Tb-4 vs sh-4 sound

CarlosG

New member
Hi!
I have questions about sound differences between TB and SH.
When I put the TB-4 into my guitar it was a bit too wide, but the poles were under the strings.
So I bought a sh-4 which fit the strings perfectly.
I noticed that the TB-4 sounded fatter and I liked it more.
I know the TB-4 has shielding around the coils and the sh-4 doesn't. I know that shielding the coils darkens the sound a bit.
I wonder if that's the only factor. TB has the same amount of wire turns, but has higher resistance and a longer wire length.
I wonder if adding a coils shield to the sh-4 will make it sound like the tb-4, or if the longer wire length also has an effect.
I know some people might call it crazy, but I can really hear a difference
 
id say both make a difference, but adding the shielding around the coil should push the sh4 in the right direction
 
There's potentially a slight difference of inductance between SH4 and TB4, but probably not great enough to make a noticeable change. The shielding protects against noise but introduces eddy currents as soon as it forms a closed loop around coils: theoretically, it erodes a bit the resonant peak and should therefore contribute to a less focused sound.
Now the tone perceived as fatter might be due partly to how the magnetic field is shaped by / with trembuckers and how it affects the balance between strings...

Anyway, it shouldn't harm to experiment with a strip of shielding around the coils. It's not even necessary to stick it on 'em: sticking it on itself should suffice if the loop is tight enough.
Aluminium should also bring more eddy currents than copper if needed. ;-)
 
and theres your answer! interesting that aluminum induces for eddy currents than copper
 
So if someone (a friend, say) took the copper shielding off his JB coils, it might conversely sound brighter and more focused? I think I have a friend who likes this idea.
 
you better be reaaallly careful since its basically glued to the coil. not saying you cant do it, but ive thought about it, then thought better of it
 
Yeah, I've heard of people doing this sort of thing easily, and I've also witnessed someone ruining the pickup.
 
So if someone (a friend, say) took the copper shielding off his JB coils, it might conversely sound brighter and more focused? I think I have a friend who likes this idea.

Well, less eddy currents theoretically make peakier the resonant peak but I'm not sure it would justify the pain to peel the shielding in such a case.
Not even sure of where the difference stated by the OP comes from, in fact: if I could induce electrically the response of a TB4 vs a SH4, I could share more than a guess but I've not these models at disposal right now... maybe CarlosG would notice the same kind of difference between two SH4's from different batches / series / eras, given the variability inherent to magnetic transducers...

The best way to make a SH4 effectively brighter, IMHO, would be to lower its inductance - by unwinding one or both of its coils, by diminishing the amount of ferrous alloy used as core / magnetic materials... or simply by putting it in parallel with a high inductance dummy coil / choke (a 14H one, like those of vintage VariTone's, would shift the inductance of a SH4 in the P.A.F. range). :-)
 
My first question is height adjustment

Do you have both pickups at the exact same distance from the strings

This
I think
Would make a larger difference on the sound of identical pickups
More than Inductance shielding
 
So if someone (a friend, say) took the copper shielding off his JB coils, it might conversely sound brighter and more focused? I think I have a friend who likes this idea.

I'm calling bravo sierra here. We're guitarists. We don't have friends.
 
I'm calling bravo sierra here. We're guitarists. We don't have friends.

Hey now, some of my best friends are guitarists!





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But yes, you've found me out... it was just me all along. I don't know anyone else IRL who's dumb enough to peel the copper tape off a pickup to see if they can hear more high end coming through.
 
I don’t think the shielding on Duncans wraps completely around though. I could swear that there’s a gap so there shouldn’t be any eddy current right?

I figure that tb/sh differences, with the amount of turns. being equal, will have a slight difference in resistance if the bobbin is slightly longer. And if the resistance is equal then there has to be less turns on the tb. Does any difference in resistance between the two fall within tolerance of the production of Duncan humbuckers? If they aim for 5-10% then the trembucker might just fall into the widest difference between any two sh4s and there are surely tb4s that sound just like other sh4s. Probably. lol
 
I don't know if I would hear a difference by the time I uninstalled one and installed the other.
 
SO wait...you are telling me a Trembucker JB is made differently than a standard one, besides the pole spacing??????
 
if you like the TB-4 more than the SH-4 you are lucky. because you can add a small parallel capacitor of a few pF to the PU to make it more like the SH-4
 
In another topic I wrote about the effect of the shielding on the sound with my FS-1.
I hear a similar difference between sh-4 and tb-4.
I did have a Roughcast A5 magnet on hand though.
I put it in the sh-4 and I got this.
It sounds great, no more that annoying thumping high end and it sounds warmer.
Much better.
From what I remember the first JB models (the most desirable ones) have roughcast a5 magnets.​
 
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