Guitar/amp feedback, the good type - how?

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pure.fusion

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Hi all,

I listen to recordings and hear that specfial guitar note where, when held, after a 3 or 4 seconds perfectly transforms into the same note but one octave higher due to feedback.

You know what I mean ( I hope).

What are the tricks of setting up your amp and guitar to promote feedback? I might add that I'm not using buckets of gain, but for the artists I've heard, I know you don't needs lots of gain to acheive it.

So, is it a volume thing?
Perhaps there are particular frequences to cut or boost?
Is it a position or angle thing? Maybe a certain distance from the amp?

Can anyone offer me some good technical knowledge on how to acheive this? I'm using a blues Jr.

Cheers,
FM
 
pure.fusion said:
Hi all,

I listen to recordings and hear that specfial guitar note where, when held, after a 3 or 4 seconds perfectly transforms into the same note but one octave higher due to feedback.

You know what I mean ( I hope).

What are the tricks of setting up your amp and guitar to promote feedback? I might add that I'm not using buckets of gain, but for the artists I've heard, I know you don't needs lots of gain to acheive it.

So, is it a volume thing?
Perhaps there are particular frequences to cut or boost?
Is it a position or angle thing? Maybe a certain distance from the amp?

Can anyone offer me some good technical knowledge on how to acheive this? I'm using a blues Jr.

Cheers,
FM
Click to expand...

Lots of compression and overdrive will do it. In my limited stable of guitars, humbuckers will do it while single coils won't.
 
What I've noticed is that certain gutiars resonate better at certain frequencies... For example, if I crank my amp up and stick my guitar in front of the speakers my "A" string will be the string giving the most feedback, this happens because that strings fundamental open frequency is closer to the guitars resonant frequency than the other open notes on a guitar. Now if you're fretting a certain note it may or may not have more or less ease of resonating due to sound waves coming from your amps speakers.
Finding what notes will resonate better than others is fairly easy... Stick your guitar in front of your amps speaker, give your guitar a flick or something so that all your strings vibrate, what should happen is the sound coming from your amp should amplify the resonance of your string(s) creating an endless loop of sound causing feedback, which ever string vibrates the most is the string that has a frequency closest to your guitars resonant frequency.

If you're just looking for steps on how to achieve feedback, the first thing you should know is that guitar feedback works the same as microphone feedback. Wiki defines feedback as such: is a special kind of feedback which occurs when a sound loop exists between an audio input (for example, a microphone or guitar pickup) and an audio output (for example, a loudspeaker). Basically you need to get your pickup close to your (preferably cranked) guitar cab/combo speaker and let a sound loop create itself by using the frequency of the note that you choose to let resonate.
 
excuse me if that post wasn't very linear... I was a tad distracted while typing it haha...
 
Volume will do it but sometimes that's not a good thing when you don't want it and get it anyway. The key is to get the amp set up so you're real close to the feedback onset and can bring it out at will with some pinch harmonics or by turning your guitar towards the amp.

It's a feel thing really. Technique helps.


lou
 
Thanks for the feedback all (Ha! the pun...)

Yes, lets narrow it down. I'm talking about that one particular note that is "more likely" to feedback. I'm not too interested about the instrument itself, lets just assume its the open A string (mentioned in the post below) that is my special "golden feedback note"

In some instances, you''ll have to tap your guitar and vibrate it a little and move around a bit before it will "catch". Other times you can't stop the f*!*ker.

I'm interested in those attributes that are associated with the latter. How to I maximise the chance of feedback? Compression has been mentioned.

What else?

Cheers,
FM
 
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pure.fusion said:
What else?
Click to expand...
Technique, as I said. Can you do a pinch harmonic anytime on any string at any fret? Once you can it's just a matter of having the guitar/amp set up for the sweet spot. You don't need pedals and such. It can be done with any guitar through any amp. Some settings will make it easier, others difficult to control.


lou
 
Sky Blue Lou said:
Technique, as I said. Can you do a pinch harmonic anytime on any string at any fret? Once you can it's just a matter of having the guitar/amp set up for the sweet spot. You don't need pedals and such. It can be done with any guitar through any amp. Some settings will make it easier, others difficult to control.


lou
Click to expand...

Excellent, thanks Sly Blue Lou.

Now, I'll narrow it down a bit more.

Let say I stand the guitar on a seat and I tie Sky Blue Lou to another seat so he can't touch it. What other elements are at play to obtain (more) feedback?

Cheers,
FM
 
pure.fusion said:
Excellent, thanks Sly Blue Lou.

Now, I'll narrow it down a bit more.

Let say I stand the guitar on a seat and I tie Sky Blue Lou to another seat so he can't touch it. What other elements are at play to obtain (more) feedback?

Cheers,
FM
Click to expand...

Maybe an EQ...? Leave all the frequencies flat except for like 440Hz (A) and have that frequency notched all the way up?

I mean... That's assuming you want feedback in A

I'm not exactly sure if there's something specific that you're expecting us to tell you cause I think we've covered it for the most part ... :confused:
 
I use this quit often but the guitar and amp make the difference.

I can usually get the feedback by location but touching the headstock to the cab is like a control element.

My PRS with my Dorado amp does this every easily.

Dorado

To a lesser extent.
M90
 
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Turn the amp up louder, get closer to the speaker. It also depends a lot on what levels of sustain your guitar is capable of and how responsive your amp is, how much gain you have etc. I've found that I can get that nice feedback a lot easier at lower volumes using my tube amp than my solid states/hybrids, which generally tend to produce less controllable feedback at higher volumes anyway.

