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P to PJ advice needed!

lel95

lel95

May 14, 2010
103
33
31
sunderland, UK
#1
right guys, this is my first serious modification im doing to the electronics on my bass and i need some help off you guys.

Im converting my Squier VM P into a PJ. I am a joiner/carpenter so i can manage routing the body but i am not too familiar with bass electronics. My bass has the standard P layout, one volume and one tone with a 'duncan designed' pup. Would i be easier to buy another pot so that it is VVT or would a stacked pot be better for the two volumes?

Also, would i have to change all the pots? Im unsure what pots are in at the moment but i can find out if i need to. The jazz pup im planning on putting in is either a duncan hotstack or quarter pounder (also which would you recomend?) and both of them are recommended for 250k pots. Lets say if my pots are 500k at the moment, would it be alright to use a 500k for the jazz pup? or is it possible to use a 250k and a 500k pot together?

sorry for all the noob questions and i really hope someone can help me out! thanks!
 
#3
lel95 said:
Would i be easier to buy another pot so that it is VVT or would a stacked pot be better for the two volumes?
Click to expand...

That's personal preference.
Do you want two separate knobs, or one concentric?

Pot values are also a personal preference. 500ks are a touch hotter/brighter than 250ks. Keep in mind that by adding a second volume pot, you are decreasing the resistance parallel to the signal, so if you have a 250k volume now, two 500k pots in parallel is 250k, but two 250k pots is 125k.
 
#4
Bongolation said:
If you must do this, don't do it V/V/T, which never works quite right (and sometimes terribly) with dissimilar pickups.
Click to expand...

I disagree. Two volumes works better than a blend for a passive bass. You're forgetting that a blend pot is two volume pots running in inverse parallel.
Every method of wiring a bass passively presents a compromise. The only way to win is if you get into active buffering.
 
#8
line6man said:
I disagree. Two volumes works better than a blend for a passive bass.
Click to expand...
I was not advocating a blend pot.

I advocate switching, as I have pointed out before, the only way to get around the inherent problems in passively wiring dissimilar pickups.

Every method of wiring a bass passively presents a compromise.
Click to expand...
In blending dissimilar pickups, absolutely, which is why I advocate switching as the best solution.
 
#10
Bongolation said:
I was not advocating a blend pot.

I advocate switching, as I have pointed out before, the only way to get around the inherent problems in passively wiring dissimilar pickups.


In blending dissimilar pickups, absolutely, which is why I advocate switching as the best solution.
Click to expand...

Switching is indeed the best solution, from an engineering standpoint, but the compromise is that you don't have the option to mix the pickups in different proportions. It's all of nothing. This does not appeal to a lot of players.
 
#11
line6man said:
Switching is indeed the best solution, from an engineering standpoint, but the compromise is that you don't have the option to mix the pickups in different proportions. It's all of nothing. This does not appeal to a lot of players.
Click to expand...

I'm dismissive of blending pickups, especially with bass, especially when it doesn't work right, as it can't with passive P/J. It's just more fiddly nonsense that doesn't matter.

Bedroom bass geeks will disagree. They live to obsess and fiddle.

To the extent that the passive P/J concept has any validity, it should be approached as the original concept intended: Pure P with pure bridge J and a possible bonus of both working together if you're lucky.

Every attempt to kludge this by mixing or winding pickups to match output or any other "paint the floor to match the dirt" scheme degrades the available pure P and J sound to some extent or the other, usually substantially. So instead of both, you're getting neither.
 
#12
Bongolation said:
I'm dismissive of blending pickups, especially with bass, especially when it doesn't work right, as it can't with passive P/J. It's just more fiddly nonsense that doesn't matter.

Bedroom bass geeks will disagree. They live to obsess and fiddle.

To the extent that the passive P/J concept has any validity, it should be approached as the original concept intended: Pure P with pure bridge J and a possible bonus of both working together if you're lucky.

Every attempt to kludge this by mixing or winding pickups to match output or any other "paint the floor to match the dirt" scheme degrades the available pure P and J sound to some extent or the other, usually substantially. So instead of both, you're getting neither.
Click to expand...

This is my personal philosophy on PJs, as well, but not everyone agrees.

I don't like the sound of two pickups played together on most basses, so I solo the pickups. Having a switch is great for that, because there is no extra resistive loading against the signal, and you get to have the wiper terminal of your volume pot(s) wired to the output, so the resistance is varied against the output instead of the pickup.

Ps and Js were never meant to be mixed anyways, as you have an unequal number of hum sources, so full destructive interference of 60Hz hum is not possible, and Ps are usually way louder than Js. The output impedance is different, as well.

The average PJ player WANTS to have some control over the pickup blend, though. This is why VVT is the most common way to wire a PJ. It all depends on what's important to you in a control scheme.
 
#15
Bongolation said:
They're wrong. It's that simple.
Click to expand...

I wasn't aware there was a right and wrong preference on bass control schemes.:eyebrow:

Some guys don't give a rat's ass one way or another, as long as their bass sounds good, others can't live without a master volume and blend. Some find two volumes adequate. Some prefer their pickups hardwired in parallel or series to a master volume. Some like no controls at all. Then there are the guys that think you aren't a real bassist if your bass has more than one pickup. Then of course, are the dudes that hate pickup selector switches because they aren't best for metal. Further still, there are the guys that will argue religiously that the best control scheme cannot be determined, as it depends on the particular bass.
 
#19
line6man said:
I wasn't aware there was a right and wrong preference on bass control schemes.:eyebrow:
Click to expand...
Sure there are, if you define them as physically (as in Physics) working relative to intent and expectation. Think about it.

Mixing dissimilar pickups will not work out the way novices think they will when they have these great ideas.

An EE on the Seymour Duncan forums some years ago explained at length why variably mixing dissimilar pickups passively can never work very well. His technical explanation was somewhat over my head (my recollection is that the problem was in circuit inductance), but empirically I know after working on instruments for over forty years that it's true. There are all sorts of peaks and cancellations and funny noises and screwy rotational response of the pots and the pickups individually never quite sound as good as they do when the other one is removed from the circuit, etc. You can't beat physics.

That's not what players expect when they think variably mixing pickups is going to be "awesome." Ergo, it's a mistake.
 

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