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Hey, pickup experts!

spidey

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Nov 21, 2003
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So, I've had WCR Crossroads in my main LP for years and tonally I love them. However, the one thing they don't do is this - when you hold a long note at high volume it doesn't trail off into cool harmonic singing feedback.

The Crossroads aren't potted but Jim apparently does do something to eliminate microphonic feedback. Do you think this is the cause? Does a pup need to be completely unpotted and need to get a little microphonic feedback to do the singing controlled feedback thing?

What do you think? I've heard some demos of ox4 pups on yt and they certainly do the harmonic feedback in spades. Perhaps it's time to try some in place of the WCRs....
 

Wilko

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what you want is more a function of the amp and/or pedals.

The crossroads are not stopping that from happening.
 

Cream Fan

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Some amps will do it at a lower volume than others. Also, I've found that effects like a chorus will dampen will hold that back. Proximity will also affect which harmonic feeds back. Often, I'll be playing, hold a note, then turn away from the amp and it'll start to sing. The proximity part of the equation is directly affected by the volume of the amp and the volume (area) of the room in which you're playing.
 

spidey

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I play loud and I have other guitars that will do this more than the Crossroads loaded LP. It may just be that the pups in the other guitars, and the guitars themselves are tonally matched to my amps more in a way that will generate feedback.
My 61 RI SG loaded with Classic 57s are way more likely to do this. I guess they are hotter pups though.
I've tried changing my position etc.
 
Y

yeti

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I'm not an expert :spabout but I believe that pickups can enhance or retard the harmonic feedback of a guitar. Part of it may be the pickup height as well.
Case in point is my cheap hamer sunburst import. Acoustically it sounds ordinary, not bad, not particularly exciting and definitely no complexity to the overtones (it's got mystery mahogany, some maple-like wallpaper under a thick gloss finish and crap-metal hardware) but after I put Firesound PAF clones on it the harmonic feedback capabilities just erupted. I get notes tipping into feedback with a brownface fender amp set to 100% clean. It's quite extraordinary. Clean tones flow into a strong harmonic w/o distortion and can be sustained almost indefinitely.
My guess is that there must be peaks and valleys in the response of the PU that happen to match what the guitar's string put into it, driving the circuit to the edge of oscillation.
Like said, not an expert opinion but PU's can have a dramatic impact on how the tone tips over into harmonic feedback when distortion/ compression is added. I have no idea how potted vs unpotted and output figures into the equation. I don't even know if those PAF clones are potted or not, and I honestly don't care. They were cheap.:eek:la
 

thejaf

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Oct 27, 2006
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IMHO, it's much more a function of the guitar (wood, nut, bridge, etc) and the amp.

I've also observed over the years (not empirically proven), and I'm convinced that absolute phase of the amplified signal has a lot to do with this. I believe that feedback is much easier to create and control when the amps output is in phase with the input signal, and not 180-degrees out of phase.
 

tdarian

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Jun 25, 2008
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I once saw Jim use a line of silicone between a cover and bobbins instead of potting. A buddy of mine bought a pickup from him at a past LA AMP Show and he applied the silicone and put on the cover right there for him.
 

FretsAlot

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Just to throw one more log on the fire... I've been doing quite a bit of pre-amp tube rolling (new, ANOS, NOS) in my '68 spec lead plexi (clone) over the past two months. I've noticed some tubes promote sustain and/or harmonics and/or overtones and/or note bloom, just to name a few variables (if you are playing thru a tube amp). I've been playing my Wolfetone DrV loaded 57ri LP, for my tube rolling efforts. The DrV's are unpotted.

One more tidbit... I bought a JCM800 4010 1x12 50w combo a month ago. At low volumes comparable to my plexi, it actually wants to take off into bloom/feedback a little faster than my plexi does - the thing is a little beast (in a good way). I make mention of it to echo the notion above that it can be a bit amp specific.

tidbit #2 - I've also been doing my own pure nickel string shootout (thread in the tone zone) on that same '57ri LP. Many of the qualities I mentioned with the tubes are promoted or demoted with different string brands of the same gauge.

Fretsalot/Scott
 
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Wilko

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One more tidbit... I bought a JCM800 4010 1x12 50w combo a month ago. At low volumes comparable to my plexi, it actually wants to take off into bloom/feedback a little faster than my plexi does - the thing is a little beast (in a good way)...

Funny you mention that amp. I've got a JCM800 4104 from a combo (that's now in a head box). That thing is the same way.

That's how KNOW the amp is a huge part of the equation.
 

spidey

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Hmmmm, so we think it's more likely to be the guitar and / or amp rather than the pups?
 

Black58

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Here's a yt link to a vid by one of our LPF brothers playing ox4 pups and the harmonic feedback is stunning

http://youtu.be/lPIFmLqNOhE

No doubt in my mind that roadrunner's Duane CB/OX4 combo is "the shit", but that video can be a little misleading with regard to the topic at hand. What's NOT being represented is the fact that that particular Marshall is Satan INCARNATE! :wow .. Seriously! I've read it here before;
It actually sounds TOO good! :hee ... :wah
 
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Y

yeti

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Sorry Yeti, thanks for the comment. The effect you are getting with your pups is exactly what I want!
Here's a yt link to a vid by one of our LPF brothers playing ox4 pups and the harmonic feedback is stunning

http://youtu.be/lPIFmLqNOhE

The reason I'm harping on this a little (sorry) is because I was so baffled after I replaced my PU's. The guitar does now exhibit a strong tendency to tip into harmonic "sustain" without any dirt, regardless of the amp. Feedback is the correct term, or oscillation, but those words conjures up images of cranked Marshalls and higher levels of distortion/ compression and the amp sure does affect it but my guitar is doing the same thing without distortion present. Nothing changed except the PU's and pots. I can play anything I want without the need to crank into overdrive, which is great at home. I'm convinced that the PU's and the way they are adjusted contribute a great deal.
 
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spidey

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Nov 21, 2003
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The reason I'm harping on this a little (sorry) is because I was so baffled after I replaced my PU's. The guitar does now exhibit a strong tendency to tip into harmonic "sustain" without any dirt, regardless of the amp. Feedback is the correct term, or oscillation, but those words conjures up images of cranked Marshalls and higher levels of distortion/ compression and the amp sure does affect it but my guitar is doing the same thing without distortion present. Nothing changed except the PU's and pots. I can play anything I want without the need to crank into overdrive, which is great at home. I'm convinced that the PU's and the way they are adjusted contribute a great deal.

I agree Yetti. I'm convinced the pups play a big part on this.
 

LesPauloholic

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Apr 24, 2002
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+1 on the silicone. I bought some pickup covers from WCR for a set of crossroads and he recommended running a bead of silicone under the cover. If yours have covers on them, this may be what is keeping them from singing.
 
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