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View Full Version : Risa Stick Amplifier Buzz Hum Help Plz



coolkayaker1
11-05-2012, 09:51 AM
I have a Risa stick soprano and it has a passive Risa pickup, and when I plug it in to either of two amps, there's a buzz/hum. It's constant, low level but noticeable. It does not occur with my two active pickup ukuleles.

When I touch anything metal on the Risa, like the bridge end, or the amplifier metal jack, it completely disappears.

Is this normal for a passive pickup? Does your Risa do this? Have I lost a ground in there somewhere? Easy fix or "work around"?

Thanks in advance for any help. Steve

ukeeku
11-05-2012, 09:58 AM
Change the chord between the amp and uke

me2cyclops
11-05-2012, 01:59 PM
and check that the amp is grounded if you are in an older house the receptical may not be properly grounded.
if you have a battery powered amp try that on batt power to check

Paul December
11-05-2012, 03:06 PM
I had an Epiphone LP uke with a passive pickup that did the same thing.
Absolutely nothing worked for me. Odd, because none of my active pickup ukes ever did it.
Seller said it must be my house...

coolkayaker1
11-05-2012, 03:36 PM
Appreciate the replies.

Changed cable, no change. Thanks, though, Tim.

Changed plug, and even took it outside the room to a different wall in the house, no change. Thanks, though, Cy.

I plugged in my active Baggs on not one but two other ukes, no issue. It is only the Risa passive pickup.

So, like my friend Paul, I guess it's this uke. So, the question is, are all passive pickups humming (or harder to tame the hum), or is something "off" in this particular uke?

me2cyclops
11-05-2012, 04:12 PM
I have this same uke and with one of my amps it will do this in an outlet that isn't properly grounded and will not hum with a good ground or on battery.
try it at a friends house (I am 3rd generation electrition 20+ years repairing sound and lighting equipment and installs ) if one room isn't correct it's probably the entire house

if you want assistance checking or fixing the grounding for the house pm me for my # and I could probably talk you through it

coolkayaker1
11-05-2012, 04:37 PM
I have this same uke and with one of my amps it will do this in an outlet that isn't properly grounded and will not hum with a good ground or on battery.
try it at a friends house (I am 3rd generation electrition 20+ years repairing sound and lighting equipment and installs ) if one room isn't correct it's probably the entire house

if you want assistance checking or fixing the grounding for the house pm me for my # and I could probably talk you through it

cyclops, you are so kind. Thanks. Okay, hey, maybe I should take it to work and plug it in and see if it does it. Also, I have a Vox battery amp...wonder if it does it with that? I'll let you know what I find out. As an electrician, I believe you if you say it could be my house grounding. Will let you know. Thanks

Rick Turner
11-16-2012, 11:25 AM
It's a shielding/grounding issue. It's a very high impedance pickup, and that factor makes it very prone to noise pickup wherever there are unshielded and grounded hot wires. Take it to a good electric guitar luthier. This is one of those dark arts areas that acoustic folks are not very good at...to make a very broad generalization.

coolkayaker1
11-20-2012, 11:45 PM
It's a shielding/grounding issue. It's a very high impedance pickup, and that factor makes it very prone to noise pickup wherever there are unshielded and grounded hot wires. Take it to a good electric guitar luthier. This is one of those dark arts areas that acoustic folks are not very good at...to make a very broad generalization.
Thank you, Rick!

Inksplosive AL
07-29-2014, 07:46 PM
This is an old thread that comes up during a search on risa and hum.

The answer was touched on here and in another newer thread and confirmed by me last night. The risa suffers from no shielding in the jack compartment and can be fixed quite easily.

http://forum.ukuleleunderground.com/showthread.php?92068-Risa-electric-background-noise

~AL~

coolkayaker1
07-30-2014, 05:18 AM
Inksplosive, that is fascinating. I read your recent post on the thread you linked. Genius! I don't really get the burnished with bent wire hanger part, but basically, you lined the wooden jack hole with foil tape and then put the jack back in...is that it? I must try that! Thank you. :)

Inksplosive AL
07-30-2014, 10:10 AM
Yeah burnished umm... pressed the tape down and formed it to the cavity making sure there was no bare wood left showing. Don't forget to do the backside of the jack plate as well.

Genius... hardly but thanks for the lift!

~AL~

Inksplosive AL
03-12-2016, 05:18 AM
I've just been asked by a new member for pictures of the inside of the compartment. I only have a crappy camera right now with no macro feature so this is the best I can come up with at this time. Sorry it is a bit blurry so you cannot see where the tape overlaps itself everywhere. Nothing is left bare I even took the jack off the cover plate and added a piece of tape there as well.

When I did the same to my konablaster soprano I used a pencil to push the tape down. That one was a bit more work than the Risa stick.

The tape I used was cheap HVAC foil tape sold from Home Depot. I believe it is this same tape. http://www.homedepot.com/p/1-89-in-x-50-yd-322-Multi-Purpose-HVAC-Foil-Tape-1207792/100030120

89201

~albenis~