4 ms·

My office stereo has physical connections between the following devices (simplifying a bit) - Speakers connect via speaker wire to monoprice 7x200 amp - Monop

My office stereo has physical connections between the following devices (simplifying a bit) - Speakers connect via speaker wire to monoprice 7x200 amp - Monoprice amp connects via RCA to denon x3800h - X3800h receives HDMI from desktop computer and sends HDMI to a monitor. - Same computer connects via Displayport to the same monitor I used to hear an infuriating buzz when my 2080TI started to work hard. It changed depending on the screen output, GPU strain, and mouse activity but was constant. It acted like a combination ground loop cum coil whine. The first fix I discovered was to ground my monoprice amp to the 2080 TI PCB by wrapping one end of the exposed-copper (12 awg, I think) grounding wire through and around one of the holes in the board and attaching the other end to the Monoprice amp's grounding pin. This fixed the issue completely. Then I realized I could fix the issue more elegantly and elminate the need for grounding: I removed the grounding wire and replaced my normal HDMI and Displayport cables with fiber optic HDMI and Displayport cables. The buzz has never recurred. I've never delved further into the problem, but my conclusion is the same as yours: there's a design fault somewhere on the board, which is causing electricity to flow in ways it shouldn't. I'm using an MSI z690 ddr4 edge wifi board. Same brand, same generation, as the board where this guy is having his SSD power issue. I still hear a weird, loud buzz through the stereo (including a separate amp and separate pair of speakers) when my partner runs her hair dryer upstairs, even though my stereo runs on its own separate circuit, so regardless of the design issues in the board, there's definitely also an issue in my electrical system.

transpute 2y ago
Power conditioner can improve AC isolation https://www.amazon.com/Furman-AC-215A-Conditioner-Auto-Resetting-Protection/dp/B003PJ6NPO/ https://www.amazon.com/Furman-AC-215A-Conditioner-Auto-Reset... https://surgestop.com/surge-products/m-474.html https://surgestop.com/surge-products/m-474.html
- globnomulous 2y ago
  Thanks, this is great advice. I'm using two SurgeX SX 2120-SEQ power conditioner+sequencers -- one for the desktop devices and one for the stereo. I'm baffled that, even with the conditioners and even though I'm a separate circuit in my office, the hairdryer is still able to do something to affect the electricity in my office.
  - alduin32 2y ago
    > the hairdryer is still able to do something to affect the electricity in my office. This may indicate that your neutral line is undersized and/or damaged.
    - globnomulous 2y ago
      How could I test this?
      - alduin32 2y ago
        A first thing to test would be that your voltages are nominal, but the exact details depend on how many phases are coming from the transformer, how they are wired, and whether you are on a TT, TN-C-S or other kind of grounding system, which depends mostly on where you live. Also, you need to take your voltages both at low impedance (simulates a load) and at high impedance (negligible load, "classical" meters are generally high impedance). Generally, you want to measure the voltage difference between live and neutral depending on the load. However, depending on the tools you have access to, taking this reading properly can be a bit tricky both because simple high-impendance multimeters can easily be tricked by ghost voltages caused by bad connections and inductions from other cables, and also because understanding what to measure requires knowing how is the electrical system wired. If you know you are in a TT system with 240V between Live/Neutral, I can tell my procedure for inspecting neutrals. In a two-pole TN-C-S system with 120V between L1/Neutral and 240V between L1/L2, I suppose it would be similar, expect that we'd have to do more tests (both L1 and L2 to neutral, and I imagine also L1 to L2). EDIT: a first simple check to do is to check, using any multimeter, if there is voltage drop in your office when the hairdryer is in use.
        globnomulous 2y ago
        Thanks so much for the write-up!
tinfever 2y ago
Interestingly, the PCIe 8-pin power cable into a GPU doesn't carry all of the return current. If you put a current clamp meter around the +12V wires and then the ground wires, you'll measure more amps on the +12V wires than the ground wires. This means some of the return current goes through the PCIe slot into motherboard and makes its way back to the PSU. This lets the GPU create audio noise because GPUs draw high current pulses at the frame rate of your monitor, which means the return current through the motherboard has high current pulses, which can create ground bounce on the motherboard where the ground voltage level moves up and down and that can affect other devices in the system. I don't totally know how that noise would traveling over the ground shield of the HDMI cable into the analog section of the Denon receiver though. Maybe some of that GPU return current is going through the HDMI cable, through the Denon receiver to mains earth, and then through your building wiring back to the ATX PSU? Grounding is freaking weird.
- globnomulous 2y ago
  Oh, wow, yeah, that's really interesting. I don't understand electricity or know nearly enough about electrical engineering to be sure I understand the effect or flow you're describing, but if I (dimly) grasp what you're saying, it would explain exactly the behavior I observed. Grounding really is incredibly weird (and, again, I say this as someone who is shamefully ignorant of electrical principles). It's no surprise that some 'audiophiles' become so superstitious about electricity. Its behavior in a stereo can be mysterious. Just looking at an amp funny seems like enough to cause a ground loop.

