Rickresource Rickenbacker Forum

My Ric 4003 hums quite a bit. I know single coils will hum and have another bass with singles and a guitar with singles. The Ric is the loudest of the three. I have heard it is supposed to hum and is supposed to be one to the characteristics that give it the Ric growl. My Ric sounds, just the hum drives me nuts, my other bass sounds great too and has no hum. It is another make from the company Leo started with those bolt on necks. I have heard people say there Ric is damn quiet. I am thinking of using foil tape bought at a home improvement store to line cavity and pick guard. I have also heard it works and others say don't waste your time. I don't want to change my pups cause I have Sergio Silva pups in there now. I read about doing the RWRP trick, but when I took the pick guard off and bridge pickup and looked at the pups it seems I will destroy my pickups if I try to mod them. Any suggestions on hum elimination?

08 Ric 4003 wrote:I have heard it is supposed to hum and is supposed to be one to the characteristics that give it the Ric growl.

That's just plain false if I may be so bold... I can record clips of my 4003 that has the RWRP mod done to it if you want and demonstrate that with or without hum the bass sounds pretty much the same, just more or less noisy. However this idea may come from the fact that older Rics with the 0.0047 cap in the circuit can't be made to utilize RWRP hum-canceling (the cap puts the bridge pickup in a perpendicular phase which is also what causes the sound to gain so much midrange tone which is normally suppressed by comb filtering--of course I'm talking only about when both pickups are at full volume).

08 Ric 4003 wrote:I am thinking of using foil tape bought at a home improvement store to line cavity and pick guard. I have also heard it works and others say don't waste your time. I don't want to change my pups cause I have Sergio Silva pups in there now. I read about doing the RWRP trick, but when I took the pick guard off and bridge pickup and looked at the pups it seems I will destroy my pickups if I try to mod them. Any suggestions on hum elimination?

Use copper foil bought from some place like Stewmac.com... the kind with conductive backing is best because you don't have to solder (much). When I shield with copper foil I use 2-3 layers of shielding to lower the cutoff frequency that gets shielded, I feel like sometimes one layer really doesn't do much. But all the shielding you can possibly put in a guitar still won't get rid of all noise, especially the really low register stuff that RWRP and humbucking are designed to fix like 60 Hz hum. And the RWRP mod certainly won't destroy your pickup, it's actually a nice and tidy little mod, but if you aren't comfortable doing it, then have someone help you (like a capable guitar tech)--feel free to show them my tutorial. Anyone who knows how to solder should be able to follow my tutorial no problem.

Is your Fender a Jazz? Then it is hum canceling via RWRP. And it probably isn't shielded at all or if so only minimally, as some Fenders come with a thin layer of carbon paint in the control cavity. I believe RWRP is the more effective mod at reducing hum but shielding also helps when done correctly.

I have noticed a stock Ric is dead quiet in an environment with good wiring but once you get in a noisy space it picks it up probably more than other instruments. The stock wiring is not intrinsically noisy, the noise is coming from outside of the bass.

I am an electrician and have been soldering for quite a while. I love doing stuff myself and I just don't want to screw up a nice Bass. The only thing I don't and can't do with guitars and basses is set them up cause I don't want to mess with the ordeal and my guitar tech only charges $50 tgo set up and to intonate it, and my last axe of my six is in the shop now getting set up, and I don't mess with truss rods once again I let my guitar tech do that, one wrong turn an there goes your neck. With Fenders you can get a Warmoth to replace it with. If your snap a Ric you just may see a grown man cry. Since I am and electrician I understand the theory behind all the mystery of electrons flowing and signals. Yes my Fender is a Jazz made in '95 with a Warmoth neck. The Fender is dead quiet, but the '08 Ric is not. I have a Acoustic B100 solid state amp which is quite quiet. I don't think the RWRP will ruin the pups, but from looking at them up close it looks like if I take them part I wont be able to get them back together. They are Sergio Silva's and sound damn good.

Joel, a set up really isn't all that difficult - check out www.joeysbassnotes.com he gives great description as to how to do it.

I was told you want the foil to touch the metal of the outside of the of the pots, but not the leads of the pots or any of your pickup wires or the cap. The conductive foil needs to touch ground somewhere to take the stray noise and hum to ground.

The last thing you want it to do is allow the foil to touch all the pots as you'll create a wonderful ground loop in doing so. That's assuming you keep the wiring harness intact. Alternatively you can remove the ground wires running around the perimeter of the pots.

You do need to connect the foil to the ground portion of the circuit but you only want to do it at one and only one point, otherwise the foil itself will become the hum problem.

