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Old 12-05-2019, 12:29 PM   #1
ivtec
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Default Wireless Headphones with Hum sound?

Hi guys i bought this wireless head phones,it works ok with batteries but it also has a input for 4.5 v dc power supply but it did not come with it,i have a few dc power supply i connect any of them and sound coming from the TV has a background ground hum ,is there anything i can do to over come this annoying hum riding with sound,it also has a few radio FM channels that don't do that only with audio source? also with batteries only in the
set doesn't do it,but it eats batteries real fast , thanks in advance and have a marry Christmas



https://www.walmart.com/ip/Professio...phone/39461871

Last edited by ivtec; 12-05-2019 at 12:31 PM..
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Old 12-05-2019, 03:52 PM   #2
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Default Re: Wireless Headphones with Hum sound?

Are you using 4.5V regulated power supply?
Does it use three 1.5V batteries?
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Old 12-05-2019, 04:54 PM   #3
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Default Re: Wireless Headphones with Hum sound?

Not knowing what type of power supply you tried makes it hard to tell whats wrong, Was it one of those adaptors with the voltage switch? what was the current rating of the adaptors you tried?
Link points to the PYLE model: PHPW5
Quote:
it also has a few radio FM channels that don't do that only with audio source
I believe the fm radio receiver is in the headset and not in the base. You could also dissconnect the tv input to the base and see if the hum is still there, if the humis still there but not there while on batteries, the hum must be from the adaptor

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Old 12-05-2019, 05:16 PM   #4
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Default Re: Wireless Headphones with Hum sound?

Thanks guys; the set uses 2 1,5 volts small batteries and it has power supply input of 4.5 vdc, i tried a few of good dc power supplies, and one of them is a great power supply that has 1.5 to 12v dc with switch that i've got when Radio Shack was still opened and it's the best power regulated supply that i ever have, i suspect that i used a different power outlet of the TV, maybe that's the issue ,i'll check after christmas, i have it wrapped up to give wife for Christmas,

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Old 12-06-2019, 10:45 AM   #5
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Default Re: Wireless Headphones with Hum sound?

Hi guys i open gift box again to try to connect it same outlet of the TV and it make no difference no matter what regulated power supply or search protector power outlet i use it's same annoying hum ridding with tv sound,i found out the thing doesn't have to be connected to the audio output source to do the hum,any more ideas before i try to return it,which probably they wont refund me,the wallmart site is just like amazon where these people sell this junk,i should used Amazon cause i always had good luck with returns and refunds.

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Old 12-06-2019, 11:05 AM   #6
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Default Re: Wireless Headphones with Hum sound?

Those cheap supplies usually use a small transformer, bridge and output cap, so the ripple willbe 60 or 120 hz. Try and use a smps adaptor, If it can handle 4.5vdc, I would think a 5vdc one would also work which are quite common these days.
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Old 12-06-2019, 12:08 PM   #7
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Default Re: Wireless Headphones with Hum sound?

Thanks R_J ,i tried a few of great power supp and no avail,here 2 good ones https://www.google.com/search?q=supp...kmOl3hM:&vet=1
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Old 12-06-2019, 12:11 PM   #8
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Default Re: Wireless Headphones with Hum sound?

Quote:
Originally Posted by ivtec View Post
Thanks R_J ,i tried a few of great power supp and no avail,here a 2 of many i tried https://www.google.com/search?q=supp...kmOl3hM:&vet=1
https://www.google.com/search?q=ac+a...HJ7dKVTrOwHuM:

Last edited by ivtec; 12-06-2019 at 12:17 PM..
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Old 12-06-2019, 04:09 PM   #9
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Default Re: Wireless Headphones with Hum sound?

Sorry, I'm lil bit confused.
Could you explain again your setup?
So you have wireless headphones and base.
Where do you connect the power supply - to the base or the headphones?
You said it can run on batteries.. is this the headphones, the base or both?
If "it" runs or batteries is there any hum?
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Old 12-07-2019, 11:19 AM   #10
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Default Re: Wireless Headphones with Hum sound?

Quote:
Originally Posted by madan1 View Post
Sorry, I'm lil bit confused.
Could you explain again your setup?
So you have wireless headphones and base.
Where do you connect the power supply - to the base or the headphones?
You said it can run on batteries.. is this the headphones, the base or both?
If "it" runs or batteries is there any hum?
Thanks madan1,appreciate your input and help; the wireless set is this;https://www.walmart.com/ip/Pyle-Pro-...ll&athena=true

and it runs both the Base and headset on 2-3v AAA batteries and with those batteries on the base and on headset it sounds good no hum,but it also has on the base a input for 4.5v dc power supply and it's with this power supply it does the hum on input on any source like TV sound,they did not supply the regulated power supply ,i have many great regulated power supply's, i have to use a external power supply cause the base just eats butteries like hell, i already complained to the dealer and requested a return and refund, i already received reply from them and they say they are going to refund me and i don't even need to return the headphones ,they said i can keep it or donate it,that's great news,i'm good with repair electronics ,if i can fix this hum that will be great,that's why i ask you experts if you have an easy fix ,i know i can do it,now since i don't have to return it maybe i can open it and put a filter cap somewhere in the circuit, or maybe the issue is because this set has also microphone and that might be the cause? maybe i can get now wireless Bluetooth headphones?,what you think about those;thanks and you all have a Merry Christmas

Last edited by ivtec; 12-07-2019 at 11:21 AM..
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Old 12-07-2019, 03:33 PM   #11
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Default Re: Wireless Headphones with Hum sound?

