WhyNot 1MOhm pots and beyond??

C

clownmanus2000

New member
Im getting somewhat agrivated by the lack of precice explanations as to how higher variable resistors effect output of my pickups.
My addiction to false harmonics has got me wanting for forum memebers here to talk me into using 1MOhm pots with my various setups.
Are there manufacturers who can provide resonably priced (Knerled-i belive it the term)pots in 250/500 and or 1MOhm or above.
Every damb technical webpage ive located fails to define their terms when describing what takes place durring "signal bleeding to ground". Or simply ambiguous terms,
I want to start a discussion on this . Please refer me to other posts as well.
thank you
Seymour Dunkan Performer Series Scortchers for Strat
 
Re: WhyNot 1MOhm pots and beyond??

Hi clownmanus2000; welcome to the forum. Its really sorta simple. I wouldn't call it "bleed to ground". Its a question of "load". In the context of a guitar, a pickup is a small AC generator. Like the Alternator in your car.

Although, an easier analogy to visualize, is the flywheel on an engine. No flywheel at all, (no load - no pot), would tend to vibrate and shake the car apart. A real heavy flywheel, (100k pot), would smooth things out at the expensive of acceleration. Its a balancing act.

Here's where the technical aspect starts to get, well . . . technical. The value of the pot also controls how much current flows through the pup. The current controls the strength of the magnetic field thats generated by the strings vibration. Not to be confused by the magnetic field created by the magnet. The current that flows through the coils influences the output and frequency response of the pup.

So . . . you can somewhat alter the character and output of the pup just by what value of pot you use. 250k for singles, and 500k for 'buckers are good starting points, but ultimately, personal experimentation is the best way to hone in on what you like.

In just a moment, I'll add another post showing how to make a dirt simple pup load tester. BRB. :)
 
Re: WhyNot 1MOhm pots and beyond??

Ok, here's a simple pot test that anyone can perform to answer this question for themselves. Using this diagram, the pup is at full volume all the time. The only thing the pot does is change the effective value of the pot load.

The lower limit is simply the value of R.
The upper limit is the value of R plus the pot value.

So, using a 100k resistor and a 1 meg pot, the load would vary from 100k to 1.1 meg.

Using a 250k resistor and 250k pot, the value would vary from 250k to 500k.

And so on, and so forth. This is a real simple way that folks can decide for themselves what pot value best suits their needs. Hope this helps. ;)

Artie

pot_test.jpg


And remember, this works with any pup installed in any position. ;)

Edit: Add the resistor and cap shown at the bottom to simulate a tone control on "10". Or, simply add a true tone control so that you can hear the affect in real-time.
 
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Re: WhyNot 1MOhm pots and beyond??

If you have a meter, and make a simple cord that consists of a standard 1/4" guitar jack on one end, and a pair of "banana plugs" on the other, (all available at Radio Shack), then after you dial in your perfect pot setting, plug the cable into the guitar jack, and the bananas into the meter, on ohms, and "snip" the black wire that goes to the pup.

Now you have your perfect pot value. You will, of course, have to match it to the closest "standard" pot value.
 
Re: WhyNot 1MOhm pots and beyond??

If you're looking at this thread, and its around 8:30 EST Sunday morning, hit F5 to refresh your browser. I corrected a mistake in the drawing. :)
 
Re: WhyNot 1MOhm pots and beyond??

Thanks Artie! Great info as always.

For me, it's real simple: treble will bleed through any pot, even if the pot is on "10" and bleed to ground never to be heard from again.

A guitar with no pots at all and with the pickups connected directly to the output jack will always be brighter than the same guitar with volume and tone controls installed because the volume and tone controls leak or bleed highs to ground.

1 meg pots will "block" that treble from "escaping" to ground more completely than 500K and 500K will block that treble from escaping to ground more completely than 250K.

Most guys who play Strat single coils would find them to bright with 500K pots or 1 meg pots...we actually prefer allowing a little treble to bleed to ground.

What you settle on is up to you! If you experiment with all three values and settle on 1 meg that's fine.

Your tone is your tone just like no one should tell you what looks good...you decide for yourself.

Personally, I like 500K with humbuckers and 250K with single coils.

But I've tried 500K pots with some particularly overwound single coils and prefered 500K with those...the 500K value retained the glassy, chimey treble frequencies and made those overwound single coils sound more like what I'm used to from a stock Strat.



Lew
 
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Re: WhyNot 1MOhm pots and beyond??

Lewguitar said:
Personally, I like 500K with humbuckers and 250K with single coils.
Click to expand...

Yup . . . me too. Although, I have gotten a little spoiled by this variable control on my Genny. Its interesting to be able to dial-in very subtle tone changes.

And, while we're on the subject, I think its important to note that whatever knowledge I have in this area, came originally from folks like Lew, and Kent S, and Robert, et al. And the great tech tips, schematics and FAQ's on this webpage. All I do . . . is draw pretty pictures. ;)

(35 years of electronics experience helps, but applying it to guitars is all thanks to this forum and website.)

Artie
 
Re: WhyNot 1MOhm pots and beyond??

Thanks Artie! But one diff I see between you and I is that you can understand this stuff in technical terms...I just know what works and sounds good! :laugh2: Lew
 
Re: WhyNot 1MOhm pots and beyond??

I'll trade my knowledge for yours any day.

I assume the guitars and amps go with the knowledge. :laugh2:
 
Re: WhyNot 1MOhm pots and beyond??

ArtieToo said:
I'll trade my knowledge for yours any day.

I assume the guitars and amps go with the knowledge. :laugh2:
Click to expand...

I dunno...this post or yours just made it into the vault ! Lew
 
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