Switches instead of pots

Is it possible, yes, but I'm not sure how well it will work. There's no accurate way to measure the volume reduction a resistor pair will provide. A typical audio taper pot will be at 15% resistance when the control is set at 50% rotation. My question is about the setting being fixed and will that be effective in all cases?

 

I mean all situations may not be covered by 2 volume levels.

 

What you do is take a DPDT On/On/On switch, externally jumpered to SP3T operation, and wire the input signal to the common. The first throw goes to ground, and the third throw goes to your output. The second throw goes to a trim pot mounted in the control cavity, and from there, to the output. An optional resistor can be placed across the output to simulate the load of having a pot. If there are no fixed resistive loads in the circuit, the resistor will be a necessity, to prevent hum when the bass is muted.

I agree with concerns about picking the right resistance to cover all situations. Variations in input impedance, as well as the tonality of various rigs at various volumes typically cause most players to want to vary their settings, and hence, "preset" based pickup selections tend to be impractical.

 

Don't see why not. Maybe a stepped rotary pot would work better, or maybe rig a 5 position Strat pickup switch.. You may be on to something, though it could get complicated with two pickups...

 

That's exactly what you need.

 

You could measure the resistance of the volume pot in several positions to help get the right resistor. Same with the tone pots. I'm not sure how effective it will be but I guess I only use a few settings anyway.

 

One configuration I really like with a two pu bass is a rotary switch pu selector + volume + tone.
The switch wired to select: neck, neck + bridge series, N+B parallel, bridge.
Having thrown this idea out- keep in mind that I favor single pickup basses or two pickups full-on.

 

Don't forget it takes 2 resistors. One resistor needs to go the ground, the other in series. This creates a voltage divider. Make sure t measure both sides of the pot.

 

No, you only need one. Series-only resistance works just fine. The only real reason that you need parallel resistance on volume pots is to allow the reduction of impedance to zero when you mute a pickup. Plenty of people enjoy ungrounded blend pot schemes, and the lack of parallel resistance can actually improve the performance of the pot.

In any case, those of you suggesting fixed resistors have the wrong idea. What you want is a trim pot. Fooling around with a fixed resistance is too much work, and impractical. A trim pot provides adjustability.

 

How would a trim pot be more work? It simplifies things greatly! All you have to do is get the initial setting dialed in before you put the control plate or cavity cover on, and then you will be all set. Should you find your setting to be unsatisfactory, later on, you can remove the control plate or cavity cover, and give it a tweak, without the need to desolder and resolder components, or worry about picking a new value. If you really wanted, you could even drill a hole in your control plate or cavity cover, and glue the trim pot in, so that it can be adjusted with a small screwdriver, without the need to remove any parts to access it.

 

You are going to have to remove your control plate or cavity cover MANY times, anyway, to find the right fixed resistance. You are also going to have to desolder and resolder each time you make a change. The trim pot is there to provide adjustment for your initial setup, and possibly a means of easily tweaking your setting if you decide that your choices did not work out, over time. It saves a lot of time and hassle, does not cost any more money, and does not take up any more space.