transpute 2y ago

Power conditioner can improve AC isolation https://www.amazon.com/Furman-AC-215A-Conditioner-Auto-Resetting-Protection/dp/B003PJ6NPO/ https://www.amazon.com/Furman-AC-215A-Conditioner-Auto-Reset... https://surgestop.com/surge-products/m-474.html https://surgestop.com/surge-products/m-474.html

globnomulous 2y ago
Thanks, this is great advice. I'm using two SurgeX SX 2120-SEQ power conditioner+sequencers -- one for the desktop devices and one for the stereo. I'm baffled that, even with the conditioners and even though I'm a separate circuit in my office, the hairdryer is still able to do something to affect the electricity in my office.
- alduin32 2y ago
  > the hairdryer is still able to do something to affect the electricity in my office. This may indicate that your neutral line is undersized and/or damaged.
  - globnomulous 2y ago
    How could I test this?
    - alduin32 2y ago
      A first thing to test would be that your voltages are nominal, but the exact details depend on how many phases are coming from the transformer, how they are wired, and whether you are on a TT, TN-C-S or other kind of grounding system, which depends mostly on where you live. Also, you need to take your voltages both at low impedance (simulates a load) and at high impedance (negligible load, "classical" meters are generally high impedance). Generally, you want to measure the voltage difference between live and neutral depending on the load. However, depending on the tools you have access to, taking this reading properly can be a bit tricky both because simple high-impendance multimeters can easily be tricked by ghost voltages caused by bad connections and inductions from other cables, and also because understanding what to measure requires knowing how is the electrical system wired. If you know you are in a TT system with 240V between Live/Neutral, I can tell my procedure for inspecting neutrals. In a two-pole TN-C-S system with 120V between L1/Neutral and 240V between L1/L2, I suppose it would be similar, expect that we'd have to do more tests (both L1 and L2 to neutral, and I imagine also L1 to L2). EDIT: a first simple check to do is to check, using any multimeter, if there is voltage drop in your office when the hairdryer is in use.
      - globnomulous 2y ago
        Thanks so much for the write-up!

tinfever 2y ago

Interestingly, the PCIe 8-pin power cable into a GPU doesn't carry all of the return current. If you put a current clamp meter around the +12V wires and then the ground wires, you'll measure more amps on the +12V wires than the ground wires. This means some of the return current goes through the PCIe slot into motherboard and makes its way back to the PSU. This lets the GPU create audio noise because GPUs draw high current pulses at the frame rate of your monitor, which means the return current through the motherboard has high current pulses, which can create ground bounce on the motherboard where the ground voltage level moves up and down and that can affect other devices in the system. I don't totally know how that noise would traveling over the ground shield of the HDMI cable into the analog section of the Denon receiver though. Maybe some of that GPU return current is going through the HDMI cable, through the Denon receiver to mains earth, and then through your building wiring back to the ATX PSU? Grounding is freaking weird.

globnomulous 2y ago
Oh, wow, yeah, that's really interesting. I don't understand electricity or know nearly enough about electrical engineering to be sure I understand the effect or flow you're describing, but if I (dimly) grasp what you're saying, it would explain exactly the behavior I observed. Grounding really is incredibly weird (and, again, I say this as someone who is shamefully ignorant of electrical principles). It's no surprise that some 'audiophiles' become so superstitious about electricity. Its behavior in a stereo can be mysterious. Just looking at an amp funny seems like enough to cause a ground loop.