Diminished Triad
New member
Anyone have some tips on how to reduce hum from fender P Bass guitar into Fender amp? I'm using a SuperBassman head...
Thanks!
Thanks!
P Bass with Fender Amp and HUM!
- Thread starter Diminished Triad
- Start date
F
Funkfingers
Guest
Re: P Bass with Fender Amp and HUM!
+1
There are things in the bass guitar that could cause hum. (Bad/dry solder joints.) There are things about a valve amplifier that can create hum and other noises. (Tired valves, incorrect bias adjustment.) There are things about the room that can cause hum. (Mains electricity issues, domestic appliances, lighting dimmer controls, computer monitors.)
Eliminate some of the possible causes by substituting one part of the signal chain at a time. e.g. The bass guitar, the cable, the amp head.
If you have effect pedals, how do you power them? Somebody I know could get expensive active guitar pickups to buzz like crazy just because of the poorly screened wall wart PSU for his Line6 POD floor pedal unit.
+1
There are things in the bass guitar that could cause hum. (Bad/dry solder joints.) There are things about a valve amplifier that can create hum and other noises. (Tired valves, incorrect bias adjustment.) There are things about the room that can cause hum. (Mains electricity issues, domestic appliances, lighting dimmer controls, computer monitors.)
Eliminate some of the possible causes by substituting one part of the signal chain at a time. e.g. The bass guitar, the cable, the amp head.
If you have effect pedals, how do you power them? Somebody I know could get expensive active guitar pickups to buzz like crazy just because of the poorly screened wall wart PSU for his Line6 POD floor pedal unit.
BlueTalon
New member
Re: P Bass with Fender Amp and HUM!
Especially if the wall outlet itself isn't grounded. I had that problem in an old house I jammed in once.
Especially if the wall outlet itself isn't grounded. I had that problem in an old house I jammed in once.
ginormous
Understatmentologist
Re: P Bass with Fender Amp and HUM!
The 'outlet' was a length of conduit with 3 junction boxes coming from the wall, stapled to the wall going around the room. Somebody must have paid off the inspector, or had the goods on someone in city hall! If I didn't have my own hum isolation and GFCI/surge protector power strip, I would have turned around and left. As it was, there was a 60Hz "weed whacker" buzz coming from the PA the whole night. No, I didn't sing or touch the mic stand.
I'll go you one better... a Mexican restaurant, last decorated in the 80s. 3 stripes of neon light going around the room, just above eye level.
The 'outlet' was a length of conduit with 3 junction boxes coming from the wall, stapled to the wall going around the room. Somebody must have paid off the inspector, or had the goods on someone in city hall! If I didn't have my own hum isolation and GFCI/surge protector power strip, I would have turned around and left. As it was, there was a 60Hz "weed whacker" buzz coming from the PA the whole night. No, I didn't sing or touch the mic stand.
Diminished Triad
New member
Re: P Bass with Fender Amp and HUM!
Really good stuff and going to kind of audit every possible reason listed.
Right away I "re-plugged" a chorus effects pedal (plugged into separate outlet from the one juicing the fender super bassman head) and might be my imagination but this alone had a good effect, I can hear reduction in hum. Thanks guys.....will take all of your advice and all makes sense!
Really good stuff and going to kind of audit every possible reason listed.
Right away I "re-plugged" a chorus effects pedal (plugged into separate outlet from the one juicing the fender super bassman head) and might be my imagination but this alone had a good effect, I can hear reduction in hum. Thanks guys.....will take all of your advice and all makes sense!
Diminished Triad
New member
Re: P Bass with Fender Amp and HUM!
http://www.fender.com/basses/precis...recision-bass-rosewood-fingerboard-mystic-red (exact model)
Using Fender Super Bassman head
http://www.fender.com/amps/bass-amplifiers/super-bassman-120v
Running a Fender 215 PRO 2x15 Bass Speaker Cabinet
http://www.musiciansfriend.com/amplifiers-effects/fender-215-pro-2x15-bass-speaker-cabinet
Thanks again!
