Phono pre hum

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Comments

  • mhardy6647
    mhardy6647 Posts: 33,802
    edited November 2017
    Probably worth noting that figuring out what to ground to what generally has to be determined empirically in cases like these. :)

    Also, perhaps, worthy of note. My Marantz (Clearaudio) TT-15S1 came with two ground leads -- one for the tt proper (connected, I suppose, to the platter mount) and the other to the (detached) motor.

    As I intoned, oh so gravely, earlier: grounding is both art & science :|
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  • jdjohn
    jdjohn Posts: 3,149
    mhardy6647 wrote: »
    As I intoned, oh so gravely, earlier: grounding is both art & science :|
    And trial and error :D Glad Bob is sorted. Another good reason to keep a few spare wires around.
    "This may not matter to you, but it does to me for various reasons, many of them illogical or irrational, but the vinyl hobby is not really logical or rational..." - member on Vinyl Engine
    "Sometimes I do what I want to do. The rest of the time, I do what I have to." - Cicero, in Gladiator
    Regarding collectibles: "It's not who gets it. It's who gets stuck with it." - Jimmy Fallon
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  • mhardy6647
    mhardy6647 Posts: 33,802
    Mark my words:

    Bag o' clipleads.
    1001 uses!
    Collect 'em, trade 'em, give 'em to your friends!
    They make great stocking stuffers, too!


    2va4tclxfjej.png
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  • lightman1
    lightman1 Posts: 10,788
    Hardy-ed up another thread....
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  • msg
    msg Posts: 10,020
    Hey, look who it is!
    I disabled signatures.
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  • mhardy6647
    mhardy6647 Posts: 33,802
    lightman1 wrote: »
    Hardy-ed up another thread....

    I'm here for youse guyses.

    Think of me as Johnny Clipleadseed.

    I should keep little gift bags of 'em here at the ol' casa.
    This could be you! (borrowed images, no warranty express or implied. Always keep one hand in your pocket when working with HV.)

    rn3r3a08v94s.png
    xch83ubm6bfq.png
    fe29z13cuw0s.png
    s0mh6ddklcg8.png



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  • pitdogg2
    pitdogg2 Posts: 25,441
    Man those pictures just scream FIRE B):*
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  • msg
    msg Posts: 10,020
    To me, that bottom one screams, "Ouch Ouch! Hot! Ahh! My fingers!"
    I disabled signatures.
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  • Viking64
    Viking64 Posts: 7,064
    I have no idea what any of that is.

    9m2v8r5et43k.jpg
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  • mhardy6647
    mhardy6647 Posts: 33,802
    Amplifier breadboards of various flavors.

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  • msg
    msg Posts: 10,020
    I like my breadboards toasted and flavored with Vegemite.
    I disabled signatures.
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  • muncybob
    muncybob Posts: 3,042
    mhardy6647 wrote: »
    It might make a difference if it is only 'asleep'.
    If you get bored some time, try unplugging the player from the AC mains and see if it changes the noise signature on your phono preamp any.

    So I was curious to see if this made any difference...it did not. I also tried other areas to ground and still no improvement over the Oppo ground. The power strip itself(Panamax M4300-EX) has a ground lug so I made another ground wire(now up to 3) and no difference. So, this is as good as it will get and that's fine. Thanks again for all the help, tunes are sounding much better :)
    Yep, my name really is Bob.
    Parasound HCA1500A(indoor sound) and HCA1000(outdoor sound), Dynaco PAS4, Denon DP1200 w/Shure V15 Type V and Jico SAS stylus, Marantz UD7007, Polk L600, Rythmik L12 sub.
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  • mhardy6647
    mhardy6647 Posts: 33,802
    Yeah, so your hum/noise is due to circuit &/or power supply, it seems.

    One other thing you could try if you get really, really bored (and if you haven't) is to either open circuit the inputs (no cables installed) or (probably better short the inputs (shorting plugs or cables with both leads connected together) and see what the "absolute" noise level of the preamp is. Shorting the inputs would isolate the preamp pretty well, such that any noise you hear is from the preamp (or - it is still possible - being induced into it from external EMI sources).

    High gain vacuum tube circuits have a tendency to be noisy. Even solid state circuits aren't immune from the hiss of "shot noise" at high gain.

    I will close by mentioning that even I ultimately settled on a (gasp!) solid state phono preamp at my house. :|

    kqywwktgvrn5.png

    (legacy photo of an experiment with the aforementioned ss phono preamp & Silk SUTs -- and plenty of clipleads!)
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  • lightman1
    lightman1 Posts: 10,788
    Doc...you're gonna burn your house down one day.....Safety First! :p
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  • mhardy6647
    mhardy6647 Posts: 33,802
    Point taken, your being a pro & all... but, in my defense, everything there is low voltage DC (well, other than the audio signals, which are AC on the order of 100s of microvolts on the "innie" side & a volt or so on the outie side).
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  • FestYboy
    FestYboy Posts: 3,861
    Wow, an "innie" AND an "outie" @mhardy6647 you must be proud :p
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