Need help reducing noise of Amp!

tommy1 · 8th February 2010, 05:15 PM

Hi everyone!
Please help me to reduce noise from my amp even the Vol. is down completely, the noise"U` u` u`" from the speaker is still there.

Thank you!
PD

AndrewT · 8th February 2010, 05:44 PM

Hi,
what's the amp? What is connected to it?
Have you measured anything?

Iain McNeill · 8th February 2010, 05:47 PM

are we talking mains hum or white noise?

a picture of the amp innerds would help, a schematic would be even better.

tommy1 · 8th February 2010, 05:49 PM

Hi Andrew!

2sc5200, 2sa1943(output Transistors) . 2sc669, 2sb649, 2sc2705, 2sa1145.
Only speakers connected to the Amp .
PD

tommy1 · 8th February 2010, 05:52 PM

This amp belongs to a small company(HOMEbusiness) I bought it a long time ago. I call them ,they said that they won't provide anything unless send it in for repair. And I did fix it but the only problem is the noise.
thanksss!
PD

Mooly · 8th February 2010, 06:13 PM

It's not enough to go on...
If it all works and nothings blown as such, then it might be a power supply fault... maybe an open circuit cap etc or a regulator fault.

Need to see a circuit really... no idea at all what the amp is. Is it stereo (2 channels) are both channels faulty ? etc etc

tommy1 · 8th February 2010, 06:33 PM

...the thing is that I took the broken part out(UPC1237HA: audio circuit protector for the speaker relay, and I've been waiting for the part). I am getting the audio output signals before the relay. The sound is normal, except the noise even I turn the VOL. down completely.

tommy1 · 8th February 2010, 06:55 PM

[IMG]file:///C:/Users/p/AppData/Local/Temp/moz-screenshot-9.png[/IMG]

I cannot send the pic. from my email. Please help!!!

PhaseLockLoopy · 8th February 2010, 08:00 PM

Hum likes it when nV/√Hz gets converted into V/√Hz Hum likes a ground loop to have a different potential

It’s so nice to hum

tommy1 · 8th February 2010, 09:58 PM

...how to fix this problem??

8th February 2010, 05:15 PM	#1
tommy1 diyAudio Member Join Date: Jan 2010	Need help reducing noise of Amp! Hi everyone! Please help me to reduce noise from my amp even the Vol. is down completely, the noise"U` u` u`" from the speaker is still there. Thank you! PD

8th February 2010, 05:44 PM	#2
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	Hi, what's the amp? What is connected to it? Have you measured anything? __________________ regards Andrew T.

8th February 2010, 06:13 PM	#6
Mooly diyAudio Member Join Date: Sep 2007	It's not enough to go on... If it all works and nothings blown as such, then it might be a power supply fault... maybe an open circuit cap etc or a regulator fault. Need to see a circuit really... no idea at all what the amp is. Is it stereo (2 channels) are both channels faulty ? etc etc __________________ ------------------------------------------------------- *A simulation free zone.* *Design it, build it, test it.*

8th February 2010, 08:00 PM	#9
PhaseLockLoopy diyAudio Member Join Date: May 2008 Location: On a mushroom	hummmmmmmmmmm Hum likes it when nV/√Hz gets converted into V/√Hz Hum likes a ground loop to have a different potential It’s so nice to hum __________________ Hum likes to have a nice "Noise to Signal" ratio To "Hum" is to be noticed Quality hum is when it pours out of Electrostatic speakers

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8th February 2010, 05:47 PM	#3
Iain McNeill diyAudio Moderator Join Date: Oct 2007 Location: Santa Cruz, California	are we talking mains hum or white noise? a picture of the amp innerds would help, a schematic would be even better.

8th February 2010, 05:49 PM	#4
tommy1 diyAudio Member Join Date: Jan 2010	Hi Andrew! 2sc5200, 2sa1943(output Transistors) . 2sc669, 2sb649, 2sc2705, 2sa1145. Only speakers connected to the Amp . PD

8th February 2010, 05:52 PM	#5
tommy1 diyAudio Member Join Date: Jan 2010	This amp belongs to a small company(HOMEbusiness) I bought it a long time ago. I call them ,they said that they won't provide anything unless send it in for repair. And I did fix it but the only problem is the noise. thanksss! PD

8th February 2010, 06:33 PM	#7
tommy1 diyAudio Member Join Date: Jan 2010	...the thing is that I took the broken part out(UPC1237HA: audio circuit protector for the speaker relay, and I've been waiting for the part). I am getting the audio output signals before the relay. The sound is normal, except the noise even I turn the VOL. down completely.

8th February 2010, 06:55 PM	#8
tommy1 diyAudio Member Join Date: Jan 2010	[IMG]file:///C:/Users/p/AppData/Local/Temp/moz-screenshot-9.png[/IMG] I cannot send the pic. from my email. Please help!!!

8th February 2010, 09:58 PM	#10
tommy1 diyAudio Member Join Date: Jan 2010	...how to fix this problem??

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