American Standard Precision Bass (Fender)
http://www.fender.com/basses/precis...recision-bass-rosewood-fingerboard-mystic-red (exact model)
Using Fender Super Bassman head
http://www.fender.com/amps/bass-amplifiers/super-bassman-120v
Running a Fender 215 PRO 2x15 Bass Speaker Cabinet
http://www.musiciansfriend.com/amplifiers-effects/fender-215-pro-2x15-bass-speaker-cabinet
Thanks again!
Diminished Triad
New member
Re: P Bass with Fender Amp and HUM!
Doesn't change when hands off strings. Continuous hum when gain/volume turned up. More with overdrive than with vintage. Bass treble etc don't seem to affect much....just gain and volume of course.
Doesn't change when hands off strings. Continuous hum when gain/volume turned up. More with overdrive than with vintage. Bass treble etc don't seem to affect much....just gain and volume of course.
Diminished Triad
New member
Re: P Bass with Fender Amp and HUM!
During a second session each day (for a much younger group of musicians)....the bass used (not the fender above) creates a hum when it turns one direction. It can "kind of" find a sweet spot where when facing this direction the hum is reduced. And it can do the opposite by facing a direction almost towards (but not exactly) the bass amp....that will increase the hum. It doesn't appear to be a speaker feedback sound at all and it's not when the bass is directly facing the head/speaker.....but clearly turning helps/hurts. Can anyone tell me what's up with that? Hands on/off the strings do not make a difference with this bass hum........
uOpt
Something Cool
Re: P Bass with Fender Amp and HUM!
If it doesn't change when you let go of the strings the strings aren't grounded. You either need to ground them, or you need to shield completely.
(unless you have plastic wrapped strings in which case shielding is the only option)
If it doesn't change when you let go of the strings the strings aren't grounded. You either need to ground them, or you need to shield completely.
(unless you have plastic wrapped strings in which case shielding is the only option)
BlueTalon
New member
Re: P Bass with Fender Amp and HUM!
The bass is acting like a directional antenna, picking up some EM/RF interference from some source(s). Shielding will help with this tremendously. It's a job anyone can do as long as they are patient.
Get some copper shielding foil tape. $20 should get you a 25 or 50 meter roll of 10-15mm shielding on ebay. Ideally, you want to remove the pickup, bridge, and controls/control cavity cover. Don't be afraid of using two much tape -- it won't hurt anything to have two or three layers, just make sure you use a pencil eraser or Q-tip to get the foil flush in the corners.
For the pickup holes, you want the foil to come up just to the edge of the hole. For control cavities, you want it to come over the top, out at least as far as the mounting screws. Some people just have little tabs of foil going to the screwholes -- I have mine spilling over all the way around the cavity.
If the back of the pickguard isn't already shielded, you'll have to shield it too. Remove the controls, and tape up everywhere where it covers the pickup/control routes. Taping up the entire back of the pickguard is not necessary, but I do it anyway, just so it will sit the same all the way around.
It isn't a Precision, but you get the idea.
Make sure the bridge wire is soldered to the shielding in the control cavity. Then, at a minimum, make sure there is copper foil where the bridge screw holes are, and make sure the bridge wire is soldered to that copper foil. Personally, I made a base of copper foil for my bridge that was almost exactly the size of the bridge, so the entire bridge is sitting on foil.
If the copper foil tape is intended for shielding, then the back side of the tape will be conductive. Still, for this, I like to err on the side of bulletproof, so I use solder liberally. It can't hurt anything, except possibly the finish on your bass if you're not careful.
Eventually, the shielding will have to be connected to the ground terminal of the jack. Once you do that, you will have a bass that is practically impenetrable to external interference.
