starter

    Location:
    New Jersey
    The TT on and off isn’t making a difference. That hum is related to the phono pre somehow. I am confident of that. I never got hum with the two other preamps I used.

    The hum just from the hafler is really really faint, I have to try and listen for it. But I can look into caps and such. It was a buddy of mine that gave it to me, and last used about 6 months ago by his brother in law and he wasn’t getting any noise

    As for the wires, they are as far away as they are getting. Really not much I can do about that.
     
  25. chervokas

    chervokas Forum Resident

    Phono cartridges and phono leads will pick up EMF induced noise very easily and of course the signal chain will considerably amplify even low levels of induced noise. Also the physical location of the phono pre relative to the other gear can cause induced hum. So there's probably some of that going on. And then you have this hum from the Hafler. Electrolytic caps don't last forever and after 20, 25 years, having leaking power supply caps causing hum would not be unusual or unexpected.
     

Share This Page