Rickresource Rickenbacker Forum

Hi guys, yesterday I did a alive radio show and had terrible time with 60 cycle hum. I was using my '73FL and tried my '82 S (I just bought from Charles). Nothing I could do except for trying to sit one position (ugh). I was reading some very intricate charts too. What can I do, copper shielding, bartolini's(I don't want to switch from stock p-ups)?? Thanks in advance - Sam

Both basses hummed. I know the ground wires are good on both basses too. I did use FL as it is my main instrument.

Turn off all the fluorescent lights?

Or maybe try one of these?

http://www.ehx.com/products/hum-debugger

We turned off the lights in the main studio and had lamps- didn't matter. I'm thinking maybe copper foil in the control cavity and adding an addtional ground wire. The hum pedal sounds interesting, I'd have to try one first. I would think it would alter your tone. What do you guys think??

Induced 60 cycle hum is many times caused by AC motors. The ballasts in flourescent lighting can cause it, but so can fans, refrigerators, freezers, washing machines, etc.

beatlefreak wrote:Induced 60 cycle hum is many times caused by AC motors. The ballasts in flourescent lighting can cause it, but so can fans, refrigerators, freezers, washing machines, etc.

Transformers in power amps - tube especially.

Whoever invents a gizmo to kill 60 cycle in an instrument could be one of the richest people on the planet. We can send a man to the moon, but can't twang a tele in Bobs Country Bunker without the noise being louder than the instrument. I think these darn scientists have their priorities screwed up.

Ever try one of these?

Hey, it's easy to get rid of 60Hz hum. Go to Europe. No 60 Hz hum - it'll be 50Hz...


Actually, it's pretty easy to get rid of the hum, the whole principle of the humbucking pickup is exactly the way to do it. Those pick up the "common mode" noise of the ambient environment with two coils that are 180 degrees out of phase and add them together causing cancellation. The string vibrations are picked up by the out of phase coils in reversed magnetic fields, giving an in phase signal that doesn't get canceled. The problem is, all the extra coil changes the sound of the pickup.

So, for single coil pickups, all you need is another coil that picks up only the common noise and then you just add that in with reverse phase to get the canceling. This has been done with a "dummy" coil, but often, you still get changes to the sound due to the loading of the coil.

So, the solution is to use the dummy coil, which should be close to the actual pickup coil to be sure it has the same hum signal, then run the pickup signal and the noise sensing (dummy) coil signal into the two sides on a differential amplifier. Unfortunately, this means you have to have some sort of powered circuit in your instrument, or run separate, but exactly identical cables from the instrument to the diff amp. If you design the amp right, it should not add any "color" to the signal, but I'm sure that there would be people who would say it didn't sound as good, or those that would say it would only sound good if it was done with tubes, etc...

cjj wrote:Hey, it's easy to get rid of 60Hz hum. Go to Europe. No 60 Hz hum - it'll be 50Hz...

60 hertz more than 50...