Stop The Feedback!

GForce83

Well-known member
Joined
Aug 4, 2008
Messages
79
Reaction score
2
Location
London, UK
Got a pair of external stick-on pick-ups for my concert uke and, while the sound the produce through the amp is really nice, the amp is screaming at me every now and then - not ideal for playing a show as the rest of the band stare angrily at me.

I'm going to run it through a Boss tuner pedal and a Boss compression sustainer pedal (got them lying around from my old guitar days) but wondered if anyone had any tips or ticks to get rid of this evil noise once and for all.

Thanks !!
 
Feedback happens when your pickup picks up what's coming from the amp, which then sends it through the amp again (thereby amplifying it more), which will be picked up by the pickup again, and through the amp again (amplifying more), etc. creating an endless loop between the pickup and the amp. Try standing further away from the amp and make sure the amp is not facing you. See if that helps.
 
Try the last part of the first post in this thread:
http://www.ukuleleunderground.com/forum/showthread.php?t=18970

Actually, I'll just repost that bit here, if that's ok with moderators.

[...]
Feedback

Feedback is often a problem with amplified acoustic instruments. Much more so than for solid bodied instruments.

There are several ways to tackle feedback. In many situations the player will need to employ a combination of these measures. The physical approaches are:

* Positioning
* String/body damping
* Soundhole blocking

There are also electronic measures:

* Phase switching
* EQ

Positioning

Simply positioning the player and his instrument away from speakers can do a lot to eliminate feedback. If the player is playing into an external mic then it is wise to ensure that speakers and foldback monitors do not point into those directions that the mic is designed to monitor. Most specifically, you don't want the amplified sound coming from behind the player and going into the mic.

String/body damping

In some marginal situations the feedback occurs when the instrument is idle. In this case it is often enough to simply place a hand across the strings, or across the strings and soundhole. This stops sympathetic vibration and reduces the tendency to feed back.

Soundhole blocking

You've probably seen guitarists with black rubber or plastic plugs in the soundholes of their guitars. These "feedback busters" can greatly lessen feedback, sometimes eliminating it altogether. They are available in several sizes, although they can be hard to find in uke sizes. However, it is easy to improvise plugs for most uke soundholes by using various plastic stoppers and plugs. For example, a mailing tube end plug can be adapted to fit a Makala soprano, and the plastic lid from a gravy granule container will fit a Kala tenor.

These plugs do have a noticeable detrimental effect on the tone of the instrument, so some players try to balance maximum feedback reduction with a minimal effect on tone by having small holes in the soundhole plug.

Electronic measures

Phase switching

A phase switch is usually just a two-position switch on a preamp or amplifier. If feedback occurs with the phase switch in one position, flipping it to the other position often cures or reduces the problem.

The Fishman Pro EQ II preamp and the Marshall AS series acoustic amplifiers both feature this facitlity.

EQ

The simplest EQ-based anti-feedback measure to use is the notch filter. A notch filter is one of the most effective measures to be found on most acoustic amplifiers. It is simply a knob which, when switched on, suppresses a narrow band of EQ frequencies. When feedback occurs one simply switches on the notch filter and then turns the knob until reaching the point where feedback is eliminated or minimised. In my opinion, this is one of the most useful features to look for on an acoustic amplifier.

The Marshall AS acoustic amplifier series models feature notch filters

If your preamp or amplifier do not have a notch filter facility, a guitar multi-band EQ can help. It is sometimes possible to locate the frequency band within which the feedback is occurring, and to cut it by reducing the level of the slider/knob controlling that band.

Guitar multi-band EQ pedals are available from Boss and, more affordably, from Behringer. [...]
:)

It's a bit long-winded - as I always am - but I hope it is of some help.
 

:agree:

Yup. Can't go wrong with it. Phase switch, notch filter and EQ in one box, and a solid gold reputation.

Another option is the Fishman Pro EQ Platinum.

Baggs or Fishman, it's a matter of personal preference. Both are great. These preamps/DI boxes are SO worth the money. They beat any onboard preamp I ever tried by miles. I would always opt for a passive pickup
and one of these outboard boxes every time.

In my Kala tenor I fitted a Fishman undersaddle pickup to which I added simple (passive) vol and tone controls. That goes through a preamp like those mentioned above. With the phase, notch and EQ controls thus available I can play decent sized venues with no feedback. I have't needed to plug the sound hole since I started sing this set up.
 
