I’m getting some humming on my late 80’s 5P, more pronounced when the piezo is on full.
Can someone provide answers to the following questions to help troubleshoot?
1) Is the jazz pickup on these basses a single coil?
2) Are the bridges on these grounded?
3) Has anyone shielded their cavities and if so was it different to pull or lift out the preamp to do so?
4) Unrelated to the hum, anyone know what the db ratings are for the bass and treble frequencies are?
The humming I’m experiencing seems to go away when piezo is turned all the way down and also when the jazz pickup is not engaged. It also seems to go away depending on how the bass is positioned in the room.
My amp and speakers are in close to proximity to my television, but My other basses don’t have any problems. I tried the TRB5P in a different room and amp but the humming was still present
Thank you,
JayT
Here's a few answers based on my OEM TRB series owner's manual, which covers the 4, 5, and 6, and my own experience with my TRB-6P.
1) Is the jazz pickup on these basses a single coil?
- Single coil according to the manual
2) Are the bridges on these grounded?
- The manual doesn't say, but I'd be amazed if it wasn't, given the active electronics and piezo system. My TRB-6P has what looks to be a think gauge wire going from the 1/4" jack to a hole in the body facing rearward, which I'm assuming is a ground. There's also a thicker wire going into the same hole, but I'm assuming that is the rear pickup lead as there is an identical one coming from another hole, and they terminate next to each other on the board with pin and socket connections.
3) Has anyone shielded their cavities and if so was it different to pull or lift out the preamp to do so?
- I have not on my TRB thankfully. Mine has what appears to be shielding paint, which is what I've typically used on other problematic instruments.
4) Unrelated to the hum, anyone know what the db ratings are for the bass and treble frequencies are?
- The manual doesn't say, but my recollection is +/- 6dB. I have nothing to back that up though ;-)
With regard to the humming, it's possible it could also be your 1/4" jack. I've replaced mine twice over the years. They are barrel jacks, which IME are a little trickier to replace.
Good luck!