My Highway One Jazz just started humming......

[Fender4Me]

Well, my new H-1 just started humming and hissing today. Goes away when I touch the strings but I can hear a pop when the strings or bridge are touched. I know I have a good ground to my bridge. My first thought was that it was caused by something I did when I modded the tone control, doing away with the "grease bucket" circuit and adding a .047mf Spraege orange drop but after checking everything, taht doesnt seem to be the problem. This bass has no shielding at all in the control cavity but, it seems odd that it would start this today adn not from day one. Any thoughts?

 

[v4tuna]

Maybe the cord? Sounds simple but quite often the problem. Especially because all was fine

 

[Fender4Me]

I tried that but it still humms..

 

[Slowgypsy]

Anything different about your environment? Such as new fluorescent light, mini fluorescent light, different room, etc. Without shielding, perhaps you're picking up some new kind of interference that simply wasn't there before?

 

[Fender4Me]

Nothing new going on that I know of. I did move my amp to another room and it didnt help. My other Jazz doesnt have the hum either. Im wondering if a pickup isnt taking a dump...

 

[lethargytartare]

So, yeah, if you touch the strings and the hum goes away, your grounding is good. Maybe that greasebucket circuit was filtering out the noise for you. Jazz bass, no shielding -- I wouldn't be surprised to hear hum. Two things you can try:

(1) put the old circuit back in and see if that ends the noise
(2) shield it up proper. That's a simple enough project if you're already comfortable enough to change the tone setup.

You can experiment by playing with different things in front of it (stuff like gypsy listed) -- if they cause different levels of hum, it sounds to me like a normal ol' bass with no shielding.

 

[Fender4Me]

Thanks guys, I did re-install the grease bucket circuit and there was no change so, I will order some shielding tape and go from there.

 

[RG]

Well, my new H-1 just started humming and hissing today. Goes away when I touch the strings but I can hear a pop when the strings or bridge are touched. I know I have a good ground to my bridge. My first thought was that it was caused by something I did when I modded the tone control, doing away with the "grease bucket" circuit and adding a .047mf Spraege orange drop but after checking everything, taht doesnt seem to be the problem. This bass has no shielding at all in the control cavity but, it seems odd that it would start this today adn not from day one. Any thoughts?

I had a hum that developed in my p bass. After changing cables and checking the ground to the bridge to no avail I changed the input jack and it solved my problem.

 

[Fender4Me]

I am thinking that I may be the casue of the hum. Well, actually, static elctricity. I just flipped a light switch on and bolt of lightening shot out of my finger that shocked the hell out of me. I think we have a high static charge in the air today which may be causing the hum. I ordered a sheilding kit from Stewart-MacDonald today that I am still going to install. It needs to be done anyway.

 

[Keano]

I did the exact same mod with the same cap as you, and I had the hiss afterwards (not the hum though). I had to fiddle with the treble on the amp to minimize it. Ymmv, of course.

edit: my hiss was a continuous one, regardless of whether I was touching the strings or not. It sounded like air escaping slowly.

 

[Fender4Me]

I should have said "hiss" in my thread title instead of "hum" becasue it is a hiss I am hearing but, it does go away when I touch the hardware or strings. It also goes away if I turn the tone knob down to 0 to about 20% . I did re-install the original grease bucket caps and resister but the hiss was still there.

 

[Keano]

Hmmm...is it a buzz or a subtle hiss like I described above?

Also, I had the snap crackle and pop when touching tone/volume on a different bass, but that was because of overall crappy soldering job on my end.

 

[lethargytartare]

So a few things --

(1) Search this forum for hum and noise threads -- I know this topic has been discussed in extensive detail over the years, so you'll find lots of approaches to analysis, and lots of fixes

(2) As I said before, if the noise goes away when you touch the strings, then your instrument's ground wiring is fine -- and so is your jack. And in a sense you're right that YOU are the source of the noise -- as we all are. What happens is that your body acts like a big antenna, collecting noise, and keeping drawing it near your instrument. A PC monitor may be worse, but you still bring quite a bit of noise right near the electronics cavity of your bass. When you touch the strings, what happens is that you create a path between the noise you are collecting and the ground lug on your jack (by way of the ground wire between the circuitry and the bridge). So touching the strings shunts that noise to ground (and thus AWAY from the circuitry that goes to the amp and gets amplified), and everything gets quiet. And that's also how you know your ground wiring is not the culprit.
(3) if the noise is the same when you restore the original circuitry, you can feel pretty good that you didn't cause it by modding the circuitry. And that's when I'd say it's worth looking into the shielding process.
(4) I could see how turning your tone down would reduce the noise -- since that drains some of the same frequencies. If you take an amp and crank the treble and drop the bass and mid, you would probably notice a hiss there too, but nothing that would indicate a problem.

I keep forgetting to ask -- do you get the noise when you have both pickups on full? Part of your analysis should be whether the noise is the same with each pickup on by itself, both on, each on full with the other on at 50%, etc. To make sure it's not just ONE of your pickups that's going haywire...

Keep us posted!