Popping sound - active pickups

The Thinker · #1 06-25-2011, 10:41 AM

Hi all:

I searched and found lots of threads related to popping sounds, but none that addressed this.

A while back I had a set of active Basslines jazz pickups (the ones with no visible pole pieces) put into a bass. They sound great, but now I get a significant popping sound any time I switch any of my pedals on or off. It also pops when I plug/unplug the cord from the amp (I never do this at my bass, only at the amp input).

Can this damage my speakers? Also, is this characteristic of the pickups, or is there a problem somewhere? I'm guessing the latter.

Thanks!

**line6man** · #2 06-25-2011, 10:57 AM

That sounds like something unrelated to the bass.

SGD Lutherie · #3 06-25-2011, 11:02 AM

That has nothing to do with the bass. It sounds like there might be DC on the signal line. Does this happen if you have no pedals plugged into the amp? One of your pedals might have a leaky coupling cap.

The Thinker · #4 06-25-2011, 12:23 PM

Interesting, thanks guys. It does not happen with my other basses (currently all passive) and I get the popping sound when connecting/disconnecting the cable at at the amp even with nothing else in the signal chain.

To verify, I will try this with a couple of different heads and without any pedals.

**line6man** · #5 06-25-2011, 12:55 PM

Quote:

Originally Posted by The Thinker

Interesting, thanks guys. It does not happen with my other basses (currently all passive) and I get the popping sound when connecting/disconnecting the cable at at the amp even with nothing else in the signal chain.

To verify, I will try this with a couple of different heads and without any pedals.

Maybe you have DC present at the bass' output.

The Thinker · #6 06-25-2011, 04:43 PM

Quote:

Originally Posted by line6man

Maybe you have DC present at the bass' output.

I don't really understand electronics very well, so I don't know what this means. But apparently I can assume that if there's DC in the chain, that is a bad thing and needs to be fixed

.

FYI, I tested on two different amps with only bass > cord > amp, and got the popping from both amps. So the bass is apparently the issue. I will take it in for some surgery.

Thanks, everyone

**line6man** · #7 06-25-2011, 04:46 PM

Quote:

Originally Posted by The Thinker

I don't really understand electronics very well, so I don't know what this means. But apparently I can assume that if there's DC in the chain, that is a bad thing and needs to be fixed

.

FYI, I tested on two different amps with only bass > cord > amp, and got the popping from both amps. So the bass is apparently the issue. I will take it in for some surgery.

Thanks, everyone

Get a voltmeter (I've seen them as cheap as $4) and measure the DC voltage at the output jack. It should be 0V.

The Thinker · #8 06-25-2011, 09:21 PM

Quote:

Originally Posted by line6man

Get a voltmeter (I've seen them as cheap as $4) and measure the DC voltage at the output jack. It should be 0V.

If there is DC voltage at the output jack, what's the fix? New jack?

**line6man** · #9 06-25-2011, 09:28 PM

Quote:

Originally Posted by The Thinker

If there is DC voltage at the output jack, what's the fix? New jack?

A coupling capacitor or isolation transformer could be used to block DC, but if DC is present, that would indicate that you either miswired, or the pickups are defective.

The Thinker · #10 06-26-2011, 06:32 AM

Quote:

Originally Posted by line6man

A coupling capacitor or isolation transformer could be used to block DC, but if DC is present, that would indicate that you either miswired, or the pickups are defective.

That's very helpful, thanks. I bought the pickups used, so I hope they are not defective. I will get this checked out. Can the pops damage speakers, or is it typically just an annoyance?