USB rechargeable onboard preamp power- Why not more common?

[krfoss]

It happened to me. Mid set and my onboard preamp batteries start dying and giving off that AWFUL sound that we all know. The MTD 635 doesnt have a passive switch, so I have to suffer through it with a lighter touch... Alas, no indicator anywhere to tell me my batteries are weak...

I've seen a bass out there that has a USB input on the back to recharge the internal battery. Why isnt this the norm on new basses with onboard active preamps? If the user could have the option to plug in their bass and charge the battery the night before a gig they could have the confidence to do it without pulling the battery, testing it, throwing away good batteries, or hoping for the best. I would love to see this as the norm.

 

[Geri O]

Good question. There was a John East preamp made for Precision basses that was a drop-in unit, requiring no extra mods to the body of the bass. It used a rechargeable battery system that was changed via USB (not sure of the method, USB jack or the 1/4” jack?)

At any rate, it was discontinued not terribly long after it was introduced. It’s still on the website listed as unavailable. Go figure.

On the dying batteries note, I change my basses’ batteries every 4 months. In all the years, I’ve never suffered battery failure.

Actually, I did suffer a suspect battery failure once. In a Stingray with a single 9V, the battery was brand new. Sounded fine at the house, the next morning during the church band soundcheck, the bass level got weak and I thought, can’t be the battery. But when I checked the battery, it was very hot. I mean, nearly burning fingers hot. A bad one out of the package, apparently. Thankfully, the church had 9Vs on hand, I put in a new one and I was good to go. I’d be dr seen this before and I haven’t since.

 

[JakobT]

There may be technical reasons as well, but from a practical standpoint the ordinary battery solution is much to be preferred, IMHO.

If you have a preamp with a USB-rechargeable battery and that battery dies for whatever reason, you’re stuck. With a preamp that uses ordinary 9V batteries you can just pop in a new one between songs and be good to go. When I still owned active basses, I always kept a spare 9V battery in my gig bag for that purpose.

It’s also fairly easy to avoid the having the battery die on you unexpectedy - just change it every six months or so. Unless the l bass is left plugged in for extended periods of time, there should then be plenty of juice on hand at all times. It’s also a good idea to use a Sharpie and mark the replacement battery with the date (you will forget what time you last put in a new one), and check the date on the battery before every gig.

For those who find it wasteful to leave a large safety margin, a solution to test the battery easily in situ is the Keith McMillan Batt-o-meter: https://www.thomann.de/gb/keith_mcmillen_batt_o_meter.htm

In any case, with an active bass you will always need to prepare before a gig, either by checking/changing the 9V battery, or (hypothetically) recharging the preamp, so it’s really a distinction without a difference, except that with a replaceable 9V battery you have options if the battery dies unexpectedly - provided you’ve remembered to bring a spare, that is.

 

[el murdoque]

It happened to me. Mid set and my onboard preamp batteries start dying and giving off that AWFUL sound that we all know. The MTD 635 doesnt have a passive switch, so I have to suffer through it with a lighter touch... Alas, no indicator anywhere to tell me my batteries are weak...

I've seen a bass out there that has a USB input on the back to recharge the internal battery. Why isnt this the norm on new basses with onboard active preamps?

Imagine the following scenario: You forgot to recharge your bass and thought it'll be fine for the gig, but mid set, your batteries start dying and giving off that AWFUL sound that we all know.
Had you brought your old MTD 635, you'd simply play with a light touch until the song's over and then quickly pop in a new battery. Not so easy with a fixed battery and USB charging.

The solution to make your life much easier is rather inexpensive: It's a sharpie.

Write the date the battery went in on the battery.
The next time you kill one, you will know exactly how long it lasted. The next time you wonder how much longer you might go, you can check the date it went in.

 

[ole Jason]

The Fishman Fluence setup (on guitar) is the only USB charged system that I've seen become somewhat common although Fluence pickups can also work with a battery.

 

[superheavyfunk]

If the user could have the option to plug in their bass and charge the battery the night before a gig they could have the confidence to do it without pulling the battery

You’re not really solving the core issue by using a USB rechargeable technology; you’re instead creating a new problem as has been mentioned by the two previous members, in that you won’t be able to recharge fast enough in between songs if your preamp dies. It’s much better instead to simply carry an extra battery with you and swapping it out when necessary.

If you did want to use newer technology to solve this problem, a solar panel - while a bit ridiculous - might work better, provided the stage lights are enough to trickle charge your preamp’s power supply while your bass is onstage. Again though, this would be a bit overkill and probably not feasible.

