Any help is appreciated. This is my first CBG build (will post a pic on my page shortly) I have read through part of the forums on this and I have made triple sure everything is grounded correctly, and I still have this Hum. (I'm Using 1 piezo, 1 volume pot and input jack).
It was also mentioned to someone else the Jack Plug could be the culprit and was the case for that particular person. I think my problem is different (maybe)....,
Is it Possible - for the guitar cord itself be the cause of the hum? When I plug the cord into the amp by itself (not hooked to CBG) I get a slight hum. When I plug the active cord into the CBG the hum gets a little louder. When I touch the outside input jack collar the hum quiets, but amp still has a very slight hum until I unplug the cord completely
Its it possible the cord is bad somehow and in some way the hum is amplified when plugged to the CBG?
Should I just replace the Jack plug or get a new guitar cord? Thanks in advance for your help.
Replies
Coupla possibilities spring to mind, both of them involving 60 Hz hum canceling:
1) you might have a cold solder joint to the back of your vol pot. You gotta scrape off some of the base metal on the back to make a secure ground. You can also twist the red and black leads going to the vol pot, and from the vol to the jack, together to get some cheapy RF shielding.
2) Did you ground your strings, by running a ground wire from the presumably metal bridge to the back of the vol pot (not the jack)?
It could also be the guitar cable. I find those $6 cheap ones are indeed noisy as heck. Upgrade to a $14 or $30 cable (I know, I know, seems ridiculous for a DIY build) is an option, mebbe...
Thanks. Yeah I scraped the back of the pot for a solid solder.., the wires are twisted together but not real tight.
I had no idea you could ground the metal bridge - thats a new one to me, but then I'm a newbie. I have to replace the bridge anyway - so I can probably try to encorporate that into it. As it is - it would make for an unsightly wire exposure. Assuming I use metal for a replacement bridge. I have to lower the nut and raise the bridge a bit. The current metal bridge is just a nail glued into a thin wooden saddle.
You describe hum.. Is it possible that 'buzz' or 'noise' is a better word? They're very different things..
Cheap cables can indeed act as an antenna to amplify existing noise it's true
Thank you Phyrgian Kid.., "noise" could be more of an appropriate word. Its more of a slight annoyance if I ever plan to record anything from my computer. As far as practicing around the house its no big thing. All I know is the noise or hum will go away when I touch the ring around where Im jacked into the CBG.
Okay - I unplugged the cord from the CBG - touched the shaft of the jack itself and the hum went away. I dont know why I didnt think about doing that before - I guess the sum of what everyone has been suggested helped to bring that trial about.
So I am "guessng" its my cord after all and not in the guitar. I'll end up ordering one later and endure the humming till then. Seriously if all you guys hadnt suggested the various possibilities the the thought would not have crossed my mind. A leads to B leads to C and so on.
Thanks a Bunches - I deeply appreciate everyone's willingness to help a guy out.
So, does the guitar work at all, or are you only getting the 60Hz humming and nothing else? If you're getting guitar sound thru to amp, then the issue of the humming could just be be ambient electric "pollution". In other words, cellphone signals, florescent lights, radio waves, etc. all create "noise" that is picked up by both the patch cord, the piezo, and the amp.
Of course, could just be the jack. I too have had trouble with jacks "cracking" during installation, effectively crossing the positive & negative leads...resulting in the same trouble you're having.
Yeah - I'm getting sound, it sounds pretty good despite the humming. I took the amp outside away from the computers and Tv's etc and I get the same hum. I can back the volume down and the hum subsides some but its not very loud. Its not my Amp - because I get the same hum when I run it through the computer as well. I sing a lot online with my computer and there's no hum normally.
There is no cracking sound like with a loose jack. I am familiar with that kind of sound from when my brother played guitar as a teen.
good idea to check the patch cord. Simply unscrew the end pin coupling, slide it back onto the cord and look at your leads. An easy solder fix if there's a loose wire.