Laptop > Dac >pre/amp > speaker buzzing (help!)

dhart86
dhart86 Posts: 1,594
edited January 2011 in 2 Channel Audio
My speakers are humming /buzzing pretty loud
Please tell me if I did something wrong. When my source is the CD player there is no problem.

Problem is from the following set-up:

Dell Laptop (usb) > musical fidel.V-Dac > rotel pre > yaqin tube buffer> adcom amp > Lsi 7's

The problem could be usb cable or soundcard? please help
Main Rig:
Antipodes DX > Roon > PS Audio Directstream Jr.>deHavilland Ultraverve 3 >Belles Reference 150a >Harbeth C7 ES3


Second Rig:
Roon> PS Audio Directstream Jr Bridge II > EE Minimax pre (Tutay mods) >Belles 150A Ref >Monitor 5 (Westmassguy-modded)


Post edited by dhart86 on
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Comments

  • doctorcilantro
    doctorcilantro Posts: 2,028
    edited January 2011
    Is the laptop plugged into its AC adapter? Take an extra stock power cord and rip out the ground prong, or use a cheater plug and see what happens.
    For Sale 2019:
    Tortuga Audio LDR passive preamp
    Decware EL34 amp
    Allnic H-1201 phono
    Zu Union Cubes
    iFi iDSD DAC, .5m UBS, iFI Gemini cable, Oyaide Tunami XLR 1.3M, Oyaide Tunami Speaker wire 1.5M, Beyerdynamic DT1990 headphones, PS Audio P3 power center

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  • dhart86
    dhart86 Posts: 1,594
    edited January 2011
    thanks doc, I will give that a try
    Main Rig:
    Antipodes DX > Roon > PS Audio Directstream Jr.>deHavilland Ultraverve 3 >Belles Reference 150a >Harbeth C7 ES3


    Second Rig:
    Roon> PS Audio Directstream Jr Bridge II > EE Minimax pre (Tutay mods) >Belles 150A Ref >Monitor 5 (Westmassguy-modded)


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  • jinjuku
    jinjuku Posts: 1,523
    edited January 2011
    Since it is a laptop, unplug it (as a test).
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  • doctorcilantro
    doctorcilantro Posts: 2,028
    edited January 2011
    if the USB is truly galvanically isolated from your PC, there could be no place for some DC to ground to. Thus, ground loop.
    For Sale 2019:
    Tortuga Audio LDR passive preamp
    Decware EL34 amp
    Allnic H-1201 phono
    Zu Union Cubes
    iFi iDSD DAC, .5m UBS, iFI Gemini cable, Oyaide Tunami XLR 1.3M, Oyaide Tunami Speaker wire 1.5M, Beyerdynamic DT1990 headphones, PS Audio P3 power center

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  • inspiredsports
    inspiredsports Posts: 5,501
    edited January 2011
    I have that same problem. When I disconnect the AC Adapter and go battery only, it gets better, but I also have a second monitor plugged into 110 and that has to be unplugged too for it to go completely quiet. I'm going to go try the 3 prong to 2 prong grounding adapters right now.

    Wow, I just noticed . . . my 3,000th post!
    VTL ST50 w/mods / RCA6L6GC / TlfnknECC801S
    Conrad Johnson PV-5 w/mods
    TT Conrad Johnson Sonographe SG3 Oak / Sumiko LMT / Grado Woodbody Platinum / Sumiko PIB2 / The Clamp
    Musical Fidelity A1 CDPro/ Bada DD-22 Tube CDP / Conrad Johnson SD-22 CDP
    Tuners w/mods Kenwood KT5020 / Fisher KM60
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    Walnut SDA 2B TL /Oak SDA SRS II TL (Sonicaps/Mills/Cardas/Custom SDA ICs / Dynamat Extreme / Larry's Rings/ FSB-2 Spikes
    NAD SS rigs w/mods
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  • doctorcilantro
    doctorcilantro Posts: 2,028
    edited January 2011
    i have a bunch of "higher" end dc-dc converters (i.e. PicoPsu) they ALL sound better with the ground floated, noise just dissapears, even real low db grunge.
    For Sale 2019:
    Tortuga Audio LDR passive preamp
    Decware EL34 amp
    Allnic H-1201 phono
    Zu Union Cubes
    iFi iDSD DAC, .5m UBS, iFI Gemini cable, Oyaide Tunami XLR 1.3M, Oyaide Tunami Speaker wire 1.5M, Beyerdynamic DT1990 headphones, PS Audio P3 power center

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  • doctorcilantro
    doctorcilantro Posts: 2,028
    edited January 2011
    inspiredsports wrote: »
    I have that same problem. When I disconnect the AC Adapter and go battery only, it gets better, but I also have a second monitor plugged into 110 and that has to be unplugged too for it to go completely quiet. I'm going to go try the 3 prong to 2 prong grounding adapters right now.

    Wow, I just noticed . . . my 3,000th post!

    3K! Let us know how it works out ...
    For Sale 2019:
    Tortuga Audio LDR passive preamp
    Decware EL34 amp
    Allnic H-1201 phono
    Zu Union Cubes
    iFi iDSD DAC, .5m UBS, iFI Gemini cable, Oyaide Tunami XLR 1.3M, Oyaide Tunami Speaker wire 1.5M, Beyerdynamic DT1990 headphones, PS Audio P3 power center

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  • inspiredsports
    inspiredsports Posts: 5,501
    edited January 2011
    I just tested with gray 3-prong to 2-prong grounding adapters in place (on Dell AC Power Adapter and extra monitor) and it immediately and completely cleaned up the noise I was experiencing.

    I'd been unplugging and running from battery only, so this tip was much appreciated!

    I hope it solves dhart86's (OP) problem also.



    P.S.: Obviously, clipping the ground prong as someone suggested above would also work, but the grounding adapters preserve the protection that prong offers when not listening to music through the DAC.
    VTL ST50 w/mods / RCA6L6GC / TlfnknECC801S
    Conrad Johnson PV-5 w/mods
    TT Conrad Johnson Sonographe SG3 Oak / Sumiko LMT / Grado Woodbody Platinum / Sumiko PIB2 / The Clamp
    Musical Fidelity A1 CDPro/ Bada DD-22 Tube CDP / Conrad Johnson SD-22 CDP
    Tuners w/mods Kenwood KT5020 / Fisher KM60
    MF x-DAC V8, HAInfo NG27
    Herbies Ti-9 / Vibrapods / MIT Shotgun AC1 IEC's / MIT Shotgun 2 IC's / MIT Shotgun 2 Speaker Cables
    PS Audio Cryo / PowerPort Premium Outlets / Exact Power EP15A Conditioner
    Walnut SDA 2B TL /Oak SDA SRS II TL (Sonicaps/Mills/Cardas/Custom SDA ICs / Dynamat Extreme / Larry's Rings/ FSB-2 Spikes
    NAD SS rigs w/mods
    GIK panels
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  • dhart86
    dhart86 Posts: 1,594
    edited January 2011
    Problem solved! Wow, the Cheater plug did it!
    Thanks Doc! Yur da best
    Main Rig:
    Antipodes DX > Roon > PS Audio Directstream Jr.>deHavilland Ultraverve 3 >Belles Reference 150a >Harbeth C7 ES3


    Second Rig:
    Roon> PS Audio Directstream Jr Bridge II > EE Minimax pre (Tutay mods) >Belles 150A Ref >Monitor 5 (Westmassguy-modded)


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