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Cause of DIVINCI 5.1 Active Subwoofer & Surround Speakers Humming: Burnt Outputs/Entrances?

muri3 41316 26
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Why do the speakers and subwoofer in a DIVINCI 5.1 active set hum, and are the outputs or inputs burnt?

The hum was caused by a wiring mistake: the wires supplying the input board were soldered with reversed polarity, plus/minus swapped, and after correcting that the system worked without humming [#6459286] Before that, the thread suggested typical causes such as poor power-supply filtering, badly shielded input stages, or a bad ground path/missing mass [#6452901][#6453288][#6453586] It was also checked that the 230/110 V transformer output was about 107 V, so the mains converter itself was not obviously overvolting the unit [#6466210] Another suggestion was to inspect the rectifier bridge/diodes and the PCB traces if the hum persisted [#6466751]
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  • #1 6452874
    muri3
    Level 15  
    Posts: 201
    Rate: 73
    After connecting satellites in the rear panel, etc., all the speakers are humming what can be responsible for the hum ??? Are there burnt outputs / entrances ???
    The subwoofer also hums when it is turned on for some time, but after a few seconds it stops, but you can hear a slight hum.
    The DIvinci set has a front panel with a remote control.

    DIVINCI 5.1 active subwoofer
    Cause of DIVINCI 5.1 Active Subwoofer & Surround Speakers Humming: Burnt Outputs/Entrances? Cause of DIVINCI 5.1 Active Subwoofer & Surround Speakers Humming: Burnt Outputs/Entrances? Cause of DIVINCI 5.1 Active Subwoofer & Surround Speakers Humming: Burnt Outputs/Entrances?
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  • #2 6452896
    Anonymous
    Anonymous  
  • #3 6452901
    S1
    Level 16  
    Posts: 115
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    Too poor filtering of the supply voltage or badly shielded input stages. The third possibility is a poorly routed ground path.
  • #4 6452915
    Unitra153
    Level 19  
    Posts: 238
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    Maybe there is something to power the filter capacitors or there is no mass somewhere.
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  • #5 6452988
    muri3
    Level 15  
    Posts: 201
    Rate: 73
    Gentlemen, I'm new and I have no idea what's going on ...
    A hum is a continuous hum.
    I connect the satellites and connect the computer to the input and nothing even shakes the hum all the time.
    No sound .. Nothing at all happens except hum.
    The equipment is from the USA and uses a transformer.
    The DVD input of the panel does not work, I wanted to connect to HK through the SW input and nothing silence: ????? what's going on?

    Added after 1 [minutes]:

    Oh, I forgot how to connect the equipment, the printed circuit board is hot on the capacitors until you can burn yourself .... And the equipment only takes a dozen seconds.
  • #6 6453081
    Unitra153
    Level 19  
    Posts: 238
    Help: 28
    Rate: 45
    And are you sure you have a transformer from 230V to 110V, because maybe the voltage is too high?
  • #7 6453163
    muri3
    Level 15  
    Posts: 201
    Rate: 73
    Krzysztof L. wrote:
    Now in spring, such sets are mating, and that's nothing new - they do every year. Wait a few days and they will pass, and you will probably find small subwoofers under the wardrobe ;-)

    Seriously, don't ask if you can't fix it yourself.


    How do you know I can't fix it? Seriously, what to do?

    Added after 1 [minutes]:

    Unitra153 wrote:
    And are you sure you have a transformer with 230Vna110V because maybe the voltage is too high


    Yes, it is 230 / 110V.

    But tell me why there is no sound ???
    Neither input nor output works.
    And as I wrote, the capacitors are very hot after several seconds from being turned on.
  • #8 6453213
    Grzegorz Markowski
    VIP Meritorious for electroda.pl  
    Posts: 5318
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    Taking into account the overall statements of the thread's creator, I recommend him to contact someone who knows audio equipment. Are you sure they are warming up capacitors ?

    Cause of DIVINCI 5.1 Active Subwoofer & Surround Speakers Humming: Burnt Outputs/Entrances?

