My Stringray fretless has a buzzing sound when amped

[Mrrockpower]

Last week when I was gigging my 1991 Music Man Stingray fretless started to buzz so much that I could not use it for the rest of that gig. I had one of my other basses there, so it did not make to much problems.

The buzz sems to decrease when I turn down the treble knob. I was using an Ampeg SVT CL amp and 4 x10 cab. The spare bass I used (also active) did not buzz at all.

Good advices to how I can fix it is very welcome.

 

[Golem]

Last week when I was gigging my 1991 Music Man Stingray fretless started to buzz so much that I could not use it for the rest of that gig. I had one of my other basses there, so it did not make to much problems.

The buzz sems to decrease when I turn down the treble knob. I was using an Ampeg SVT CL amp and 4 x10 cab. The spare bass I used (also active) did not buzz at all.

Good advices to how I can fix it is very welcome.

Bad ground. You make a long test wire, one version is a 1/4" plug with a wire connected only to its sleave [tip not connected]. Plug that into your amp to pick up the amp's ground and then touch it to the outer collar of the bass's jack, to pot casings [chrome control cover will do], etc. This reconnects the bad ground and is your diagnotic tool [you should hear the buzz go away]. Obviously, test with the treble turned UP.

You mention it's fretless. IF you use plastic strings, you have no grounding to the bridge thru your fingers. OTOH, I don't actually know if the bridge is grounded on MM products. Bridge grounding is the predominant practice, but for safety reasons, some builders choose not to ground their bridges.

 

[higher1]

my 89FL and 92 sr5 bridges are definitely grounded.

 

[Golem]

my 89FL and 92 sr5 bridges are definitely grounded.

Then one particular test using the previously described grounding test wire is to check for a difference in test result between the bridge and the jack collar and control plate. If grounding the bridge fixes it, but grounding the control plate does not, the strings are picking up interference cuz the bridge ground wire is oxidized and/or embedded into the body finish.

The bridge ground wire is under the bridge and under pressure will sooner or later go deeper into the body finish and not be pressed tightly against the underside of the bridge. If that is the case, remove bridge, clean stuff, put a bit of brass or copper foil between the wire and the body. Avoid aluminum [oxidizes too fast]. Or just clean and reposition the wire, and expect to have to do this again, in another 15 years!

There may be a similar wire like the bridge ground, but between the control plate and body. Same deal if there is one. My Ray is also a '91 but so far I've never had to open it up. Nut broke last week. That's its first failure ever

 

[mmplayer89]

I had a problem similar to my yamaha fretless bass. I totally refinished the bass myself and stained it but I had to take the pickups out. When I soldered them back into place my treble would buzz really bad. I opened it back up and saw the the solder job I did for the treble knob was really sloppy and the solder was touching more than 1 point that it should have been touching or whatever its called. So im guessing maybe you have a loose solder possibly and its touching another point OR you might have a problem with your jack. I could be completely wrong because I have to teach myself all this stuff and I just learn as I go.