Single sized humbucker into a strat

[Cederick]

A friend is going to switch a single coil for a SC sized humbucker, and it has on-off switches for all pickups.

I guess the pot needs to be changed for a 500k one, should there be some kind of special resistance things for the single coil pickups? I'm a bit noob on this so sort me out here

Oh and it has one volume and one tone only

 

[Dan025]

it's probably best to start with simplicity first. just swap the pots for 500k and see if the singles start to sound too bright before trying to add resistors. if it is felt that 250k is needed then you can find a pair 470 or 510k k resistor to short the singles individually. or if the switches are dual pole you may be able to use a single resistor, or even the tone pot to load the circuit to 250k. but we can get into that after your friend tries the guitar at 500k for everything. the only reason i even suggest swapping the pots at all is the single sized buckers have lighter windings and less robust magnets, part of the output the have comes from less loading. it has a little higher risk of sounding like mud if you stay with 250k than a larger humbucker in my oppinion.

loading the circuit creates a low pass filter with the pickups inductance, it also prevents a resonant spike created by the inductance of the pickup and the capacitance of the cable, humbuckers have the resonant spike in a more desirable range on the audible spectrum so they need less loading to sound good, more load can cut the output and make them sound darker. singles risk the "icepick in the ear" effect if the rest of the guitar is very bright or the strings are light. but that's also why we have tone controls and it's easier to subtract treble than add it so that's why i say to try it without any special circuit treatment, it may be perfectly acceptable to your friend.

another reason for 500k in gibsons is also that they have dual volumes that both load the guitar in parallel in the middle position. the truth is that this alone may be what set the tradition, gibsons had 500k and fenders had 250k, latter people with pickups swapped into fenders started to notice something was different and rationalized the science into it rather than the pot choice being ideal, there was a convention already in place that may have had more to do with manufacturers getting the best preices on one or the other. as long as your not an order of magnitude away you will likely find the pot choice acceptable.

 

[Cederick]

Thanks but all that was a bit too much for me to understand. I need some more simplicity

 

[Cagey]

Just put in a 500K pot and call it a love story. If the single coils get too edgy, there are tone controls on the guitar, sfx, and amp. Back 'em off a notch.

 

[Dan025]

uhh thanks. i dont know why i always ramble when i answer people.

 

[Cagey]

You may have noticed that I'm not without sin in that area, either <grin>

 

[Cederick]

Just put in a 500K pot and call it a love story. If the single coils get too edgy, there are tone controls on the guitar, sfx, and amp. Back 'em off a notch.

He doesn't want to do that. It would be really hard to get the tone in the exact same level if it hasn't got steps or maybe a point in the middle where it "clicks" (which is a GREAT feature by the way, and the almost only reason I would ever use a tone knob when recording... I have those on my Ibanez bass! )

 

[Jumble Jumble]

I've got single-sized humbuckers in a Strat with all 250K pots and they're fine. So, try that first.

 

[Re-Pete]

Concentric pots 250K/ 500K ? Available at Allparts. Be aware the knobs will stand up a bit more from the body & the pot casing is a bit longer so check you have cavity clearance. Use the 500K for the sc sized humbucker & the 250K for the single coils...

 

[Nightclub Dwight]

Just put in a 500K pot and call it a love story. If the single coils get too edgy, there are tone controls on the guitar, sfx, and amp. Back 'em off a notch.

He doesn't want to do that. It would be really hard to get the tone in the exact same level if it hasn't got steps or maybe a point in the middle where it "clicks" (which is a GREAT feature by the way, and the almost only reason I would ever use a tone knob when recording... I have those on my Ibanez bass! )

Keep in mind that by changing pickups (or anything really) it may be impossible to get the "tone in the exact same level" no matter what you do.  Its like substituting honey for sugar in a recipe; they are both sweet but the finished product may have discernible differences.  You really have to experiment and try it to see how much it changes.  The good thing is that it often works out well both ways.

 

[Jumble Jumble]

One difficult thing here is: when you have one single coil and one humbucker activated, what do you want the volume control value to be? 250K, 500K or something else?

 

[Dan025]

One difficult thing here is: when you have one single coil and one humbucker activated, what do you want the volume control value to be? 250K, 500K or something else?

250k would be good. it's a mater of balanceing load vs inductance. low inductance, high load (low ohm) high inductance, low load (high ohm). parallel inductors have less inductance than a single inductor. when you are in the middle position on a gibson you effectively have 250k load if there are 2 volume pots. if the pickups are similar you can base it on the ideal ohms per pickup and go as low as half the ohms when you combine them (optional). if they are drastically different you can go by the brighter pickup.

 

[Jumble Jumble]

Thanks for that - very informative.

So what we're saying really is that the only time we want a 500K pot is when the humbucker is active on its own. Or we always want 250K whenever any of the single coils is active. Right?

 

[AutoBat]

I'd use 500k pots all around. It's more into personal preference than enormous tonal change.  Either way you'll be fine.

The single coil sized humbucker set I have in my strat (Fender Vintage Noiseless (1st gen)) came with 1meg pots.  I plan on changing them to 500k because the volume isn't as smooth as I'm used to (and I haven't changed anything on that guitar in over a year).

 

[Cagey]

I use 500K pots on everything. I don't care if we're talking single coils, double coils, helical coils, noiseless, straight, inverted, inside-out, mobius strips, humbuckers, whatever. The only exception is active pickups, but they're a different beast altogether.

Here, you can see the end result of using 250K pots on steel coils. Trees start growing out of them, fer crissakes!

Clearly past their sell-by date​

 

[Dan025]

Thanks for that - very informative.

So what we're saying really is that the only time we want a 500K pot is when the humbucker is active on its own. Or we always want 250K whenever any of the single coils is active. Right?

right, that would be ideal. but if you can get away with all one pot simplicity is sometimes better. try it with one pot and if you need to do something funky you can use the load the brighter pickup prefers for the combined positions.

 

[Jumble Jumble]

Well, like I said, I'd just use a single 250 or 500 pot if it was me. I'm just trying to visualise the perceived "ideal scenario".