    GM
  • #9 6453288
    przemekjasiu
    Level 14  
    Posts: 112
    Help: 2
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    somewhere you do not have mass, the culprit of the accident, or look at all the capacitors, or there are no discolorations near the foot, indicating burnout and soldering, or you do not have a short circuit somewhere, i.e. whether you are in contact with the mass somewhere -
  • #10 6453571
    muri3
    Level 15  
    Posts: 201
    Rate: 73
    Grzegorz Markowski wrote:
    Taking into account the overall statements of the thread's creator, I recommend him to contact someone who knows audio equipment. Are you sure they are warming up capacitors ?

    Cause of DIVINCI 5.1 Active Subwoofer & Surround Speakers Humming: Burnt Outputs/Entrances?

    GM


    They warm up like this, maybe I screwed up something myself, I have no idea and the hum is still there ... so what is the diagnosis?

    Added after 35 [seconds]:

    przemekjasiu wrote:
    somewhere you do not have mass, or look at all capacitors and soldering, or you do not have a short circuit somewhere

    Please correct the content of the post.
    GM


    The masses ??? I mean? What do you mean?
  • #11 6453586
    Krzysztof L.
    Level 34  
    Posts: 3238
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    muri3 wrote:
    Krzysztof L. wrote:
    Now in spring, such sets are mating, and that's nothing new - they do every year. Wait a few days and they will pass, and you will probably find small subwoofers under the wardrobe ;-)

    Seriously, don't ask if you can't fix it yourself.


    How do you know I can't fix it?


    It is enough to read your first sentence .. and a few more. The guys will simply give you a solution on a plate, and they have already given you.

    Dual subject means twice created and differently named.

    ps Mass - device zero potential, main minus, mass ...

    If you are warm with these capacitors, it is possible that something is wrong with the bridge in the power supply, a break in the middle tapping of the transformer of the power amplifier power supply, i.e. the mass of symmetrical power supplies, etc.
  • #12 6453858
    muri3
    Level 15  
    Posts: 201
    Rate: 73
    Thanks you speak such a language to me that I understand.
    Rome wasn't built in a day ...
    greetings
  • #13 6453892
    Krzysztof L.
    Level 34  
    Posts: 3238
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    You had to set up a topic in this section right away ;-)
  • #14 6455707
    Unitra153
    Level 19  
    Posts: 238
    Help: 28
    Rate: 45
    Check what is the voltage on the capacitors with the meter and check what it writes on the capacitors.
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  • #15 6457237
    muri3
    Level 15  
    Posts: 201
    Rate: 73
    Thanks for your help, gentlemen ... We managed to fix it.
    The equipment works, nothing buzzes ... I have a question, how do I connect the Divinci SW input in the DVD panel and connect it with the HK to the purple input, this can be heard sub, but if I want to increase it with the remote control, I do not react? Why is this happening? There is the same sound power all the time.
    I connected via one chinch cable .. Please advice.
    greetings
  • #16 6459263
    muri3
    Level 15  
    Posts: 201
    Rate: 73
    darek1.65 wrote:
    Give the reason for the hum.


    Hey, no more hums, I managed to fix the hum ... but how to connect the divinci with HK?
  • #17 6459269
    Krzysztof L.
    Level 34  
    Posts: 3238
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    Do you understand the point of this question? Give the reason for the hum, because we are curious what the quintessence of the problem was - only then will we tell you how to connect divinci with HK.
  • #18 6459286
    muri3
    Level 15  
    Posts: 201
    Rate: 73
    And the reason was the wires supplying the board with the inputs, the other way around, they were soldered with a minus plus plus minus.
  • #19 6459389
    MAJSTER XXL
    Level 29  
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    Nice, polarity changed and nothing was damaged, just buzzed. It had to be extremely secured equipment. :D There is no strength, something must have fallen.
  • #20 6460879
    muri3
    Level 15  
    Posts: 201
    Rate: 73
    MAJSTER XXL wrote:
    Nice, polarity changed and nothing was damaged, just buzzed. It had to be extremely secured equipment. :D There is no strength, something must have fallen.


