So your bass has a hum

[oakley86]

Where the cloth insulated wires run through the hole connecting the pickup to the controls. Do I need to wrap the wires with copper? Also the pick guard doesn't cover any cavities, does it still need copper on the back side

 

[BlueTalon]

Pickguard is optional, I think, in that circumstance. If the control cavity on your bass is routed in the rear, and the pickguard covers nothing but wood, then the shielding can all be done internally, and shielding the back of the pickguard would be unnecessary. (If what I just described doesn't sound like your bass, a picture or two would help me understand what you're describing.)

Regarding the wires: I addressed this on my bass by using cut-to-length bits of copper tube between the routes. Admittedly that is overkill, but I don't mind overkill. In your case, I think wrapping the wires with copper tape would be a good move, but I'd probably wrap them first with a bit of paper so the adhesive doesn't stick to the cloth insulation. Then make sure one end of the copper tape is securely connected to the shielding.

And finally, make sure your shielding job is connected to ground.

 

[oakley86]

Here's a photo

 

[BlueTalon]

Thank you for that. There would be no point in shielding the back of the pickguard.

 

[oakley86]

Thanks for your continued help

 

[DiabolusInMusic]

Here's a photo

You will want shielding in the pickup and control cavities. I like to add some tape under the bridge for a better connection. I wouldn't stress about the wiring channels or the wires since your bass has exposed pickup poles - there will be considerably more surface area exposed. I would recommend twisting the leads though.

Cross posting from your other thread, the ground wire is the one coming from the bridge. This looks like a modern single coil P since it has the wire channel but the old ones used a brass strip from the bridge that ran along the top to get a ground connection. From the looks of it, your bass definitely needs shielding. I don't think that was the source of your hum though. Shielding isn't constant, it stops when you touch metal/strings/bridge on the bass.

 

[oakley86]

This one's pretty old I'd say. It's ser. #349 patent pending

 

[sunbeast]

You will want shielding in the pickup and control cavities. I like to add some tape under the bridge for a better connection. I wouldn't stress about the wiring channels or the wires since your bass has exposed pickup poles - there will be considerably more surface area exposed. I would recommend twisting the leads though.

Cross posting from your other thread, the ground wire is the one coming from the bridge. This looks like a modern single coil P since it has the wire channel but the old ones used a brass strip from the bridge that ran along the top to get a ground connection. From the looks of it, your bass definitely needs shielding. I don't think that was the source of your hum though. Shielding isn't constant, it stops when you touch metal/strings/bridge on the bass.

I imagine the issue here is the use of those tapewound strings from the picture above, which eliminate the traditional body grounding from touching the strings and render the bridge ground connection useless. When using tapewounds, proper shielding is really the only way to eliminate EMI buzz that your body is inducing into the signal (unless you want to run a wire from your skin to a ground connection, which is not the most safe solution- I have done this in the studio before though, with a wire running from my output jack sleeve and taped to the skin at my waist under my belt).

This one's pretty old I'd say. It's ser. #349 patent pending

 

[BlueTalon]

I like to add some tape under the bridge for a better connection.

I do that too. I make a copper tape bed for the bridge that is almost the same size as the bridge, so virtually all of it is connected. And the ground wire is soldered to that copper bed.

 

[Larry Balara]

Hey Guys,

Is it normal for a Ritter bass to hum when the high and mid boost is at max? It doesn't matter whether it is in single or hymbucking. Doesn't do this in passive mode.

Thanks in advance!

 

[E2942]

You're increasing the Gain in certain frequencies, so it's to be expected.

 

[ChrisDev]

You're increasing the Gain in certain frequencies, so it's to be expected.

Not with Ritter Electronics

 

[E2942]

They must be magic then, because I've never met an active instrument where you can bump any of the onboard preqmp EQ to the max without injecting some noise.

 

[Greenstreet]

I agree

 

[Larry Balara]

More info! The hum is minimized when the mid boost is off! So it seems to me, you are right. However, it has been suggested it is a simple grounding issue! It seems to me if it was a grounding issue the hum would be present no matter what mode or controls were on and would cut when I touched the strings or something. On the otherhand, I maxed out the high boost on my other Ritter and it hisses. I maxed out both high and mid boost and it hums just a little bit.

