500K vs 250K tone pot

[coolhandjjl]

Say I've got two audio taper pots, one meters out to 250K, the other at 500K. With all other things being equal, will the 500K dialed down a bit give me the same tone as the 250 on full, or is the 500K wasting anything?

[weemac]

Yep, you will get a bit more highs out of the 500K pot (sounds like a drug reference). If you turn it back a bit it will sound much like the 250K one.
What pickups are you using it on?

emac.

[coolhandjjl]

single coil

[weemac]

Well... anything below an 7Kish winding and you may be better off using the 250k pot. But if you are talking Hi-gains or P-90s stick with 500K pots..

emac.

[cassius987]

Just my two cents, but with my rig (bass>MXR-M80>TC Classic450>fEarful 15/6), I prefer modern 11k Hi-Gains with the stock wiring harness, which loads down to 165K. I have crafted "brighter" sounding harnesses and thought they sounded harsh detracted from the overall tone.

[aceonbass]

4001's used to have 8K pickups with 500K/250K harnesses, so if anything were gonna sound bright or harsh, that would. When I finally got good enough at wiring my own stuff, I selected the best components based on advice given to me by people who knew. My 4008CS has a RIHS and 8.5K toaster in it. It uses 500K tone and 250K volume pots with .047uF tone caps. Everything is within 5% of rated value and the bass sounds open and huge and perfect. I used to have stock RIC pots in it that speced out at about 180K each. Never again will I use such dull sounding components again. I replaced every one of these in my basses with the Bourns pots and Cornel-Dublier caps (same caps RIC uses now).

[coolhandjjl]

My 2009 4003, with its 330 tone & vol, and 500 push/pull measure at 290, 273, 270 and 533 respectively. All audio taper.

My 1993 4003s with its 250 tone & vol measure at 188, 194, 196, 198.

However, all that matters is the final tone. These things work together as a system that also includes the pups, strings, cable, pre-amp, amp, cabs, playing style, etc, etc. So I really can't single out any one item as being a dud.

But being a forum member, means I am by nature, a tweaker and a fiddler. Same holds true for my profession with the various photo and printing forums I participate in.

So what does this all mean? Well, it always bothered me that the bridge's push/pull tone pot value didn't match the neck tone pot. The push/pull pots available are Alphas I believe, and are audio tapers. Having bought many, they meter out anywhere from 490 to 566K. Another thing that bothered me was the abrupt cut out of either pup when dialing down its respective volume pot. This leads me to believe that audio taper, while great for tone pots, make for lousy vol pots in a bass. Linear seems to be a much smoother, gradual, more controllable volume roll off, at least for me. I've read the same on other forums. And finally, I hated that when the vol pots were dialed down, all the highs drained out.

I'm making two new harness's for both my 2009 4003, and my 1993 4003s (The 4003s gets the RIHS and mock toasters, metered DC resistance at 10.6K and 11.4K respectively). Since there are no linear taper push/pulls, the push/pull has to stay in the tone position. To make it balance better with the neck tone pot, I have 'swamped' the push/pull pot with a 470K resistor from The Shack. Brings it down to 250K. Now it's just a matter of ordering some audio taper pots that meters at 250K for the neck pup tone pot, which will not be a problem. To address the lack of highs when the vol is dialed down, I'll be ordering some .001 treble bleed bypass caps to be installed under each vol pot.

But it doesn't end there

Yesterday, I put in two 194K audio taper vol pots (from my 4003s) and two swamped push/pull tone pots into my 2009 4003 just to get it up and running, but put in two monster size Orange Drop 716P .068 600V amplifier caps in it instead of the stock .047 axials. I did leave in the .0047 with the bypass feature wired. I did it just to see...... (or hear). Now that made a change. This thing can now be cranked to get clean massive booty shaking lows with none of the honky/horny resonance that the maple sometimes added. I know, this is Ric sacrilege because it may not be Ric-ish, but to my ears and plugged into my system, it has great Roger Glover growl with early Geddy Lee articulation. My 4003 simply never had that before. I feel like Charles Goodyear when he accidently stumbled upon vulcanization.

