My Favourite Active Bass And Guitar Battery Hack

[@gerodoth]

all over the world problems with backstage absence are the same. great tips, thanks.

[@hallanvaara6106]

Another great tip! Thanks Rob! I just checked my Stingray battery before the gig tonight.

[@rlbink2498]

Active bass battery woes 1) the battery has leaked and corroded the circuit after I left it in for a long time 2) the battery drained when bass was left plugged in amp with power on too long and 3) to solve this problem, I installed a removable battery case . Putting the battery in and out of the case led to the contact wires to the removable case breaking. Bass hasn’t been used for months now 😢

[@simoncolvex]

great info. And you answered my question right at the end around adding an on/off switch at the battery. Danger averted! Thanks.

[@RobMods]

Ha ha. Yes, not a good idea! A very well known high end guitar company bought out a bass back in the 90's that had a battery-off switch. It send a huge pop through the amp/PA. I have a mate with one. A very nice bass, but he got sick of getting yelled at by sound techs, so I modded it to work as a regular true bypass switch. FWIW, I don't believe that company have brought out any more basses since then...

[@trbbass]

Thanks a lot for sharing! Can I add an Active/Passive switch on my Yamaha TRB? Actually, the main question is that TRB pickups are initially Passive and an onboard preamp joins to the circuit? How can I have Active/Passive switch on an original Active bass?

[@RobMods]

You should be able to, but whether it is easily achieved and retains blend and volume functionality is another matter. The old TRBs I've worked on have individual fet buffers for all four coils! (Two per pickup.) This arrangement is essentially an active blend control, sort of like I did with Project Berocca. Then a low impedance volume control on the ouput of the preamp. (I'm not sure all TRBs have this set up though.) With typical active/passive set ups, you have hi impedance (passive) blend and volume controls before the preamp's input. This way, when bypassed, the blend and vol still work. If your TRB is like the one's I've seen, having the blend and vol controls still available in passive mode would be quite difficult to make happen. Also, I think realistically, the pickup coils would have to be wired in series to have a good tone and output as passive pickups.

[@trbbass]

​@@RobModsThank you very much! I understand completely what you mean. I try to work on it and find out! Thanks again.

[@CaptainWrinkleBrain]

@@RobModsI’m installing an Artec QDD2 (active onboard distortion) into my MiM strat with stock, passive pickups. I’ll have the pickups run through a passive treble cut+bass cut dual concentric pot, then 500k master volume, then the distortion before the output. Do you think I’ll have issues with impedance or anything else? I have a diagram

[@peternoya]

I really appreciate all this informations. Thank you so much.

[@RobMods]

Thank you Peter.

[@toddbrittain1060]

Rob, apart from the great information, that is the nicest looking Maton JB IV bass I have ever seen !

[@RobMods]

Ha ha. Yes it was a score. I bought it 9 or 10 years ago from its first owner. It is my main gigging bass and it is the one bass I'd keep if I had to. (Yes, I'd keep this over my '73 P!) It was all original down to the jack and wiring, case etc etc. But I have replaced the P pickup with an under wound alnico. Plus I have a fet pre in there as well... It is so good mate. It has the thickest, meatiest mid range of any bass I've played!

[@Expedient_Mensch]

Nice one mate. Actually useful advice. Thanks a heap.

[@omarrosas7210]

Cool video, I always wondered how to put a circuit to turn off the preamp, I ask because I built a 70s musicman pre, it sounds wonderful but sometimes it distorts, can you do a video about that?

[@RobMods]

Hi Omar. There is a couple of videos already on my channel where I work on vintage stingray preamps, so check ' em out. I'm not sure what would cause yours to distort. It could be many reasons... A dry joint, a faulty pickup, a low battery, a damaged op amp, a faulty pot or battery snap. Hard to say...

[@mossaagent]

Thanks sir..

[@RobMods]

My pleasure mate.👍

[@davidking519]

excellent video. thanks!

[@uriahvoltairealt]

I keep all my new 9v batteries in old medicine bottles. They fit perfectly and they keep them from making contact.

[@RobMods]

That's a great idea! When I have to use a 9v from my gig bag it's usually got really old masking tape on the top that I have to peel off, lol.

[@Bassman1999]

Excellent thank you! 👍

[@RobMods]

Thanks Keith!

[@germinal_ok]

great !!!!!!!!!!!!!!!!

[@torsens]

I've tried this hack but it seems like my EMG equipped guitars drop around 1 volt compared to measuring directly from the battery

[@RobMods]

Hmm, probably a voltage drop across a reverse polarity protection diode. It's very common to use a silicon diode in line with the 9v rail and there's a drop of 0.6 to 0.7V. You can still check the battery though. Just take this into account if course, when you do so.

[@rebeccabarbera6323]

Will it work with any acoustic?

[@RobMods]

As I mentioned, there are a few exceptions I've come across. Matons have a different jack wiring and power arrangement. And recently I worked on a Vox semi-acoustic that was actually powered with super capacitors and charged with a usb cable, so this won't work for that I'd say. But yeah, for just about any acoustic with a 9v battery, I think this will be fine. A multimeter has a very high input impedance, so there's no harm in trying as it won't do any damage simply probing the ring and sleeve. Cheers!