 

[mikewalker]

Rechargeable lithium 9V

then add a USB port trickle charger circuit (maybe with an LED that starts to flash discreetly when it drops below a certain voltage)...

If you have time, plug in the charger. In an emergency, just pull the 9V out and replace with any standard 9V.

Problem solved?

here is a link to an example off-the-shelf power drain sensor... BassXX Power-Elektronics – BassLab – Basses & Guitars

 

[swink]

In any case, with an active bass you will always need to prepare before a gig, either by checking/changing the 9V battery, or (hypothetically) recharging the preamp, so it’s really a distinction without a difference, except that with a replaceable 9V battery you have options if the battery dies unexpectedly - provided you’ve remembered to bring a spare, that is

+1

 

[Cave Puppy]

I wouldn’t want a USB rechargeable pre-amp for the following reasons:

1. Inconvenience - Yet another charging cord to carry and possibly lose.
2. It would be easier for me to replace a battery than to plug in an entire bass to charge.
3. If I were to get another active bass (I wouldn’t) it would have to come with a passive/active switch for this very reason.
4. What does a person do when their on-board USB battery dies? You’d have to replace the whole pre-amp.

 

[RattleSnack]

As a musician, you have a check list of things to look at before going to a gig. Just add one more thing: measuring battery voltage.
Plug cable into bass guitar, pop the lid off the back and check voltage with multimeter. Most preamps will work properly with 8V or more. It could be even lower than that, but no reason to risk it. If it's 8V, replace battery.
And that's it, you will never have same problem again.

 

[swink]

I am wondering how I am going to charge my 9V circuit with a 5V USB connection.

 

[scubaduba]

I like the Audure preamp system which has a LED indicator where every time you insert a cable into the input jack it gives you a visual reading of status of battery. To me, that is more useful than a USB charging system which would be slow.

 

[4stringfarley]

I’m more curious as to why more companies don’t use the 9V battery door. Real quick to change a battery, could even do it mid measure of a song and be right back into it.

If you’re using an instrument that requires a 9V to function you should be keeping a spare in your tool bag. Rechargeable batteries eventually stop holding a charge. USB ports can go bad. USB cables go bad or get updated. I can only imagine playing a gig and realizing my $150 specialty designed battery died and there isn’t any USB XYZ to 6.0 cables to be found.

Edited to show battery box.

 

[herndonbassist]

I agree with the general consensus here; all of my main basses are active, and I just have to remember to change batteries, but I can guarantee that a 7-11 or the like will always have a battery I can use. If you want rechargable, I really like this style (never tried them) where you don't need a special cradle, I could plug these in to charge in the car... I may have to get some!

 

[swink]

To me, that is more useful than a USB charging system which would be slow.

Free drinks on the bassist's tab until his internal battery is charged.

 

[JRA]

my newest active ax (late march 2022) needed its first battery swap in early march of this year --- after faithfully unplugging after every use (except twice: both overnight). the battery died while practicing at home, so no big deal, but now i know a little more about that axe's use of one 9volt.

i'm with the "change your batteries at regular intervals" group. and if you're inclined to be a worrier change them more often than annually!

 

[Klangfarbe]

Superior German engineers took all your concerns into account.

 

[Gorilla Monsoon]

Am I missing something here? The Sharpie is your friend. I’ve never had a battery go less than six months; I write the install date directly on the battery, and if I think I’m even close, I pull the battery and check it on a meter. As a caution, though, a battery can read 9v and still be unsuitable under load. Rechargeable 9v batteries are unsuitable for me for this very reason. I’ve never been happy with smaller rechargeable batteries, even the AAs don’t last. Just spend the $5 every six months- no extra cords, no extra holes in your cavity plate that could prove problematic later, no need to hook up to a USB. Keep it simple.

 

[ardgedee]

USB based chargers have upsides and downsides. On the upside, USB3 has some pretty high power capabilities, you could potentially charge up from nothing within 10 minutes (which isn't helpful if the battery dies in the middle of a set, but reasonably practical between sets). On the downside, we don't know how long the connector and charger will be common before getting superseded by other technology -- might be hard to get a replacement charger appropriate for your bass in five years.

4. What does a person do when their on-board USB battery dies? You’d have to replace the whole pre-amp.

I don't think that would be a concern. Batteries are usually outboard from the amplifier circuitry. At worst you'd have to re-glue a new battery into its compartment and resolder some wires.

 

[joel the bass player]

I'd rather have a battery door and a 9v. But progress is something I guess.

Some of my basses don't get used a whole lot for long stretches of time. That rechargeable battery going to still be charged in 6 months?