I don't plan on putting those same caps in my 4003s, as that bass will get the Fender 9050CL flats. Don't want to snuff out the thing. I'm going to try .056 caps in that one just for grins.

[weemac]

I'm going to try .056 caps in that one just for grins.

That will make it darker!

emac.

[MichaelStewart]

Does the 500k tone/250k volume arrangement work well with hi-gain bridge pickups as well?

Where is a good place to buy Bourns pots and Cornel-Dublier caps?

[aceonbass]

The answer to the first question is yes, and the answer to the second question is Mousser Electronics.

[tmossman]

The answer to the first question is yes, and the answer to the second question is Mousser Electronics.

Dane, I think you have your hair care and electronics sites mixed up.
Mouser Electronics

[aceonbass]

What's an "S" between friends

[mhalstead]

Ok, someone with better electronics knowledge check me out here, but as I remember from school so many years ago:

[1] the dc resistance of the 0.47uF at any given frequency is 1 divided by (2 x pi x freq X capacitance)

[2] therfore at 100 Hz, the capacitor has a resistance of 1 over (2 x 3.14 x 100 X 0.000,000,47) or about 3.4K ohms

[3] consequently at 1k, the capacitor has a resistance of 340 ohms, and at 10K, 34 ohms

assuming Ruick uses a 2-connector tone pot system e.g signal is connected to the pot slider, and the cap is connected between one end of the pot, and ground, the loading effect will be as follows

500K pot fully open
at 100Hz, load across pickup = 503.4K
at 1KHz, load across pickup = 500.34K
at 10KHz, load across pickup = 500.034K

250K pot fully open
at 100Hz, load across pickup = 253.4K
at 1KHz, load across pickup = 250.34K
at 10KHz, load across pickup = 250.034K

Clearly, the capacitor makes very little difference when the pot is open, irrespective of whether the pot is 250K or 500K Any change in sound from changing the tone pot is going to be due to the same loading effect as changing the volume pot. The cap doesent really enter into the equation.

[MichaelStewart]

I went to Mouser and searching for potentiometers I had to answer 3 questions I had not considered:

1) What power rating?
2) What shaft type?
3) What shaft length?

What is the best answer to each of these questions?

[coolhandjjl]

Ok, someone with better electronics knowledge check me out here, but as I remember from school so many years ago:

[1] the dc resistance of the 0.47uF at any given frequency is 1 divided by (2 x pi x freq X capacitance)

[2] therfore at 100 Hz, the capacitor has a resistance of 1 over (2 x 3.14 x 100 X 0.000,000,47) or about 3.4K ohms

[3] consequently at 1k, the capacitor has a resistance of 340 ohms, and at 10K, 34 ohms

assuming Ruick uses a 2-connector tone pot system e.g signal is connected to the pot slider, and the cap is connected between one end of the pot, and ground, the loading effect will be as follows

500K pot fully open
at 100Hz, load across pickup = 503.4K
at 1KHz, load across pickup = 500.34K
at 10KHz, load across pickup = 500.034K

250K pot fully open
at 100Hz, load across pickup = 253.4K
at 1KHz, load across pickup = 250.34K
at 10KHz, load across pickup = 250.034K

Clearly, the capacitor makes very little difference when the pot is open, irrespective of whether the pot is 250K or 500K Any change in sound from changing the tone pot is going to be due to the same loading effect as changing the volume pot. The cap doesent really enter into the equation.

This is good stuff. I can't remember the last time I dialed down a tone pot. Even volume pots I rarely fiddle with. Once in a while, I lower one of the pup volume pots a tiny bit.

So with the tone pot at full, it's as if there is no cap at all? My playing since I did all this, all pots have been on full, so perhaps the difference in tone I experienced was more due to the max ohms of the tone and vol pots themselves being lower than the bass came with.