More Pot's & Caps Questions

[Zeus_Mutation]

I've been reading so much I'm getting really confused. Hoping for clarity on the subject.

Goal: Change electronics in my Squier Classic Vibe P-Bass. w/Maple neck/fingerboard

Tone Pot:
- 250k stock w/.047uF cap

I'm trying for more clarity in the mid section, while keeping those piercing highs down. I can get the attack definition I want, but at the cost of being too bright. If I get the lower frequency sound, the attack is too muddy.

Please correct my mistakes here

Tone Pot - I thought cap value only affected the frequencies when the pot is turned to zero? So, if you roll your pot towards 10, the cap has stopped doing any cutting/filtering?
If correct… and for arguments sake, between 3-9 on the dial, nothings is actually happening. Does a Linear pot positively change that sweep or audio tapers still preferred due to our volume perception?

My Tone Desire - Rich, Full, Dark, Deep, and Clear. No underwater muffling or bright tin like sounds.

In oversimplified terms, 250k = warm, darker vs 500k = brighter
Is there any data showing the actual frequency range effected?

Does a cap alter the tone differently when used with a 500k or 250K pots? Cap of the same value btw.

I've two different sets of pickups to try and get my sound with…
Seymour Duncan SPB-4 w/DC resistance of 13k (Steve Harris Signature pups)
Fender '62 Custom Shop P's w/DC Resistance at 10.5k

I'm trying to understand if:
1. 500k pot will add clarity
2. 500k pot should be the Tone, Volume, or both
3. 500k pot will bring out the mid's more so when mixed w/SPB-4
4. 250k pot will help warmup or darken the SPB-4's
5. 250k pot - Keep It Simple Stupid?

Finally, adding the ability to switch between two different cap values. Looking for the how to wire such a thing thread. Any key words that'll help me narrow that search?

Thanks!

 

[line6man]

Tone Pot - I thought cap value only affected the frequencies when the pot is turned to zero?

No.

Does a Linear pot positively change that sweep or audio tapers still preferred due to our volume perception?

Linear taper pots should never be used for tone controls unless you have a bypass switch. They behave like on/off switches. You need a high resistance at the end of the rotation, and a quick transition to lower resistances, so with a linear taper, you have to roll down most of the way before you start cutting treble.

In oversimplified terms, 250k = warm, darker vs 500k = brighter

Yes, but people tend to get fixated on pot values, when the actual difference is only subtle.

Does a cap alter the tone differently when used with a 500k or 250K pots? Cap of the same value btw.

Resistance is resistance. If you have the same resistance dialed in, it does not matter whether you have a 250k or 500k pot. The difference comes down to the taper of the sweep, and the brightness at the end of the rotation.

I'm trying to understand if:
1. 500k pot will add clarity
2. 500k pot should be the Tone, Volume, or both
3. 500k pot will bring out the mid's more so when mixed w/SPB-4
4. 250k pot will help warmup or darken the SPB-4's
5. 250k pot - Keep It Simple Stupid?

1. Only a tiny bit.
2. That's a personal preference.
3. That depends on pickup impedance.
4. Somewhat, yes.
5. That's for you to decide.


Sorry if this post sounds a bit dismissive, but like I said, people get all wound up about pot values, and they don't make a huge difference.

 

[Zeus_Mutation]

Thanks Line6man - No, not dismissive.

Impedance is my next hurdle. How do I find the pickup impedance. I don't see it listed on the manufactures website or on the packaging. I know it has Alnico 5 rod magnets and a DC resistance of 13k.
I'm going to try a Tonestyler, that said does a 500k pot give a more broad sweep of volume too or the "taper of the sweep, and the brightness at the end of the rotation" only applies when used as a tone pot?

I was going to experiment with different cap values, now I'm going to see if that Tonestyler fill's my need. Time is the most important commodity for me, even the wealthy can't buy 5 minutes of it. lol

 

[line6man]

Thanks Line6man - No, not dismissive.

Impedance is my next hurdle. How do I find the pickup impedance. I don't see it listed on the manufactures website or on the packaging. I know it has Alnico 5 rod magnets and a DC resistance of 13k.
I'm going to try a Tonestyler, that said does a 500k pot give a more broad sweep of volume too or the "taper of the sweep, and the brightness at the end of the rotation" only applies when used as a tone pot?

I was going to experiment with different cap values, now I'm going to see if that Tonestyler fill's my need. Time is the most important commodity for me, even the wealthy can't buy 5 minutes of it. lol

Impedance is frequency dependent, and thus very hard to measure. In general, high impedance pickups work better with high resistance pots. (And hence the common pairing of overwound pickups with 500k pots.) This is both for technical reasons relating to the behavior of the pickups under load, and for the fact that higher impedance pickups in general (overwound pickups, anyway) tend to be a bit warmer.

A tonestyler would probably be better off with a 250k pot. Why? You have a selection of many capacitances, so you don't need to go up to a high resistance to bypass the tone control, since you can simply select a low capacitance to achieve the same effect. The lower resistance range of a 250k pot will lend itself to a more useful taper.

 

[Zeus_Mutation]

Gotcha! Thnx

 

[ex-tension]

I've been reading so much I'm getting really confused. Hoping for clarity on the subject.
...

Speculating about it is going to confuse you more. Understanding a standart guitar control circuit will give you the definitive answers. A quick Google search returns these pages:
Invalid Link Removed
GuitarNuts.com - Understanding Volume and Tone Controls
Invalid Link Removed

 

[iiipopes]

I think the OP is actually asking about inductance, measured in henrys, as the alternative technical spec to simple DC resistance, which some boutique pickup manufacturers, like Bill Lawrence and TV Jones use, and which they say actually describes the performance of the pickup better than either DC resistance or Z-impedance.

Yes, since an alnico magnet is ferrous based, it will create more inductance and lower the resonant frequency of a pickup compared to the same coil with a ceramic magnet. We all found that out in the early '70's when one of the first pickup mods was an aftermarket ceramic magnet. You could unscrew the four screws on the bottom of a Gibson humbucker that had the cover removed and swap out the magnet. The problem was that those ceramic magnets had too high a gauss, and saturated the coil. The side effect was more top end due to decreased inductance of the pickup, and a little bit of distortion or harsh tone. The downside is that many great pickups were ruined when the alnico bar magnets were thrown away.

Larry DiMarzio exploited this with his original distortion pickup, using thinner wire to get more wire on the coil bobbin so the ceramic magnet would match better. In short order, Seymour Duncan created his Custom #5 pickup the same way, with thinner wire and a ceramic magnet with less gauss. I had an original Custom, and it was a great pickup: clean, clear, good top end, a little shy on the bass, perfect for darker sounding guitars.