Active pre batteries going flat when no cable attached

[fleabag]

This is a bit more awkward then it seems, as the bass has 2 mag pups and a piezo bridge,  and the bridge G intonation ran out of adjustment, and i dont really use the piezo, so i changed the bridge to a regular one.  There were 2 wires to the original bridge , one for the earthing as per standard basses  ( bare wire squashed when mounting the bridge ) and one that was soldered to what look like some tracks underneath the piezo brisdge , though they're not gold, but silver

 

I  left the normal black earth wire under the new bridge, obviously, but the  black piezo wire i coiled up and left inside the hole that it emerges from, which incidentally, is the same hole that the regular earth emerges from.  Is this my problem ?  The batteries are brand new 9v's   ( one each for Piezo and Mags  i presume ) and are going flat with  bass cable removed in less than a week  after a full charge

 

 

[Woodinblack]

1 hour ago, fleabag said:

This is a bit more awkward then it seems, as the bass has 2 mag pups and a piezo bridge,  and the bridge G intonation ran out of adjustment, and i dont really use the piezo, so i changed the bridge to a regular one.  There were 2 wires to the original bridge , one for the earthing as per standard basses  ( bare wire squashed when mounting the bridge ) and one that was soldered to what look like some tracks underneath the piezo brisdge

 

 

 

Not sure on the wiring there, but yes, the general idea if is a new problem started when you changed something, it is almost certainly the thing you changed.

 

Generally the switching of the battery is done between the regular earth and the negative terminal of the battery, and i suspect what you connected to the bridge now connects those two where it didn't before. Not sure why the piezo wire is still there if you removed the piezo, maybe it is connecting something.

The only place the battery negative should go is to the jack socket and not be connected to the earth until the plug is in.

[fleabag]

Maybe that piezo wire needs to touch the underside of the new bridge ? It isnt right now.  What i can say is there is only pot that affects the piezo, which is it's own volume.  There is no tone pot for it, although there is a 3 way blend switch for mags only , piezo only, or blending both

[Count Bassy]

23 hours ago, fleabag said:

Maybe that piezo wire needs to touch the underside of the new bridge ? It isnt right now.  What i can say is there is only pot that affects the piezo, which is it's own volume.  There is no tone pot for it, although there is a 3 way blend switch for mags only , piezo only, or blending both

More likely, I'd have thought, that the Piezo 0v wire is touching the bridge and the bridge is earthed to the socket, so it is seeing a link between the Socket Earth and the Socket ring - which is what normally turnes the whole system on. SHould be fairly easy to find whatever it is.

[fleabag]

Nah CB,  the Piezo wire is not touching the bridge, as noted in your quote,  so i was thinking, maybe incorrectly, that it DOES need to touch the underside of the bridge, which is the opposite of wha you say, but that also doesnt seem like a solution either.

 

Looks to me like i need to contact my  mate Dave Smart, who's some wizard extraordinaire with electronics

[Hellzero]

Maybe giving the brand and model of the bass could be a great idea as it might help a LOT !

[Woodinblack]

The only reason that your battery can drain is that the negative terminal of the battery is being connected to the earth of the bass. The only place that the black wire from the battery should go is to the jack socket, but it seems like it is shorting elsewhere. Find that, and you solve the problem.