AudioNervosa

Systemic Development => Amplification and Preamplification => Topic started by: lilbud on December 21, 2019, 07:51:53 AM

Title: PAM8610 Amp Board humming
Post by: lilbud on December 21, 2019, 07:51:53 AM
Hello,

I recently bought a PAM8610 amplifier board for use in a project (using old car speakers for an arcade cabinet). But I've run into a problem recently.

No matter what I do, I always get a humming/static-y noise from the speakers. Even if no aux is connected to the board. I currently use a 12v 3a power supply, but I've tried up to 15v 4a and I still get the static noise. What would be the best way to remove the extra noise?  I can post pics of set-up if needed.

Thanks in advance

Title: PAM8610 Amp Board humming
Post by: Guy 13 on December 21, 2019, 03:04:32 PM
Hello,

I recently bought a PAM8610 amplifier board for use in a project (using old car speakers for an arcade cabinet). But I've run into a problem recently.

No matter what I do, I always get a humming/static-y noise from the speakers. Even if no aux is connected to the board. I currently use a 12v 3a power supply, but I've tried up to 15v 4a and I still get the static noise. What would be the best way to remove the extra noise?  I can post pics of set-up if needed.

Thanks in advance



Welcome to Audio Nervosa lilbud.
I can't help you, but I am sure some more knowledgeable than me members
will gladly jump in to help you trying to solve your problem.

Guy 13
Title: Re: PAM8610 Amp Board humming
Post by: S Clark on December 21, 2019, 03:24:59 PM
oops, double post. 
Title: Re: PAM8610 Amp Board humming
Post by: S Clark on December 21, 2019, 03:26:06 PM

Hello,

I recently bought a PAM8610 amplifier board for use in a project (using old car speakers for an arcade cabinet). But I've run into a problem recently.

No matter what I do, I always get a humming/static-y noise from the speakers. Even if no aux is connected to the board. I currently use a 12v 3a power supply, but I've tried up to 15v 4a and I still get the static noise. What would be the best way to remove the extra noise?  I can post pics of set-up if needed.

Thanks in advance

This sounds like something right up member Folsom's alley.  He should be along later to comment.  And welcome to Audio Nervosa.
Title: Re: PAM8610 Amp Board humming
Post by: HAL on December 21, 2019, 04:37:13 PM
Are the speakers tied to the amp grounded at the chassis at any point?  The amp has balanced outputs, so the speakers cannot be grounded to the chassis.
Title: Re: PAM8610 Amp Board humming
Post by: Folsom on December 21, 2019, 06:32:57 PM
Hello,

I recently bought a PAM8610 amplifier board for use in a project (using old car speakers for an arcade cabinet). But I've run into a problem recently.

No matter what I do, I always get a humming/static-y noise from the speakers. Even if no aux is connected to the board. I currently use a 12v 3a power supply, but I've tried up to 15v 4a and I still get the static noise. What would be the best way to remove the extra noise?  I can post pics of set-up if needed.

Thanks in advance

How loud is the static noise?

What about with the inputs shorted?

Pics are nice.
Title: Re: PAM8610 Amp Board humming
Post by: lilbud on December 21, 2019, 07:58:27 PM
Thanks for warm welcomes everyone!

HAL, I'm sorry, I'm not sure what you mean, (I'm new to audio tech and amps and the like). Could you explain this a little simpler?

Folsom, static noise is tied to the volume of the output (the board has a built in volume knob). So the noise can get really loud at points, even audible over the media being played. Plus, it's just annoying to hear even with nothing connected or playing.

I could just leave the output volume quiet, But I intend to have the volume knob functional in my cabinet, so I'd need a better solution.

Not sure what shorting the inputs is.

Some pictures (I know conditions aren't ideal, but the noise persists no matter where I set it up)

https://photos.app.goo.gl/PrqDnBBbzgttW2EV9

https://photos.app.goo.gl/tRLWABgYPvXhGp5S8

Title: Re: PAM8610 Amp Board humming
Post by: HAL on December 21, 2019, 08:28:06 PM
If you use an ohm meter, check the ground side of the speakers to see if it is connected to the car chassis.  The amp will not work correctly if one side of the speaker connection is tied to the chassis.

Title: Re: PAM8610 Amp Board humming
Post by: Nick B on December 21, 2019, 08:44:19 PM
Welcome to the forum!
Title: Re: PAM8610 Amp Board humming
Post by: lilbud on December 21, 2019, 08:50:02 PM
If you use an ohm meter, check the ground side of the speakers to see if it is connected to the car chassis.  The amp will not work correctly if one side of the speaker connection is tied to the chassis.

I'm not using this for a car, I'm using the board and speakers in a wooden arcade cabinet. The speakers are old car speakers I believe, but this whole setup will not be going in a car.
Title: Re: PAM8610 Amp Board humming
Post by: HAL on December 22, 2019, 06:22:07 AM
From the pictures it looks like as long as the 12V power supply is quiet (a picture of the power supply might help), the amp looks correctly wired from the Parts-Express webpage. 

I would suggest contacting the place that sold it to you.  It should work without any problems as long as the stereo input is wired correctly and power supply is clean.  You would need an O'scope or meter with scope function to look at the signals to determine what is going on.   

Might just be a bad board, unless you have tried a second unit.
Title: Re: PAM8610 Amp Board humming
Post by: lilbud on December 22, 2019, 07:00:05 AM
Hal

This problem happened with the first board I bought. That board shorted out and wouldn't start up. So I got a replacement.

Truth is, this humming happened with first amp I bought (MAX 98306). But I no longer use that, so it's none of my concern.

I believe the humming to be a problem with the design of the amp itself.
Title: Re: PAM8610 Amp Board humming
Post by: S Clark on December 22, 2019, 07:42:05 AM
Honestly, is it worth fixing?  For less than the price of a hamburger, get a TDA7297 amp.  They sound better and are still dirt cheap.  Dozens available at Ebay for under $7.   There can be audiophile quality with a simple parts upgrade. 
Title: Re: PAM8610 Amp Board humming
Post by: lilbud on December 22, 2019, 08:16:05 AM
I'd like to fix it if possible, I'll keep the TDA7297 in mind for a future project. The few I see don't have a power input, rather a split + & - wire input, which would mean damaging an existing power cable.

If there is a way to fix the current amp, that'd be great. It works with my cabinet right now and I kinda have the front designed to fit it. (I had to cut a dowel down to act as a shaft extender to fit the volume knobs I have.

I'd simply like a way to cut down on the excess noise. I remember seeing somewhere online that a Resistor across the input should help it, but it's doesn't really do anything.
Title: Re: PAM8610 Amp Board humming
Post by: HAL on December 22, 2019, 08:19:47 AM
If you disconnect the input source, does it still make the noise as the volume control is increased?

Title: Re: PAM8610 Amp Board humming
Post by: lilbud on December 22, 2019, 08:20:58 AM
Yes, even when there is no aux cable connected. The noise still rings out of the speakers.
Title: Re: PAM8610 Amp Board humming
Post by: lilbud on December 22, 2019, 08:38:42 AM
Thought about it, and found a TDA 7297 on Amazon for cheap with 2 day shipping. I'll see how it works.