USB rechargeable onboard preamp power- Why not more common?

[adje]

Alembic had an external power supply 50 years ago. Notice the 5 pin XLR jack, so it's not phantom power. I'm sure they had a reason for doing it this way.

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The 5 pins are so you can run the pickup outputs as separate signals, hence the Bass and Treble outputs on the psu. When the Treble output is not in use, or the Stereo/Mono switch is set to Mono, the pickup signals are summed through the Bass output. IIRC the system runs on +18/-18V, so it's not the standard 48V phantom anyway.

BTW you have the option to run a Series instrument on two 9V batteries, but allegedly they won't last much more than about 20 hours.

 

[groooooove]

a passive switch is a lot more practical. survive the gig, change to new battery when you get home.

 

[Jamvan]

Just get one of these and have it in your case so you can check your battery before every show. Easy peasy.

 

[swink]

I would love to leave the ancient 9 V behind and just use a USB style to charge my instrument. rechargeable batteries are the norm now they’re in every bloody phone we own and people seem to manage to keep those charged. And if my rechargeable system needs a certain type of usb connection, I buy one of those and keep it especially in my gig bag for that so the whole scenario of not having the right charger at the time is a moot point really. Also, 9 V battery or not I would never own an instrument that had to have a power source to operate. All my actives have the passive option.
At the very least we should all be going rechargeable 9v’s, the single use disposable 9 V really is a waste…. and very outdated.

Ultimately, both internal and rechargeable are also disposable batteries. And let's not close our eyes, the stored energy is not made by eco-friendly fairies. As long as the most reliable simple solution for me is the disposable 9V battery I will continue to use it.

 

[lowfreqgeek]

Alembic had an external power supply 50 years ago. Notice the 5 pin XLR jack, so it's not phantom power. I'm sure they had a reason for doing it this way.

View attachment 5027261

Yes, 2 pins were for separate pickup outputs, 2 pins for +/- supply voltages (15 or 18V, I believe), and one pin for common. The separate supply voltages meant no need for DC-blocking caps in the signal path. Also, this could supply the necessary current to the circuitry. It's been a long time since I've seen schematics, but the Alembic electronics were more or less audiophile grade circuitry that would've been found in consoles and studio gear. When they were first doing on-board electronics, IC opamps were pretty much in their infancy (anyone remember the 741?) and were not optimized for audio or battery operation. There were discrete opamps at the time, but they were large modules and required high voltages and large amounts of current.

If I recall, 48V phantom power is limited to about 10-15mA. That's enough to work with using today's low-power/audio-optimized IC opamps, but those didn't exist 50 years ago.

 

[DWBass]

Reminds me I need to change the batteries in my basses.

 

[hbarcat]

This sounds to me like a solution looking for a problem.

All of my basses are active and I just make it a habit to change out all the batteries once a year. Every April 1st, I replace batteries in my smoke alarms, basses, and other devices and appliances.

One thing to consider with a USB charging port built into a bass, you might accidentally try to charge a non rechargeable battery, which could easily result in a battery meltdown inside your bass. That possibility would actually make me want to internally disconnect the USB charging port to prevent that from ever happening.

I should mention that decent 9v batteries last at least 2,000 hours of playing time (usually far longer than that) which means they have more than enough juice to last me a year before being changed. That's at least 3 hours of play time every single day of the year.

Just don't make the mistake of buying "discount" batteries in an attempt to save money. There's a lot of junk batteries for sale, but that's a false economy. Cheap, generic batteries are garbage and they will fail on you.

 

[hbarcat]

a passive switch is a lot more practical. survive the gig, change to new battery when you get home.

I agree with this, except that isn't an option with EMG pickups. Their design makes them non functional without power.

 

[krfoss]

This sounds to me like a solution looking for a problem.

Its actually just a solution to a problem. I found the problem. This is a solution. Not the only one, but a good one.

 

[Hounddog409]

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!

.new bass....battery probably 6 years old.

Always put a fresh battery with a new bass.

 

[jjcarswell]

I prefer the tried and true 9v alkaline. The batteries get changed with the strings most of the time. I also bought a cheap battery tester from Home Depot. It has paid for itself by not having to question if a battery is weak.

 

[ComicBass]

I just replace the battery before shows if I'm not sure about how much juice it has left.

 

[Jogobass]

I always lick the battery before a gig. If it doesn't tickle much I put in a fresh one.

 

[-Asdfgh-]

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.

I initially read that as Fishman Flatulence...

 

[jmlee]

Or the bass owner could just change the battery before the show?

how long has the battery been in there?

All of my active basses: when they were new I used a battery tester to check how long I can leave a 9v battery in there. I came up with over two years.
I cannot see the need for a recharger that I'd probably have to use every other show, when a std 9v lasts well beyond two years.

Link Removed

One of the great things about the Batt-O-Meter gadget is that it measures the voltage delivered by the battery under the load from the guitar or pedal and gives you both that and an estimated hours until exhaustion. The downside is that it can't read an 18V preamp.

 

[Bassamatic]

There is an EASY end to batteries and battery problems. 20+ years ago, when guitars and basses and pedals became more common, the amp and guitar makers could have agreed on a "phantom power" system using 3 conductor instrument cables for pedals and active devices, and 9V power to the input jack from a tap on the amp's power supply. Mic and mixer makers did this many years ago, adding 48V phantom power so the "new" condenser mics didn't have to be battery powered. Why couldn't the guitar and amp makers do it?

I think it is inertia. This industry is so stuck in the Old Ways. (Push back wiring, Orange Drop caps, etc.) I am sure guitar and amp makers would be afraid that people would complain that the online power is "something different" and is changing their sound. SO - we are stuck with the battery blues. It could still be done if someone major like Fender did it with their amps and guitars. Everyone else would be forced to go along. (Are you listening, Fender?) Plus, it can be totally backwards compatible with un-powered guitars. It would add only a couple $ to an amp's build cost and essentially zero for a guitar.

 

[devnulljp]

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

I can see some Apple exec going "Hey! What a great idea!"

 

[DrummerwStrings]

Have you seen the cobalt mines used for rechargeable batteries?

Yeah, they’re bad too - can’t think of a mine that’s been called clean. If there was a Magic Bullet answer (Solar? The panels have to be made…), we would be using it, so the best we can do is look at the entire lifecycle (materials used, construction, transportation, & end of use) of what we use & minimize the negatives. I’ve been using rechargeable batteries for decades, since I visited a dump: when I noticed the charge doesn’t last as long as a Duracell, I did what others here mentioned earlier & bought another set & swap batteries more often. Keep a multimeter nearby, if you’re worried swap in a freshly charged 9v before you pack your gig bag, take a spare or 2 with you, & over time you’ve thrown out a tiny fraction of what you used to & you have more $ in your account.

I think it’s worth a small investment in time. Still would like to see a nice solar charge option…

 

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The first time I saw a reachargeable bass it was a Lightwave System. I had one for years and it worked fine.

Vaudoo Audio has 2 kits you can install on any instrument.
Les Power Blocks - Fin des piles 9V - Vaudoo Audio

 

[mikewalker]

...

BTW you have the option to run a Series instrument on two 9V batteries, but allegedly they won't last much more than about 20 hours.

I seem to remember that John Entwistle had an "episode" with this at a show once, and it was 'the last straw' that led him to ditch Alembics and start his Buzzard Quest...