Why Can I Hear The Radio Through My Amp?

[longtimepilgrim]

A guy gave me a Cort Action Bass that was all snap, crackle & pop. I used a schematic found here (Click Action Bass Series > "Action Bass (2006)" for a look) as a guide to resoldering the broken or weak connections. I'm pretty confident that I have it wired properly & I even checked the connections with a multimeter. Everything checks out as far as I can tell. I plug it in & I hear the notes of a bass guitar coming out of the amp. But...

...then it goes all Spinal Tap on me & I'm hearing the radio through my amp? Some talk radio show interfering with the signal? Have I gone wrong somewhere? What's up with this phenomenon?

[vapochilled]

There's a ghost with a crappy radio in that bass. J/k All joking aside It's possible I forget all the details why usually RFI, iirc. Actually there was an electrical socket in my 5th grade grammer school class room like that, that made me laugh and kid. Essentally somewhere bass, cable, amp, power cord, socket, or even the wiring where you play. is acting as an antenna. The sounds you hear could actually be feedback into the power.

First I would try two things shield the bass and a different power source. I.e. a socket on a different circuit, ideally isolated, but at a minimum on that is not shared with light switches or the A/C unit. That will drop allot of power "noise". If that doesn't work try different cables or amps you may have access to see if you can isolate the source of interference.

[chroma601]

You are likely fairly near that radio station. Somewhere in the chain your cable shielding is not correct, and the powerful RF in the area is being detected. It should be an easy fix.

[subdude99]

This has happened to me twice in my life. One time I replaced my instrument cord and that fixed it. The second time I plugged into a different outlet and that fixed it. So right in line with what the others have said.

[scottbass]

Does the problem go away when you plug in a different bass? If so, then the shielding on that Cort needs to be better. Line the control cavity with copper foil (available from www.stewmac.com and many other places) and ground it to the bridge. If the problem happens with other basses, too, then try the whole setup (your amp & bass) physically sitting in the same place but plugged into a long extension cord to a different circuit. If that solves the problem, you have a noisy circuit. Call an electrician. If neither of the two conditions described previously exist, you then have to try a different instrument cable. Still getting the radio? Then the problem is in your amp and it's going to be a lot harder to diagnose & fix.

[zac2944]

If the suggestions from post #4 don't work, use a choke on your cable and if necessary your power chord too. Much simpler solution than shielding the control cavity. The appropriate ferrite choke will run you about $2. Do a TB search on "ferrite choke" for more info. I don't feel like typing it all up again.

[fdeck]

The most common cause of radio pickup is a loose ground at the input jack, either in the amp, cabling, or bass. This could be something unscrewed, or a solder joint wiggled loose.

[jsingles]

happens ALL THE TIME when i play my ibanez practice amp hahah

[stewart8980]

my old teacher taught me on a starter pack squire amp...and he would just kick it....