How much is too much resistance ?

[andeeeroooo]

Hi, I’ve been working on a wiring Project where resistors are being used to block the signal path in one switch position, but then allow the signal to come through in the other. How much is too much resistance that will kill the signal from a pick up? I’m attempting this on a bass guitar, both pick ups seem to measure about 10.6 ohms . My schematic seems to work in theory, with the wiring layout program, but is 100 ohms resistance going to effectively kill the signal? Does anyone know what a good resistor value would be to use to allow signal to come through when needed, as the shortest path, but then act as a limiting device to prevent the connection in the other?
Thanks, any help would be greatly appreciated

[newey]

Aug 3, 2024 10:20:26 GMT -5 andeeeroooo said:

How much is too much resistance?

How long is a piece of string? The answer is "It depends . . ."

Adding any resistance in parallel with the signal will cut output to some extent, it's like setting your volume control in a fixed position at something less than "10". Well before you would get to the point of "no output" you would get to a point where the output would be useless to you, and before that, you'd hit a point along the way where it sounded "meh". The type of pickup(s) in question will matter as well.

You can sim these sorts of things using JohnH's "Guitarfreq" software. Or you can experiment IRL, using a resistor substitution box (Simple enough to build: a box of some sort, two jacks and resistors of different values). Another way is to turn the volume pot down to the point you want, and measure the resistance across it at that point. Chose a resistor value close to that value.

But the more basic question is: "Why?" Typically, switching a resistance in/out is done for one reason only, to better match the outputs of two different types of pickups, so that one doesn't overpower the other. If that's the purpose, fine. If it's something else, why do it?

[andeeeroooo]

Hey Newey, Thanks for the information, some of the things that you said seem like they would help trying to sort this out. I’m trying to design a circuit where things will still function correctly, and the signal is not lost in certain switching positions

[JohnH]

These kind if relationships tend to be a fairly soft sliding scale. Any high resistance in parallel with a pickup will tend to soften the tone, and gradually diminish it. At the other extreme, any low resistance in parallel will still let some sound through.

The same is true with resistance in series with high resistances still letting some through and low resistances blocking a bit.

Your pickups sound like they are probably around 10k ie 10000 Ohms? My guess is that x100 or x1/100 of that would let through or block most of it depending what its connected to.

But what's the overall design goal? Can it not be achieved by switches?