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Ground wire from bridge
- Thread starter Level5wizard
- Start date
- Apr 18, 2008
- 16,024
- 1
- 31,760
- Disclosures
- I'm highly opinionated and extremely self-assured
Technically, none of our instruments "need" a ground wire from the bridge. They will work perfectly without one. But if the pickups and electronics are poorly or incompletely shielded, then the circuits can pick up noise from ambient electrostatic interference. Rather than doing a full shielding job, the designers decided to take the easy way out, and make the player part of the circuit, so your body gets to do the shielding instead. But if your pickups and wiring harness don't pick up any noise, then you don't need a bridge ground.
Active EMGs are famously well shielded and quiet, and therefore EMG recommends not connecting the bridge to ground.
Active EMGs are famously well shielded and quiet, and therefore EMG recommends not connecting the bridge to ground.
Ground is ground and can be tied into anywhere in the circuit. The back of a pot is usually where I'd land it.
Not necessarily. All grounds, from the pickup shields through to the jack, should be in a progressive manner to avoid ground loops that will increase the hum, not disperse it. But in this case, yes, generally, a bridge ground soldered to the back of a pot, usually the closest one to the bridge which is usually the tone pot on Fender-ish basses will do very well.
New issue. The pickups work. But the volume and tone controls don't work. It is wired like the layout above.
But when plugged there is sound.
New CTS pots. But they could be toast.
L5W
But when plugged there is sound.
New CTS pots. But they could be toast.
L5W
- Apr 18, 2008
- 16,024
- 1
- 31,760
- Disclosures
- I'm highly opinionated and extremely self-assured
They make no change volume or tone. Just raw to the amp.
QUOTE="ctmullins, post: 25928964, member: 115884"]Can you elaborate on "don't work"? Do the volume and tone knobs do anything at all? What resistance value pots did you use? Active EMGs use 25kOhm pots, which are very different from the usual 250kOhm or 500kOhm pots that are correct for passive pickups.[/QUOTE]
QUOTE="ctmullins, post: 25928964, member: 115884"]Can you elaborate on "don't work"? Do the volume and tone knobs do anything at all? What resistance value pots did you use? Active EMGs use 25kOhm pots, which are very different from the usual 250kOhm or 500kOhm pots that are correct for passive pickups.[/QUOTE]
Ground loops are absolutely a real phenomenon, and in many types of gear, it's wise to avoid them. That's particularly true if a device has a power transformer, or inputs AND outputs to other pieces of gear. I've designed a lot of gear where strict attention to ground loops has made a big difference in the noise level of a device. That said, the ground currents in a bass are so small that you can safely ignore them in a bass or guitar - just make sure everything is grounded, it'll work fine.
Sorry, it is a just a p-bass pickup. Yes real emg.
But this pickup is from the mid 90's. From a old bass of mine. Didn't fine the wiring harness.
But this pickup is from the mid 90's. From a old bass of mine. Didn't fine the wiring harness.
You don't need a harness, the whole solderless connections is a relatively new thing for EMGs. The diagram looks right but pot values have to be right (as mentioned above) and you have to know which lead is which from the pickup.
Just snap a pic and post it. There are folks on this thread already that can diagnose what's going on.
With one major exception I know about: a Rickenbacker Ric-O-Sound instrument, whether a 400x bass or one of the guitars: 360, 620, etc. I have had ground loop hum that required re-wiring on both my 4002 (yes, "2," not "1" or "3") and my 360-12 guitar. Then again, this ties into your comment about power transformers and such, since the purpose of a Ric-O-Sound is to run the split output of each pickup into two separate amplifiers, which increases the propensity of ground loops greatly.
Absolutely agreed - if you use the Stereo feature, you are tying together two other pieces of audio gear, with the Ric in the middle. Instant ground loop potential.
Just heat the back of the pot with the soldering iron until a small pool of solder adheres to it (heat the pot casing directly and touch the solder to it until it melts, don't melt the solder with the iron). When you have a little pool, melt it, lay the end of the wire in it, remove iron and let cool. I always tin (get a small layer of solder on) the end of the wire too before making any connections.
I'd use that tone pot, it's got a nice clean area on it that should take the solder well.
I think you need to reference your diagram agam though, you should already have things soldered to the top of the pot but I don't see any.
I'd use that tone pot, it's got a nice clean area on it that should take the solder well.
I think you need to reference your diagram agam though, you should already have things soldered to the top of the pot but I don't see any.
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