TBX mods for bass

[Mikelamury]

I'm about to rewire my fender mustang bass. It has pj pickup configuration. I'm wanting to get rid of the pickup selector and run each pickup to a stacked volume pot then to the TBX then to output. Probably replace the pickup switch with a kill switch.

So my main question is what are your favorite mods to the TBX circuit for bass? I've seen one that involves a 1M resistor and an additional capacitor for bass cut. Does anyone know any other modifications to adapt the TBX to suit the bass better? Thanks for any feedback.

 

[ICTGoober]

Seem to work fine in most Fender basses without modding. I have one in my old Yamaha BB-300, and it sounds terrific. No mod needed. I mean, the TBX IS the mod. Why you feel the need to jack with it?

 

[solspirit]

ICT, explain the difference in the PHAT EQ on my Ibanez to a TBX please.

 

[ICTGoober]

I'd need to know something about the Ibanez, and since I haven't opened one up... I shouldn't speak to any differences. One cool thing about the TBX is its passive - no battery. I assume the Ibanez is active?

 

[idsnowdog]

What I have found with passive bass cut circuits is you don't notice much of a difference at low volumes but as the volume increases you start to notice it. However, an active circuit is more effective.

 

[Mikelamury]

Seem to work fine in most Fender basses without modding. I have one in my old Yamaha BB-300, and it sounds terrific. No mod needed. I mean, the TBX IS the mod. Why you feel the need to jack with it?

I thought it was meant for guitar in the wiring diagram that came with it shows the setup for strat and tele. Ive heard that using it in a bass requires a larger capacitor value. What value capacitor is on your bass TBX?

 

[solspirit]

I'd need to know something about the Ibanez, and since I haven't opened one up... I shouldn't speak to any differences. One cool thing about the TBX is its passive - no battery. I assume the Ibanez is active?

Yes

 

[PFDarkside]

ICT, explain the difference in the PHAT EQ on my Ibanez to a TBX please.

I'd need to know something about the Ibanez, and since I haven't opened one up... I shouldn't speak to any differences. One cool thing about the TBX is its passive - no battery. I assume the Ibanez is active?

Correct me if I’m wrong…. The TBX has a center detent. From 0-5 it functions as a standard tone control, rolling off highs based on the cap and pot value. From 5-10 is it just adding resistance in series to ground, reducing load and therefore increasing presence/treble/raising the resonance frequency? At 10 you basically have 1.082M to ground and the standard “tone” side is removed from the circuit due to the no-load trace?

The Phat EQ on the other hand is an active treble and bass boost. As you turn it up the bass gets louder and it’s like a graphic EQ with a smile rolled in.

 

[ICTGoober]

I thought it was meant for guitar in the wiring diagram that came with it shows the setup for strat and tele. Ive heard that using it in a bass requires a larger capacitor value. What value capacitor is on your bass TBX?

I used the stock stuff Fender sold me.

TBX Tone Control Potentiometer Kit | Parts (fender.com)

 

[solspirit]

The Phat EQ on the other hand is an active treble and bass boost. As you turn it up the bass gets louder and it’s like a graphic EQ with a smile rolled in.

. . It's not just bass or treble, it's both at the same time, right?

 

[idsnowdog]

I thought it was meant for guitar in the wiring diagram that came with it shows the setup for strat and tele. Ive heard that using it in a bass requires a larger capacitor value. What value capacitor is on your bass TBX?

Try it first. Bass and guitar aren't so vastly different that you need tailored circuits.

 

[PFDarkside]

. . It's not just bass or treble, it's both at the same time, right?

Yes, similar to a contour or loudness type control.

 

[Mikelamury]

I used the stock stuff Fender sold me.

TBX Tone Control Potentiometer Kit | Parts (fender.com)

So the tone cap is only active in the regular tone circuit from 1-5 correct? So I assume changing cap values will just affect your treble roll off from 1-5, is that correct? Thanks alot for everyone's input!