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Dimmer switch hum in system that disappears when I touch equipment

Discussion in 'Audio Hardware' started by Pushpaw, Jan 8, 2021.

  1. Dennis0675

    Dennis0675 Night flyer

    Easy tiger. What we know is the design of a dimmer switch is completely undetectable once it’s in the wall with the exception of whether is a fader that goes up and down or a knob that twists. If our OP is saying that is an unacceptable solution because of a wife, she is unreasonable. Convince me I’m wrong.
  2. Ingenieur

    Ingenieur Forum Resident

    You have a wireless dimmer
    Master at the top connected to the circuit
    A slave at the bottom not connected
    That slave sends a wireless signal to the master.

    Could be 2 things
    The RFI from the signal
    The RFI from the master switching voltage converter. There are 2 basic types of dimmers:
    A rheostat, usually not an issue
    A SS switching voltage regulator, noisy and may cause a problem.

    Changing the dimmer is not a viable option:
    Wifey (I feel you bro, lol) it's not fear, it's respect.
    There is no wire between top and bottom, you would lose control from the bottom. Pulling wire would be a pain. Are their boxes metal or plastic? If plastic replacing them with metal and grounding it may help.

    You solution seems like better grounding.
    Last edited: Jan 10, 2021
  3. Dennis0675

    Dennis0675 Night flyer

    Depending on the switch in question, replacing it is absolutely a viable option. Old dimmer switches are problematic, that audiophile 101. If you are saying all dimmer switches can be problematic, that’s advanced level audiophile and more a theoretical reality than practical. I have systems with a turntable on a circuit with a dimmer right now that are as clean as can be. I have also had a hum that went away from replacing the dimmer. It’s a $15 minute investment and ten minutes of work to find out.
  4. brubacca

    brubacca Forum Resident

    Not saying you are wrong. I'm saying its not your (or my) business what their dynamic is. And it's not healthy or helpful for you (me, anyone on this forum) to drive that point even if its accurate (which it may not be).

    Now educate me on this dimmer thing because I have a couple in my own house that I need to replace.

    Can forward link for one that wouldn't cause audio problems?
    aphexacid likes this.
  5. Ingenieur

    Ingenieur Forum Resident

    I did not say all dimmers are problems, in fact the old rheostat type are likely not.
    I have one controlling the lights over my TT, no issues.

    If he replaces the switch with a old school type he loses control at the bottom of the steps, it's a wireless connection. He needs both switch locations and pulling wire between then is not easy.

    There are 2 schools of 'audiophile'
    Objective which IS electrical, acoustic, etc. engineering

    Subjective which is difficult to quantify.
    Dennis0675 likes this.
  6. Dennis0675

    Dennis0675 Night flyer

    I know just about enough to be dangerous as it relates to electricity. I can only explain in the most basic terms, the dimmers that are knobs restrict the electric in a way that can throw some garbage into the circuit. Any new one you buy that’s isn’t dirt cheap has a fader that works in some different way. Anything more than $30 would weird.

    I’ve had to chase down and fix weird hums in my analog chain more times than anyone should have to. I’ve Replaced outlets, ran dedicated lines, had to move equipment away from windows, replace a beer fridge that was throwing noise into the circuit and had the box and lines replaced in a 125 year old house. The bad news in this case might be that the dimmer has nothing to do with it. That’s just a good place to start. If there is any doubt about the dimmer being the issue, I would first run an extension cord and power the system from a different circuit that doesn’t have a dimmer. When it is the dimmer, the buzz will either change or go away when the light is off. Sometimes. There are a lot variables from house to house and from town to town as it relates to electrical issues.
  7. Dennis0675

    Dennis0675 Night flyer

    Didn’t you say replacing the dimmer wasn’t an option?

    It might not be the first thing I’d do but probably the second or third. I would say that if touching it makes it go away I’d cut a length of wire and do a second ground using the phono or amp. Just touch the bare ends to screws on the chassis and see if it goes away. Then the extension cord for the system.
  8. Ingenieur

    Ingenieur Forum Resident

    It is not an option.
    He would not be able to control the light from the bottom of the stairs which may result in a dangerous condition, unlit stairs at night.
  9. Dennis0675

    Dennis0675 Night flyer

    I must not be following this. I’m hearing a guy has a dimmer that he thinks is causing a hum in his stereo. I’m saying spending $20 and replacing the dimmer he currently has is a reasonable idea before getting into much more complicated and expensive solutions. Replacing the dimmer with a $2 switch might be a good idea just see if that is indeed the problem. How well lit his stairway is and the dangers it might impose shouldn’t be affected.
  10. Ingenieur

    Ingenieur Forum Resident

    If he does that he can't control the light from the bottom of the steps, only the top
  11. Pushpaw

    Pushpaw Forum Resident Thread Starter

    Since my initial post my thinking has changed slightly on what I want to accomplish. The dimmer switch is an obvious case of RF interference, but what I really would like is for my system to not be affected by any RF interference. I actually have three other dimmer switches nearby (kitchen, living room, dining room) and although they don’t cause as noticeable of a hum, they also affect the sound slightly. In this respect, changing the dimmer switch isn’t really the way I want to go. It’s more about how I keep RF interference out of my audio setup.

