Undercover Or Exposed

[Snake Aces]

Re: Undercover Or Exposed

There is definitely a difference. Some hear it, some don't. I have been playing uncovered humbuckers exclusively since 2012 now. I tend to prefer them even though I really dig the covered look on some guitars. I'd rather sacrifice aesthetics over tone.

 

[Andy.tech]

Re: Undercover Or Exposed

There is definitely a difference. Some hear it, some don't. I have been playing uncovered humbuckers exclusively since 2012 now. I tend to prefer them even though I really dig the covered look on some guitars. I'd rather sacrifice aesthetics over tone.

I agree with you, I think the covered looks nive on certain guitars but I do kinda prefer the brighter tone. Oh geeezzzz this isn't so easy :smash:

 

[DreX]

Re: Undercover Or Exposed

We are all entitled to out own opinions though.....for me NO DIFFERENCE

I measured the inductance of a '59 the other day and then pushed a cover over the of it without changing anything else, and the inductance changed. The reason is the cover causes eddy currents, effecting inductance, effecting the resonant peak.

OTOH, knowing that people's senses and perceptions are easily guided by expectations (finding that which you look for), it's possible that people hear a difference because they expect that difference, or it's possible that they blow a small difference out of proportion by combining a little bit of real with a lot of imagined.

 

[Demanic]

Re: Undercover Or Exposed

+1 to this.

Sent from my MotoE2(4G-LTE) using Tapatalk

 

[austin]

Re: Undercover Or Exposed

We are all entitled to out own opinions though.....for me NO DIFFERENCE

Given on what you are basing your opinion on, it is invalid. It's like having an opinion on a movie you haven't seen.
-
Austin

 

[DrNewcenstein]

Re: Undercover Or Exposed

OTOH, knowing that people's senses and perceptions are easily guided by expectations (finding that which you look for), it's possible that people hear a difference because they expect that difference, or it's possible that they blow a small difference out of proportion by combining a little bit of real with a lot of imagined.

Which is basically what I said before.
If you have a preconceived notion of the existence of a difference when certain conditions are met, you can convince yourself that difference actually exists if you are aware of the conditions being met.
"I see a cover on the pickup, ergo I know it will sound different".

Even in a blindfold test, your fingers will touch the pickups and you'll know if they're covered, thus your brain filters what you hear to suit your preconceived notion.

However, the material of a typical pickup cover cannot block a magnetic field, thus can't have an affect on it. It may be possible that the cover fits tight enough to compress the coil wires somewhat, influencing their vibration (much like sticking the head or body of a guitar to a hollow section of a wall or even an empty box will transfer resonance to that material/space), or applying slight pressure to a piezo disc transducer will increase its response.

To me, the audible difference is best described with an actual sound reference, and what better sound reference than Black Sabbath:
Uncovered = the guitar tone on Paranoid (the song)
Covered = the guitar tone on Wheels Of Confusion

What I hear from a covered pickup under distortion is the "honk" from Wheels of Confusion's tone.

 

[Andy.tech]

Re: Undercover Or Exposed

Do you think the materials that the covers are made of make a difference or do Silver Nickel covers really do help?

 

[DreX]

Re: Undercover Or Exposed

Do you think the materials that the covers are made of make a difference or do Silver Nickel covers really do help?

The cover material definitely makes a difference. The more conductive the metal cover, the more eddy currents you get, the resonant peak drops and another strange dip occurs ahead of the resonant peak as well, altogether causing the tone to become darker. The plastic bobbins don't matter because they of a non conductive material. This eddy current issue is also applicable to the "power plate" on the underside of a Tele bridge pickup, and it's also part of the reason why different AlNiCos grades sound different. Ceramic pickups are not conductive and don't have eddy currents, which is part of the reason they tend to sound "harsh", especially compared to a strong ALNiCo like an A8.

http://i.imgur.com/yO1hfWO.gif

The influence of eddy currents
As mentioned earlier, this overview has been simplified to make it easier to understand. Up to this point, it has not taken into account the influence of eddy currents in metal parts. Such currents appear wherever an alternating magnetic field flows through electrically conductive parts. These parts are mostly the cores of magnetic coils – that is, either permanent magnets (in which the currents are relatively weak) or soft iron parts such as screws or fixed slugs (where the currents are stronger). Strong eddy currents can also occur in metal covers; these currents vanish when the covers are removed. To some degree, the currents’ strength depends on the dimensions of the metal parts as well as their constituent materials. The decisive factor, however, is the parts’ specific resistivity, which is highly variable. There are thousands of iron and steel core types, whose properties can differ widely, resulting in variable frequency transmission characteristics. Metal covers are made of either brass (copper/zinc) or German Silver (copper/zinc/nickel); the latter has a higher specific resistivity and is therefore less conductive to eddy currents. Plastic covers are not conductive. To a lesser extent, eddy currents can also occur in base plates as well as in metal magnets located underneath the coils.

