Problem Never Encountered Before

[dramatwist]

Happy Holidays, folks.

I have a David Eden 15" speaker cab (D-115-T) rated at 200 watts. When I set it up with a brand-new TC Electronic BAM200 head (rated at 200 watts) and I touch the strings on my bass (Yamaha P/J passive) I get no sound until I take my fingers off the strings... then, the sound of the vibrating string comes through. The bass is fine through my other amps.

Been playing for 50 years and have never come across this. Guessing it's a grounding issue.

Thoughts or suggestions?

 

[Downunderwonder]

Lay off the eggnog?

All my basses work the same way. Mute by touching the string. Make a note by pulling on string and letting it go

 

[mmbongo]

Does the amp have a noise gate built in? Does it sound okay during normal playing?

 

[brstma]

Might have automatic limiting if the gain is too high. Try lowering the gain if you haven’t already

 

[JimmyM]

That's bizarre. Those aren't digital preamps, right? They look too simple to use if they had digital. Try it through another cab or two. If it works with them, there's some sort of miscommunication. If not, I'd just exchange it.

 

[Downunderwonder]

That's bizarre.

Ah... a comedian.

The bizarre brings it out.

 

[ashtray]

Have you tried another bass? Does the sound cut out if you touch the bridge? If so, the bass may have a wiring issue where the ground to the bridge was wired to the lead of the output jack instead of the ground. If so, touching the strings or bridge would ground out the pickup and essentially turn it off.

(Technically, the bridge ground should be wired to the back of the volume pot, not directly to the output jack - but “follow the path” logic still applies.)

 

[agedhorse]

The bridge ground should be wired directly to the output jack sleeve terminal. So should any other grounded part of the bass.

 

[HolmeBass]

Sounds like a grounding issue of some sort. I get this with my jazz bass, which doesn’t have a ground wire from the bridge to, um, well I guess what agedHorse said. I just know I’ve seen many jazzes with the wire but mine doesn’t have one.

For recording I make a bracelet from a string, wrap in around my plucking hand, and secure it to the bridge. This results in the same amount of background hum whether my fingers are on the strings or not.

The strange thing I have noticed is same jazz, same amp, different room and it’s not an issue. Which doesn’t make sense to me but I have observed it enough times that I have no doubt that it is an actual phenomenon.

The hum I am talking about is louder and additive to single-coil pickup hum, and occurs even with both pups on full volume.

Try the string bracelet trick and see if that works.

 

[dramatwist]

I appreciate the helpful suggestions. I'll try them out and see how it goes. Thanks, guys.

 

[ahc]

Have you tried a different instrument cable?

 

[Element Zero]

Have you tried turning it OFF and ON again?

Have you tried pressing ANYKEY?

Have you tried throwing it down a flight of stairs? I’ve heard that works sometimes.

Did you know you can use USED MOTOR OIL to fertilize your lawn?

I wish I could be more help. Instructions weren’t clear. Head stuck in car door.

 

[Nevada Pete]

Sounds like a grounding issue of some sort. I get this with my jazz bass, which doesn’t have a ground wire from the bridge to, um, well I guess what agedHorse said. I just know I’ve seen many jazzes with the wire but mine doesn’t have one.

For recording I make a bracelet from a string, wrap in around my plucking hand, and secure it to the bridge. This results in the same amount of background hum whether my fingers are on the strings or not.

The strange thing I have noticed is same jazz, same amp, different room and it’s not an issue. Which doesn’t make sense to me but I have observed it enough times that I have no doubt that it is an actual phenomenon.

The hum I am talking about is louder and additive to single-coil pickup hum, and occurs even with both pups on full volume.

Try the string bracelet trick and see if that works.

<The strange thing I have noticed is same jazz, same amp, different room and it’s not an issue. Which doesn’t make sense to me but I have observed it enough times that I have no doubt that it is an actual phenomenon.>

Your right. It is indeed an actual phenomenon. Depending on house (AC) wiring, AC wiring on the various stages, etc., different physical locations will have different levels of stray 60Hz electromagnetic fields, and therefore, different levels of that pesky "hum". As you noticed, sometimes it's a big problem. Other times, not. You will also notice if you point the neck of your electric bass or electric guitar in a different direction, the "hum" will change.

 

[dramatwist]

Have you tried a different instrument cable?

Yes.