I wonder if it is ground loop problem. Do you hear the hum if the base audio input is not connected the TV audio line out?
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Old 12-07-2019, 03:46 PM   #12
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Default Re: Wireless Headphones with Hum sound?

you could try plugging the power supply into a different outlet .plus you could also try an isolation transformer on the signal inputs
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Old 12-07-2019, 04:41 PM   #13
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Default Re: Wireless Headphones with Hum sound?

Thanks guys;budem i can hear the hum when it's not connected to the tv output also ,

petehall347; how i build an isolation transformer circuit?
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Old 12-07-2019, 05:12 PM   #14
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Default Re: Wireless Headphones with Hum sound?

Try connecting it to a phone or mp3 player... anything that runs on batteries and has no connection to the mains... or you can just connect the left and right channel inputs to the unit's ground.

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Old 12-07-2019, 06:18 PM   #15
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Default Re: Wireless Headphones with Hum sound?

Quote:
Originally Posted by ivtec View Post
Thanks guys;budem i can hear the hum when it's not connected to the tv output also ,

petehall347; how i build an isolation transformer circuit?
i have a ready made one with rca connectors .like this
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Old 12-07-2019, 09:34 PM   #16
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Default Re: Wireless Headphones with Hum sound?

Quote:
Originally Posted by ivtec View Post
Thanks guys;budem i can hear the hum when it's not connected to the tv output also ,

petehall347; how i build an isolation transformer circuit?
Then it is not ground loop or isolation problem since it still hums as stand alone.
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Old 12-08-2019, 10:54 AM   #17
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Default Re: Wireless Headphones with Hum sound?

Quote:
Originally Posted by ivtec View Post
Thanks madan1,appreciate your input and help; the wireless set is this;https://www.walmart.com/ip/Pyle-Pro-...ll&athena=true

and it runs both the Base and headset on 2-3v AAA batteries and with those batteries on the base and on headset it sounds good no hum,but it also has on the base a input for 4.5v dc power supply and it's with this power supply it does the hum on input on any source like TV sound,they did not supply the regulated power supply ,i have many great regulated power supply's, i have to use a external power supply cause the base just eats butteries like hell, i already complained to the dealer and requested a return and refund, i already received reply from them and they say they are going to refund me and i don't even need to return the headphones ,they said i can keep it or donate it,that's great news,i'm good with repair electronics ,if i can fix this hum that will be great,that's why i ask you experts if you have an easy fix ,i know i can do it,now since i don't have to return it maybe i can open it and put a filter cap somewhere in the circuit, or maybe the issue is because this set has also microphone and that might be the cause? maybe i can get now wireless Bluetooth headphones?,what you think about those;thanks and you all have a Merry Christmas
if you can open up the base station and look at how the microphone circuit has been implemented, you might consider trying to disconnect it or at least part of it to see if it has any impact... might be an issue of "ground isolation" to the microphone such that noise coming thru the adapter's "negative" is providing a "hum cycle" in the microphone's preamp stage.

It appears from the manual that the microphone circuit is always on (ie. it can't be "not selected").

Last edited by budwich; 12-08-2019 at 11:11 AM..
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Old 12-08-2019, 11:14 AM   #18
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Default Re: Wireless Headphones with Hum sound?

Quote:
Originally Posted by budwich View Post
if you can open up the base station and look at how the microphone circuit has been implemented, you might consider trying to disconnect it or at least part of it to see if it has any impact... might be an issue of "ground isolation" to the microphone such that noise coming thru the adapter's "negative" is providing a "hum cycle" in the microphone's preamp stage.
thanks budwichh ;i'll give it a try after christmas,there is also some options on line to build an isolation audio transformer ,if i find any audio transformers similar to these in my scrap; i just don't want to spend any money on this; https://www.youtube.com/watch?v=6Gc8nZG_-F8https://www.aliexpress.com/item/32814995677.html

Last edited by ivtec; 12-08-2019 at 11:18 AM..
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Old 12-17-2019, 05:03 PM   #19
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Default Re: Wireless Headphones with Hum sound?

hi guys , new update on this hum issue ,i had an old PC power supply in my scrap and connected it to the 5 v dc line and much better,not perfect but it's usable , but it's kinda expensive on electricity to have a PC power supply for this,but if i have no alternative will use it and turn it off when it's not in use ,have an happy Christmas
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Old 12-17-2019, 06:50 PM   #20
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Default Re: Wireless Headphones with Hum sound?

You can find 5v adaptors all over the place, many cheap routers etc. use them, you could also make a usb to 5v cable and use that if the tv has a usb port.
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