Installing an active passive switch.

[rapscallion]

Hi guys. I have a Cort GB34 with active preamp, but I'm wanting to install a switch to send the MM pickup either hot to the output, or through the preamp. I've been to maplins and bought a DPDT togglre switch, but I'm confused as to how to wire it, because there are six posts under the switch - [url="http://www.maplin.co.uk/Module.aspx?ModuleNo=2340&DOY=19m7"]http://www.maplin.co.uk/Module.aspx?Module...40&DOY=19m7[/url].
If any of you could help I'd be apreciative
Thanks,
Will

[BOD2]

For reference, the metal parts on the switch are called the switch "contacts" or "poles"

You can check what the switch does with a multimeter.

With a DPDT switch you can think of the 6 contacts as 2 rows of 3 contacts like below

1 2
3 4
5 6

Contacts 3 and 4 are the "common" contacts and operating the switch changes which other contacts these common ones are connected to.

In one state, the contacts are connected as follows -

3 to 1
4 to 2

When you operate the switch again the contacts are connected as follows -

3 to 5
4 to 6

The two sides of the switch (i.e. 1,3,5 and 2,4,6 do not connect to each other at all).

[rapscallion]

so I would be taking the wires from the pickup to 3 and 4? then to the preamp from say 1 and 2, and to the output from 5 and 6?

can i attach two sets of wires to the output? sorry, i'm a major electrical n00b

[BOD2]

Is this the circuit diagram for your bass ?

[attachment=11066:GB34A.pdf]

[rapscallion]

certainly is!

[BOD2]

Ok - I think this will work. Have a look at the diagram and make sure you understand it before you do anything.

[attachment=11231:ByPass.jpg]

First of all this circuit should allows both pickups (including the blend and volume control) to bypass the preamp and got straight to the output. There's no other way to do it.

The only wires you need to alter in the original circuit are the red wire from the volume control to the preamp and the white wire from the jack to the preamp. LEAVE ALL OTHER WIRES UNTOUCHED. I've not shown them in the diagram as it would get too complicated. I've had to show the "white wire" in yellow in order for it to show up on the diagram.

What the switch does is flip the output from the volume control between the preamp or the jack, while at the same time disconnecting the preamp from the jack.

Note that the battery is not disconnected so it may still draw power even when the preamp is bypassed. This shouldn't be a problem, just remember always to unplug the bass when you're not using it.

If you've any questions then ask away.