The bass is acting like a directional antenna, picking up some EM/RF interference from some source(s). Shielding will help with this tremendously. It's a job anyone can do as long as they are patient.
Get some copper shielding foil tape. $20 should get you a 25 or 50 meter roll of 10-15mm shielding on ebay. Ideally, you want to remove the pickup, bridge, and controls/control cavity cover. Don't be afraid of using two much tape -- it won't hurt anything to have two or three layers, just make sure you use a pencil eraser or Q-tip to get the foil flush in the corners.
For the pickup holes, you want the foil to come up just to the edge of the hole. For control cavities, you want it to come over the top, out at least as far as the mounting screws. Some people just have little tabs of foil going to the screwholes -- I have mine spilling over all the way around the cavity.
If the back of the pickguard isn't already shielded, you'll have to shield it too. Remove the controls, and tape up everywhere where it covers the pickup/control routes. Taping up the entire back of the pickguard is not necessary, but I do it anyway, just so it will sit the same all the way around.
It isn't a Precision, but you get the idea.
Make sure the bridge wire is soldered to the shielding in the control cavity. Then, at a minimum, make sure there is copper foil where the bridge screw holes are, and make sure the bridge wire is soldered to that copper foil. Personally, I made a base of copper foil for my bridge that was almost exactly the size of the bridge, so the entire bridge is sitting on foil.
If the copper foil tape is intended for shielding, then the back side of the tape will be conductive. Still, for this, I like to err on the side of bulletproof, so I use solder liberally. It can't hurt anything, except possibly the finish on your bass if you're not careful.
Eventually, the shielding will have to be connected to the ground terminal of the jack. Once you do that, you will have a bass that is practically impenetrable to external interference.
Last edited:
F
Funkfingers
Guest
Re: P Bass with Fender Amp and HUM!
How close together are the bass guitar and the mains transformer inside the bass amplifier?
Does the amplifier have a ground lift switch? If so, what position is it currently in?
How close together are the bass guitar and the mains transformer inside the bass amplifier?
Does the amplifier have a ground lift switch? If so, what position is it currently in?
Diminished Triad
New member
Re: P Bass with Fender Amp and HUM!
Bass player about 6 feet away from bass amp. I will check out ground lift switch...thnx!
BlueTalon
New member
Re: P Bass with Fender Amp and HUM!
Something I didn't mention about shielding. With a single-pickup Precision, the pickup route and control cavity route and wire channel are all the same hole, covered by the pickguard. On any other bass, though, including two-pickup Precisions, there will be a hole drilled under the surface of the wood connecting the pickup hole to the control cavity. In those situations, if you don't already have shielded pickup wires, it's important to shield the inside of that drilled wire hole as well.
Something I didn't mention about shielding. With a single-pickup Precision, the pickup route and control cavity route and wire channel are all the same hole, covered by the pickguard. On any other bass, though, including two-pickup Precisions, there will be a hole drilled under the surface of the wood connecting the pickup hole to the control cavity. In those situations, if you don't already have shielded pickup wires, it's important to shield the inside of that drilled wire hole as well.
uOpt
Something Cool
Re: P Bass with Fender Amp and HUM!
Any chance you gonna reply to this post or am I just wasting my time?
Any chance you gonna reply to this post or am I just wasting my time?
F
Funkfingers
Guest
Re: P Bass with Fender Amp and HUM!
+1
Post #9 namechecks the Fender American Standard Precision Bass.
Post #12 mentions some undisclosed student instrument.
Which bass guitar is involved in the hum problem? If the offending instrument is not the Am Std P, it would help to be told was is.
Looks like another of Midget Triad/Diminished Koala's trolling threads.
+1
Post #9 namechecks the Fender American Standard Precision Bass.
Post #12 mentions some undisclosed student instrument.
Which bass guitar is involved in the hum problem? If the offending instrument is not the Am Std P, it would help to be told was is.
Looks like another of Midget Triad/Diminished Koala's trolling threads.
