RBX 375 devouring batteries

Riddleweaver · #1 01-11-2013, 04:38 AM

That beast eats a new 9V alkaline battery in 20 hours of playing. I have no idea what could be causing the problem. Preamp? Bad cable works? Has anybody had this problem?

MrLenny1 · #2 01-11-2013, 05:41 AM

Make sure you disconnect the guitar cable when not using it.
The pre-amp is on when the cable is plugged in causing battery drain.

Stealth · #3 01-11-2013, 06:19 AM

Aside from what MrLenny1 says (and it's absolutely true), there's one other thing.

I had this problem with that 6-string I talked about in the other thread. In order for an active bass like the RBX375 to work properly, it has to have a TRS (so-called stereo) output jack, and it closes the circuit whenever you have a cable inside. Normally the TRS contacts are soldered like this:

TIP: output from volume control
RING: minus contact (black) from the battery compartment
SLEEVE: ground from preamplifier, casings of all pots and the pickup ground and cold (non-signal) wire.

That bass had the minus contact from the battery soldered to the sleeve so it would suck the battery dry in two weeks because it was constantly connected. It was a two-minute job with the soldering iron and worked flawlessly since. Yours may just have been carelessly soldered at the factory.

Riddleweaver · #4 01-12-2013, 08:00 AM

Is it possible to make it work like a passive? Without any batteries?

Rune Bivrin · #5 01-12-2013, 08:34 AM

Quote:

Originally Posted by Riddleweaver

Is it possible to make it work like a passive? Without any batteries?

It definitely is. The pickups are regular passive pickups, so if you wanted to you could rip out the electronics and go passive. But you'd probably have to change the pots to higher value ones.

I have an RBX 375, and the battery lasts literally half a year, which is probably a few hundred hours of playing time. If your bass runs down the battery in 20 hours of playing time there's definitely something wrong. But as mentioned, don't forget to unplug the cable from the bass when you put it down!

Troph · #6 01-12-2013, 09:48 PM

I have an RBX375 that chews through batteries as well. I have read others with the same problem. Seems to be a common issue/gripe with these.

And no, it's not because we're leaving the input jack connected...

Riddleweaver · #7 01-13-2013, 12:13 AM

I'm prob. gonna turn it passive, way cheaper then the batterie -_-

Stealth · #8 01-13-2013, 04:28 AM

As I explained before, it's not a specific RBX375 issue, either the output jack been improperly wired or the batteries you buy are flat to begin with. The more expensive the battery, the longer it usually sits on the shelf because people didn't buy it and it simply loses charge - unless it was bought at a specialized battery shop because they usually stock higher quality batteries (quality and price don't always follow each other, after all). There's also a small chance the preamp chip malfunctioned, but warranty should take care of that.

Either way, here's a possible passive wiring for an RBX375, as someone else on Talkbass wanted to passivize the instrument and see how it sounds a few weeks ago. I kinda liked the sound.

Riddleweaver · #9 01-13-2013, 08:54 AM

I've spend five euros on the alkaline battery, bought it in a regular mall, not a specific shop. But it happened twice. So yeah, I doubt it's about the battery. I have never done anything with electronics so yeah, I'll try to get somebody who can read this stuff xD

Riddleweaver · #10 01-15-2013, 03:46 AM

Quote:

Originally Posted by Stealth

As I explained before, it's not a specific RBX375 issue, either the output jack been improperly wired or the batteries you buy are flat to begin with. The more expensive the battery, the longer it usually sits on the shelf because people didn't buy it and it simply loses charge - unless it was bought at a specialized battery shop because they usually stock higher quality batteries (quality and price don't always follow each other, after all). There's also a small chance the preamp chip malfunctioned, but warranty should take care of that.

Either way, here's a possible passive wiring for an RBX375, as someone else on Talkbass wanted to passivize the instrument and see how it sounds a few weeks ago. I kinda liked the sound.

Can you make a scheme like that but for the active stuff?

Stealth · #11 01-15-2013, 12:37 PM

I haven't taken the RBX375's preamp apart, so I have no idea how the whole thing is wired. All I know is the sequence is pickups > passive blend (MN500K) > preamp with bass and treble > active volume (A25K) > output jack.

The blend is a high-impedance pot because it connects to pickups. The volume is a low-impedance pot because it comes after the preamp.