 

[DiabolusInMusic]

Not with Ritter Electronics

I would be curious to know more about this circuit because, like @E2942 , I have never heard a pre-amp that could be boosted to the max without adding noise.

They must be magic then, because I've never met an active instrument where you can bump any of the onboard preqmp EQ to the max without injecting some noise.

More info! The hum is minimized when the mid boost is off! So it seems to me, you are right. However, it has been suggested it is a simple grounding issue! It seems to me if it was a grounding issue the hum would be present no matter what mode or controls were on and would cut when I touched the strings or something. On the otherhand, I maxed out the high boost on my other Ritter and it hisses. I maxed out both high and mid boost and it hums just a little bit.

It really just sounds like you are boosting the signal a lot and introducing noise. Try flattening the controls and boosting the amp, see if the noise persists. I would wager they don't.

 

[SubHuman]

Hey man…great information. This guide would fix 99.9% of the bass players that are baffled by noise and hum in their instruments. Always that 0.1% unexplained! Good job.
I personally like the EMI adhesive copper foil tape and tack solder the seams which makes the faraday cage a lot more rigid. I have several whisper quiet basses and guitars. I have done friends instruments too and they’re blown away. Fun stuff!

 

[FatFunk]

I was about to embark in this task, to try to tackle some shielding issues (hum goes away when I touch anything metallic on my bass), when suddenly I'm experiencing what now sounds like a grounding issue. I'll elaborate.

I have an old Ibanez SR905 that had the MK1 pickups & electronics. I swapped the preamp with one of the newer Ibanez preamps, the ones that have a frequency selector.
Now, if I recall correctly I did that job myself, and my soldering skills are limited. However it has been working for several years now. There was always some humming that I wanted to start working on.

Today I plugged the bass and got very little signal from it, way below what I would normally get (however the hum was still there). I started working with the knobs to try to troubleshoot the issue. As usual, the hum goes away or it's greatly reduced if I touch the strings, knobs, bridge, etc.
What really puzzles me is that now the hum remains even if I turn the volume completely off, and it is affected by the eq knobs (in volume and frequency), even with the volume off.

I'm assuming this is now some kind of grounding issue, does anyone have any pointers on what part of the circuit could be causing this?
I'll try to work on it during the weekend, but I would like to mess as little as possible with it.

Thanks much

 

[ex-tension]

I have an old Ibanez SR905 that had the MK1 pickups & electronics. I swapped the preamp with one of the newer Ibanez preamps, the ones that have a frequency selector.

"...one of the newer Ibanez preamps" This doesn't say a lot. I'm guessing you cut the pickup cables from the MK1 preamp. Then how did you connect them to the new preamp? It has pickup input terminals? Or the pickups are connected directly on the blend pot? What is the blend pot value?

I'm assuming this is now some kind of grounding issue, does anyone have any pointers on what part of the circuit could be causing this?

Without knowing the circuit we can't elaborate. If you put some photos of the electronics and explain the signal path, we can try.

Today I plugged the bass and got very little signal from it, way below what I would normally get...
... What really puzzles me is that now the hum remains even if I turn the volume completely off...

These two suggests volume pot problems.

 

[FatFunk]

Hello.
Thanks for the feedback.
I took the weekend to take out and re-assemble the whole circuit, and also perform the shielding job I had originally intended to do.

I've pretty much isolated the buzz sound to an active passive switch that is mounted on a pcb board.
I've tried in the past to remove that switch and replace it with a push pull volume pot. I was never able to de-solder it from the board, but I obviously managed to mess up the solder joints.

Right now, after working those solder joints a little bit, the buzz seems to be gone.
However, I'm going to have this re soldered by a friend that has both the expertise and the tools to do so.

Now, the shielding job has not completely solved my original hum issues.
What's more, I've now noticed another something that puzzled me:

Does it make sense that the hum gets louder when my volume is at half? I usually run it full open, so I'm not sure if it has always been like that.

Thanks!