Installing a cap selector switch in a Precision Bass

[petrus61]

This is the second pic I meant to post showing the outside...perhaps I'm I the wrong thread?

 

[T-34]

Awesome

 

[meatwad]

If you have an old broken PC lying around (desktop style, not the laptop), they usually have a ton of wire inside going from the power unit to the motherboard and peripherals. It is usually 20 and 22 gauge, good quality stranded wire 100% useable for guitar wiring...

My Strat was re-wired from what we pulled out of an old Commodore 64, just for fun. We had tons of wire on a roll available, but I wanted some old school PC guts stuffed in there.

 

[T-34]

Does your Strat sound kinda low-fi 8 bit synth now?

 

[Southway]

So I made an outboard version as well. I'm thinking of wiring an ON OFF ON selector to my bass so I can have the middle position completely bypassing the tone pot when I want to use the box (not likely to be very much...just a fun project). Can anyone tell me how both sets of caps (in the bass and the box) are functioning when both are engaged? Am I getting a sum total capacitance between the box and bass? I built a tone pot into the box. So when I choose, say, a .047 on the box and the .047 on my bass, am I getting the total capacitance of those two caps or is one canceling out the other somehow?

My test version comprises a .0047, .01, .022, .047, .068 and .1. I'm going to change these out and swap until I find the most natural progression of tone going upward. I also grabbed a shorting 6 position 2 pole rotary to hopefully eliminate any static pops when cycling through. It's going into a custom pedal board I'm working on. So I'll have my original .01/.047/bypass selector onboard and the rest will go to the box.

Still trying to determine if not bypassing the tone pot completely when using the box is having enough noticeable effect to making a bypass in my bass worth it.

For Capacitors in parallel, you add the values. So if you have a .047 in the bass, and and a .047 in the box, and both tone controls are at 0, you would have a total capacitance of .094. Or if you have a .01 and a .047, the total would be .057. I don't know exactly how the resistance would affect the value if the controls are not at zero.

 

[petrus61]

For Capacitors in parallel, you add the values. So if you have a .047 in the bass, and and a .047 in the box, and both tone controls are at 0, you would have a total capacitance of .094. Or if you have a .01 and a .047, the total would be .057. I don't know exactly how the resistance would affect the value if the controls are not at zero.

Thanks. That's what I was guessing. I have the three way selector on my bass so when I roll my tone off, Im doubling my capacitance. Pretty neat, if not practical. It basically adds a new set of slightly different values to the equation depending on what value I use on my bass. The biggest roll off being the .2 I get when running both .1 caps. Neat.

 

[MothBox]

Just set one of these up as .022, .047, .068, .1, .2

Found the biggest difference in the 0.68, .1, and .2 caps, the 0.68 and .1 probably being my favourites.

During initial testing I found little noticeable variation below .022 and find the difference between .022 and .047 to be very subtle. May be my setup limiting the tone.

Definitely worthwhile doing and it's something I'm going to look at doing with my P-Bass also.