Lots of buzz/ hum

[Gaspasser69]

Used to be a ibanez gtr 70. (p bass with j pu) the p is himbucking but the j is a quarter pounder I changed 12 years ago. Master volume to 6 way rotary series in / out of phase, parallel in /out, neck then bridge. To the sd stc 2s preamp. I aligator clipped it to hear the sounds and I have alot of hum. Maybe when its all shielded it might better but what can I do to kill the buzz? I was the thinking a noise gate. Suggestions?

 

[Snake Aces]

Re: Lots of buzz/ hum

I would double check all the connections, especially the ground to the bridge. If the circuit is not grounded there will be hum. Since you do not have a bridge on the bass right now I would assume that is the culprit until you address it.

 

[Gaspasser69]

Re: Lots of buzz/ hum

It was assembled when i tested it, i didnt have bridge ground though. The j is at sd right now since the black lead fell off. I asked them to used shielded wire and ground if possible. Try to shield everything on the j .

 

[BlueTalon]

Re: Lots of buzz/ hum

It was assembled when i tested it, i didnt have bridge ground though. The j is at sd right now since the black lead fell off. I asked them to used shielded wire and ground if possible. Try to shield everything on the j .

Shielded wire is not necessary if the bass itself is properly shielded. A good shielding job should take care of all ground issues as well. I recommend using copper tape with conductive adhesive -- it's inexpensive, and it conducts better than aluminum or conductive paint. Shield the pickup routes and the control cavity, making sure the shielding comes over the edge of the control cavity so it will have positive contact with the metal control panel. The pickup wire channels should also be shielded. I use 1/4" copper tubing from a hardware store to shield the wire channels -- I know it's overkill, but I believe in bulletproof shielding.

You can choose not to shield the wire channels if you prefer to use shielded pickup wires, but you still have to make sure the pickup route shields are grounded to the control cavity shield, and the control cavity shield is grounded to the output jack ground. The advantage to using copper tape is you can solder the bridge ground directly to the cavity shield.


One of the disadvantages of a PJ pickup arrangement is when the J pickup is a single coil, there is no hum canceling for it. And the SD quarter pounder is a high-output single coil. You're pretty much stuck with the hum any time you use that pickup. If you really want a quiet bass free of the possibility of unwanted and unintended noise, you're going to have to get a hum canceling J pickup to go with your P pickup.

 

[Snake Aces]

Re: Lots of buzz/ hum

+1 to getting a hum cancelling J. I have used both the STK-J2 Hot Stack (bridge) and the STK-J1 Classic Stack (bridge) and I love them both. I really think the Hot Stack plays nice in a PJ though.

 

[Gaspasser69]

Re: Lots of buzz/ hum

I use shielding paint. I havent added it to this bass yet. I just started rehauling it. I left it stock except the new sd j pu 12 years ago. The control cavity was damaged since they made the top real thin where the pots stick through. The wood was like 1mm thick and tone pot was flopping around from damage. One bump and the controls are loose. Thats why i got a jazz plate. Im putting it in reverse. Im asking sd to put sheilded w
Ire so i can do what you are suggesting. I like the idea of copper tubing if you dont have sheilded wire. Good idea. I may have to get a stacked if the noise is rediculous.

 

[Funkfingers]

Re: Lots of buzz/ hum

IMO, the STC-2S-BO Blackouts for Bass EQ is accentuating the normal RF interference that affects the single coil J pickup. Any weak connections along the signal path also get boosted.

I have only ever used this specific EQ accessory with active bass guitar pickups.

 

[Mr. B]

Re: Lots of buzz/ hum

Try putting all that electronic stuff and wires on the inside of the guitar. That might help. :laughing:

 

[ginormous]

Re: Lots of buzz/ hum

Blue Talon and Funkfingers both nailed it.

The bridge itself will need a ground wire as a matter of safety.
Painting, braided wire and/or copper foil will bring the noise down, but not eliminate it entirely.

In a normal Jazz Bass, the pups cancel hum when used together (RWRP).