Cold Sweats

[Doadman]

I've had the Cold Sweat set of pups fitted to my guitar now and you can certainly tell the difference. The sound when playing lead is far more articulate and crisp but power chords, especially with the bridge pup are a problem. The further I move up the neck, the more the sound deteriorates and gradually turns to mush. It's difficult to describe exactly what it's like but if I play a power chord and let it ring out the sound seems to slowly oscillate rather than maintaining a crisply defined and even distortion, almost like a wah. As I've only just got the guitar back from the tech I'm thinking there could be a few different explanations:

1) The pickups have been wired in wrong in some way, but how?

2) These new pups are showing up the shortcomings of my amp (Crate GT65 solid state)

3) I need to adjust the way I have the amp set

Any ideas?

Thanks, Andy

[Crazy_Joe]

Try adjusting the height of the pickup, most of the time moving the pickup closer to the strings makes a big difference to the overall sound.

[WITH FULL DISTORTION]

Wah wah Sound? then i think it may be out of phase. check the wirign again!?

[Doadman]

The screw poles are certainly in the right position on both pups but other than that I can't say but I'll mention it to the tech today. The only other way I can think of describing it is that when the chord is sounding it's as if somebody is moving the volume control up and down a bit. I repeat that it sounds fine on single notes, or at least it isn't as noticeable and the effect gets worse the further I go up the neck. Playing a G5 at the 15th fret sounds awful as the notes mush together and the effect I'm trying to describe is really quite pronounced.

[Jongpil Yun]

The only other way I can think of describing it is that when the chord is sounding it's as if somebody is moving the volume control up and down a bit.

Sounds to me like you're hearing beats from a poorly intonated guitar. My guess would be that you've always had the problem but the previous pickups were too mushy for you to really notice.

See http://en.wikipedia.org/wiki/Beat_(acoustics) for what I'm talking about. Try tuning your guitar as perfectly as possible, then take a capo on the 12th fret and check the tuning again. If it's either sharp or flat then you need to properly intonate the guitar (ie, make sure it's in tune all the way up the neck). I don't know what kind of guitar you have so you'll have to do some google-fu to find out how to do it on your guitar, but it's a pretty easy process on pretty much every guitar I've played.

[Twinfan]

I'd try lowering the pickups a touch.  As you fret higher up the neck, the strings get closer to the pickups and the magents prevent them ringing out.  I've found BKPs to be VERY sensitive to pickup heights with regard to tone.

Fret your top E string at the top fret and measure the height of the pickup poles from the underside of the string.  Adjust them so they're between 2-3mm away for each pickup.  Do the same with the bass E too for the other side of the pickup.

See how that goes...

[Doadman]

Well, I've spoken to the guitar tech who tells me that the pups were originally set to the standard low action height for humbuckers, which was 6/64's at the treble and 8/64's at the bass. He found that the Bare Knuckles were maxed out at that so they were lowered a bit due to the power of the pup. To try to clarify the situation a little as he works quite a distance away, I put the phone on speaker, increased the volume of the amp and let him listen to it. Even over the phone he could hear the effect I was on about and said that it sounded like a 'cycle' problem (I think that's what he said) and seemed to be a fault with the pup. I've tried phoning BKP but there's just an answering machine so I assume they're all at the London guitar show. I'll try again on Monday and let you know how I get on. At least I now know it is noticeable over the phone so the guys at BKP can have a listen as well.

[Jongpil Yun]

Still say its an intonation problem. Everything you've said points towards it.

1) Problem is only apparent with chords

All the notes (up the neck) are subtly out of tune, but you don't notice unless they're causing alternating constructive/destructive interference, as in with a power chord. If it were a problem with the pickup, it shouldn't discriminate between single notes and chords, and you'd hear an oscillation with single notes as well.

2) Problem becomes apparent as you move up the neck

The first few notes will be pretty close to perfectly in tune (hence no beats), but as you move up the neck it becomes more and more out of tune, hence, the beats become more apparent. Once again, if it were a problem with the pickups, there's no reason I can think of that it would only be apparent higher up the neck.

3) The sound "slowly oscillates" as if someone were moving the volume control up and down a bit.

The tones (and/or higher harmonics) are causing alternating constructive (gets louder) and destructive (gets quieter) interference due to their waveforms not matching. I'd guess the interference is going at a rate of between .1-10 cycles/second (ie it gets louder, then quieter, between once every couple seconds and ten times a second). I've heard plenty of problems with pickups in my time, but none that causes a constant alternation of volume, only with chords, that only becomes apparent as you move up the neck.

It's definitely a much more simple explanation than something being wrong with the pickups or amp, and as far as the guitar tech, 9/10 of the time they don't know what the hell they're talking about.

[MentalTan]

Still say its an intonation problem. Everything you've said points towards it.

1) Problem is only apparent with chords

All the notes (up the neck) are subtly out of tune, but you don't notice unless they're causing alternating constructive/destructive interference, as in with a power chord. If it were a problem with the pickup, it shouldn't discriminate between single notes and chords, and you'd hear an oscillation with single notes as well.

2) Problem becomes apparent as you move up the neck

The first few notes will be pretty close to perfectly in tune (hence no beats), but as you move up the neck it becomes more and more out of tune, hence, the beats become more apparent. Once again, if it were a problem with the pickups, there's no reason I can think of that it would only be apparent higher up the neck.

3) The sound "slowly oscillates" as if someone were moving the volume control up and down a bit.

The tones (and/or higher harmonics) are causing alternating constructive (gets louder) and destructive (gets quieter) interference due to their waveforms not matching. I'd guess the interference is going at a rate of between .1-10 cycles/second (ie it gets louder, then quieter, between once every couple seconds and ten times a second). I've heard plenty of problems with pickups in my time, but none that causes a constant alternation of volume, only with chords, that only becomes apparent as you move up the neck.