I've also found that the right setting on a delay pedal can help it on it's way.
 
Sonixx said:
I can usually get the feedback by location but touching the headstock to the cab is alike a control element.
Click to expand...

This works well. I jam the end of the headstock up against the speaker baffle and hold it solidly. The vibration of the amp cabinet is transferred to the guitar and cause the strings to vibrate. It's like mechanical feedback. THen I can get some sweet harmonic feedback without a ton of gain. I usually play pretty clean and when I lean on the guitar up against the amp, I can get it to completely razz the strings against the fretboard.

My strat's sweet note is B, but my hollowbody's is in between A and Ab, but it's pretty easy to get it anywhere.
 
pure.fusion said:
Hi all,
So, is it a volume thing?
Perhaps there are particular frequences to cut or boost?
Is it a position or angle thing? Maybe a certain distance from the amp?
Click to expand...

Yes, yes, yes, and yes. :)

Volume is probably the main element in achieving feedback in the first place. You've got to drive your rig hard enough for the speakers to vibrate the strings to start the feedback loop. Your distance from the amp, angle relative to the amp, etc. will determine what kind of feedback you get. I don't have to stand very close to get it, but I play relatively loud.

An EQ at more extreme settings would help you sculpt your feedback but it doesn't make as big of a difference in feedback as you might think. An EQ actually makes it easier to avoid feedback at certain frequencies.

A compressor will definitely help. The settings I use on my CS3 produces easy feedback when I'm playing, uncontrollable feedback when I'm not. With my overdrive engaged, I get easier feedback as well.

With cleaner settings, the techniques the guys described above are good ideas.
 
Sonixx said:
I can usually get the feedback by location but touching the headstock to the cab is alike a control element.
Click to expand...

I'll do this too. Even then you need a fair amount of volume, but it's worth considering what feedback is - it's a, literally, 'feedback loop' where the sound waves coming out of the amp are picked up by the guitar and induce sympathetic vibrations on the guitar, which in turn get fed back into the amp, where they're amplified, sent back out as waves, and picked up by the guitar all over again.

You can get damned near anything, singlecoils or humbuckers, to feed back if you're playing loud enough even without making physical contact - it's a question of finding the right position in relation to the amp. So, at gigging volume, play a note, hold it, and walk around the stage a bit until it starts to bloom into feedback, re-picking as needed until you find the 'sweet spot.' Some guys (for instance, Satriani does this) will go so far as to mark the stage with an X of tape just so they'll know where that spot is every night, so they can induce feedback at a certain pitch whenever they need to.

Also, this falls into the 'cheating, but it works in a pinch' category - you can get feedback-like effects out of an ebow, particularly one of the newer ones with the harmonic mode. This works pretty well for recording if you're just trying to generate a wash of feedback as a textural effect.
 
DrewPeterson7 said:
Also, this falls into the 'cheating, but it works in a pinch' category - you can get feedback-like effects out of an ebow, particularly one of the newer ones with the harmonic mode. This works pretty well for recording if you're just trying to generate a wash of feedback as a textural effect.
Click to expand...
I don't think using an ebow is cheating at all. It's an effect, like flanging or distortion, to be used when it gives the appropriate sound for the song. I use mine live on a couple of songs.
 
Theres alot that effects feedback, but one thing I noticed over the years is that stock gibson and fender pickups are best for a variety of notes. Many after market pickups just seemed to find one note/tone, beyond that they just whistle.
 
ggunn said:
I don't think using an ebow is cheating at all. It's an effect, like flanging or distortion, to be used when it gives the appropriate sound for the song. I use mine live on a couple of songs.
Click to expand...

Cheating maybe if you're a feedback purist, and it's kind of hard to replicate "traditional" feedback mid solo sort of stuff. If you just want the sound of a soparing, endlessly sustaining guitar, however, they absolutely rule. I'm practically incapable of recording anything without like 5 tracks of ebow harmony. :D
 
Thanks for your replys.

Yes, I am probing a bit. You never know who lurks at forums, we could have had info concerning rules of distance or angle or .. i don't know - that's why I asked.

It's all about trying to record with (what's fast becoming my favourite amp) the Blues Jr. Gone are my younger days of using lots of distortion, the BJr at full noise is way dirty enough for me.

My new cheap-a$s guitar was chosen out of dozens 'cause it had heaps of sustain - never seen a guitar like it in fact, it's freaky. I'm now preparing to record some lead tracks to a song I'm excited about and I'm thinking of that polished "held note, turn to feedback" thing that started this post.

I've had some experimentation with playing with feedback - I *can* get it with my gear, but it doesn't come easy. Maybe the BJr just isn't big enough (enough volume) to do what I want…

Also, the vol for the BJ is also tied to the sound, since more vol will mean more gain and I don't necessarily want more gian - that would change my target sound.

Cheers,
FM
 
I don't do this much, but when I get feedback on a single note, it's not going to be an open string for starters, but I control its volume and length by angling self/guitar slightly away from amp - you can extend it forever that way...

It doesn't really need to be huge volume either - position of guitar in relation to amp, level of distortion on amp etc. are both factors. I can get feedback at household friendly volumes, no prob...

Or, use an eBow with the harmonic option! So much easier..

Cheers:laughings:
 
One thing that can help a guitar go into feedback is vibrato (the string bending kind, not the Fender amp kind). It's another way to keep feeding a bit of energy into the string.
 
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