MOVE TO FULLRANGE PLEASE??? --- Help with ground loop? and "distant" highs.
PLEASE SEE IF THIS SHOULD BE MOVED TO THE FULLRANGE SECTION?
Hello all. I am building a mono, internet enabled, wifi radio and I have two problems.
1. I am running into what I believe may be a grounding issue. When I turn the system on, I hear all kinds of noise coming from both my computer component and my wifi dongle.
a. I know that the wifi dongle is contributing to the noise because if I remove it, some of the noise is gone. b. If, I use a completely different sound source, such as a battery powered mp3 player, I get very little noise.
c. I am thinking I may need a ground loop isolator, but curious as to whether anyone else has suggestions.
2. I am not sure why, but aside from the noise, the vocals sound very far away...the lows seem to play OK, but the high stuff is almost missing.
Here is a diagram of my circuit (sorry its a bit crude) NOTE: I am providing extra power to the USB hub because I do not believe the computer (its a pogoplug) can put out enough power over a single usb.
I am using Zaph's filter (as my receiver is a HiVi B3N)
zaph|audio
And I am using a stereo to mono summing box here:
Why Not Wye?
Any help would be greatly appreciated.
Thanks!
PLEASE SEE IF THIS SHOULD BE MOVED TO THE FULLRANGE SECTION?
Hello all. I am building a mono, internet enabled, wifi radio and I have two problems.
1. I am running into what I believe may be a grounding issue. When I turn the system on, I hear all kinds of noise coming from both my computer component and my wifi dongle.
a. I know that the wifi dongle is contributing to the noise because if I remove it, some of the noise is gone. b. If, I use a completely different sound source, such as a battery powered mp3 player, I get very little noise.
c. I am thinking I may need a ground loop isolator, but curious as to whether anyone else has suggestions.
2. I am not sure why, but aside from the noise, the vocals sound very far away...the lows seem to play OK, but the high stuff is almost missing.
Here is a diagram of my circuit (sorry its a bit crude) NOTE: I am providing extra power to the USB hub because I do not believe the computer (its a pogoplug) can put out enough power over a single usb.
I am using Zaph's filter (as my receiver is a HiVi B3N)
zaph|audio
And I am using a stereo to mono summing box here:
An externally hosted image should be here but it was not working when we last tested it.
Why Not Wye?
Any help would be greatly appreciated.
Thanks!
Last edited:
Ground loops only cause low frequency hum or buzz. If you are hearing all kinds of noise, then it's not a ground loop.
To troubleshoot, simplify. Use a battery powered music source and start at the amp. Then add one component at a time.
To troubleshoot, simplify. Use a battery powered music source and start at the amp. Then add one component at a time.
Ok, well maybe it isn't a grounding problem...
If I power the usb hub (which hosts the sound card, wifi, and usb stick) I still get the noise.
I am wondering if the problem is just the sound card? Others have used it without any problems...
If I power the usb hub (which hosts the sound card, wifi, and usb stick) I still get the noise.
I am wondering if the problem is just the sound card? Others have used it without any problems...
Well the sound card is OK, I tested it on another computer. I also think the amp is fine. I tested with a different usb-hub (powered from a different source) and I still hear the noise.
Interesting note: when I ssh into the pogoplug, every time I type a letter, I hear noise on the speaker. Its like anytime the processor does, noise is created.
Interesting note: when I ssh into the pogoplug, every time I type a letter, I hear noise on the speaker. Its like anytime the processor does, noise is created.
I switched to a raspberry pi and switched sound cards, sound is not much better.
But, I found when I use separate power supplies (12V for the amp and 5V for the pi) the noise is completely gone.
So I was using this step down transformer to take 12V to 5V for the raspberry pi when I had the problem:
5X LM2596S Step Down Adjustable Power Supply Module Output DC 1 5V 35V Blue US | eBay
Maybe that is the problem...can anyone recommend a good alternative?
EDIT:
I just found this thread, but it was not very encouraging:
http://www.diyaudio.com/forums/class-d/235091-ground-loop-usb-5v-adaptor-2.html
But, I found when I use separate power supplies (12V for the amp and 5V for the pi) the noise is completely gone.
So I was using this step down transformer to take 12V to 5V for the raspberry pi when I had the problem:
5X LM2596S Step Down Adjustable Power Supply Module Output DC 1 5V 35V Blue US | eBay
Maybe that is the problem...can anyone recommend a good alternative?
EDIT:
I just found this thread, but it was not very encouraging:
http://www.diyaudio.com/forums/class-d/235091-ground-loop-usb-5v-adaptor-2.html
Last edited:
SOLVED...kinda.
Well I do not know if the problem was a "ground loop" per say, but after reading a bit more and searching online, apparently the raspberry pi and pogoplug have terrible methods for filtering power...?
I was only able to solve the issue by using two separate DC adapters.
Well I do not know if the problem was a "ground loop" per say, but after reading a bit more and searching online, apparently the raspberry pi and pogoplug have terrible methods for filtering power...?
I was only able to solve the issue by using two separate DC adapters.
I have the same issue as you with the "noise" with is not a humm or a buzz. It's all sorts of odd noises coming through the speakers. I'm going to try tonight and isolate the power sources and see if that cures the issue. I was advised to use a 5v to 5v murata device before I started to build as the grounds can't be shared and would cause this kind of issue.
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