AMP help please

[wolf08]

My TDA2009 is making a loud pop sound in the speakers every second or so.

i am powering it with 12v at 150 ma it says 8-24v at 1-2amps so im not over powering

i checked everything (components) its a kit and everything checks out

 

[wolf08]

my amp is picking up a radio station ? i hear a radio station when nothing is plugged into it ?

 

[blueroomelectronics]

Did you build it yourself? Do you have a schematic?

 

[wolf08]

heres the site ------> **broken link removed**

also it makes loud buzzing noises when it plays i am using a wall wart but i have a 30,000uf cap so its not from that. Also if i touch one of the big caps on the circuit it will make a loud buzzing sound

please help :|

 

[ronv]

The input and the volume control (if you have one) should be close to the board or use shilelded wire. Is your power supply DC and large enough? To see if it is noise pickup short the inputs to ground.

 

[wolf08]

i figured it out. i was testing with a 9v which could not supply enough current to the amp so i popped in and out. I will get shielded cable for the input.

could you please look at the schematic and tell me where i could add ONE volume control that would control them both

thanks heres the site ------> **broken link removed**

 

[audioguru]

Buy a stereo volume control (it has two potentiometers joined onto one shaft and uses one knob) that are audio-taper (logarithmic) each with a resistance of 10k to 50k ohms. One end is the input, the other end is connected to the circuit's and the input's ground and the center slider connects to the input coupling capacitor of an amplifier.
The cable from the signal source to the volume control should be shielded audio cable.

 

[wolf08]

i took a wire from my input ground ran the to the ic's heat sink and all the buzzing,humming and radio stations stopped is that ok for the ic?

 

[audioguru]

i took a wire from my input ground ran the to the ic's heat sink and all the buzzing,humming and radio stations stopped is that ok for the ic?

The datasheet for the TDA2009A amplifier IC shows that its heatsink tab is already connected to its ground pin #6, so maybe your IC had a bad connection. It is fine to add your own wire that fixed the problem and I am glad that you discovered it.