Amp Help(Electronics problem)

I'm making my 2nd CBG and decided a matching amp would be nice. I've made other amps (noisy cricket) so I followed that again but omitted the tone knob. I had it working on the bench but now that I have it all installed in the box I have really low volume and lots of noise/static. The weird thing is if I open the amp and touch one of the speaker chassis the noise is cut down and the volume comes up. If I touch the speaker and the shaft of the cable jack pin it's perfectly quiet and has nice clear volume.

I'm a relative noob to electronics so the only test equipment I have is a multimeter.

Any help or ideas would be much appreciated.

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Permalink Reply by RTZGUITARS on September 17, 2012 at 12:18pm

didn't see that i dont use .05uf I use the 47nf like the cricket

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Permalink Reply by TruckDrivingFool on September 19, 2012 at 10:33am

I have't had time to get back to it yet but I'm working off of this schematic from Beavisaudio.

My changes were to omit the circled tone part in the circuit, use the two speakers previously linked, powering it with a six AA battery pack, and add a hot wire from the power to the grit to include an LED (uses same switch but separate contacts) to show when the grit is on.

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Permalink Reply by TruckDrivingFool on September 21, 2012 at 6:00pm

Not sure if it's grounding but a wire from the speaker to the tube of the jack has made it work. As I worked with the touch method I noticed I could one handed touch a speaker mounting screw and the jack mount nut to get the fix. So I wrapped a length of wire around a mount screw, tightened it down, and started probing with the other end.

After trying the speaker ground at the speaker, the ground at the board, and the ground tab at the jack - nothing

Touch the mount nut or the tube(shield tube?) - bingo!

Once I had it figured out that I needed a connection from the speaker chassis to the center of the jack I routed the wire, pulled the jack and wrapped the other end around the tube. Retighten jack nut done.

Now the bad, I'm not happy with it I get a sweet clean sound out of the treble strings/notes but the bass is muddy. Not too mention the volume is low. I think asking the NC to drive the two speakers is asking too much. So all this tinkering and I may pull the PCB out and try a little gem2.

That is unless someone has some other ideas as to what else I may have messed up.