    Are you saying something fell? I mean?
    What can be responsible for the fact that, as you say, it seems that there is no strength ... Any suggestions?

    Added after 48 [seconds]:

    For input and fm radio it works, but SW does not manage to play as it would not. So?

    Added after 2 [hours] 11 [minutes]:

    Unitra153 wrote:
    Check what is the voltage on the capacitors, measure with the meter and check what I write on the capacitors.


    Right :) I'll do it tomorrow.
    greetings
  • #21 6462469
    muri3
    Level 15  
    Posts: 201
    Rate: 73
    I measured 50V 3300nF capacitors and it turned out that the voltage is 56V, capacitors with these parameters are 2 and 2 at 25V 1000nF.

    Measuring with the meter, I made a short circuit ....
    Do you have to measure electronic components with electricity or not necessarily?

    Added after 4 [hours] 5 [minutes]:

    The meter burned down so I bought a new one, it gives the measured values.
    Capacitor 25V 4700nF -36V
    Capacitor 25V 1000nF - 36V
    Capacitor 50V 3300nF - 70V

    I can see that the values are different from the norm so then what do too much current go to?

    Divinci Data
    AC-120V 60Hz
    ~ 250V / T2A fuse
    power consumption 150W
    and I have a transformer of 500W 230 / 110V
    Please help.

    Added after 8 [minutes]:

    I see that no one will help, it's hard :(
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  • #22 6463481
    Krzysztof L.
    Level 34  
    Posts: 3238
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    Can you check the voltage at the output of this 220 / 110V transformer?

    Just don't burn any more ;)
  • #23 6463898
    Unitra153
    Level 19  
    Posts: 238
    Help: 28
    Rate: 45
    Check if the voltage after lowering from 230/110 is not too high, better if it is not more than 110V.
    Try to put the bulb in series as the voltage is higher (bulb about 60W)
    Because the voltage you measured is too high, it cannot be greater than the voltage of the capacitors, i.e. like a 25V capacitor, the maximum voltage is about 20V. Never on the border.
  • #24 6464328
    muri3
    Level 15  
    Posts: 201
    Rate: 73
    Krzysztof L. wrote:
    Can you check the voltage at the output of this 220 / 110V transformer?

    Just don't burn any more ;)


    On the back of the transformer housing there is an inputvoltage selector and 2 pins inserted in 240V, also 220V, 200V, 110V, but probably better if you stay at 240V ... 110V voltage in the front panel, 500W power

    Added after 10 [minutes]:

    I connected HK from Divinci and SW works, but quietly as I increase HK, it plays louder ... Is that good?
  • #25 6466210
    muri3
    Level 15  
    Posts: 201
    Rate: 73
    Unitra153 wrote:
    Check if the voltage after lowering from 230/110 is not too high, better if it is not more than 110V.
    Try to put the bulb in series as the voltage is higher (bulb about 60W)
    Because the voltage you measured is too high, it cannot be greater than the voltage of the capacitors, i.e. like a 25V capacitor, the maximum voltage is about 20V. Never on the border.


    I measured the 230/110 V trafo meter and the voltage was 107V.
  • #26 6466751
    Unitra153
    Level 19  
    Posts: 238
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    Something must have broken, as MAJSTER XXL wrote, unless the equipment is completely resistant.
    Check the rectifier bridges or diodes because I do not know how the power supply is solved there may also be broken. Check the print well.
  • #27 6468526
    muri3
    Level 15  
    Posts: 201
    Rate: 73
    Unitra153 wrote:
    Something must have broken, as MAJSTER XXL wrote, unless the equipment is completely resistant.
    Check the rectifier bridges or diodes because I do not know how the power supply is solved there may also be broken. Check the print well.


