T-T-B on a PJ Pasive

[fruity2x]

OK Folks I seam to be wanting to do something that cant be done but I'm just not convinced. I want to do a tone for each pickup and a blend ( I just don't use the vol )

I've bought new pots and poured over MANY wiring diagrams and read MANY articles to try to figger this out and thru a lot of trial and error it just doesn't want to work "all the way right". It is TRYING to work but with a lot of buzz and an almost complete loss of vol at dead center of the blend. The tones are affecting the pups like I want but its just not quite right.

I'm open to suggestions but the final goal is to have a tone for each pup and not adding any holes to the bass as it is an early 90s Charvel CX 490 "Fender head" I bought as my first new bass.

Thanx in advance!!!

 

[line6man]

The only way you are going to get such a setup to work is to isolate the pickups from each other using resistors in series with the output from each pickup, with the tone controls parallel to the pickups. Otherwise the tones are going to interact to various degrees, from acting as masters at the center detent, to independent controls at either extreme.

The problem with the resistors, however, is that they will reduce your output and give you a darker tone. Straight out of the pickup, you are converting the signal to thermal dissipation. This isn't desirable to most people.

 

[walterw]

yep, multiple tones are useless on parallel-wired pickups, since each tone affects everything when they're both on. they also cause loss even when they're all the way up, so adding more of them has a price in tone.

(they make some sense on two-pickup gibson electrics because there's a pickup switch, usually used to quickly go from one pickup by itself to the other by itself. with the switch in the middle, the same problem happens, both tones affect everything.)

 

[Stealth]

Line6man, can the darker tone be offset with smaller-value capacitors, like switching from .047 μFs to .033 μF or .022 μF? By all calculations it should since the corner frequency is both resistance- and capacitance-dependent.

 

[line6man]

Line6man, can the darker tone be offset with smaller-value capacitors, like switching from .047 μFs to .033 μF or .022 μF? By all calculations it should since the corner frequency is both resistance- and capacitance-dependent.

Things change with pot positions when you have interacting tones.
The blend pot determines the degree of interaction, and then the tones themselves can be adjusted to increase the capacitance, or not. It's really dependent on how you set the controls. For example, with two 0.047uF caps, if you set the blend to the center detent and roll down both tones, that's 0.094uF parallel to everything. Roll the blend off to one side and keep one tone up, and you've got 0.047uF on one pickup.

 

[fruity2x]

Line6man could you please draw up a diagram of how you would wire this thing if you were to try it? It sounds like it "might" do what I want it to....I just can't find the gremlen in my attempt @ it and the buzz is crushing.