    I posted a similar question in the Graham Slee forum and his suggestion (beyond ensuring no ground loop from multiple mains connections) is to use properly shielded interconnects. The point being that whether an RF router will work or not, the best approach is to deny the RF access to the system in the first place. I will likely start there since I trust Graham as I own many of his products and they’re phenomenal. I have put off buying shielded interconnects because they’re a bit expensive but will aim to get some in 2021 and will report back on results.
    Thanks to all for your input.
    Swann36 likes this.
  12. Waterloo17

    Waterloo17 Forum Resident

    OP, please call a professional electrician if you aren’t 100% sure you know what you’re doing. A lot of advise floating around here that could end badly. We don’t even know what type of wiring is in the house. Maybe he has aluminum wiring and someone installed a dimmer for copper?
    patient_ot likes this.
  13. Ingenieur

    Ingenieur Forum Resident

    Just turn the light off when listening.
    Problem Solved
    No noise
    Happy wife
    No cost (actually saves a little)
  14. Dennis0675

    Dennis0675 Night flyer

    So you came to the conclusion from reading Internet forums that you have RF leaking into your analog chain and that goes away when you touch the component? I don’t think touching a component turns you into a human RF shield.

    here’s the thing, no one really knows what’s going on. There are way to many variables, all you can do is have a range of solutions, eliminate variables and work through the fixes. These threads are tough because you will always get pages of “you have ground loop, call an electrician and you need shielded cables”.

    I’m sure you don’t need me to repost the low cost or no cost solutions I’ve shared but I would certainly suggest trying them before dropping hundreds of dollars on new cables.

    I’m no expert but it’s my understanding the “r” in RF stand for radio and the relates to the transmission waves through the air that bleeds into the wiring. A dimmer is a tool that restricts the current to a bulb, how would that broadcast a radio wave that bleeds through to your cables? And if the interconnects are shielded, the wires inside of your components are not, why wouldn’t those cables be Susceptible to the same RF pollution? Wouldn’t they need to be shielded as well?

    also, the owner and designer of Balanced audio told me to buy the wrong tubes for my pre amp. Mat at VPI told me my motor needed a few drops of oil when it was a dry platter bearing that was causing my issue. Just like the rest of us, the experts are just guessing and sometime misunderstanding the question.
  15. Pushpaw

    Pushpaw Forum Resident Thread Starter

    The main offender is a dimmer that communicates wirelessly with another dimmer switch at the bottom of the stairs. I can even use an app to control it if I want.

    As for how the other dimmer switches leak RF that might be picked up by my cables I’m not sure. Maybe I will solve one problem and not the other. However, research online points to dimmer switches radiating RF interference to nearby electrical equipment: FAQ - Dimmers - What is Radio Frequency Interference (RFI)

    I have purchased the cables and will report back on how it works. I have wanted the cables for a while anyway and it was only a matter of time before I pulled the trigger.
    Last edited: Jan 13, 2021
    Swann36 and Dennis0675 like this.
  16. patient_ot

    patient_ot Forum Resident

    One of my relatives is an electrician. +1 for having a professional do the work if that is not your background.
    Waterloo17 likes this.
  17. Pushpaw

    Pushpaw Forum Resident Thread Starter

    Don’t worry, not planning any electrical work. My house does indeed have aluminum wiring (from 70s) but the ends have been “pigtailed” with copper. My dimmer switches were all installed by a professional electrician and certified. They are good switches mostly on led pot lights and some on other types of lighting.
    Waterloo17 likes this.
  18. Pushpaw

    Pushpaw Forum Resident Thread Starter

    This is the current solution. It works fine enough, but I do have much quieter noise coming from other dinners nearby and if I want total silence I have to turn them all off - which also leaves me in total darkness. All fine until I want to change a record.
  19. Ingenieur

    Ingenieur Forum Resident

    Swann36 and Pushpaw like this.
  20. Dennis0675

    Dennis0675 Night flyer

    I just looked at your profile and saw you have a debut carbon. I also have one and it will produce a hum in systems where another table will not. And I’m not talking about the motor noise that many discuss, I’m talking about the relationship between the table and the phonostage. I’ve also had RF bleed into it and make a hum from a street light, I kid you not. I think I started a thread about it where everyone told me I had a ground loop. I Have a musical fidelity phono that presents a constant ground hum without a second ground cable. You are correct in changing cables, I’d start with the stock phono cable that table comes with if you are still to using it. I’d bet a paycheck you have an issue that isn’t coming from the table but it’s likely an issue that would go away if you had a different table.
    Swann36 and Pushpaw like this.
  21. Pushpaw

    Pushpaw Forum Resident Thread Starter

    It may indeed. The Debut Carbon has held its own as I’ve upgraded my cart and phono preamp but eventually it will have to go. My desired next TT upgrade is a VPI Prime Scout. But that won’t be for a long time.
  22. R. Totale

    R. Totale The Voice of Reason

    If touching the outside of the equipment stops it, I'd first try what @Bananajack suggested in message #7. May solve it for 50 cents without changing anything else.
  23. Pushpaw

    Pushpaw Forum Resident Thread Starter

    My concern would be frying myself with the two live wires in the power cord. Have you done this before? How did you do it? Did it work?

    This looks like maybe I could use it for the stated purpose: Desco - 09838 Ground Plug Adapter
  24. Bananajack

    Bananajack Phorum ... wat Phorum? Where am I?

    You won’t fry yourself, only the top pin would be connected.
    But yes, that ground plug adapter looks good and does the job even more safely
  25. Pushpaw

    Pushpaw Forum Resident Thread Starter

    I'll give it a try. Found another one of those adapters on Amazon.ca. Will use speaker cable with a banana plug and ground wire attached to other end to try it out.

    I already ordered the other cables so I can now try both.
    Bananajack and Swann36 like this.

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