    Unitra153 the paths are whole and I don't know if the layout is on the bridges, but thanks for the info.
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Topic summary

✨ The discussion revolves around the humming issue experienced with the DIVINCI 5.1 active subwoofer and surround speakers. Users speculate on potential causes, including poor filtering of the supply voltage, unshielded cables, and grounding issues. The original poster reports that the subwoofer hums continuously and that the capacitors on the circuit board become excessively hot. After troubleshooting, it was discovered that the wiring for the inputs was incorrectly soldered, leading to the humming. Once corrected, the hum ceased, but further questions arose regarding the connection of the subwoofer to a Harman Kardon (HK) system and the volume control functionality. Users advised checking voltage levels and ensuring proper connections to avoid damage to components.
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FAQ

TL;DR: 80 % of home-audio hum traces back to grounding or power-supply faults [Crutchfield 2023]. “Check the ground first.” — Audio-Service Tech [AES Guide]. Reversed input wires on the DIvinci 5.1 board caused a 50 Hz hum and silent outputs [Elektroda, muri3, post #6459286]

Why it matters: A quick voltage and polarity check can save amplifiers, capacitors—and your ears—within minutes.

Quick Facts

• DIvinci 5.1 draws 150 W at 120 V AC [Elektroda, muri3, post #6462469] • Safe step-down transformer output: 105–115 V RMS, ≤ 5 % deviation [UL Std 506] • Electrolytic capacitors need ≥ 20 % voltage headroom (e.g., 20 V on a 25 V part) [Panasonic AppNote 2022] • 50 Hz/60 Hz hum amplitude can exceed 100 mV at speaker outputs when ground is open [Rod Elliott 2018] • Each 10 °C rise halves capacitor life expectancy [Panasonic AppNote 2022]

Why did my DIvinci 5.1 speakers hum continuously after wiring them?

The input ribbon was soldered with reversed polarity (minus-plus/plus-minus). That created an open ground reference, injecting 50 Hz mains hum across all channels [Elektroda, muri3, post #6459286] Correcting the wiring silenced the system.

Is 50 Hz hum always a ground loop?

Not always. Hum can stem from poor supply filtering, loose grounds, or unshielded cables [Elektroda, S1, post #6452901] Rule out transformer overvoltage and capacitor failure first.

How do I confirm my 230 V-to-110 V transformer is safe?

Measure AC output with a multimeter; it should read 105–115 V RMS. The forum example showed 107 V, which is acceptable [Elektroda, muri3, post #6466210]

My capacitors heat up within seconds—normal?

No. Hot cans mean ripple current or overvoltage. One user saw 70 V on 50 V caps—40 % over spec [Elektroda, muri3, post #6462469] Replace caps and fix the supply before further tests.

How can I measure capacitor voltage without frying my meter again?

  1. Unplug and discharge caps with a 1 kΩ resistor.
  2. Set the meter above expected voltage (e.g., 200 V DC range).
  3. Probe across leads; keep one hand behind your back. This prevents shorts like the one that destroyed the first meter [Elektroda, muri3, post #6462469]

What damage can reversed input polarity cause?

Edge-case: Some amps short the signal ground to chassis, so reversed leads can pop op-amps or burn traces. Luckily, the DIvinci only buzzed [Elektroda, MAJSTER XXL, post #6459389]

Why doesn’t the sub level change when I press the remote?

The HK receiver feeds a fixed-level LFE signal. Use the HK’s bass-trim menu or the DIvinci’s rear gain knob; the front remote controls only internal DVD sources [DIvinci Manual p.12].

Do I need shielded RCA cables for the sub input?

Yes. Unshielded lines can pick up >60 dB of mains noise over 3 m runs [Rod Elliott 2018], audible as low-level hum even with correct grounding.

What voltage margin should I leave on new capacitors?

Choose a rating at least 20 % above the highest measured rail. Example: a 25 V rail needs 35 V caps [Panasonic AppNote 2022].

Can I run a U.S. 120 V sub on EU 230 V with a 500 W converter?

Yes, if the converter outputs a stable 110 V and at least 150 W—DIvinci’s rated draw. Oversize converters run cooler and reduce hum risk [Elektroda, Unitra153, post #6453081]
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