active bass eating batteries?

[Dom in Dorset]

I'm re-stringing and setting up some basses for someone and they've also asked if I can help with another problem:
They have an active Yamaha bass, I don't know the model , it's a four string with two soap bar pick ups.
He noticed a few years ago that it seemed to be rather battery hungry so he went over to removing the battery when not in use. I've got two active acoustics that I keep the batteries in with no ill effects.
He thinks the problem is getting worse, the last battery survived three gigs before being consumed.
Any ideas?

[SteveO]

[quote name='Dom in Somerset' post='1050160' date='Dec 7 2010, 08:52 AM']I'm re-stringing and setting up some basses for someone and they've also asked if I can help with another problem:
They have an active Yamaha bass, I don't know the model , it's a four string with two soap bar pick ups.
He noticed a few years ago that it seemed to be rather battery hungry so he went over to removing the battery when not in use. I've got two active acoustics that I keep the batteries in with no ill effects.
He thinks the problem is getting worse, the last battery survived three gigs before being consumed.
Any ideas?[/quote]
The usual culprit for short lived batteries is leaving the bass plugged in, in this case I think the problem is the Yamaha. My Yam (375) also eats batteries, so much that I get fresh batteries every time I gig with it (which is not often). This has come up a few times in the past on here with yamaha owners. If I knew how to do it or could be bothered I'd see about measuring the current drain and comparing it with other basses.

Of course it could be that he's using the batteries that are 10 for a quid in poundland... A quick google shows that a Duracell 9v battery is about 580mAH, but you can get them as low as 100mAH

[henry norton]

Like SteveO says, actives are normally switched on when you're plugged in - the actives are wired 'on' all the time and plugging in usually completes the negative/earthing side of the circuit, so the first place to look would be the wires coming from the circuit to the jack socket.

[mart]

[quote name='henry norton' post='1050188' date='Dec 7 2010, 09:02 AM']Like SteveO says, actives are normally switched on when you're plugged in - the actives are wired 'on' all the time and plugging in usually completes the negative/earthing side of the circuit, so the first place to look would be the wires coming from the circuit to the jack socket.[/quote]

You can check this by putting a multimeter in between one of the battery terminals and its connector. With the jack lead not plugged in you should see no current going through the meter, but with the lead plugged in you should see a small but noticeable amount of current.

Actually, probably the first thing to check is this: is the jack socket stereo? If not, then the battery will be on all the time. You can modify this by replacing the jack socket with a stereo one, and linking the black lead from the battery to the "extra" tab on the socket.

[dan670844]

[quote name='SteveO' post='1050167' date='Dec 7 2010, 08:12 AM']The usual culprit for short lived batteries is leaving the bass plugged in, in this case I think the problem is the Yamaha. My Yam (375) also eats batteries, so much that I get fresh batteries every time I gig with it (which is not often). This has come up a few times in the past on here with yamaha owners. If I knew how to do it or could be bothered I'd see about measuring the current drain and comparing it with other basses.

Of course it could be that he's using the batteries that are 10 for a quid in poundland... A quick google shows that a Duracell 9v battery is about 580mAH, but you can get them as low as 100mAH[/quote]

I have a RBX374 that also does the same even without being plugged in, must be a characteristic of the preamp, don't use it anymore, really must put it up for sale!

[xilddx]

I think it's wired incorrectly. Can't remember what, but people on here have had the same issue installing onboard preamps incorrectly. Get a techie to look at it. There should be no battery consumption if there is no jack plugged in. A decent battery (I only use Duracell Procell) should last a few hundred hours.

[MarkBassChat]

[quote name='silddx' post='1051079' date='Dec 8 2010, 12:49 AM']I think it's wired incorrectly. Can't remember what, but people on here have had the same issue installing onboard preamps incorrectly. Get a techie to look at it. There should be no battery consumption if there is no jack plugged in. A decent battery (I only use Duracell Procell) should last a few hundred hours.[/quote]Yes, this is exactly this case. The rule is simple: no jack plugged in -> no battery consumption. Mart explained how the problem should be solved.
The preamp should not be connected to ground but to jack's third conductor that is connected to the ground only when a jack is plugged in.

Mark

[Dom in Dorset]

I've had a chance to take a look inside, the wiring looks pristine, I suspect all original, this is a drawing of the jack:
(my camera isn't up to the job)

[RAY AGAINST THE MACHINE]

Had problems with my Steinberger. It kept eating batteries,also the jack was faulty.
Got a repairman to sort it out. It's a tricky problem,so I'd say take it to repairman/woman.

[MarkBassChat]

[quote name='Dom in Somerset']I've had a chance to take a look inside, the wiring looks pristine, I suspect all original, this is a drawing of the jack:
(my camera isn't up to the job)[/quote]Looks good although I don't understand what is the meaning of the question mark on the drawing .
As Mart explained in[post="1050629"] post #4[/post] above testing the problem with a multimeter is simple. The problem can be caused by the battery connector shorted to the ground inside the jack (this also can be easily tested with a multimeter). If this is the case, you have to replace the jack.

Mark

[Dom in Dorset]

The question mark is because the wire goes into a hole pointing in the direction of the battery compartment. It's about 1 1/2" away, I can't be 100% certain that it goes to the battery (95%)

[mart]

[quote name='Dom in Somerset' post='1053714' date='Dec 10 2010, 09:00 AM']The question mark is because the wire goes into a hole pointing in the direction of the battery compartment. It's about 1 1/2" away, I can't be 100% certain that it goes to the battery (95%)[/quote]

From that picture it certainly looks like the wiring is correct. I'd do the multimeter test - to see what the current drain is without a cable plugged in (which, based on that picture, will be zero, I expect) and with the cable plugged in. If the preamp is eating batteries then it may be that somehow it is drawing a large current when it's switched on.

To check the current draw, twist the battery so only one of its terminals is plugged into the connector, and then put the multimeter between the other connector, and the other battery terminal. It doesn't matter which way round you put the meter. You'll need it set to a fairly fine setting, because the current should be a small number of milliAmps.

[mart]

[quote name='MarkBassChat' post='1053664' date='Dec 10 2010, 06:52 AM']....
The problem can be caused by the battery connector shorted to the ground inside the jack (this also can be easily tested with a multimeter). If this is the case, you have to replace the jack.

Mark[/quote]

I hadn't thought of that, but yes, there could be a short within the jack. Put your multimeter across the two pins (on your jack socket) that have black wires attached and measure the resistance - it should be infinite. If not, then replace the socket - Maplins will have a replacement for a couple of quid.

[Spoombung]

I have the same problem with my Iceni Bass. Batteries last for 3 weeks with minimal use

[xgsjx]

I've never seen a battery eating a bass before!


(sorry, I couldn't resist responding to the title).

Could it be a case of the jack socket being wired incorrectly or a loose strand of wire causing a short somewhere else in the compartment?

Like is said, get a lend of a multimeter & go testing. Hope you find it soon.