pots for phat cats

[marty_the_westie]

Hi. Does anyone know what pots your supposed to use for the phat cats? Are they 500k like humbuckers, or 250k ike singles?

[Kelsey]

Re: pots for phat cats

The SD schematic indiactes 500K, but I just had a Phat Cat neck pup installed in a Tele with the stock 250K pots, and it sounds good so far.

[Tweed]

Re: pots for phat cats

You could try 500k pots for starters, then solder a 1 meg resistor across the outer terminals of your pots...changing the value to 250k (or close enough to see how the PCs sound in that setup). Some like 500k, some 250k. Use whatever sounds best to you.

[theboatcandream]

Re: pots for phat cats

I'd imagine that 300k would work best... given that 250k are used for single coils, 500k for humbuckers... though gibson has used 300k or 500k in their humbucker equipped guitars.

[ArtieToo]

Re: pots for phat cats

You could try 500k pots for starters, then solder a 1 meg resistor across the outer terminals of your pots...changing the value to 250k (or close enough to see how the PCs sound in that setup). Some like 500k, some 250k. Use whatever sounds best to you.

Actually, it takes a 500k resistor to make it a 250k "load".

1 meg would make it 333.333k.

[theboatcandream]

Re: pots for phat cats

I know what the difference is with tone pots, but what's the difference between having 500k and 250k volume pots?

[ArtieToo]

Re: pots for phat cats

I know what the difference is with tone pots, but what's the difference between having 500k and 250k volume pots?

A guitar pickup is a small AC generator. The value of the volume pot controls how much "work" you're asking that AC generator to do. If it were an "ideal" AC voltage source, the amount of current, and the subsequent strength of the magnetic field, would increase as you lowered the volume pot resistance - or "load". In other words, your pickup would drive more current through a 250k pot, than it would through a 500k pot.

But . . . and it's a big but, the p'up is far from ideal. It has a practical limit on how much current it can push. So, you have a delicate balancing act between adjusting the load, (volume pot value), against the amount of current, (magnetic field strength), that the p'up can handle to find that right "tone". A 500k pot will give a humbucker a nice voltage swing, with a certain amount of treble. A 250k pot will "load-down" the p'up a bit more, and decrease the treble slightly. This can actually have a "smoothing", or nice effect, that you may desire.

Experimentation is the ultimate way to find the right value, but since it is difficult to keep changing pot values, relying on conventional wisdom works too.

I'll post a simple diagram showing how to build a simple pot "evaluator" in a few moments. (Dinner is ready.)

[ArtieToo]

Re: pots for phat cats

Here it is:



You don't even need to remove the other components from the guitar.
Just wire up a pot, with a series resistor, across the pup. Play with the "level" until you find that "sweet spot". Then, carefully, without moving the knob, cut one of the wires to the pot, and measure its resistance with a meter.

That will be the value of pot that you want. Obviously, you'll need to round the figure to commonly available pots.

The series resistor isn't absolutely necessary. It just prevents you going all the way to "zero". The values I show above allow you to "load" the pup with anything from 1.1 meg to 100k. That should cover any range that you'ld need. You can certainly skip the 100k resistor if you want, in order to make the circuit a bit easier. Just remember that you can go to far.

Won't hurt a thing - it'll just give you values lower than are usable. Might actually be interesting to see what your pup sounds like with a 25k load - or lower.

[ArtieToo]

Re: pots for phat cats

Here's another way that uses a simple 3-way switch:



This way just tells you which of the standard 3 pot values, 250k, 500k, and 1 meg, works best for you. No need to measure resistance.