Got a pair of external stick-on pick-ups for my concert uke and, while the sound the produce through the amp is really nice, the amp is screaming at me every now and then - not ideal for playing a show as the rest of the band stare angrily at me.

I'm going to run it through a Boss tuner pedal and a Boss compression sustainer pedal (got them lying around from my old guitar days) but wondered if anyone had any tips or ticks to get rid of this evil noise once and for all.

Thanks !!

Out of curiosity what external pickup did you get? Been thinking of getting one, got any advice :confused:
 
The least expensive option is just to stuff the soundhole with newspaper. Feedback is the product of regeneration. Every ukulele has a frequency of resonance - a natural vibration frequency. If you can eliminate it by "notching it out" with a device such as a Baggs Para DI or tone controls or an equalizer you will be able to tame it. Some ukes are built to physically reduce feedback:

The Ovation Applause UAE20 acoustic/electric incorporates "Adamas holes", which project the sound outside the strings, instead of underneath them. These ukes can be played amplified with a lot of gain before feedback. I own two and they are my favorites for performing:

http://folk-instruments.musiciansfr...ic-Electric-Deluxe-Soprano-Ukulele?sku=516727

230083.jpg


The solid body Risa ukuleles have no soundholes and work similar to the solid body Fender Stratocasters and Gibson Les Pauls

http://www.ukulele.de/menu
 
Out of curiosity what external pickup did you get? Been thinking of getting one, got any advice :confused:

I got a Shadow external pick-up - 2 little bugs. Came highly praised by a guy in a music shop I trust and I'm happy with the results except for the obvious feedback issue.
 
In my Kala tenor I fitted a Fishman undersaddle pickup to which I added simple (passive) vol and tone controls. That goes through a preamp like those mentioned above. With the phase, notch and EQ controls thus available I can play decent sized venues with no feedback. I have't needed to plug the sound hole since I started sing this set up.

I've got a Fishman undersaddle but haven't got around to putting it on my Bushman concert yet - I think, out of all my ukes, my Bushman is the one I enjoy playing live the most so I will probably look at getting it installed. Don't think I'll be able to do it myself as it's going to involve playing with wires and solder and I'm a website designer and therefore terrible at these sorts of things.
 
I've got a Fishman undersaddle but haven't got around to putting it on my Bushman concert yet - I think, out of all my ukes, my Bushman is the one I enjoy playing live the most so I will probably look at getting it installed. Don't think I'll be able to do it myself as it's going to involve playing with wires and solder and I'm a website designer and therefore terrible at these sorts of things.

Depends which pickup you have, mate. Mine came with a 2.5mm jack on the pickup and an endpin jack with an equivalent socket. There was no soldering (until I later added tone and vol controls), Just two holes to drill.

Being a web geek doesn't automatically disqualify you form uke DIY... I'm an SEO consultant and if I can fit a pickup, almost anyone can! :D
 
Depends which pickup you have, mate. Mine came with a 2.5mm jack on the pickup and an endpin jack with an equivalent socket. There was no soldering (until I later added tone and vol controls), Just two holes to drill.

Being a web geek doesn't automatically disqualify you form uke DIY... I'm an SEO consultant and if I can fit a pickup, almost anyone can! :D

Unfortunately Mine came with the undersaddle and a lovely clean wire coming out or it and then the endpin jack. There was no jacks mid-way to allow me to clip it together. I'd be completely happy with the drilling of the holes, filing of the saddle and putting it all together if it wasn't for the soldering and not knowing which parts of the wire go where - I think I'm gonna consult a professional.

In other news I just got back from an eBay holiday and am having a LR Baggs Para Acoustic DI delivered as we speak. Next week will be a much different show to last week!

Cheers for all the help and advice. Gotta love the UU forums!
 
Just checked - the pickup in my uke is a Shadow. It was a guitar I put a Fishman in. That one did need some soldering.

Yep, a pro is probably the way to go. Luckily, my neighbour is an electronics nut who builds amplifiers and things. He does my fiddly, small-scale soldering for me because I'm rubbish at it.

Hope it works out for you.
 
He does my fiddly, small-scale soldering for me because I'm rubbish at it.

I refer you back to my original comment about us computer geeks being no good at this sort of thing :D

In other news, my LR Baggs pre-amp hasn't arrived yet and now we're in the middle of a postal strike in the UK so I don't expect to get it before my show on Friday. When it does arrive I'll be making a video at our next show so you can see my big smile showing my appreciation of all your advice.
 
Top Bottom