500K vs 250K tone pot

[johnallg]

Martin, it is a 0.047uF cap, not 0.47uF. Also, capacitors do not have dc resistance, but ac impedance, which is frequency dependent.

[aceonbass]

Not everyone can be good at everything. Some people are better served by letting a pro do the work. Some of these questions indicate that some should put as much distance as possible between them and a soldering iron.

[coolhandjjl]

One thing I have found out is with the tone pot dialed on full, the tone cap is not yet doing anything. Only when you begin to dial down the tone pot does the cap come into play. So a 500K pot dialed down some will have a different effect than installing a 250K and leaving it on full.

Not exactly related to tone pots in and of themselves, but has anyone ever experimented with a V/V/T configuration, and with a switch for selecting series wiring on the pups?

[bassduke49]

John Luke, you coming down to Milwaukee for the Confluence next weekend?

[coolhandjjl]

Paul- we haven't decided yet. My wife recently lost her job (IE Cobra = $1425/mo) so we're practicing austerity measures right now.

[bassduke49]

Yikes!

[Wiker]

One thing I have found out is with the tone pot dialed on full, the tone cap is not yet doing anything. Only when you begin to dial down the tone pot does the cap come into play. So a 500K pot dialed down some will have a different effect than installing a 250K and leaving it on full.

Not really. 250K Ohms is 250K Ohms. It doesn’t matter if it’s a 250K pot at full, 500K pot dialed down to 250K, or a fixed 250K resistor. It’s just that a "500K pot dialed down some" will likely be way off 250K, and therefore not compare to a 250K pot at full.
A 500K logarithmic/audio pot tappers off very fast at first. The resistance is down from 500K to 150K-200K during the first 1/4 turn, so it’s very hard to put it at 250K without a multimeter.

[tmossman]

... has anyone ever experimented with a V/V/T configuration, and with a switch for selecting series wiring on the pups?

I have my 4004 wired (copied from cj's) with three position slide switches (for each pickup) that are configured series(15.2), parallel (3.9), and coil-cut (7.eight). I played with having series and parallel switching between the pickups as well but dropped it as I could not hear any difference when switching.

[Wiker]

Not everyone can be good at everything. Some people are better served by letting a pro do the work. Some of these questions indicate that some should put as much distance as possible between them and a soldering iron.

mm...
Some of the questions indicate that not everyone is well versed in guitar electronics and electronics theory. Myself I’m not very good with electronics theory, but I do quite well with a soldering iron. And, no one will get better with the iron if they keep it at a distance.

[coolhandjjl]

One thing I have found out is with the tone pot dialed on full, the tone cap is not yet doing anything. Only when you begin to dial down the tone pot does the cap come into play. So a 500K pot dialed down some will have a different effect than installing a 250K and leaving it on full.

Not really. 250K Ohms is 250K Ohms. It doesn’t matter if it’s a 250K pot at full, 500K pot dialed down to 250K, or a fixed 250K resistor. It’s just that a "500K pot dialed down some" will likely be way off 250K, and therefore not compare to a 250K pot at full.
A 500K logarithmic/audio pot tappers off very fast at first. The resistance is down from 500K to 150K-200K during the first 1/4 turn, so it’s very hard to put it at 250K without a multimeter.

I think it has something to do with the tone pot having all three lugs being used, each side of the resistive arc, plus the wiper. In a 500K pot at 250 ohms, you have 250 on either side of the wiper, but with a 250 on full, you have 250 on one side, and close to 0 on the other.

[coolhandjjl]

I think it has something to do with the tone pot having all three lugs being used, each side of the resistive arc, plus the wiper. In a 500K pot at 250 ohms, you have 250 on either side of the wiper, but with a 250 on full, you have 250 on one side, and close to 0 on the other.

My bad. It is just the vol pots that use all three lugs.

[MichaelStewart]

Not everyone can be good at everything. Some people are better served by letting a pro do the work. Some of these questions indicate that some should put as much distance as possible between them and a soldering iron.

mm...
Some of the questions indicate that not everyone is well versed in guitar electronics and electronics theory. Myself I’m not very good with electronics theory, but I do quite well with a soldering iron. And, no one will get better with the iron if they keep it at a distance.

+1

[coolhandjjl]

Here's another interesting tid-bit I discovered- Dropping the volume pots actually smoothens out the pickups' resonant peak. I actually prefer this method of tone control over dialing down the tone pots. On the stock Ric audio (log) taper vol pots, it's like going from 10 down to 7. On my new 250K linear taper vol pots, it's right in the middle of the sweep.

[analogpackrat]

There's a lot more going on in a guitar (and amp input) than just a few DC resistance values and a tone cap. The pickup has inductance in the 1-10H range as well as parasitic capacitance (one of the reasons scatter wound pickups sound different). Then there's the cable with its parasitic capacitance and finally the amp's input. What you typically see with an electric guitar is not a flat response up until the tone control cutoff frequency, but rather a response with a resonant peak which is due to interaction of the inductance, capacitance, and resistance of the entire guitar-cable-amp input circuit.

Here's a nice web page that gives some examples of the effect of a few of these variables--primarily the cable capacitance:

http://terrydownsmusic.com/technotes/gu ... cables.htm

And another one:

http://buildyourguitar.com/resources/lemme/

None of this touches on the vibrating string in magnetic field stuff which is also very interesting. The shape of the magnetic field and the placement of the pickup along the vibrating string is a huge factor:

http://www.till.com/articles/PickupResponse/index.html

If you want to play with the pickup/string effects try this out:

http://www.till.com/articles/PickupResp ... index.html

Fun stuff!

If you don't like math, avoid this last link...

http://online.physics.uiuc.edu/courses/ ... Fall09.pdf

[coolhandjjl]

Great links. Thanks.