Humming/static introduced by dac power

adityasrivastava26

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Hey, i have a topping e30 dac, yesterday as I completed my chain i heard a decent amount of static/humming from my speakers, did some testing to search for the culprit and it turns out to be the dac. E30 doesn't provide any adapter so I was using a normal phone adapter, changed the adapter which resulted in a decrease in the humming but it was still audible, by sheer luck i decided to plug e30 power chord which has a usb end to my laptop and it worked perfectly, complete silence. Currently powering the dac through my laptop usb port but it couldn't be a long time solution. Should i continue testing out different adaptors ? Moreover on a different note switching on any appliances ( be it tv, fridge and even a fan) has a instant static feedback on my speakers. Switching on a fan while the audio chain is on sounds like a gunshot through the speakers.
My power chain : normal wall socket-> belkin surge protector
Audio chain : wiim mini-> topping e30 -> indiqaudio PA + FS
 

mbhangui

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You have a serious issue of EMI in your mains.

Your laptop SMPS has a EMI filter (In fact all decent SMPS, including cell phone chargers have EMI filter). The indiqaudio PA is not able to filter the EMI coming in the mains. If you have a power strip with EMI filter, try that out (belkin surge protector doesn't have emi filter). Or if you have a headphone amp, connect that to the RCA out of E30 dac and see if you are getting static/hum.

There are costly solutions too, the so called power conditioners. But most of these power conditioners made here in India are glorious EMI filters. Don't sink your money there. I would urge you to find out where this EMI is being generated. Possbily some very noisy equipment in your house. Usually I have found the TV to be the biggest culprit. Remove the TV plug from the walls to eliminate the TV.

If you are getting noiseless audio playback using laptop, try a good quality power supply. That will be much cheaper than getting a power conditioner, isolation transformer, etc.
 
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Subbu68

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Hey, i have a topping e30 dac, yesterday as I completed my chain i heard a decent amount of static/humming from my speakers, did some testing to search for the culprit and it turns out to be the dac. E30 doesn't provide any adapter so I was using a normal phone adapter, changed the adapter which resulted in a decrease in the humming but it was still audible, by sheer luck i decided to plug e30 power chord which has a usb end to my laptop and it worked perfectly, complete silence. Currently powering the dac through my laptop usb port but it couldn't be a long time solution. Should i continue testing out different adaptors ? Moreover on a different note switching on any appliances ( be it tv, fridge and even a fan) has a instant static feedback on my speakers. Switching on a fan while the audio chain is on sounds like a gunshot through the speakers.
My power chain : normal wall socket-> belkin surge protector
Audio chain : wiim mini-> topping e30 -> indiqaudio PA + FS
It is the SMPS in the wall warts that causes this hum. A good regulated linear PS should solve this.

Your Belkin surge protector is not going to solve any thumping issues when switching other equipment at home. surge protectors act only at high voltages (read high for the equipment) like 450V or even 750V or above. When switching fridge etc. there will be RF interference (can't avoid it) that is getting picked up by the system.
 

adityasrivastava26

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Thanks for the suggestions, so a good quality power supply will possibly solve the humming issues. For thumping issues while switching on the other appliances, do these issues have a deteriorating effect on the audio components and need to be handled ASAP? Because it sometimes sure sound as if the drivers are crying for help.
 

souravin

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Hey, i have a topping e30 dac, yesterday as I completed my chain i heard a decent amount of static/humming from my speakers, did some testing to search for the culprit and it turns out to be the dac. E30 doesn't provide any adapter so I was using a normal phone adapter, changed the adapter which resulted in a decrease in the humming but it was still audible, by sheer luck i decided to plug e30 power chord which has a usb end to my laptop and it worked perfectly, complete silence. Currently powering the dac through my laptop usb port but it couldn't be a long time solution. Should i continue testing out different adaptors ? Moreover on a different note switching on any appliances ( be it tv, fridge and even a fan) has a instant static feedback on my speakers. Switching on a fan while the audio chain is on sounds like a gunshot through the speakers.
My power chain : normal wall socket-> belkin surge protector
Audio chain : wiim mini-> topping e30 -> indiqaudio PA + FS

You may wish to try using a power bank (phone power bank) with a phone chord and observe if it is silent.
 

adityasrivastava26

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Get a Allo Nirvana and your problem is solved. If you can spend a bit more Allo Shanti is even better.

Personally using Nirvana myself , it’s more than enough for my DAC.
Got an allo Nirvana, but unfortunately the hum has increased even more😕. E30 connected to the laptop is still completely silent. Any suggestions?
 

adityasrivastava26

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Solved it. So this was a grounding issue. When it even didn't work with allo nirvana i was scared there might be an equipment fault. Tried different dac/cables, problem still existed. Finally connected the grounding post from amplifier to the nirvana and it is completely silent now, no feedback. But as it always goes, broke the optical input door/flap in the process. Have to do a bit of "jugaad" to make the optical input work. The bass is definitely tighter now while powered by nirvana instead of laptop/ipad. Thanks for the input everyone.
 

adityasrivastava26

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Hey, even though i was able to fix the humming, the "thumping" issue while switching on/off any other equipment in the audio room still exists. Up till now I believed the amp was picking up emi/rf from the wall socket, but today i tested the amp without the rca cable connected and no such "thumping" existed. Pushing the experiment forward, i tried by connecting rca back to amp but disconnecting dac on the other end and the " thumping" crept in same in intensity as before ( without anything connected at the other end of the rca cable ), i didn't have any other rca cable to test but had an amazon basic rca to aux, tried the same test and now the thumping was still present but of very low intensity compared to my rca cables. my rca cable is belden 1694f.
 

mbhangui

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Hey, even though i was able to fix the humming, the "thumping" issue while switching on/off any other equipment in the audio room still exists. Up till now I believed the amp was picking up emi/rf from the wall socket, but today i tested the amp without the rca cable connected and no such "thumping" existed. Pushing the experiment forward, i tried by connecting rca back to amp but disconnecting dac on the other end and the " thumping" crept in same in intensity as before ( without anything connected at the other end of the rca cable ), i didn't have any other rca cable to test but had an amazon basic rca to aux, tried the same test and now the thumping was still present but of very low intensity compared to my rca cables. my rca cable is belden 1694f.
If you connect RCA at one end only, the cable will have high impedance (open circuit). This kind of cable will catch low powered emi radition (it will be predominantly 50 Hz hum of your AC mains).
 

adityasrivastava26

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HI, So the issue was shared AC mains line, i connected to an independent line from mains and interference now is minimal.
I am looking for a servo stabilizer. Talked to McMillan systems in Bangalore and got a quote of 8800 for 2kva + emi/rf + surge. I know vertex is generally the suggested options but can anyone please look at the configuration/features in the file I have shared and rest my worry of whether this will work for an audio system or not.
 

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Love4sound

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HI, So the issue was shared AC mains line, i connected to an independent line from mains and interference now is minimal.
I am looking for a servo stabilizer. Talked to McMillan systems in Bangalore and got a quote of 8800 for 2kva + emi/rf + surge. I know vertex is generally the suggested options but can anyone please look at the configuration/features in the file I have shared and rest my worry of whether this will work for an audio system or not.
What are you hoping to achieve with a servo stabilizer?
 
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