FYI, I've shielded probably 30 instruments with copper foil and clad PCB material over the years; some were my own and others were at the request of friends. I keep hearing people swear how much this procedure has dropped the level of hum but I have never had the experience that it did much of anything. There's usually other things that need to be addressed . . . cords, amps, power sources, lighting in the room.

Not meaning to hijack the thread, but I've noticed that my tube amps hum very little if at all, and my solid state amps hum like crazy if I get near them with my single coil Ricks or near any of the things that JH just mentioned.

Not sure why. I'm not an electronics guru at all, it's just an observation.

Maybe Ricks want to play through tube amps?

johnhall wrote:FYI, I've shielded probably 30 instruments with copper foil and clad PCB material over the years; some were my own and others were at the request of friends. I keep hearing people swear how much this procedure has dropped the level of hum but I have never had the experience that it did much of anything. There's usually other things that need to be addressed . . . cords, amps, power sources, lighting in the room.

+1

I am no electrical engineer, just an electrician and I have worked with and studied electricity and electronics over the past 20 years. I have noticed that sometimes when I play my basses or guitars throught same amp with the same effects and the same DC islolated power supply powering them up it can sound quiet or you may hear annoying hum. If I hold my Ric close the flourecent lights in the room I jam in it will hum like a SOB. But just like an amp the pickups are doing there job. Pickups don't know we only want the chord or note we played sent to the amp to make sound instead of hum and hiss and pops and static, the same way and amp doesn't care what it amplifies it will amplify a pop or hiss or a nice sounding E chord.

johnhall wrote: FYI, I've shielded probably 30 instruments with copper foil and clad PCB material over the years; some were my own and others were at the request of friends. I keep hearing people swear how much this procedure has dropped the level of hum but I have never had the experience that it did much of anything. There's usually other things that need to be addressed . . . cords, amps, power sources, lighting in the room.

Ah yes, electromagnetic shielding - something of a black art with all sorts of myths surrounding it.

Copper (or aluminum) shielding can be quite effective at blocking noise, BUT, as always, it depends on many factors. First of all, this sort of shielding will do NOTHING for stopping magnetic fields. This is a big factor in hum, magnetic fields radiated by things like transformers and such. In order to shield against those, you have to use something with a high magnetic permeability such as mu metal or permalloy. Then you'd need a pretty thick (and heavy/expensive) layer of it. And then again, the pickups themselves are great "antennas" for this sort of noise, and shielding them with mu metal would stop them from working all together.

Now, copper foil will shield against electric fields, BUT again, it depends. For high frequency stuff like radio frequencies, it works great. But, as you get lower in frequency, you get less effect. So, down at line frequencies (50/60Hz) it's practically useless.

I could go into all of the boring details of this as it's something I've done for decades in my "day job" - designing and testing electronic products to pass various regulatory electromagnetic compatibility tests, but you don't really want me to do that...

I also fall into the camp that says it's more about what kind of electricity you have going in the room around you.

My band's rehearsal studio has two standard light bulbs, and my 4003 is dead quiet in that room. The place was wired with musicians in mind, and it shows.

My church, on the other hand, is in a building that's about 60 years old and is full of fluorescent lights. For all I know, the wiring throughout is original. The hum emanating from the same 4003 has given the sound engineer fits!

This may be a "Well, DUH!" moment for most or all of you who have posted here, but I've dealt with customer basses that were missing a ground connection in one or several of the key areas on the bass and caused significant buzz. Before considering any of the fixes mentioned here, it would be a good idea to check the ground wires that connect to the tailpiece, bridge pickup, and neck pickup. Simplest test without opening up the harness - the touch test. If you have a noticeable buzz, touch the strings without touching any other hardware on the bass - if the buzz goes away, great - your tailpiece is grounded. If there's no decrease in the buzz, there's a chance that the ground wire came disconnected either at the tailpiece itself or the wiring harness. Do the same thing with the bridge pickup without touching any other part of the bass. It also has it's own grounding wire. Expect the same activity as you would from the tailpiece test. It's particularly revealing when one is connected and the other isn't; then you can hear a distinct difference in the results. This is a different problem that the radio & magnetic wave hum issue, but good to check off the list before moving on to other options.

My 4003S was shielded completely by the previous owner. He also added Bartolinis. You can take both hands off the bass & no buzz. My Fender has no shielding & buzzed rather badly until I replaced the single coil with a Fralin split coil pickup. My squire has the paint shielding & still uses the stock single coil & has a slight buzz at times. You have to keep contact with the strings to keep the 60cycle to a minimum on these.

... I did this and now there is no hum wherever I play (neonlights, transformer stations,...)