Hum & single coil in the same gtr?

[bcalder01]

Hi all, my apologies if this simple questions has been asked already, I haven't been able to find it.

I have a Strat copy with humbuckers in the neck & middle & a P90 in the bridge, with a 5 way switch. All are wired to a 500K master volume, no tone. I want to split the P90 out to a 250K volume pot, as it's too bright right now, and this is a simpler & cheaper way to start vs. playing pickup roulette! I think the wiring would be similar to a Les Paul, except with no tone controls & a 5 way instead of a three way, but I'll be darned if I can figure it out.
Thanks in advance,
Bruce

[newey]

Bruce-

Hello and Welcome!

What you want to do is easy enough. Someone will be along shortly with more specifics.

There are several different styles of 5-way switches, and although they all operate basically the same, terminal locations differ somewhat. It would be helpful to know what you have in there now.

Basically, your new bridge Vol pot will be wired across the bridge pickup, between the pup and the switch. Then, your existing Vol control, instead of exiting from the common terminal of the switch, will be moved so that it is active only in positions 2-5.

[bcalder01]

Hey Newey, thanks for the quick reply. The switch is this one from our friends at GFS:

store.guitarfetish.com/st5swwifrtis.html

Can't quite picture how the second part will work ... looking forward to my eduaction!! :-)

[ashcatlt]

Unless you're actually looking for independent vollume control for the bridge pickup, why not just wire a 470K resistor across the pickup and leave everything else as is? Why 470K? Because it's easier to find than 500K, and when in parallel with the master volume will come out close enough to 250K. Of course, in switch position 2, this is going to load your middle pickup a bit more than an HB might want. That's usually a kind of thin and bright postion anyway though, so it might work fine.

Else, you could wire a 500K pot across the bridge and leave everything else as is. Then you'll have the bridge volume in parallel with the master, totalling 250K again. These volume knobs will interact to some extent depending how you wire the new pot. You've still got the issue in position 2.

Or, you could try wiring the existing 500K along with a new 250K on the spare pole of that switch in a scheme similar to the way tone pots are connected in standard strat wiring. In this case, position 1 would have only the 250K pot active. Position 2, though, would have both in parallel, totaling 166K, and each volume would tend to act as a somewhat unpredictable master.

I vote for the resistor since it's the simplest and cheapest option.

[ChrisK]

I vote for the fixed 470K or 510K resistor as well.


To be fair tho', I've never encountered a P-90 that I thought was excessively bright.....

[bcalder01]

Thanks all for the posts. We'll try door #1, "wire a 470K resistor across the pickup". Now for the noob, could someone explain where & how to wire the resistor? It's a three-wire pickup, hot, negative & case shield. I sincerely have no idea what it means to wire it across the pickup ... yet. ;-)

[ChrisK]

From "hot" to "negative" (parallel with the coil) (although positive and negative in an AC system indicate phasing, not polarity).

On the 5-way switch there is a connection for the "hot" from the P-90. There is also a place where the "negatives" from the pickups go to, in common.

The resistor's leads span these two points.

[bcalder01]

OK, I have a embarrasingly lowbrow question ... I saw how the cap is suppsed to wire. My electronics shop has the cap, but asked me what voltage I wanted ... I looked at him and said, "Uh, it's for a guitar". I bought a 470uF, 25V cap that at least looks like the right shape. Are these the correct values?

[D2o]

Oct 20, 2008 14:59:14 GMT -5 bcalder01 said:

OK, I have a embarrasingly lowbrow question ... I saw how the cap is suppsed to wire. My electronics shop has the cap, but asked me what voltage I wanted ... I looked at him and said, "Uh, it's for a guitar". I bought a 470uF, 25V cap that at least looks like the right shape. Are these the correct values?

Hi calder,

Your bemused response to the voltage question was right on the money, I'd say.

It's not terribly important in anything other than a DC blocking cap, which you are not talking about here ... right? ... you aren't mixing things up with a previously mentioned 470K resistor, are you?

What I think you are talking about the tone cap wired into the tone pot, which should be 0.047uF - unfortunately not the 470uF you mention.

D2o

[bcalder01]

I realize this affects my karma points terribly ... yes, now that I'm re-looking at the previous posts, I will slink back to the electronic store & buy a 470K resistor. :-(

So since the voltage is important for this component, what value should I ask for?

Thanks to all for their patience & help.

[ashcatlt]

It happens.

I don't think D2o was implying that the resistor requires any specific voltage either. I think resistors are generally specified in maximum wattage, anyway. Unless something goes terribly wrong with your amplifier, you've never got too terrible much of either voltage or current in the guitar itself. 1/4 watt should be fine.

[D2o]

Sorry, calder

I had two thoughts and decided to edit them into one ... on second read it may make it sounds like the 470k resistor and DC blocking cap have some relationship to each other. That is absolutely not the case.

Ash is correct, a 1/4 watt 470K resistor is the correct specification if a resistor is what you are after.

D2o

Oh, and your karma will never be negatively affected around these parts.