Eddy currents have a threefold effect: First, they reduce resonance superelevation, sometimes to the point of eliminating it completely; secondly, they steepen the slope of frequency transmissions at a height far exceeding the resonant frequency, where 18 dB/octave slopes can be measured. This slope is inversely proportional to the threefold power of the frequency. Thirdly, they cause the frequency transmission curve to drop slightly below the resonant frequency, as shown in Fig. 5:

 

[Andy.tech]

Re: Undercover Or Exposed

The cover material definitely makes a difference. The more conductive the metal cover, the more eddy currents you get, the resonant peak drops and another strange dip occurs ahead of the resonant peak as well, altogether causing the tone to become darker. The plastic bobbins don't matter because they of a non conductive material. This eddy current issue is also applicable to the "power plate" on the underside of a Tele bridge pickup, and it's also part of the reason why different AlNiCos grades sound different. Ceramic pickups are not conductive and don't have eddy currents, which is part of the reason they tend to sound "harsh", especially compared to a strong ALNiCo like an A8.

http://www.buildyourguitar.com/resources/lemme/

Awesome! Thank you

 

[playas]

Re: Undercover Or Exposed

Hey, is there a huge difference with Humbuckers that are exposed and those that have the chrome covers?

And is it difficult to remove the covers and the Wax? :?:

No and not really, no.
There is definitely a difference, but it's not huge. I personally preferred the sound afterwards, especially on the neck pickup of the set I removed them on.

It's a little work to remove the covers, but I'm sure it's not something you can't manage. In guitar repair terms it's a very minor job...just be careful and take your time. If you search you'll find a thread on the forum with a link to a good video with instructions.

Note that I recorded the same piece on the same guitar with the same amp settings before and after and the difference was noticeble - but not huge. I'd describe it as clearer sounding

 

[Aceman]

Re: Undercover Or Exposed

Sure and you are welcome to your opinion, But there are some people here who are giving evidence and not opinions.

Ummmm - they are giving evidence? Of their opinions.

The "scientific" issue here is complex. IF we took the same guitar, and played the same licks, and did a BLIND rating….which NEVER gets done in these situations, you might be surprised. And individuals would hear/prefer differently as well. Even if you could reliably pick the "brighter" one, one guy might call it harsh, another decide it was clear. There is an awesome test of tube screamers like this…the results were interesting.

 

[Edgecrusher]

Re: Undercover Or Exposed

Ummmm - they are giving evidence? Of their opinions.

Nope in particular the BKP video is decent evidence done by a reputable company. It is not scientific nor was it intended to be.

Dont give a rip about the science.

But all this is secondary to my point. The guy i was talking to was basing his opinion off 2 different guitar with 2 different pickup sets. His opinion couldnt possibly be valid scientific or otherwise. If he cant hear the difference between the korean made pups in an agile and a JB/jazz set i doubt very much he could hear the difference between a covered, uncovered or elephant fart.

 

[DreX]

Re: Undercover Or Exposed

You can see in the BKP video that the screw heights were changed in addition to the cover being added/removed.

I don't consider any pickup maker to be an objective source of truth when it comes to pickups, because it's in their best interest to make pickups seem as complicated and magical as possible, to suggest that their own brand of pickups are more complex and more magic than all the rest. I put much more faith in people like David Collins of Ann Arbor Guitars who's experience comes from repair work or rewinding to order, with winding luthiers like Rick Turner being a close second sine they sell whole guitars and not pickups, but reputable guys like that rely on good relations with OEMs and the rest of the industry so they don't get blackballed, cold shouldered and crap talked, so they're not about to call an any major players.

 

[Andy.tech]

Re: Undercover Or Exposed

No and not really, no.
There is definitely a difference, but it's not huge. I personally preferred the sound afterwards, especially on the neck pickup of the set I removed them on.

It's a little work to remove the covers, but I'm sure it's not something you can't manage. In guitar repair terms it's a very minor job...just be careful and take your time. If you search you'll find a thread on the forum with a link to a good video with instructions.

Note that I recorded the same piece on the same guitar with the same amp settings before and after and the difference was noticeble - but not huge. I'd describe it as clearer sounding

OK!! Thank you!!