Re: Please explain pot resistance

Think of it this way... zero resistance between the hot and ground
wires of the pickup would be a dead short. That would mean NO output.
Turning the pot down to zero will essentially give you zero ohms, or a
short across the pickup leads. 250,000 ohms of resistance will let a
lot more current pass through. That's because, although the two leads
are technically connected, the pot is 'resisting' the flow of current
between the hot and ground. Jumping up to a 500,000 ohm pot means even
more resistance between the two, or less conductivity. So at full
volume, there's less conductivity between the two wires. Even less
when using a 1 meg pot.

A pot, or resistor RESISTS the flow of current. By turning it down,
you're basically shorting out the output, gradually until you get no
volume. The high frequencies are affected more than the lower
frequencies. That's why the sound gets warmer as you turn the volume
down on the guitar.

I've heard of custom pots that remove all resistance at full volume. I
think Fender used/uses them (???). At full volume, there was zero
resistance, which effectively removes the pot from the circuit,
supposedly to maximize volume and minimize high-frequency loss.

Depending on the guitar type, pickups, and how you set you amp
controls, you may not notice a difference by switching to 500K or 1M
pots. On my old Gibson Grabber bass, I removed the tone control and
replaced it with a 2-way switch which allows me to bypass the volume
pot altogether. I don't notice any increase in treble when doing so,
but I also don't use a great deal of treble in my bass tone to begin
with.

~jp

GuitarPsych wrote:
I hear about people changing out their 250K pots for 500k or 1M k pots
to increase treble. For some reason conceptually this seems backwards,
which makes me think I don't fully understand. It seems if the
resistance of the pot is higher, then less highs would get through it to
the amp. For instance, it seems a 0k pot would have the widest range of
signal passing through it, similar to if there were no pot at all.

Or wait, I just thought of something. When a pot is referred to as
250k, does that means it is adjustable to let between 0 to 250 k signal
through it?

Did a light bulb turn on over my head or am I still walking in the dark?

.

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