Installing 2 identical pickups

[Marcelo1281734115]

Hello,

 

I see a lot of guitars on the internet that have 2 of the same pickup type installed, like 2-P90s. I never get to see and test such an animal in person, so I wanted to ask you guys out there if the sound from each of the pickups is identical when you switch one off and each pickup is played on its own?

 

My guess is that if you closely watch a string vibrate, it tends to oscillate very little near the bridge location (where the lead pickup is) and the string oscillates a lot near the neck (where the ryrthym pickup is). Since a pickup is basically a magnet, even the same identical pickup should make a different sound depending how far down the string is located (because the string is moving differently at the different location). Is this correct?

 

The reason I was asking is that I saw somebody selling a humbucker that is the size of a single coil pickup. That would mean that I could place 3 of these on a Strat without having to do a major mod. I just wanted to know whether I should only replace the bridge pup, or if I change all, would each of the three give me a different sound?. Thanks.

[pohatu771]

They do all sound different. The Strat sounds different in each position now, doesn't it?

[Marcelo1281734115]

The Strat I have is a Peavey clone and all the 3 pickups do sound different as far as the 5-way switch allows me to tell. From what you are saying, all 3 pickups on the Strat are supposed to be identical in spec (but I cannot tell as I never took this guitar apartto check), but they sound different only because of their specific location.

 

What got me all confused was that Gibson offers a 490 and 498 pickups on their SG Standards, so I thought that they chose 2 different pickups because putting 2 identical pickups would give the same sound. So, they must have some other reason for choosing to use 2 different pickups for this guitar.

[pohatu771]

I'm hardly a pickup expert, but this is the best I can explain it...

 

The first reason is a physical issue - the strings are spaced differently at the bridge than they are at the neck.... the nut width is less than the bridge width, and the gradual "narrowing" will cause the stings not to be picked up in the optimal spot.

 

The second reason is due to the movement of the strings. As you said in your original post, the strings are vibrating differently at different points - closest to the node is less movement, closest to the anti-node is the most movement. The pickups are designed differently to maximize the effects with that position on the string.

 

Again, not an expert, so I'm sure someone can come along and explain it better, but that's how I understand it.

[carverman]

I'm hardly a pickup expert' date=' but this is the best I can explain it...

 

 

The second reason is due to the movement of the strings. As you said in your original post, the strings are vibrating differently at different points - closest to the node is less movement, closest to the anti-node is the most movement. The pickups are designed differently to maximize the effects with that position on the string.

 

Again, not an expert, so I'm sure someone can come along and explain it better, but that's how I understand it.[/quote']

 

 

Well I'm not an expert either..but I'd like to play one on tv someday...

 

String vibration and string nodes are a complex issue because not only of the fundamental

vibrations but the inclusion of harmonics and overtones at specific areas of a respective

string.

I've done some experimenting and find that the string itself gets magnetized at

specific areas due to the influence of the p_up magnet beneath it. The vibrating

string provides linear motion to the pickup coil(s) directly underneath. The response

will depend on several factors: no of turns, how the turns of copper wire are done

on the bobbin, magnet type and strength, and height of the pole pieces in respect

to the string.

 

The guitar p_up can be (somewhat) viewed as a linear signal generator. The

moving part is the string which moderates the steady state flux of the coil(s)

underneath it and inducing a corresponding weak voltage in the order of

a few millivolts.

 

Because there is less excursions on the string at the bridge, the bridge p_up

has to be ( usually but not necessarily) wound a bit hotter (overwound),

to pickup the strings at the same volume level as the neck.

 

..well that's my .02cents worth..maybe others can add to that.

[Ricochet]

The same PU will sound different in different locations(neck, bridge).

It will have less volume nearer to the bridge(less amplitude of the string).

To match the volume, the bridge PU is often higher in output.

 

Fitting a Single-coil sized humbucker won't give you true humbuckersound. You can't mimic the wide magnetic fluxfield of a humbucker with a single row of magnets/poles/dual blades whatever. However it will give you the benefits of dual-coil noise cancelation typical of humbuckers.

[sjtalon]

On Gibson humbuckers

 

Guitars (Studios) with two 490's ( Alnico II) for instance are for a "more contemporary humbucking sound" similar to the '57 classic.

 

Gibson makes two 490's, the 490R (rythum or neck) and 490T (treble or bridge). The only difference is the 490T pole spacing is different to line up with the strings better at the bridge and it has a few more windings to compensate for the lessser string vibration at the bridge (hereformentioned).

What they do is give BALANCE to the two pickups when played combined. A person does this when adjusting the height of the pickups as well (balance).

 

 

498T's are higher output treble (bridge) pickups (overwound and Alnico V ) and are for blowin' the windows out- ROCKIN' big time.

 

So it all boils down to the type of music you play for the most part.

 

Some Strat pups (N-M- are all the same like 57/62's and some have different values, again it's what tone the player wants.

[10drum]

I think the easiest way to understand this is to pick the string near the bridge and then pick the string near the neck, unplugged. Strings oscilate differently the entire lenght of the string.

[Dave]

As Carverman said, hotter windings are needed at the bridge because of the reduced amplitude of the oscillations at that point in the string. More windings mean higher output for the same deflection across the coil's pole pieces. You can raise a pickup to increase output, but at some point the magnetic pole pieces will begin to "capture" the string and you get a funky sound due to the reduced oscillation of the string in a strong magnetic field. You are better off to get the output you need from a higher winding count.

 

That's why there are "neck" pickups and "bridge" pickups, although two hot pickups of the same type can be installed in a guitar. When this is done, you usually end up having to lower the neck pickup all the way to equalize the output in relation to the bridge.