Little Gem Amp Problem Answered
I am quite new to electronics but I am very interested in it. I have built a couple circuits before but nothing with an IC chip.
So now I have decided to move onto slightly more complex projects, and I found the Little Gem Guitar Amp: http://www.runoffgroove.com/littlegem.html
I have built it on a veroboard from these diagrams but I changed the layout slightly. Obviously everything is connected the same way I just moved the 100uF cap a little up. I have also added a 10Ohm resistor to the output and used headphones instead of the speaker.
When I connect the 9V battery, without an audio source, I can hear is a soft buzz, quite a high frequency. The gain pot makes the noise louder and softer so I assume the LM386N-1 chip is fine.
If I put my finger on the ground part of the 1/4 inch jack, the noise become much loader and lower frequency. The same thing happens if I connect an audio source. Is there an obvious cause for this problem that I don't know about?
I have connected the jack to the board with shielded twin core wire. I have used the shield as ground and the core as signal. Is this correct?
Any help would be appreciated, I would like to get this working.