It's definitely a much more simple explanation than something being wrong with the pickups or amp, and as far as the guitar tech, 9/10 of the time they don't know what the hell they're talking about.

Makes sense, I remember hearing about this in physics, try setting up the intonation, could save you a bunch of trouble.

[Doadman]

OK, I've made some headway here and it's completely by accident. I've switched from hybrid to regular slinkys and I've been surprised at how much tighter the strings felt when I got it back from the shop. I ignored it, thinking I'd just get used to it. The whole thing feels different as the action is slightly lower than before and the bridge is now sitting absolutely flat in relation to the body for the first time since I bought it (it was always angled slightly up before). All this sounds great but when I checked the tuning last night the whole thing was tuned way too high so I set about altering it. Once I got it tuned correctly I plugged into the amp and tried it again. The problem I had can still be heard but it is now significantly better than it was before and for the first time since I got the guitar back I was starting to appreciate why I have Bare Knuckle pups. The problem now of course is that the bridge has sunk somewhat into the cavity as I've loosened the strings and the action is too low so I'm getting some buzzing. Clearly it will have to be reset.

Forgive me if I talk cr@p here because I'm in no way a technically minded person but it seems to me that having the guitar tuned too high shouldn't, in itself, make a difference but as I have this floating bridge, whenever I change the tension in the strings that must surely change its position in relation to the nut. The upshot of this must surely be that if you tighten the strings, the bridge must move closer to the nut and therefore the intonation must be then incorrect. Is that right?

If I am right in thinking this, it must mean that whoever/however the guitar ended up tuned too high must have knocked the intonation out by quite a way and the fact that I still have some of the original sound problem I mentioned at the start of this thread means that the intonation is now closer to being right but is not yet perfect. To my ignorant mind that seems to make sense.

[MentalTan]

I didn't know that you were tuned too high, make sure that your guitar is set up perfectly. If you don't know anything about tech stuff that's ok, just take your guitar to a tech, and ask him to set it to the tuning you want, the action you want(make sure you tell him you don't want buzzing, cause some people like a little buzzing), and tell him to inotate it.

But if you want to do it yourself... Since the bridge has sunken into the trem cavity that means that the tension on the springs in the trem cavity is greater than the tension on the strings. So all you have to do is take the trem cover off the back of the guitar, and loosen the two claw screws( they are the screws attached to the Spring anchor block, see diagram). You want to try to loosen them as evenly as possible, after you loosen them take off the locking nut and tune the guitar with an electric tuner, then tighten the locking nut again. After that the trem should have moved, if it is still sunk in you'll have to repeat the process of loosening the springs and tuning. If the bridge is to far up, you'll have to repeat the process, but tighten the claw screws. You're gonna have to repeat this proccess a couple times until the bridge is flat to the body or make sure the baseplate of the bridge is at a 90 degree angle to the posts the bridge pivots on. It'll probably take a while but you'll save money and a trip to the guitar tech.

Just curious, what do you tune to?

EDIT: oh yeah, if you still get that cycling sound you'll have to inotate it, but lemme know, I can run you through the inotation proccess.

[Doadman]

I have the guitar tuned to standard and the annoying thing is that the guitar was supposed to have been set up that way. I did pay for a full setup when I asked for the pups to be fitted. When I got it back the guitar looked fine in terms of action, bridge position etc. and it simply never occured to me that the tuning was wrong. It seems that the set up was done beautifully but done based on an incorrect tuning. Just how that's happened I've absolutely no idea!!

[MentalTan]

I have the guitar tuned to standard and the annoying thing is that the guitar was supposed to have been set up that way. I did pay for a full setup when I asked for the pups to be fitted. When I got it back the guitar looked fine in terms of action, bridge position etc. and it simply never occured to me that the tuning was wrong. It seems that the set up was done beautifully but done based on an incorrect tuning. Just how that's happened I've absolutely no idea!!

Wow. He did tune it too high, don't trust that tech. :lol:
If I lived near you, I'd do it for you.

[Doadman]

Right now I wish you did !!

A few things have gone wrong here and I've no idea why as he's set up a guitar for me before and it was done to a remarkably high standard. It's what makes this situation all the more surprising.

[CJ]

I didn't know that you were tuned too high, make sure that your guitar is set up perfectly. If you don't know anything about tech stuff that's ok, just take your guitar to a tech, and ask him to set it to the tuning you want, the action you want(make sure you tell him you don't want buzzing, cause some people like a little buzzing), and tell him to inotate it.

But if you want to do it yourself... Since the bridge has sunken into the trem cavity that means that the tension on the springs in the trem cavity is greater than the tension on the strings. So all you have to do is take the trem cover off the back of the guitar, and loosen the two claw screws( they are the screws attached to the Spring anchor block, see diagram). You want to try to loosen them as evenly as possible, after you loosen them take off the locking nut and tune the guitar with an electric tuner, then tighten the locking nut again. After that the trem should have moved, if it is still sunk in you'll have to repeat the process of loosening the springs and tuning. If the bridge is to far up, you'll have to repeat the process, but tighten the claw screws. You're gonna have to repeat this proccess a couple times until the bridge is flat to the body or make sure the baseplate of the bridge is at a 90 degree angle to the posts the bridge pivots on. It'll probably take a while but you'll save money and a trip to the guitar tech.

Just curious, what do you tune to?

EDIT: oh yeah, if you still get that cycling sound you'll have to inotate it, but lemme know, I can run you through the inotation proccess.

you do realize it's intonation, not inotation, right?