Ladies and Gentlemen
I recently finished my first CBG. I put in the Gold Nugget Piezo pickup w/volume pot that I got from CB Gitty. I'm plugging into a Danelectro Honeytone. Getting a loud background hum, but it goes away if I touch the volume pot knob, or the metal ends of the cable. I'm hoping there is a way to eliminate or minimize the hum. Any suggestions greatly appreciated. Thanks!
Sounds like an earthing or polarity problem to me.
Are you sure that the earth wire from the piezo is soldered on to the sleeve tag on the phone jack?
Also on your volume pot there are 3 tags on the pot...1 is earthed to the pot metal cover, 2 is connected to the tip tag on the phone jack 3 is connected to the positive wire from the pup. The pot metal cover also needs to be earthed, so basically you have a wire from the 1st tag on the pot going to the pot metal cover, and then to the negative sleeve tag on the phone jack.
That should solve your humming issues.
I agree with bruce, it sounds like its not earthed properally which is what you are doing when you touch the cable.
i always struggled to earth the pot's casing, as it needs to get really hot, may be try there first?
Cheers and goodluck
Ahhhh...soldering to pots!
There is only one way to do it, or you risk destroying the pot:
Prepare the metal surface of the pot by scratching a small patch on the pot with an awl or even a nail.
Then clean that area with some soldering flux or spirits of salt.
Next melt a blob of solder on the iron.....it needs to be a fair sized blob, and it needs to be almost dripping off the iron.
Hold the iron as close as possible to the prepared patch on the pot so that only the blob of solder touches the pot....not the iron!
Once the blob has heated the patch enough it will flow onto the patch.
You can then momentarily swirl it around on the pot with the iron.
I quickly attach a length of wire to the blob on the pot....then leave it alone.
I only ever attach one wire to the pot like this....other earth wires I attach to negative tags & the length of wire soldered to the pot.....not the actual pot. This eliminates the possibility of ruining the pot by further heating.
I learnt this from reading Josh Gayou's article from Smokehouse guitars.
Looking him up on the net for some very good information.
Thanks for the replies. Greatly appreciated. The piezo I used was pre-wired / soldered from CB Gitty as I figured I could avoid any problems with it on my first build. I'll open 'er up and take another look. Thanks again.