Cool idea. Maybe like the EHX Hum Debugger?
oh, yes, a sharp notch filter at 50 or 60 Hz and the next relevant overtones! +1
The Kemper's global "noise gate" -- not the gate stomps but the one controlled by the dedicated knob -- is actually more of a hum eliminator than an actual gate. Have you tried adjusting it to suit your pickups?
This knob controls the Noise Gate, which eliminates the noise and hum of your guitar in a very smart way. Turn the
NOISE GATE knob to the right, until noise and hum have disappeared; do not turn it beyond that point, as this might
alter the sound of your guitar. When set to the appropriate position, you will notice that noise and hum are
eliminated, even when the strings are still sounding.
Surely a hum elimintor just needs a sharp vut at 50hz and the next few multiples with a very narrow Q. Can that not be achieved with the Studio EQ in Stomp A?
oh, yes, a sharp notch filter at 50 or 60 Hz and the next relevant overtones! +
I think the existing low cut would be quite sufficient for a guitar sound.
Also for a normal bass - the low E has about 82 Hz
Harry, I think the low cut is a shelf EQ which doesn’t really take out hum in isolation but affects a wide range of frequencies.
Harry, I think the low cut is a shelf EQ which doesn’t really take out hum in isolation but affects a wide range of frequencies.
Yes, but below 80 Hz I don't need anything.
For the e-guitar I have basically set a low cut between 80 and 100 Hz and a high cut depending on the type of profile and guitar from 6500 to 7500 Hz. (For accustic a little more)
I don't think net hum really matters at the KPA. The power supply is very stable.
But I wouldn't play guitar right next to a transformer if I had a bad shielding in the guitar.
I totally agree with you about the necessary frequency range Harry. However, I don’t think a low cut will solve the issue of hum because you get the main fundamental at 50hz (or 60hz depending on county) plus the higher octaves which are above this.
The one thing is is crucial with any attempt to use eq to elimate hum is to make sure the eq goes right at the start of the signal chain so that you can kill the hum BEFORE any of the higher octaves get compressed and amplified.
I totally agree with you about the necessary frequency range Harry. However, I don’t think a low cut will solve the issue of hum because you get the main fundamental at 50hz (or 60hz depending on county) plus the higher octaves which are above this.
I hear you, you think of harmonics acc. fourier. However, I believe that most power supply networks aim for a sinusoidal waveform, so that harmonics play little role.
I am thinking that most hum isn’t from main AC in developed countries like the UK and Europe. our American friends seem to have a different experience with their power though. In my experience, most hum is either a ground loop which is best solved at source or from pickup induced noise or poor shielding. The noise being picked up is generally related to mains frequency but has already been affected by other things such as dimmer stiches and computer monitors etc.
I could be wrong though and maybe I have just been luck with power so far.
I could be wrong though and maybe I have just been luck with power so far.
No, it's conclusive what you're saying.
Obviously we live in countries with well developed infrastructure. 
But monitors, dimmers, older fluorescent tubes, electric monitors, etc. can cause interference.
But I don't think that a tight notch filter at 50 or 60 Hz is a solution, because the mentioned interferences are not limited to 50 or 60 Hz.
A better solution is a good shielding of the guitar, an intact earthing system of the domestic system and surely also avoidance of places with such pollution.
This should also have negative effects on people. A humming guitar is then the lesser problem.
But I wouldn't play guitar right next to a transformer if I had a bad shielding in the guitar.
good point.
I love single coils and have quite a few guitars equipped with those - P90s, Lipsticks, Goldfoils - and a proper shielding is key.
If done right and with a little practise (orienting oneself on stage) SCs can be used live without issues IMHO.
P90's are the kings of pickups as long as you are good enough at yoga to get your body in just the right position and hold it there to avoid the noise 
P90's are the kings of pickups as long as you are good enough at yoga to get your body in just the right position and hold it there to avoid the noise
I recently ordered 2 hand-wound P90's (HB format) in Germany (Rübezahl).
These I intend to install in one of my Strats.
But nobody has pointed out to me that yoga skills are needed.
I think I need to order a full body condom made of wire mesh fence for screening
But nobody has pointed out to me that yoga skills are needed.
I think I need to order a full body condom made of wire mesh fence for screening
You can start by practicing singing (or rather chanting) a very low "hummmmmmmmm"
Three times a day should get you ready for anything!!!
You can start by practicing singing (or rather chanting) a very low "hummmmmmmmm"
You think that "do, re,mi, fa, so ,li, do " is not sufficiantenough. 
This and some other similar exercises I practised ev'ry day
Well, it's the "hummmmmmmmmm" you got to get used to!
Maybe if you do the "hummmmmmmmmm" while playing, you get a noise cancelling effect!?
I recently ordered 2 hand-wound P90's (HB format) in Germany (Rübezahl).
nice!
