Advice please - Installing Passive switch in Modulus

[basszoned]

Hi All,

I hope this is the right forum for this request.

I have a Modulus Quantum 5, with Bart's..

Has anyone ever installed a passive switch in a similar bass? Is this something someone with basic skills can do? I have not had much luck finding someone in the area I trust to touch my bass.

I love the bass and the sound, I only want to do this for emergency purposes when the batteries die while on stage.

Thanks much !

[3506string]

Push/Pull knob.

[BitterRoot]

Originally Posted by 3506string

Push/Pull knob.

Will that work with any active preamp? How dose one wire that in?

[3506string]

Hopefully someone more knowledgeable can chime in, but I believe as long as your pickups are passive you should be able to wire a active/passive switch. You would just have to make sure that you can find the correct value volume pot. Best bass gear carries 250K, 500k, and 25K. You could also wire one of your eq pots for an active/passive switch if you have 50K eq pots.

You can add an active passive switch for active pickups but if the battery dies it would kill the output even in passive mode. I'm not 100% if this is correct so don't quote me on it.

The procedure for wiring the pot would be the same as a standard dpdt switch. There are quite a few threads on those. active passive switches

[line6man]

Originally Posted by 3506string

You can add an active passive switch for active pickups

No, you can't. There is no easy way to bypass the internal preamp on active pickups. You can, however, bypass onboard preamps, which are much more common than active pickups.

Assuming you have passive pickups with a preamp, it is usually possible to add an active/passive switch to bypass the preamp, under the condition that the volume pot(s) is working with the same impedance signal in both modes. You will need 250k/500k volume(s) running before the input of the preamp. If you have a 25k/50k/100k volume after the preamp, it's going to have to be moved before the preamp, and swapped for a higher value, so that the high impedance signal from the pickups does not get loaded down by the pots.

Active/passive switching can be done with a mini toggle or push/pull switch. The wiring is exactly the same in both cases.

[walterw]

+1, but "emergency passive" switching is pointless, if you pay any attention at all to your tone.

as long as you use a normal alkaline, you'll get plenty of advance notice as your battery gradually starts to get weak, in the form of a gritty, grungy sound.